The physiological parameters of photosynthesis of flag leaf of winter wheat (Triticum aestivum) cultivars with big kernels were determined. The results indicated that there existed large differences in physiological properties of photosynthesis among different wheat genotypes. The means of apparent photosynthesis and photorespiration were 15.54±4.56mgCO2?dm-2?h-1 and 26.77%±9.19% respectively. High concentration of oxygen and high temperature inhibited photosynthesis by 43.26% and 43.25% respectively. In the contrast, low level of oxygen stimulated photosynthesis. As oxygen concentration decreased by 1 %, the photosynthesis rate increased byl.46%. Forty-one cultivars tested were classified into four groups by cluster analysis based on the parameters measured: Group 1 with high intensity of photosynthesis, Group 2 with low intensity of photosynthesis, Group 3 with photosynthesis resistant to stresses and Group 4 with photosynthesis sensitive to stresses.

The test cross was made by use of various types of recessive genie male-sterile materials and different varieties of foxtail millet. The seeds from the sterile spikelets. which was born through mixed open-pollination in F2, were mixed for sowing and pollenizing. Then the exogamy sterile spikelets were selected in the following successive generations for divorsing (the score of thier fertility and sterility was 1:1) , and mixed open-pollination was made among them to change and recombine the genes fully and set a synthetic and dynamic gene pool, from which a suitable and excellent variety-syntheticvariety of millet-was selected. The resuh showed that the synthetic variety-had stronger adaptability and resistibility to diseases, drought and lodging than the varieties obtained through pedigree selection or conventional crossing.

This paper reports two new Genus and four new species of Fulgoroidea collected from China.New Genus: 1.Neoalcathous gen.n. Type of the Genus: Neoalcathous huangshanana sp.n. New Genus: 2. Ganachilla gen.n. Type of the Genus:Ganachilla zhenyuanerisis sp.n. New species: Neoalcathous wuyishanana sp.n. Kalidasa lui sp.n. The type specimens are deposited in insect collection room of Shijiazhuang Pomology Institute.

The female parthenogenesis of Taigu genie male-sterile wheat was induced by tomatotone, kinetin, nicotinic acid, inositol, 2,4-D and so on. The induction effect was various in different method of application of the chemicals, and the injection method was a little better than spraying, but the spraying was easy to use. The different extent of glume-cutting also exerted obvious and different influence to the induction. A moderate extent of cutting would help raise the induction effect. The feasibility and advantage of Taigu genie male-sterile wheat taken as experimental material of induced pathenogenesis was demonstrated in this papr.

Rhizosphere and nonrhizosphere soils were sampled from winter wheat field at early growing stage.The total number and genus of the bacteria mineralizing lecithin or dissolving phosphate were measured.It was found that phosphobacteria in rhizosphere soil were higher than those in nonrhizosphere soil.However,the organic phosphobacteria were much more than inorganic phosphobacteria either in rhizosphere or nonrhizosphere soil.There were a lot of diverse genera of phosphobacteria in rhizosphere soil,but a few in nonrhizosphere soil.The main organic phosphobacteria were pseudomonas, and advantageous inorganic phosphobacteria were pseudomonas and Erwinia in rhizosphere.However,there were not any advantageous phosphobacteria in nonrhizosphere soil.

遗传漂变又称遗传漂移, 是指在一个小群体内, 由于基因频率不能随机地使上下代保持不变, 从而形成的波动现象。国内外学者对此均有论述, 但目前国内在试验中证明这一遗传规律的尚少, 在豇豆上更未见报道。作者于1985-1986年用豇豆的2个杂交组合, 对其3对质量性状, 对F₂代的分离现象进行了观察研究。通过对2000多个单株调查, 发现生长在植株不同部位的果荚, 存在遗传漂变现象。

Methematic models for relationships of yield to water supply and planting density was established and analyzed based on data gathered from rainshelter and field experiments during 1986 - 1990. The relations of yield and water amount in any density could be considerably well expressed by a complex model ofIt was shown that a proportionate phase between increments of water (?w)and yield (?y) existed before the maximum yield was reached, and the upper crossing point(X1, Y1)between the parabola and the straight line was the locus suitable for water saving with high yield. The total water input for both water saving and high yield should be ranged from(X1, Y1)to the maximum of the parabola(Xm, Ym)with significant difference in total but no or less difference in that irrigated among years. When the same amount of water was given, the yield from water of 210mm given at stages of stem elongation, heading, and middle grain filling of wheat would be higher than any other watering patterns. The relationships of density and yield under any water conditions could be highly fitted by a deformed quadratic hyperbola Y = X/(A+BX +CX2).It was shown by this model that the density should be within 170 - 220 thousand plants per mu with no irrigation or water-saving irrigation patterns, and higher density would be needed when less irrigation or water stressed post-stem-elongation stages. Models above would be valuable in the establishment of integrated wheat husbandry modeling system for water saving.

18 wheat cultivars or lines and 27 Lr gene lines are inoculated with 15 cultures of Puccinia recondita f. sp. tritici respectively for postulating resistance genes based on infection types. The wheat cultivars or lines may be sorted into 7 groups on the basis of reaction to P. recondita f. sp. tritici shown by the Lr gene lines. (1)CA8646 carries Lrl5; (2)Henong’ai 3 carries Lr26, and 87-4314 Sui 13 seems to have Lrl5 and Lr26;(3)Tang 86-4043 may carry Lr2a or Lr26; (4)Baomai 2 and Shandong 03201 carry Lr1 and Lr26, and Shandong 110021 has Lr1; (5)C4102-5 may have either one or more genes of Lr21, Lr23, Lr25, and Lr27; (6) 6 cultivars or lines, such as Fengkang 9 , etc, seem to possess additional resistance genes which did not includ in the Lr gene lines studied; and( 7 )4 cultivars or lines, such as Jizao 15, etc, do not seem to have any resistance genes to the cultures studied.

The activities of the Hill reaction and ATPase of isolated chloroplast in wheat (Triticum aestivum) leaves could be increased by choline chloride. Meanwhile the activities of ribulose-1,5- bisphosphate carboxylase (E.C. 4 .1. 1.39) and glyceraldehyde- 3 - phosphate dehydrogenase ( E.C. 1 .2.1.13 ) in wheat leaves was found to be increased by choline chloride too. When choline chloride was introduced into the cytoplasm by vacuum infiltration method, the activity of ATPase was increased to 1.9 times and the activity of RuBPC-ase was increased to 1.7 times compared with that of the control. When choline chloride in suitable concentration was sprayed upon the wheat plants at different stages of development, the activities of the RuBPCase and G-3-PDH were higher than that of the control. It is possible that choline chloride was converted to phosphatidyl choline which caused an increase of the activity of the three enzymes. Higher concentrations of choline chloride appeared to inhibite the activities of these enzymes.The amounts of both protein and chlorophyll in the leaves were increased by choline chloride treatment. The pho-tosynthetic rate was increased by choline chloride too.The above data suggest that the effect of choline chloride may be pertained to both light reaction of photosynthesis and to the enzymes involved in dark reaction.

The response of immature embryos of 10 wheat genotypes to in vitro cultures on 6kinds of medium was analysed in this paper. The result indicated that doubling the concentration of inorganic solts or adding 1g/1 of NaCl and KCl each on the basis of MS medium cut down the callus induction frequency, while substituting dicamba (4mg/l) for 2,4-D (2mg/l) increased the callus induction frequency. The callus induction frequency of 10 wheat genotypes tested were more than 95%. Callus regeneration frequency varied from 73.7%to 92.5%, and the average was 84.6%. Genotype is a very important factor effecting callus induction and callus regeneration of wheat immature embryos.

The genetic diversi ty of 23 maize inbred lines and one te osinte accession was analyzed based on microsatelli te (SSR) and AFLPs markers. With 40 pai rs of SSR primers, total ly 202 polymorphic f ragments were detected. Twelve AFLP primer combina tion (Pst/Mse ) were used, and total ly 444 polymorphic bands were produced. BothSSRs and AFLPs were highly polymorphic. The average of polymorphic informat ion content (PIC) was 0. 6 for SSRs. Percentage of polymorphic AFLP bands was 72%.The resul ts of cluster analysis showed that the acces sions asses sed could be clustered into five groups in both marker sys tems. This is partly in accordance wih the previous classi fication based on conventional methods but wi th some dif ference. It was suggested that both sys tem can be used to analyze the genet ic diver sity of maize inbred lines.

Mature embryos or inflorescences of 113 genotypes of millet(Setaria italica L.) were screened for callus initiation, in which 89% of genotypes produced compact calli. In the preliminary experiment, it was found that the compact calli derived from mature embryo or inflorescence culture could not be directly used for protoplast isolation and culture. By altering the medium composition, the vigorous loose calli were selected from compact calli of the cultivar Jigu No 11 and were successfully used for protoplast isolation and culture which resulted in a high frequency of cell division (33.5% at day 14) . Since protoplast-derived calli were loose in appearence which could not differentiate, the medium composition was again altered by which the compact calli were selected from loose calli and 129 plantlets regenerated. The regenerated plants were transplanted into experimental plot. Among them 101 plants grew to maturity.

Fifty-nine winter wheat varieties were inoculated respectively with six yellow rust cultures at seedling stage in green house. Genotypes of winter wheat varieties and pathogen were analysed based on infection types expressed by the method of interorganismal genetics. Twelve resistance genes (1h1-1h12) were determined. The results were fundamentally coincident with what observed in field and therefore were useful for disease resistance breeding program and deployment of varieties released. The limitations of application of interorganismal genetics were discussed in this paper.

Results of pot experiments showed that even slightly water deficit from jointing to flowering stage reduced winter wheat yield, while no yield reduction was found when mild water stress was imposed at turning green stage and milky stage. At different level of water deficit, the yield sensitive index (or coefficient) to water stress varies. After winter wheat undergoes a short term of water stress and when water supply resumed, its growing speed will increase, which is the compensatory growth effect. Then yield reduction is smaller compared with the decreasing in evapotranspiration. The stomatal conductivity and leaf water potential of winter wheat decrease with the decreasing of soil water content when soil moisture is lower than 60% of field capacity, otherwise they don't change very much when it was over 60%.

On the medium of headening plantlets containing 3 mg/1 MET(multi-effect triazole)and 8%sucrose and under 22? for 30 days, a rootless plantlet of wheat anther regenerated 7.5 roots on an average, the root length was 2.7 cm, and the rooting frequency of the plantlets was 89.4%.In the course of summering, MET in the medium pleyed an abvious role in restraining development and growth of the anther plants and increasing the tiller number for plantlets. After 30 days of transplanting,survival rate of anther plants could be 95.2% and increased 29.7%compared with that in medium without MET.

The contents of amino acid, sugar and chlorophyll in different cucumber varieties with different resistance to downy mildew of cucumber were tested. As a result, the contents and the kinds of amino acid in germinated seed, cotyledon and true leaves on different nodes of cucumber plant were quite different. The results showed that there were significant positive correlations between the contents of cystine, phenylalanine, NH₃and the resistance to downy mildew of cucumber, and between the contents of soluble to talsugar in cotyledon and true leaves on different nodes of a same cucumber plant and the resistance to the disease. There were a significant negative correlation between the contents of reducing sugar, the reducing sugar to total sugar ratio, chl.a and the resistance to the disease. But there was ignificant correlation between the total amounts of chlorophyll as well as chl.b and the resistance to the disease.

植物的游离小孢子离体培养方法最先在毛叶曼陀罗（Datura innoxia）上, 以后又在烟草、矮牵牛、马铃薯等茄科植物上试验成功。八十年代初, 在十字花科芸薹属的油莱（Brassica napus L.）上获得突破, 后相继在该属的埃塞俄比亚芥菜（B.carinata）、黑芥（B.nigra）、大白菜（B.campestris spp.pekinensis）和结球甘蓝（B.oleracea spp.capitata）上获得成功。在植物育种应用方面, 游离小孢子离体培养方法较花药培养表现了更大的应用前景。

The experimental results indicated that two wheat varieties showed remak-able differences in the length and number of leaf hairs, the number, structure and opening extent of stoma, the distance of leaf veins, the ratio of bipolar germination of condia, the time and way of their penetration, the number of infected points, and the time of hypha development and tissue necrosis and so on. The inoculation results of seedlings showed that both of the wheat varieties also displayed clear difference in the ratio of infected plants and leaves, and in the lesion number in each leaf. But there were lots of lesions in the leaves of resistante wheat varieties indeed. Therefore, it is considered that the resistance of wheat varieties to H. sativum is mainly showed in antipenetration, and the morphological structure of host plays an important role in the disease-resistance.

The chemical extraction was used to study the effect of organic acids on phosphorus release from different synthetic phosphate compounds.It was indicated that phosphorus release was significantly stimulated for all of 5 synthetic phosphate compounds tested,and positively correlated with the concentration of organic acid.The ability of organic acids in mobilizing phosphorus from synthetic phosphate followed the order:citricoxalictartaricmalic acid.The extent of phosphorus mobilized from synthetic phosphate compounds followed the order:Ca₂-P＞Ca₈-P＞FePO₄＞Ca₁₀-P＞AlPO₄.

With temperature decrease, maximum fibre elongation of cotton decreased and elongation period increased. Night temperature showed larger influence on fibre elongation than daily average temperature. While fibre break strength was increased with cotton boll age, it was reduced when temperature dropped. Fibre maturity was increased as fibre developed and the rate of increase decreased with boll age. Fibre fineness decreased with fibre development. Daily average temperature of 16.7 ℃ and cummulated temperature of 1142.9 ℃(≥15 ℃) are the critical points of fibre fineness. Fineness decrease rate was reduced when temperature was below this temperature. At the same boll age, fineness increased when temperature was decreased.

Fifty-five leaf samples were adopted from thirty-eight pear orchards in the original growing and main producing areas of "YALI" pear, and contents of ten elements (N, P, K, Ca, Mg, Fe, Mn, Zn, B, Cu ) were analyzed. The standard values of mineral element contents in the " YALI " pear leaves and their variable ranges were drawn up in the light of the mean of multiple regression values and standard errors from the regression of the mineral element contents in the leaves of "YALI" pear growing over ten years through the correlation test and multiple regression statistics. The contents of P, K, Mg, Mn, Zn in the leaves of fruiting pear trees under ten years were distict from that in the older trees. The contents of N, P, K, Ca, Mg and Mn in the leaves of "HSUEHUA" pear were higher than that in the leaves of "YALI" pear under the same condition. The sampling stage suitable to " YALI " pear for diagnosis is 70-90 days after flowering.

The high molecular weight (HMW) glutenin subunit compositions of 1642 wheat varities germplasm resources and their sedimentation volume were analysed, and a lot of important quality parameters of 242 wheat varieties were determined.The results indicated: (1) A subset of data was analysed by three-factors anova.Two conclusions emerged from this work.The first was that single-locus additive effects were considerably larger than the interactive effects when subunits 5 +10 were present, and additive effect of Glu-D1 locus was the largest among all the effects.The second was that the effects of Glu-B1 loci on bread-making quality were partitioned into additive single-locus effects and interactive (two-locus and three-locus) effects when subunits 5 + 10 were absent,and the additive effect of Glu-Bl locus was the same important as the interactive effect among Glu-Bl locus and Glu-Dl locus.(2) Considering the effects of alleles at each locus on bread-making quality,the ranking of Glu-Al locus was 2^*>1>Null.Subunit 2^* was slightly better than subunit 1, and both subunits 2^* and 1 were much better than Null.The ranking of Glu-Dl locus was 5+ 10>4 + 10>2 +12,subunits 5 + 10 were significantly better than the other subunits,and 7>7 + 8>7 + 9 for Glu-Bl locus.

Inheritance of microspore embryogenic ability in B.napus was examined by 4×4 diallel crosses using 2 high responsive cultivars (`Topas' and `Lisandra') and 2 low and no responsive ones (`Kizakino' and `Kamikita').Most of F₁ hybrids showed that embryo yields similar to the high responsive parent and some showed embryo yields similar to the mid parent value.Diallel analyses showed that both additive and dominant effects were significant at 1% level in the genetic control of microspore embryogenic ability.Additive gene effects were predominant.High embryogenic ability was controlled by dominant nuclear genes.The broad-and narrow-sense heritabilities were 97.2% and 81.1%,respectively.From the results of segregation of embryo yields in F₂ population of`Lisandra'×`Kamikita',it is concluded that the microspore embryogenic ability was controlled by two loci with additive effects.

The town of Nanshao, Changping county in Beijing has 264 hectares of land. One hundred and six soil samples were collected and analyzed for soil organic matte,total N,available N,available P and available K in 1993. The spatial variation of these soil properties was quantitatively analyzed by geostatistical methods. The contour of these soil characteristics was also drawn by Kriging method. The geostatistical method showed some importance in studying and estimating the spatial variation and changes of soil nutrient sona large scale.

Growth and development of cucumber in spring greenhouse were affected obviously by low light,such as thinness of stem, decreasing dry weight of plants and yield,and increasing abnormal fruit ratio, etc. In low light,the content of Chlorophyll and net photosynthetic rate (Pn) decreased. For the cucumber seedlings that were treated by low light,whether in normal light or low light,its Pn decreased obviously, and the experiment on stomata conductance and intercellular CO₂ concentration showed that in the low light the stomata factors resulted in decreasing the Pn of cucumber seedling,while in the normal light the non-stomata factors probably cause the decreasing of Pn. Fv/Fm of cucumber seedlings and plants didn't change obviously after low light treatment. The slight differences in different treatment indicated that Fv/Fm did not cause the qualitative change by low light stress. And low light resulted in decreasing the content of carotenoid and would lead to photoinhibition. The reaction of cucumber lines to low light stress was different,and effect of different low light treatment to cucumber growth and development were also not same. Several tests data showed that inbred line Q21 has better resistance than T94 to low light,which accord with the observation in past years. The Chlorophyll and carotenoid that play an important role to the absorption and converting of energy in photosynthetic activity was destroyed slightly and was the foundation of resistance to low light.

The objective of this study is to provide a technique for high2yielding spring maize cultivation by analyzingeffects of different nitrogen managements on dry matter accumulation,partition and transportation. There are three nitrogenmanagements:Zero nitrogen fertilization(ZNF),Recommended nitrogen fertilization(RNF),Traditional nitrogen fertiliza2tion(TNF). The results showed that neither RNF nor TNF could obviously improve dry matter accumulation,LAI,ear2leave photosynthetic rate and grain yield in the first year. However,in the second year,ZNF achieved yield reduction of1210 % and 1116 % comparing with RNF and TNF respectively. Furthermore,RNF could not only reduce nitrogen input,but also improve dry matter transportation from other organs to grain,the proportion of which reached 2211 %,and was611 % higher than TNF.

A location test was made in Zhangbei county, on the Bashang Highland in the northern part of Hebei province from 1987 to 1989 in order to get the coefficients of both water consumption and precipitation utilization in this region, and a great deal of data was accumulated. After a series of parameters were corrected, a budget estimation formula for productive potentialities suitable to local conditions was established with FAO Wageningen method. It was proved in the field test that the potential value was reliable and feasible. The productive potential value of natural precipitation, and coefficients of both water consumption and precipitation utilization were calculated On this basis the different climate types and the utilization situation of precipitation throughout the year in this region were analysed. Therefore, the theoretical basis was provided for effective development and utilization of the precipitation resources in this region.

The morphology, habit and damaging stage of main pest insects of pleurotus were studied in 1986-1988, including Lycoriella sp. , Cecid midges, Aceuvoglghus ovatu. These pest insects were controlled by lower temperature or with chamicals and some materials with special odour or colour.

Auricularia polytricha (Mont.) Sacc. var. argentea Zhao et Wang is a new variety of the species Auricularia polytricha.lt was discovered by Zhao Dazhen in 1987. The sporophore is pure white. It has desirable characters, namely, its beautiful appearance, big and thick fruit bodies, tolerance to high temperature, resistance to trichoderma contaminations, high biological efficiency, nutritious, and good taste. It has been well proved that it is a kind of edible fungi being of important value to develop. Through five years and three generations acclimatizing cultivation and research, its biological characteristics and condition for growth were found out, three essential factors forming good structure of its body-substrate density, uniformity and its surface smoothness-were advanced, and a complete set of culture technics-making "U" holes on the wall of the culture polybag, sealing the polybag top and then capping it with a piece of plastic film,and hanging the bag in ditch -was worked out. These technics provided a scientific basis for developing and utilizing the edible fungus.

The residual effect and the fixation and transformation principles , the efficiency of water-soluble phosphorus fertilizer during experiment period on a calcarious soil are studied from 1982 to 1989.The economic efficiency of different distributions is also evaluated. The results show a significant residual effect for phosphorus fertilizer exists and, a longer dosage, the residual effect duration is longer. At the application rate of 16kg/P2O5/mu, its residual effect lasts at least 4 years. There is less than 20% of phosphorus which remained soluble and about 80% of phosphonus which converted into insoluble phosphates after been applying the soil. The formed afterwards insoluble phosphate in soil can be released and used by the crop again. The forms of phosphorus converted to insoluble phosphate are mainly Ca-P and Al-P which is converted to Ca-P during the 4 year period. Al-P also has a high correlation with available phosphorus. The correlative equation shows every 10ppm increase in Al-P may result in 3ppm increase in available phosphorus. Therefore, it is regarded that Ai-P has a relatively high availability and it produces mainly the residual effect.The most optimum application is 4kg P2O5/mu yearly. Instead of a big dosage at one time,suitable ones yearly are recommended.

The Changes of four plants'endogenous hormones were investigated during winter periods. The results showed the big difference between the genotypes of the winter wheat and spring wheat, the higher ABA contents in more resistant varieties, the higher GA3 contents in spring wheat; and the higher IAA contents in the genotypes with more resistant to coldness before winter, the more stable Z+ZR contents in the genotype of spring wheat. Thus it could be concluded that there were close relations between the four plants'endogenous hormones and cold resistance in wheat. In addition, the active changes of the endogenous hormones reflected effective metabolism, which did not stop with coldness.

Ornamental characters of 20 introduced Drought-tolerent perennial Ornamental Grasses were evaluated using gray-correlation analysis based on the plant growing situation,ornamental character,inflorescence aesthetic feeling,leaf color and overwintering survive rate.The results showed that Elytrigia repens,Festuca ovina,Stipa krylovii,Arrhenatherum elatius and Eragrostis curvula have better ornamental effects and can be used for landscaping directly.The correlation degree of Anemathele lessoniana and Imperata cylindrical with ideal species are very low,only 0.4435 and 0.5535,respectively.The ornamental value of rundo donax is highter,but its overwrintering survival rate is very poor.

A bivalent plant expressing vector carrying TMV cp and CMV cp and CMV cp has been constructed. Transgenic plants resistant to kanamycin have been obtained from to pepper cultivars, Nong da40 and Xiangyan no.1, based on the high efficient pepper gene transformation protocol established previously. The results of molecular assay indicated that sixteen plants presented positive dot blot signals with two of which presented negative PCR signals. The results of leaf surface virus inoculation test indicated that even plants presented immunity to TMV and CMV.

The result of five years’ survey on the physiologic races of P. recondita f. sp. tritici indicated that races 1 , 2 , 3 , 38 and Lovrin 10 race group which was virulent to important sources of resistance were prevalent ones. Race 2 remained stable, race 1 slightly increased, race 3 and 38 slightly decreased, and Lovrin 10 race group incrcaced rapidly from 18.33% in 1985-1986 to 57.65% in 1989-1990 in frequency.Besides using the traditional method to monitor the races, effert was made to improve the viewpoint and method of research. The taxonomic point of view of distinguishing the races was abandoned and a view of interorgani-smal genetics was adopted to study host-parasite interaction. Seven of 8 differential hosts established by Chinese workers were replanced by 8 sources of resistance and cultivars which were important in relation to wheat production as well as breeding program. Metheds of virulence frequency and virulence association were used to analyze the interaction of wheat cultivars and the population of pathogen. Virulence frequency method revealed that some important sources of resistance such as Lovrin 10, Lovrin 13 and Predgornaja 2 were not ideal resistance parents for breeding. The virulence association method seemed to be useful in designing variety deployment rationally.

Based on the soil fert ility and fert ilizer effect of Beijing brown chao soil in the way of micro-trial of winter wheat-summer maizer continuous cropping, the annual grain yield and the ten-year soil organic matter change show that the crops yield, soil organic matter and soil fertility can be improved significantly by using N P K chemical fertilizers together with organic material under lower soil fertility. The effect can be greater with organic material increasing. The effect of using organic material is best, the second is using wheat straw. The effect of maizer straw combined with chemical fertilizers is similar to that of chemical fertilizers.

The sugar content in sorghum stem were studied with 77 grain sorghum material and 21 sweet sorghum material.It showed that the sugar content of sweet sorghum were higher than that of grain sorghum by 2-5 times.The stem in sweet sorghum was waxy with higher sap content.The sugar content was different in every internod.4 different types of internode sugar change were exist,but the low-high-low type was the main type in sweet sorghum.The average of internode 4,7,9 sugar content couled be used as the plant sugar content.The sugar content in the stems would raise gradually as the water lost after harvest,but it would reduce sharply after 25 days.

The oviposition preference of Atherigona biseta and the dead heart rate of millet seedling after inoculating ova or larvas of Athengona biseta have been tested by use of millet varieties different in resistance.It has been proved that the experiment result of inoculating with freshly hatched larvas was not different from that of field natural infestation. The advantage of this method is accurancy as well as quickness.

The effect of maturity on physical properties,chemical components and content of neutral aroma constituents in flue-cured tobacco leaves were studied.The results showed the optimun filling value,thickness of leaves,dragging force and tensile strength came from the middle leaves with proper maturity or yet-maturity,and the upper leaves with proper maturity or overmaturity.In the middle leaves with proper maturity or yet-maturity,the sugar content was high,and the contents of total N and nicotine were feasible.The inner quality of upper leaves with proper maturity or over-maturity was good,chemical components being harmonious.The contents of many neutral aroma constituents reached to their climax in middle leaves when proper maturated,and then declined,while they kept incease in upper leaves,and reached to their climax till over-maturated.

The activity of peroxidase(POD)?polyphenol oxidase(PPO)?phenylalanine aminolyase (PAL) and the content of phenols in the roots and leave of 4 cotton cultivars with different resistance to V.dahliae after inoculation were studied.The results showed that the activity of POD?PPO and PAL all were increased remarkably in 4 cotton cultivars after inoculating pathogen.Normally activity of enzymes raised peak value after inoculating 3-5 days,but the change of activity of enzymes in resistant cotton cultivars were faster and higher than susceptible ones.The content of phenols in the roots and leave of 4 cotton cultivars also increased obviously after inoculation,but whether before or after inoculation the content of phenols in the roots and leave of resistant cotton cultivars were higher than susceptible ones.

High-pressure injection machine was used to inject a kind of systemic insecticide into the walnut trunks making it transport throughout the tree for controlling the low-age larvae of Airijuglans hetachci Yang which had invaded into the fruits. Meanwhile, the Variation regularities of both the amounts of insecticide in the tree body, especially, in the pericarp and kernel of the fruits, and the number of the pest insect were also investigated . The results showed that application of insecticides by injection only once a year at the peak period of the adults obtained over 80% effectiveness without any damage to the tree. The insecticide residues in the harvested walnut were within the maximum limits for pesticide residue of UN.

A study on the biocontrol efficacy of the actinomyces strains Ⅲ-61 and A-21 against fusarium wilt and gray mold of vegetables was launched for the sake of evaluating the application significance of the two strains for the biological control of plant diseases,and providing scientific basis for the follow up research on their development.In which,the antifungal bands of 17.5-20.9 mm wide produced by living colonies of the two strains against ones of Fusarium oxysporum f.sp.cucumerinum and Botrytis cinerea were obtained by using the method of culturing colonies confronting each other on plate.The suppressing rates of 76.5%-100% to the growth of pathogen mycelia with the method of growth rate,the inhibiting rate of 100% to the conidial germination of pathogens with the method of germinating on concave sheet glasses were presented by their germfree ferment filtrate diluted by 5 times,and the distorting rate of 100% to germ tubes of the conidia by the filtrate diluted by 100 times were also observed.The fungilytic action to Hyphae of the pathogens on plates was presented by the two strains too.In greenhouse potting trial with the ferment solutions diluted by 4 times,the relative control efficiencies to cucumber fusarium wilt were 60.61%-65.15%,to gray molds of tomato and pepper were up to 62.49%-89.76%.The result showed that the two strains are excellent biocontrol materials with good prospects of development and application.

In this study, rules of water demands and consumption by summer maize were analyzed.T here is a totaLwater demand of 359.8 mm during the whole growth stage of maize.Daily water demand in the whole growth period appeared to be a parabola:low in seedling stage, increased untiLreach its peak while from node elongation to tasseling and decreased gradually after tasseling and grain filling.RainfalLand irrigation provides most of water consumed by summer maize, while soiLwater supply con-tributes little, in some cases, there is even minus supply.But when some certain growth stage was in-spected, especially when there is a water stress, soiLwater supply may be the main source and contribut-ed much.

Three maize hybrids that utilized widely on maize production in China were chosen as the materials for the study on correlation between stem characters and lodging resistance. The result indicated that: the planting density,stem pull,stem puncture strength,stem diameter,plant height and ear height were significant relationship with lodging resistance at 0. 01 level; the support root numbers was significant relationship with lodging resistance at 0. 05 level. Planting density,stem puncture strength,stem diameter and ear height were the principal direct factors for variety lodging resistance. They could act the target for variety lodging resistance.

The quality of 40 wheat varieties in Henan were determined and analysed in 1999. The results showed that the quality of Henan wheat varieties are very different. 75% of them belong to middle gluten flour varieties, 20% strong gluten flour varieties and only 5% weak gluten flour varieties. Yumai 47, Yumai 34, Yumai 49 and Wan 798 are strong gluten flour varieties, Yumai 50 and Yumai 60 are weak gluten flour varieties. The high yield and good quality were combined quiet well in these varieties. They adapt to be planted widely in wheat planting area between Yellow river and Huai river. The new varieties, such as Zhengzhou 9023, Xiaoyan 54, Luoyumai, Shanyou 225 and Gaoyou 503, also are strong gluten flour varieties and Luohan 2 is weak gluten flour variety. Besides, the wheat quality properties are easily influenced by environmental factors.

The nutrition characters, leaf colour of 3 rice varieties and their nitrogen fertilization techniques were studied in the area along the Yellow river. The results indicated that the amount of N, P and K absorbed by the tried varieties of rice was different during the period of growth. The absolute absorption amount of N, P and K was the most for Zhengdao 6, and the least for Huangjinqing. The N accumulation amount of Zhengdao 6 was less at the early middle stage and more from earing stage to mature stage, compared to the other tried varieties. Therefore, the nutrition characters of rice should be considered when applying nitrogen for ensuring the high yield of rice and high nitrogen efficiency. There was closely relationship between the second-top leaf color of rice and the application rate of nitrogen fertilizer. The SPAD value changed from 41.8 to 22.1 as the low amount of nitrogen fertilizer (112.5 kg/ha)was used, and it changed from 44.3 to 26.4 in the middle amount of N(225.0 kg/ha)application and from 44.1 to 32.3 in the high amount of N (450.0 kg/ha)application. The SPAD value of rice second-top leaf could maintain 37 and above before the ear-filling stage, especially the leaves maintained green and not too rich at the later stage when the middle amount of N (225.0 kg/ha)was applicated. So, 37, the SPAD value of the second-top leaf before the ear-filling stage could be a reference index of the nitrogen fertilizer application.

The study on the nitrogen metabolism in tobacco leaf under different temperature and humility condition during curing process indicated that the total nitrogen content in flue cured tobacco leaf was high under high temperature yellowing and high humility color fixing condition.The influence of curing temperature to the content of nicotine was not significant.The degradation of protein was hindered under low humility condition,but it was opposite under high humility condition,and so the protein content in tobacco leaf cured under high humility was lower than other treatments.Comparing to protein,the ammonia acid was on the contrary,and it's content was high in tobacco leaf cured under high humility.The high humility was propitious to nitrate reductase activity and the accumulation of nitrite.But the influence of the curing humility on the nitrate content was insignificant.

Carmine spider mite is one of the most important pest insects of cotton in Henan Province,Resistance of the mite to insecticides was studied during 1986-1987, Susceptibilities of thirteen strains of the mite collected from diff-erent cotton areas to two principal acaricides-dicofol and omethoate were determined by slide dip method. The result showed that the resistance had appeared almost all cotton counties sampled.The toxicities of 23 kinds of selective pesticides to the female adult of susceptible strain (Baiquan strain) and resistance strain(Xinxiang strain) were eveluated still by the slide dip method, The strain of Xinxiang had a high degree of resistance to organoph-osphor，especially parathion(466.8-fold at LCS。)，but no resistances were found to methrin，PP32I，plictran，propargite，ect,

The characteristics of field water consumption of winter wheat were studied from soil water content, crop growth and meteorological factors. The results showed: the changes of water consumption intensity by winter wheat showed "double peaks" curves at better soil water conditions. Though the time and value of the peaks in different irrigation treatments were different, they accorded with the irrigation time. Irrigation reduced the ability in using pre-seeding soil moisture. Before jointing stage, the field water consumption of winter wheat and the atmospheric evaporation were of significant positive and linear correlation. After jointing stage, there was a positive linear-correlation between water consumption and dry matter accumulation or soil water content. Jointing stage is the critical stage of water consumption of winter wheat.

The North CarolinaII(NC II)mating design was used to evaluate the genetic bases of 36 hybridized combinations in six maize synthesized populations and six inbreds from different germplasm.The results of field data showed that the GCA of plant grain of LBM was the highest, and second is WBM.They are better than BSSSR and BS16 from USA,9 elite heterosis cross models were fo rmed according to SCA of plant grain.The grain value of it from WBMX HZ85 was the highest,and it reached 108.75g. Through the estimation for variance parameters from elite heterosis models.We known that therewere anumberof different value at plant grain character in same cross,it indicated that they contained strong genetic selected potential.The value and distribution rate of plant grain could help breeders select lines.Synthetic maize populations have abundant genetic diversity and belong to different heterosis type respectively. They come from a variety of maize germplasme. They are elite population for choosing inbred line and recurrent selection.

Roots play an important role in water and nutrient uptake by crop. The investigation of root system development of winter wheat and the effect of nitrogen, phosphorus and soil moisture on its growth in the North Plain of China was made in 1990 and 1991. Roots were sampled by coring and the changes of root weight and length were determined in five development stages. The root weight growth rates were 0.845, 0.386, 1.921, 2.500 and 0.427g/m²· day and root length growth rates were 0.062, 0.0329, 0.310, 0.221km/m²· day in seedling, overwintering, jointing, heading and seed filling stages, respectively. The total root length and total root weight with time could be described by logistic growth function, and the exponential model was suggested for describing root system distribution with soil depth. N and P fertilizer application could promote the growth of winter wheat root system. Water stress reduced the root dry weight and root length, but root length and weight was greater in 0.3-1.20m depth under water stress than that of irrigated wheat. Irrigation could significantly increase roots in the stages of vegetative development and extend the root lifespan in the stages of reproductive development.

A large number of soil fertility analysis and field trials were carried out in different regions of China.Results confirmed that soil nitrogen fertility in 20 tested soil types is low.The crop relative yield in N treatment is 69% in average,of which 65% accounts for"low nitrogen level",35% for"medium level",and none is"high"in nitrogen.Soil phosphorus fertility in these soils medium.The crop relative yield in-P treatment is 86.4% in average,of which 32% accounts for"high level"59% for"medium level",and 9% is"low"Soil potassium ferility in these soils is from medium to high.The crop relative yield in-K treatment 93.7% in average of which 41% accounts for"high level",56% for"medium level",and only 3% is"low".Soil fertility index for the 20 soil types have been worked out in accordance with soil test results and crop relative yields.

Experiments of root zone temperaturet reatments were carried out at seedling stage of cucumber ( cucumis sativus L. ) in solar greenhouse. Comparison of sub-optimal treatment and low temperature treatment with optimal temperature treatment indicated that contents of K, Mg in root increased, while contents of N, P, Ca, Fe, Mn, Cu, Zn in root decreased; contents of N, K, Ca, Mg, Fe in stem increased, while contents of P, Mn, Cu, Zn in stem decreased; contents of K in leaf increased, while contents of N, P, Ca, Mg, Fe, Mn, Cu, Zn in leaf decreased. Cultivars Jinchun No. 3 showed larger root resistance to low temperature stress in maintaining relative stabilization of some contents of mineral elements than that of cultivars Jinchun No. 2; Volume and absorbent area of root decreased, while succinic dehy drog enase activity of root increased. Low ering root zone temperature increased contents of some elements in seedlings, but contents of elements( do not include K) in leaf decreased. Grow th and development of shoot of cucumber seedlings ult imately were hindered by these decreased elements that maybe were limiting factors.

The effects of different meaures of fertilizer application on crop yield and accumulation of NO-3-N in the profile of three major soils were studied according to the result of a 18 years located experiment.The results showed that the mixed application of N and P or N,P and K would be an efficient way for raising crop yield and had accumulation of NO-3-N in the profile of three major soils.

Assay for salt tolerance and drought resistance of transgenic wheat e xpressing betaine aldehyde dehydrogenase, obtained through part icle gun method,were conducted under simulated salt drought s tress condi tion. The resul ts in dicated that the transgenic wheat has many obvious advanta ges over its donor plants, such as the greater germinating ability under osmotic st ress up to-0. 3 Mpa, the more vigorous development of seedlings, especially the well developed roots under drought st ress condi tion, as well as the improved plasma membrane protection of excised leaf and the lower transpi ration rate under field condi tion. But the water los s rate for e xcised leaf was not obviously di fferent from its donor cont rol plants.

<正> 甜椒F₁杂种优势强,整齐度好,增产显著,但在育种实践中存在选亲不当达不到预期目的和耗费大量人力物力进行广配F₁筛选等问题.本文对甜椒优势组合亲本选配方法进行了初步探讨,为有目的地进行F₁育种推断提供依据.

In order to establish molecular marker-aided selection system of the gene for disease resistance to powdery mildew on Cucumis melo L,with six generation population P₁,P₂,F₁,F₂,BC_r and BC_s from a cross between a resistant variety 1A151 and a susceptible variety Hengjing R. R. S. as materials, genetics and molecular marker of the disease resistance gene was studied using wind media inoculation method and bulked segregant method. The results showed that disease resistance was controlled by a single partial dominance gene,and a molecular marker RAPD-S329 linked with the gene loci for disease resistance to powdery mildew was found,the distance between them is 6.81±1.67 genetic unit.

The Effects of different temperature and humidity yellowing conditions on the aroma constituents of tobacco leaves during bulk curing were studied using the electric-heated flue-curing barn designed and made by Henan Agricul-ture University.The result showed that the treatment of low temperature and medium humidity yellowing condition(dry-bulb temperature 38℃ and relat ive humidity 85%-80%)could increase the contents of acids and neutral aroma constituents.The contents of oxalic acid,malic acid and noctadecanoic acid,which contributed importantly to the fragrance of tobacco leaves,were increased remarkably,and the total contents of neutral aroma const ituents including the benzyl alcohol,phenyl acetaldehyde,phenyl ethyl alcohol,furfural,furfuryl alcohol,acepyrrol,B-damascenone,geranyl acetone,dihy-droactinolide,megastigmatrienoneⅡ,megastigmatrienoneⅣ,3-hydrogen-B-damascone and solanone were also increased to a certain degree.

The aromatic compounds in different cultivars of melon during the fruit ripeness were studied.Head-space solid phase microextraction(HS-SPME) was used to extract aromatic compounds in different cultivars of melon during the fruit ripeness.Aromatic compounds were determined and analyzed by gas chromatograph-mass spectrophotometer(GC-MS).The melon of 25 d after anthesis was unripe period.The major aromatic compounds of 4 cultivars melon in this period were aldehydes and alcohols.30 d after anthesis was the period that translated aldehydes and alcohols to esters.The melon of 35 d after anthesis was ripe period.The major aromatic compounds were esters,except for fewer aldehydes and alcohols.There were 6 kinds of mutual aromatic esters in this 4 cultivars ripe melon,including Acetic acid,hexyl ester;Acetic acid,phenylmethyl ester;Acetic acid,2-methylprolyl ester;Acetic acid,butyl ester;1-Butanol,2-methyl-acetate and 2,3-Butanedioldiacetate.The proper aromatic compounds and the kinds and contents of characteristic aromatic esters were also different.Those were the result of aroma type difference among melon cultivars.So the different cultivars of melons had their typicality aroma.

Seven SSR primers and 192 maize hybrid were used to comparatively analyze SSR markers between capillary electrophoresis with fluorescence detection and denaturing PAGE(polyacrylamide gel electrophoresis) silver-staining detection.The results indicated that SSR markers fragment sizes explored by two decetion systems were relatively similar.Capillary electrophoresis with fluorescence detection has the advantages of high accuracy,sensitiveness,cost effectiveness and high-throught.Therefore,the capillary electrophoresis with fluorescence detection system is suggested to be suitable for scaning and analyzing large-scale material.While denaturing PAGE silver-staining detection would be used in examaining a few samples,especially in screening SSR markers.

Characters of climatic potential of wind erosion and which effects on field environment have been revealed based on observation and analysis of field wind erosion and its effective factors in different soil patterns in dryland farming area of the north foot region of Yinshan mountain, Inner Mongolia. The effects of different types of strip intercropping, cereals with grasses, cereals with potato, and bush with grasses as well as stubble cover, on reducing wind erosion were observed and studied. It is pointed that there are better effects of strip intercropping on controlling wind erosion in dryland farming areas of the north foot region of Yinshan mountain where windbreak forest is difficult to plant. And the reasonable patterns of strip intercropping in different degraded fields and the series techniques of increasing yield have been made clear.

The research was carried out on the relationships between physiological characteristics and spike kernel weight of different types by using new big kernel wheat strain Lankao 86(79) (source-limiting type)、Yumai 18 (sink-limiting type) and new big spike wheat strain Huang 8124 (source-sink-interacting type) as test materials. The main results was as follows: (1) The sources formation and development of source-limiting type and source-sink-interacting type varieties is more reasonable than sink-limiting type one. They have bigger photosynthetic superiority, longer continued time of leaf area, higher photosynthetic reduction efficiency, stronger photosynthetic property of leaves.(2) Source-limiting type and source-sink-interacting type varieties grain weight increases quickly, their spike characters are superior to sink-limiting type one. (3) Leaves of source-limiting type variety、leaf sheaths of source-sink-interacting type one、stem of sink-limiting type one contribute more to kernel's increasing weight than other organs. (4) Kernel milking speed of source-limiting type and source-sink-interacting type varieties increases quickly in earlier stage and decreases slowly in later stage, it presented significant positive correlation between grain weight and milking speed, but to the sink-limiting type variety, this correlation isn't evident.

he phenotype of thirty cultivars against powdery mildew,those cultivars widely-used in Henan province during the past fifty years,was evaluated.Pm gene contained in these cultivars was identified by the PCR-based markers tightly linked with Pm2,Pm4,Pm8,Pm13,Pm21 and Pm24.Among these cultivars there were only three resistant(against) powdery mildew.Before 80s nearly none of these Pm genes were used.After 80s Pm8 was widely-used,with the limited use of Pm2,Pm4 and Pm24,while Pm13 and Pm21 did not exist in these cultivars.With the same markers above,the cultivars used more than 6.67×10 ^ha during 2004-2005 were also analyzed.Back-cross breeding combined with molecular marker selection was taken to transfer Pm genes such as Pm13,Pm21,Pm30 and Pm33 to Zheng 9023 which is now widely-used.Lines and NILs of Zheng 9023 resistant against powdery mildew were obtained.Combined hybrid breeding with molecular marker selection,Zheng mai 835 and Zheng mai 863,pyramids of different Pm genes,and Zheng mai 883 containing Pm21 were bred.

The content of Chla content,Chlb content,Chla/b value of Number4zhongshu and Number9zhongza in low light and poor light were studied. The research results showed that when light intensity is 5 000 lx or 2 000 Ix,temperature treatment 20℃(day)/10℃(night),20℃(day) /5℃(night ),15℃( day ) /10℃(night)and 15℃(day)/5℃(night) have a significant effect on Chla content,Chlb conten and Chla/b value of tomato, Which have different effect on different treat time.

Use maize Jidan 261 and Jingdan 28 as materials. Research the effects of water stress on chlorophyll fluO₂ rescence parameters of maize leaf. The result sho wed that the light2saturated net photosynthetic rate, light compensation point and light saturation point and values of intrinsic quantumefficiency for CO₂uptake were decreased on water stress. The basis fluorescence of the maize leaveswas significantly increased. The max fluorescence, the variable fluorescence and photochemical efficiency were significantly decreased. With the increased of light, The photochemical quenching coeffi2 cient and actual photochemical efficiency were significantly decreased. But the non2photochemical quenching coefficient and apparent electron transport rate were increased slowly. Result showed that the photosynthesis competence ofmaize leaf was lo wer under stress.The inverse proportion of PS ò was unfolded slowly.The capability of electron transport of photO₂ synthesis was decreased, and PS ò latency active was restrained. The superabundance light was dissipation by other aP₂ proach such as non2photochemical quenching mode.To protected photosynthetic structures from injure.

Randomly amplified polymorphic DNA(RAPD)markers were applied to distinguish purity of commercial F1-hybrid seeds of Chinese cabbage. DNA from two F1-hybrid cultivars, Beijing No.57 and Beijing No.106, and their parental lines were screening with 50 primers. Primer OPE-20 generated in F1-hybrid Beijing No.57 specific RAPD markers. Primer OPH-06 and OPH-07 generated in F1-hybrid Beijing No.106 specific RAPD markers. These markers enabled a clear distinction to be made between F1-hybrids and their parental lines. These primers were used in purity control of hybrid seed production of Beijing No.57 and Beijing No.106 . This result indicated the practical usefulness of RAPD markers in commercial hybrid seeds purity tests of Chinese cabbage.

The kernel quality of 425 maize inbreds and 1 125 cross combinations were analyzed in this paper by using near infrared spectroscopy transmission(NIT) analyzer made by FOSS Company.The heterosis of roughfat(oil), protein and rough starch and the relativity between hybrids and their parents were also discussed.The study showed that the variance range and the variance indexes of roughfat and protein contentwere large, and those of roughstarchwere minor. The average content was 4.24%, 12. 17% and 71. 10% respectively for the roughfat, protein and roughstarch in inbreds, and 4. 86%, 9.93% and 72. 56% respectively in cross combinations.The relativity of the three components be tween hybrids and their parents was minor.The midadvantage and superadvantage were positive for roughfat, and nega tive for protein.The cross advantage variance range was larger for roughstarch, and the average value was minor. NIT is a new method for quality analyzer in crop breeding.

The experimental results showed that the resistance of cucumber varieties to downy mildew displayed positive correlation with chlorophyll content, sugar content and the catalase activity in the leaves.The inocula-tion results of seedlings showed that the resistant varieties increased 2 bands of peroxidase isozyme, but the susceptible varieties increased only 1 band.

Under different water treatments,leaf free proline of two wheat cultivars,Henong 859 and Yunlai 49 were studied.The main results showed that under different extent of water stress leaf free proline increased.In short-term water stress,free proline accumulation of two cultivars had little difference,but free proline accumulation of strong-drought cultivar Henong 859,with continuing and intensing of water stress,was less than that of Yumai 49.

In order to reveal characteristics of source and sink,source2sink relationship,and the effect of source and sink on grain yield,find out the restrictive factors of grain yield,a study was conducted with three hybrids (Jingdan28, Zhengdan958,Nongda108) in four plant density (4. 5 × 10plant/ ha,6. 0 × 10plant/ ha,9. 0 × 10plant/ ha) under lim2 ited light and heat conditions. The results showed that the population total leaves area and the dry matter production ca2 pacity increased with the increase of plant density,but the population total leaves area decreased rapidlyfrom 30th day af2 ter silking under high density condition ( 9. 0 × 10plant/ ha). Increasing the plant density was an effective approach to increase the total leaves area and grain yield by decreasing the leaves senescence from 30th days after silking and increas2 ing the dry matter production capacity. The grain numbers per ear and grain weight decreased with the density increased, while the ear numbers,grain numbers per ear and the maximum potential sink capacity per unit area increased and was 16.7 % - 103 %,4. 7 % - 87 % and 8. 4 % - 73 % higher of the high density (9. 0 × 10plant/ ha) than those of the other treatments respectively. Increasing the plant density was an effective to obtain a larger sink capacity and higher grain yield. The sink2source ratio decreased gradually with the plant density increased. Under high plant density,both source and sink had effect on the formation of grain yield,but sink was the major restrictive factor. Increasing planting density with enlarging sink capacity and strengthening source was the key approach to obtain high grain yield of summer maize in Hebei Province.

The kernel rot caused by F.monili fame is one of the most serious diseases of corn in recent years in Chine.The experimental results showed that the inbred lines differ widely in their resis-tance.The lines Ernan-24 and 330 were very resistant;Mol7 and Mo20 were suscepti-tible.5 inbred lines of normal and Opaque-2 genotypes were inoculated with isolates of F.monilifome.Opaque-2 were less resistant than the normal types.The R×R(resistant)and R×S(susceptible)cross were resistant,S×Scross were not very susceptible.

Heterosis would be a well known genetic phenomenon in the fields of biology, which has been successfully exploited on breeding of many plants and animals, but the genetic basis of heterosis might still remain uncertainly puzzles by far. In this paper, the mechanisms of heterosis were reviewed, some new opinions about genetic basis of heterosis were summed up on the base of the classical theories and hypothesis on the genetic mechanisms of heterosis. Discuss the relationship of the heterosis between heterosis group and molecular mark. Finally this paper has looked forward to the direction of heterosis.

Two winter wheat cultivars with Yumai 66 and Yumai 49, were used to study their C-N metabo-Lic characteristics and source-sink relationship during grain filling stage.Changes of photosynthetic rate, SPS ac-tivity and WSC content in flag leaf appeared to be a single-peak curve, but Yumai 66 reached the peak a little later than that of Yumai 49, and leaf metabolic activity decreased slowly during later filling stage.It showed that/Source0had strong supplying ability of assimilating matter.NR activity of flag leaf in two cultivars had the same trend, but Yumai 49 was superior to Yumai 66 during 5-20 d after anthesis, it had an opposite trend dur-ing 20-35 d after anthesis.Change of IAAO activity in kerneLcame to be a double-peak curve.Starch accumu-lating rate of Yumai 49 had a double-peak curve during the whole filling stage.But that of Yumai 66 had a sin-gle-peak curve, the peak came a little later than that of Yumai 49, but it sustained a long time.It showed that Yumai 66 maintained stronger/sink0activity during the later stage.

Pot and field experiment were conducted to study the effects of different bio-activated organic fertilizer levels on growth of flue-cured tobacco in 2006 Results of pot experiment showed that the application of bio-activated organic fertilizer could increase the nitrate reductase act ivity,chlorophyll content and root act ivity,and reduce the content of MDA compared with CK.Results of field experiment revealed that it can effectively increase total sugar,reduce sugar,the ratio between reduce sugar and total sugar.It can increase phosphor,magnesium,zinc,calcium,iron and copper content,too.

In order to study the effects of spacing form and planting density on grain yield and population quality,an experiment by split plot designs was hold with a winter wheat cultivar Henong 822.The experiment included three spacing forms such as 15 cm,20 cm and 16.7 cm+16.7 cm+26.7 cm and four planting density such as 180×104 basic seedlings per hectare,300×10⁴ basic seedlings per hectare,420×10⁴ basic seedlings per hectare and 540×10⁴ basic seedlings per hectare.The results showed that the interaction between spacing form and planting density was not significant.The grain yield,population total stems number,leaf area index and dry matter accumulation were almost the highest under the treatment of 15 cm,followed by row spacing of 20 cm and 16.7 cm+16.7 cm+26.7 cm.On the other hand,the leaf area index,dry matter accumulation and grain yield of 300×104 basic seedlings per hectare was almost the highest,followed by 420×10⁴ basic seedlings per hectare,180×10⁴ basic seedlings per hectare,and 540×104 basic seedlings per hectare.The population total stems number increased with the adding of basic seedlings.And the population total stems number of treat of 540×10⁴ basic seedlings per hectare was the highest,followed by 420×10⁴ basic seedlings per hectare,300×104 basic seedlings per hectare,and 180×104 basic seedlings per hectare.To get higher yield,the optimum spacing form and density on henong 822 were 15 cm and 300×104 basic seedlings per hectare.

Maize rough dwarf disease caused by Rice black-streaked dwarf virus(RBSDV) is one of the most important diseases on maize production in North China.Studies were carried out to measure and calculate each of the healthy and infected plant height and the yield of 1003 plants of 3 cultivars.The result showed that disease severity was closely correlated to the plant height and yield.When diseased plant heights were 1,4/5,2/3,1/2,1/3 of the healthy plant,disease severities were graded from 0,1,2,3 to 4;and the yield losses ranged from 0%,25%,50%,75% to 100% respectively.By analyzing the data of disease index and yield loss from 10 cultivars with SSPS,a regression equation was established,which is Y=-0.253+1.02X(Y:yield loss;X:disease index).The equation was validated with the data from 16 cultivars.The result supported the feasibility of the equation to predict the yield loss caused by maize rough dwarf disease in production.

Two tomato cultivars were selected for the study,the whole-plant morphology,physiological characters as well as leaf ultrastructure of two tomato cultivars to differential light availabilities were examined in controlled environment.The results showed that,under the low light stress,the growth of the plants was inhibited.The total plant dry weight declined significantly and the reduction was 22.43% of the common tomato (Meifen-2) and 28.87% of the cherry tomato (Hongsheng),and the healthy index decreased 33.53% of Meifen-2 and 51.48% of Hongsheng,respectively.Chl and Car content of the two cultivars grown under low light condition increased significantly,the Chl a/b ratio decreased during acclimation.Compared with control plants,the amount of soluble proteins and soluble sugars were drastically decreased by low light treatment.As the light intensity was lower,the net photosynthesis rate (Pn) and stomatal conductance (Gs) decreased,but intercellular CO₂ concentration (Ci) increased.The decrease of net photosynthetic rate was considered as a result of non-stomatal restriction.The blade thickness became thinner under low light stress,and the thickness rate of palisade and sponge tissue declined.The number of chloroplast and starch grain decreased as a result of low light intensity,the number of grana and lamella increased,the size of chloroplast and starch grain minished.The objective of this study revealed the relationship between photosynthetic system characters and low light stress,which could tolerate low light stress.

The paper aimed that analyzing the fat composition and the differences of fatty acids composition and contentappear in different walnut varieties kernel by the method of gas chromatography(GC).The results showed that the fatcontents were about 66 % in all of the walnut kernel.12 kinds of fatty acids,including Tetradecanoic(C14∶0), Palmitic(C16∶0), Palmitoleic(C16∶1n7), Heptadecanoicn(C17∶0), Cis -10 -Heptadecenoic Heptadecanoicn(C17∶1n7),Stearic(C18∶0),Oleic(C18∶1n9c), Linoleic(C18∶2n6c), α-linolenic(C18∶3n3),Arachidic(C20∶0),Cis -11 -Eiscosenoic(C20∶1),Docosanoic(C22∶0)were detected in the six walnut varieties kernels.The carbon numbers of the fattyacids were mainly between 16 and 18.The fatty acids in walnut kernel mainly included Polyunsaturated fatty acid andMonounsaturatedfatty acid,less saturated fatty acid.The varieties of Qinglin and Yuanlin had the highest and the lowestLinoleic acid contents,reached to 42.19 g/100g and 36.12 g/100g,respectively.

This article has carried on the comparison of polyphenols material and the main chemical composit ion of the tobacco leaf of the 5 main areas in our country. The result indicated: The polyphenol content of Yunnan and Guizhou tobacco is higher than that of others. The nicot ine content is medium. The total sugar and the return sugar content are relatively higher than that of others. The nicotine content of Anhui area is slightly high. The polyphenol, the total sugar and the return sugar content of Liaoning and Anhui tobacco leafs are generally low. The coordination of leaf tobacco of Liaoning and Anhui are bad, while the Yunnan and Guizhou tobaccos are generally good.

Powdery mildew was one of the major diseases inCucumis sativus L.production.In order to establish its molecular marker-assisted selection system,we aimed to identify molecular markers linked to the resistant gene.With a F-population between a resistant parent(WIS2757)and susceptible parent(19032),we found two codominant SSR markers SSR97.200 and SSR273-300 were linked to the powdery mildew resistant gene,the genetic distances was 5,13 cM respectively.These SSR markers could be useful in marker-assisted selection in cucumber breeding.

In 2004,the effects of fertilizer concentration on growth and physiological characteristics of flue-cured tobacco seedlings in the floating system were studied with K326 coated seeds.The treatments (calculated by nitrogen concentration) were:0(no fertilizer),50,75,100,125,150,175and 200mg/L.The fertilizer contains many kinds of microelements,provided by Ye-xian county floating system materials factory.The fertilizer ratio was 20-10-20(N-P₂O₅-K₂O).The results showed that at 30 and 35 days after seedling,with the increasing of nutrient solution concentration,stem length,number of leaves,plant dry weight and the number of first-order and second-order lateral roots of seedlings increased;at 45 and 50 days after seedling,Fertilizer within 100-150mg/L could make a better growth of tobacco seedlings.At 46 days,NR activities decreased with the increasing of nutrient solution concentration,except which,NR activities and the contents of water-soluble protein in the whole period increased with the increasing of fertilizer levels within 0-125mg/L,then decreased over 125mg/L.INV activities decreased from 0-150mg/L,then increased over 150mg/L during the whole seedling period.

Pepper (Capsicum annuum.) anthracnose caused by colletotrichum capsici is the most destructive disease reducing marketable fruit yields and decreasing fruit quality of pepper in China. This experiment as a fundamental research for resistance breeding was conducted to establish more reliable screening method based on sporulation of colletotrichum capsici for inoculum preparation, and inoculation methods combining inoculation stage, inoculation method, inoculum concentrations, post-inoculation wetness duration and evaluation date for testing resistance. Sporulation of colletotrichum capsici was most abundant on Cowpea pod tissue medium for 10-14 days under 28 ℃ with darkness. A 0.02 mL droplet of irroculum(3×106 spores/mL)was placed on the wound-ripe red fruits pricked with multi-pins, and keep humidity of 90%-100% at (26±2) ℃ for 3 days with darkness, the 7th day after inoculation was the optimal period for evaluation resistance in pepper. With this screening method,7 resistant varieties (lines) was obtained from 19 pepper germplasm, which can be used to pepper breeding of disease resistance.

Substrate cultivation experiment was carried out in greenhouse to study the effect of different rate of organic fertilizer combined with same level of chemical fertilizers on growth of cucumber and its nutrients uptake.All the fertilizers were applied once as base fertilizer,among which chicken manure was chosen as the organic fertilizer for study.The results showed that high rate of organic fertilizer,which rate were 50,100kg/m³ respectively,inhibited cucumber growth at early stage significantly,and therefore reduced their early stage yield.Nitrogen,phosphorus and potassium nutrients uptake by cucumber increased with higher fertilizers rate.Available nitrogen in the substrate of all treatments was very low and evident symptoms of nutrient absence in cucumber plants appeared to certain extent 74 days after cucumber transplanting.The study demonstrated that application of high amount of organic fertilizer once could not supply enough available nitrogen for vegetable long-term growth.

This study evaluated the combining ability, heterosis and heterotic pat terns of yield for the crosses between 4 line-testers represent ing the main heterotic groups of Chinese corns and 13 elite populations improved from the research groups. The analysis of variance showed that highly significant differences were observed for grain yield among genotypes, GCA of populat ions and SCA between populations and testers. The SCA of populat ions of WBM-C4, Yuzong No. 5, Liaoluzongqun, Zhongqun No. 14 and Huangzongqun were higher than that of others tested. Among 12 crosses with higher SCA and grain yields near to that of the check averaged from four commercial crosses, compared to 52 crosses, four cross comb-i nations of 478×Huangzongqun,Huangzao 4×Zhongqun No. 14, Dan 340×Huangzongqun andHuangzao 4×Yuzong No. 5 had the best special combining ability and higher yields than checks with heterosis of 2.29%~4.82%. The results not only showed the research progress in the population improvement of China, but also provided scientific basis for further improvement and utilization of these populations, and the establishment of heterotic patterns of chinese corns.

The experiment was conducted using organic soil culture which mixed corn or wheat straw, mush-lawn grass, melon straw and manure with soil as substrates to select the better culture ingredient. The results showed that organic soil cultures were better than soil culture in yield by increase fruit numbers.

The Sr18 fungal metalolites were used in controlling tomato root-knot nematodes(Meloidogyne.sp.)in the greenhouse.The results showed that the metabolites of Sr18 could increase plant height by 14.5%,which means that it did no harm on the tomato plant, and that, it could also reduce the number of second stage juvenil(J2)of tom ato rood knot nematodes by 68.2%.T he result of investigation at harvesting period showed that the control effect was significant and the tomato yield increased by 61.72%.These results indicated that Sr18 fungus could be a prospective strain to develop a new kind of biological control agent for nematodes.

The influence of tartary buckwheat extracts (TBE) on blood sugar of hyperglycemia rat caused by tetraoxygen pyrimidine and blood lipid of hyperlipidemia animal were observed.The results showed that TBE had no influence on the blood sugar of normal rats,high and middle dose of TBE could significantly decrease blood sugar of tetraoxygen pyrimidine caused hyperglycemia big rats ,and improved sugar tolerant dose of tetraoxygen pyrimidine caused hynerglycemia.High dose of TBE could significantly decrease the concentration of total cholesterol of blood serum of rat,and middle dose of TBE could significantly decrease the concentration of total triglyceride of blood serum of rat.

The activities of superoxide dismutase(SOD), peroxidase(POD) and polyphenol oxidase(PPO) in germinated seeds, cotyledons, true leaves on different nodes and the leaves inoculated with Pseudoperronospora(Berk. et Curt.) Rostov. of cucumber varieties with different resistance to downy mildew of cucumber were measured. The results showed that SOD activity in germinated seeds and cotyledons of resistant varieties were 54.15% and 35.51% higher than that of the susceptible varieties. SOD activity in true leaves on different nodes of resistant varieties was 131. 51% higher than that of the susceptible varieties. Activities of polyphenol oxidase in germinated seeds, cotyledons and true leaves on different leaf nodes of resistant varieties were 62. 14%, 60. 00%, and 12. 93% (mean of 3 leaf nodes) higher than that of the susceptible varieties respectively. Activities of prooxidase in cotyledon and true leaves on different nodes of resistant varieties were 74. 47% and 28. 76% higher than that of the susceptible varieties respectively. When the leaves on the second node was inoculated with Pseudoperonosis (Berk. et Curt.) Rostov, the activity of polyphenol oxidase decreased with increase of the time after inoculation (i. e. increase of disease index). However, activities of two enzymes in resistant varieties were higher than those of the susceptible varieties all time,activity of SOD was going down firstly and then rising, but that of the resistant varieties was always higher than that of the susceptible varieties.It was concluded that there was a negative correlation between the activity of SOD and resistance to downy mildew of cucumber, and there were positive correlations between the activities of polyphenol oxidase and prooxidase and the resistance to downy mildew of cucumber.

The activities of superoxide dismutase and peroxidase in leaves of cotton with different resistance to Fusarium wilt and the difference of the two enzymes activities between infected plants and intact plants in the same cultivar (line) were studies. The results indicated that the disease-resistant cultivars (lines) , under the field condition , displayed low membrane lipid peroxidation, weak SOD and POD activities and high soluble protein content;on the co in the same disease-sensitive cultivar,the membrane lipid peroxidation and the enzymes actvities of infected plants oppcarcd significantly higher than that of intact plants, but the solable protein content of infected plants was significantly lower than that of intact.

Based on national supervision base for aqu-i cinnamon soil fertility and fertilizer benefits in Changping,Beijing( 1991- 2004) , the effect of long-term fert ilization on crop yield and Soil organic matter. were invest igated. Themain results obtained are as follows: Compared with the check( CK, no fertilizer applicat ion) and single nitrogen fertilizer(N only) , combined applicat ion of N and P( NP) significantly increased both biomass and grain yield of winter wheat by400% and summer corn by 100% ; Compared with NP, treatment , N only, combined appplication of P and K( PK) , andcombined application of N and K( NK) , increased crop yield not significantly.The yield increament for winter wheat andsummer corn follows the following order: NPK+ pig manure( NPKM) or NPK + straw> NPK> NP. The content of soilorganic matter(OM) of NPKM treatment was higher than that of single chemical fertilizer treatment significant ly. In comparisonwith CK, soil OM with treatments of NPK+ Straw,NPKM, NPK, NP and N only increased by 7190% , 14156%,6151%, 5189% and 2156%, respectively. Therefore, balanced application of N, Pand K, and combined applicat ion ofNPK with Crop yield and organic materials play a very important role in improving soil OM status.

The effects of different soil N supply on SPAD chlorophyll meter readings and plant sap nitrate concentration were studied for winter at shooting stage. By study the correlation between SPAD chlorophyll meter reading and sap nitrate concentration with soil N_min, and total N content, the accuracy of the two plant N status diagnosis methods were studied. It is showed that the two methods could predict the winter wheat N status conectly, and the plant sap nitrate test is a better method than SPAD chlorophyll meter test. The SPAD chlorophyll meter could be used to as a plant N status diagrosis tool, and could be used in N fertilizer recommendation.

Studies on tiller regularity of the middle tillering part and productive forces of rice with main stem and differentt illeres of 14 t illering part of rice variety Gigeng 14 were carried out.The results show ed that there were two tiller turning points on the main stem of middle or late maturing rice variety. The main stem was divided into the below , the middle and the upper three partes. The tillering part of main stem 3-n1 means the middle tillering part. In the middle tillering part, up one g rade t illering of the main stem n part and below one grade t illering of the main stem n2 part follow st retching regularity of n2 tillering and tillering. During main stem grows two leaves at vertical tillering grade increases one grad at crossw ise. 1st grad tillering of n1 and n2 tillering parthave the biggest productive potent ial in all 1st g rad t illering; 2nd grade tillering of n3 and n4 tillering parthave the biggest product ive potentialit ies in all 2nd grade tillering; 3rd grade tillering of n5 and n6 tillering parthave the biggest productive potentialities in all 3rd grade tillering. Therefore if superiority of the middle tillering part is utilized rationally,there will be 14.9% potent ial of increase yield.

Based on the principle of quantitative economics and the method of Coblb-Doglus preduction funotion,the mathematics model for some main economic indexes on input and profit of agricultural was set up in Inner Mongolia The present of input and profit of agricultural was dims cussed,the quantitative relation between input and profit was studied.Some suggestions of raising the profit of input in dryland farming were also given.

Salt stress experiments of rice seedlings of two lines with a gene encoding for BADH,51一22，52 一7 and the recipient Zhonghua No. 8，were conducted under the Na⁺CI concentration of 0，3. 0，5. 0，7. 0 g/L. The results showed that the rice cultivars with a gene encoding for BADH demonstrated higher salt tolerance than its recipient;The gene encoding for BADH could reduce the salt injury by increasing CAT activity,root ac-tivity,chlorophyll content and cell membrane osmosis,and by decreasing the Na⁺十concentration in the seedlings under high Na⁺CI stress (Na⁺CI concentration:5.0, 7. 0 g/L) ; The CAT activity, SN。十/K* and chlorophyll content are the main physiological indexes affecting the seedling growth.

F₁, F₂, BC₁and BC₂seedswere obtained through crossing, self crossing and backcrossing by Chinese cabbage( Brassica campestris ssp.pekinensis)of yellow and white heading, orange and white heading, two white headings( one of parent s flowers is also white) in order to study the hereditary characteristics of heading colors, flower colors and pertinency between them.Results showed Chinese cabbage heredity of orange and white flower colorswas controlled by pairs of recessive allele.Heading colors of orange and yellow showed differ ent heredity characteristics.Heredity of orange heading was controlled by pairs of recessive allele, while that of yellow heading showed quantity characteristics.F₁, BC₁ and BC₂ of yellow heading separated different white, yellow and middle color heading types.Meanwhile orange heading and orange flower color were linked, that is, orange heading color showed the same flower color and heredity characteristics.While white and yellow heading colors were not linked to flower colors.Therefore, for orange heading F₁, two parents must be orange heading, and for yellow heading F₁, two parents must also be yellow heading.

Using pools in waterproof installxtion, set up two factor and three standard. The effects of water use efficiency and economic benefit in summer corn under different water use efficiency and economic benefit in summer corn under different water coordination fertilzer have been studied.The results show: the water use efficiencys under high fertilizer-low water, middle fertilizer-low water, low fertilizer-low water are lower; and economic benefit are no good; the water use efficiencys are higher under middle fertilizer-middle water, low fertilizer-middle water, it is the best coordination which reach steay yield and higher benefit; the water under efficency is the highest under high fertilizer-middle water, but the consume water coefficient is the lowest, it is the best coordination which obtaining high yield and saving water; the water use efficiency and the economic benefit are the best, the yield surpass 13 500 kg/ha, it is the best coordination that realizes superhigh yield in summer corn under high fertilizer-high water.

The effect of enhanced UV_B radiation on the growth and photosynthesis of cucumber (Cucumis sativus L.) seedlings was studied.The results showed that the seedling height was significantly inhibited by the UV_B radiation.The root growth and root activity of cucumber seedlings,the chlorophyll synthesis and photosynthesis were promoted by the UV_B radiation at low dosage.But high dosage of UV_B radiation inhibited the roots activity,and caused great damage of chlorophyll and decrease in photosynthetic rate (Pn).The content of SOD and POD of seedlings was higher than that of the control at low dosage of UV_B radiation.However,the content of seedling SOD was lower than that of the control but the content of seedling POD was higher than that of the control at high dosage of UV_B radiation.It suggested that the strong seedlings were facilitated by low dosage UV_B radiation.

This study was conducted for the purpose in detecting the effects of different plant densities on photosynthetic-physiological characters and yield traits of the "compact-type" maize variety Chaoshi No.1 grown in spring season on a super-high yielding paddy field.The results showed that in the range of plant densities from 67 500-97 500 plants/ha,with increasing of plant density,population leaf area index(LAI),leaf area duration(LAD),and capture efficiency of photo-synthetically active radiation(PAR)of canopy increased correspondingly;the relative chlorophyll content(SPAD)and spicel leaf weight(SLW)decreased on the contrary;and the photo-chemical quenching(qP)and non-photo-chemical quenching(qN)of ear-nod leaf at grain filling stage increased,too.Under high plant density(D3)condition,the effective quantum yield(EQY)of ear-nod leaf and the electron transport rate(ETR)showed low,indicating slow-down of the sunlight energy transformation efficiency;the speed of dry matter accumulation(DMC)of a single plant decreased,but the population DMC and grain yield increased;the grain No.per ear and 1000-grain weight decreased.

The effects of VB_(1) and desiccation on callus induction and bud differentiation of immature embryo from 14 wheat genotypes were studied.Result indicated:there was a significant difference between the various genotypes in bud differentiation frequency,and ZhengXin 992 was the highest(71.9%).VB_(1)(10 mg/L) supplemented into the induction?subculture and differentiation media can improved the embryogenic callus development and increased the bud differentiation frequency.12 h desiccation before differentiation culture improved the bud differentiation frequency of calli.

In pool culture, the ef fects of nitrogen rate on chlorophyll content, photosy nthesis rate, grain filling rate and yield w ere studied w ith strong-gluten w heat 8901 and w eak-g luten w heat 1391. The results ind-i cated that chlorophyll content and photosy nthesis rate of the tw o dif ferent gluten cult ivars w ere grow ing higher w ith the increasing of N. But in 240-360 kg/ ha, the t rend was weaken. In the condit ions of this experiment, w e found that the chlorophyll content, photosynthesis rate andYield of the two cult ivars were hig her under the moderate nitrogen t reatment ( 240 kg/ ha), and the g rain filling course w as reasonable. We also discovered that photosynthesis rate in f lag leaves and grain filling course of tw o different genetic-type cult ivars differented signif icantly. In the reproduct ive stage, the photosynthesis rate was posit ively correlated w ith grain yield and the chlorophyll content of the flag leaf.

Buds of 3 0～5.5mm in length of broccoli (Brassica oleracea var.italica) were removed from the raceme,surface sterilized with full strength commercial bleach (7% sodium hypochlorite)for 15 min and rinsed 3 times with sterile deionized water.Then they were squeezed,filtered,prepared and centrifuged.The density of the suspension was cultured in modified liquid medium 1/2 NLN lacking growth substances.They were sealed with parafilm and incubated in dardness at 32.5℃ for one day and then incubated at 25℃ continually.13 genotypes of broccoli were used in the isolated microspore culture study.Microspore derived embryos were produced in 8 genotypes and 207 microspore derived plants were produced in 5 genotypes. Of the eight genotypes in which microspore derived embryos were gained,the best one was"Balu broccoli"which produced 37.08 embryos per bud.Genotypes influenced isolated microspore culture of broccoli significantly.The addition of active carbon suspension to culture media and the alternation of culture media were also studied.

Under the condition of certain water stress.17 wheat varieties were compared with different drought resistance and its content of SOD,CAT,Pro,soluble protein and soluble sugar of flag leaf after anthesis,then we analyzed the feasibility of identify index.The results indicated that three kinds of wheat have the same of trend in the above biochemical characters,the wheat varieties with stronger drought resistance was super to other kinds of wheat,three kinds of types wheat varieties have difference in anti-oxidized protection enzyme as well as seepage adjustment matters.Content of SOD at 7 days after anthesis,content of CAT and Pro after anthesis,content of soluble protein and sugar at 14 days after anthesis could do the identify index of drought resistance.

This study include two experiments. In experiment No.1, the content of pentosan in 9 wheat cultivars was determined in 1999-2000. Significant differences were found inpentosan content of different cultivars, ranging from 6.25% to 8.23%.In experiment No.2, the bioassay of 64 cocks was used to describe the AME and nut rientingredient digestibility of two wheat cultivars with or without an commercial enzyme (mainly xylanase).

Using twenty wheat varieties (lines) in this experiment, the correlations between the canopy characteristic and yield with its components were studied by canonical correlation analysis, Results showed that yield was significantly correlated with its components and the plant characteristic; the number of kernels per ear, the number of ears per plant and population exit the biggest effects on the yield. The weight of dry substance and the plant height in plant characteristic exit the biggest effects on the yield. The length of leaf was significantly correlated with the yield; the effect of length of top 3rd leaf was biggest for average yield; the effects of 3 leaves were similar for the grain yield per plant; The yield components were signifficantly canonical correlated with canopy characteristic. The stem diameter were signifficantly correlated with stem wall thickness and length between knots. In canony leaf characters, every two groups exit signifficant correlation except between the leaf width and the degree of spreading.

Forty eight inbre’s-lines of corn were divided into 12 groups by measurement of genetic distances and clustering analysis.The relationship between the genetic distance and heterosis in corn was also discussed.Conclusions were as follows: (1) None inevitable inner relation existed between the clustering results and the consanguinity, and geographical sources of these materials used in this study.Genetic distance could not stand for the genetic divergences of inbred-lines of corn; it might reflect the morphological differences of the inbred-lines.(2)Evident heterosis existed in yield, but had no significant linear correlation with the genetic distance.Therefore, to predict the heterosis in corn by means of genetic distances of inbred-lines is restricted.

From 1996 to 1999,the investigation of Laodelphax stratellus Fallen-a vector of maize rough dwarf virus(MRDV),the experiment of different sowing dates and MRDV disease incidence were carried out in Xinji city of Hebei.The results showed similar tend with disease incidences.All results reveased that in vector severe or moderate occurrence year,06-15 and later was the suitable sowing period.Otherwise different sowing dates had no obviously difference on disease incidence.It was concluded that sowing date was the key factor,vector number was the important factor for MRDV occurrence and spread.Therefore predicting the vector occurrence and sowing in suitable period could control MRDV disease.

The harvesting time has obviously effect on forage nutritive value of corn. The experimental results indicated that maize forage nutritive value was not optimum at the black layer stage, on the contrary, forage nutritive value of LD 50 and HO 115 was optimum at the end of the milking or at the early waxen stage, that of KD 8 was optimum at the milking stage. Furthermore, among three type corns the biomass and the crude protein outputs of KD8 were the highest; the ether extract content and output of HO 115 was the highest.

The experimental results for two years showed that the leaves of four wheat cultivars produced osmotic adjustment under long soil water stress and slowly soil dewatering conditions. The osmotic adjustment ability of ear pregnant stage and grain filling stage was stronger than that of others. The degree of osmotic adjustment was 0.40-0.64MPa in wheat leaves. The ability of osmotic adjustment of cultivars with strong drought resistance was stronger than that of cultivars with weak drought resistance. The turgor pressure of wheat leaves was almost not changed by osmotic adjustment under mild stress or 60% of soil water content. For four treatments of five development stages, the results of regression analysis of turgor pressure and leaf water potential showed that turgor pressure decreased units when leaf water potential changed one unit: Changle NO. 5 (0.146)

The effect of irrigation combined with fertilization in different stage of wheat on photosynthetic characteristics and yield in dry land field were studied with breeds of wheat called jinmai 47.The results showed that the effect of photosynthetic characteristics and yield under different combination of irrigation and fertilization in different stage of wheat were significantly affected.The water and fertilizer combination at elongation of wheat was the best.Its yield were higher than the way without supplement water in whole growth term.According to the correlation analysis,spike number per area was highest in the three patterns,kernel number per spike was second and 1000 kernel weight was low.

Cotyledon sxplants from three pepper cultivars were co-cultured with an agrobacterium strain carrying a binary Ti vector in which a foreign CMV_cp gene was inserted after the 35 spromotor After kanamycin-resistent selection and regeneration culture five transgeneplants and their offsprings were obtained.The transformation rate is 10%.Results of Southern and Northern Blots as well as ELISA tests indicated that the CMV_cp gene has incorperated, transcripted and translated in transgeneplants and their offsprings.Virus inoculation tests prove the resistance of the transgeneplants and their offsprings to CMV virus.

The parameters of maize roots system were studied systemically in a pot experiment by the method of washing roots.The experimental results showed that the differences among the morphological,anatomical and physiological activity resulted in the differences in drought resistance in maize.The relationship betw een roots system and drought resistance was closely related,which should be used in drought resistance identification.

Two winter wheat cultivars differing in drought resistance (Taiyuan 633, drought-tolerant; C609, drought-sensitive) were used to study the changes in protein synthesis and the relation between these changes and drought resistance of plants under the water stress. The results of two-dimensional PAGE-SDS-PAGE electrophoresis showed that water stress(-2.0MPa) caused obvious differences of protein changes in leaves of two winter wheat cultivars. The water-stress-induced protein in Tai Yuan 633 presented earlier than that in C609. The results indicated that there was a close connection between the proteinchanges in drought-tolerant and drought sensitive cultivars caused by water stress and thetime of water stress. After rewatering the protein changes could recover immediatly. The experiment of using the inhibitor showed that the emergence of the water-stress-induced proteins could be inhibited. The results implied that the gene expression of the proteins relating to adaptation to water stress was regulated mainly at transcriptional level.

There is a transition from grassy marshland grassland and typical grassland to deserted grassland and desert because of the difference of climate.And this change is from east to west in Inner Mongolia.The climate warming postponed frostless period,decreased snow,hailstone,thunderstorm,gale and day count of dust storm,increased rainfall.But it wasn't change humidity that determined the distribution of grassland genre nearly.A few years recently,grassland degeneration and deserted going with grassland assart and the instance of vegetation destroyed.High and continuum temperature accelerated the process of grassland degeneration,and in some degree changed its trend and pattern from 1999 to 2001.

The effects of different NaCl solutions on the morphological and physiological indexes of Zhuliu plants under sand-cultured were studied.The results showed that,with the increase of NaCl concentration,the height and the stem diameter decreased continuously,and significant difference was observed compared with the control..The leaves of Zhuliu appeared different degrees of dry rot yellowing,and growth vigor recession.And the water content,electrical conductance,MDA content increased gradually.The content of chorophy,proline,soluble sucrose were increasing at first and then declining later,showing regularity changes.The salt tolerant threshold of Zhuliu was deduced as 0.5% and survival threshold was 0.8% by observing visual form and analyzing physiological index.The research provided the scientific basis for exploitation and utilization of Zhuliu in saline-alkali land.

The seeds of Spinacea oleracea,Chrysandthemum coron vium,Coriandrum satium were treated with GA₃,Thiourea,KNO₃ and H₂O₂ at various concentrations respectively.The results showed that GA₃ slightly promoted at low concentration or inhibited athigh concentration the germination of three seeds,in contrast,the germination of three kind of seeds was promoted by usi ng Thiourea solution with optimal concentration of 0.2% for spinacea olera cea and coriandrum satium,0.5% for coriandrum satium KNO₃ with 0.2% concentrationhad the best effect for three kind of seeds,but 30% H₂O₂ only had primitive ef fective for spinacea oleracea.Treatment with KNO₃ Thiourea reduced electrolytes and UV absorbent substances leaked from the effective treated seed,which sugge sted that Thiourea,KNO₃ can keep the stability of cell membrane.

Comparative observations on microspore development in a male sterile 95305 and fertile plants of L.esculentum were made with light and transmission electron microscopy. The results showed that the microspore abortion occurred at the stage of microspore mother cell, tetrads and uninucleate microspore. The tapetal cells were desolved completely earlier than that of normal male fertile material, or divided into multilayer to press the microspores. Other kinds of microspore abortion such as the failure of exin deposition also were reported. In addition, some anthers were deformed and had pistillody.

The Cucumber mosaic virus (CMV)，Tobacco mosaic virus (TMV) and Potato virus Y (PVY) are sig-nificant worldwide plant viruses which harm to agricultural production. Mixed infection with several viruses usuallyoccurs complex symptom.rapid sensitive and specific method by which several viruses can be detected simultane-ously is needed urgently. In this study according to three kinds of viral coat protein gene sequence，primers andprobes were designed，gene chip was prepared.

We studied the resistance to powdery mildew in 357 varieties of melon in air-conditioned greenhouse by wind media inoculation.The result showed that 69 varieties were resistant,52 of which come from foreign varieties,10 of which from seed markets or research institutes in China.6 var.makuw a makino and 1 var.f lexuosus naud were resistant in 133 landraces on Melon.This indicated that the population of landraces has resistant genes which have a potential value to melon breeding.The number of resistant plants was bigger than that of susceptible plants in inbreeding off spring of resistant sources,and the inheritance of these resistant genes may be dominant.

The contents of protein, lysine and fat in 209 varieties of foxtail millet ( Setaria ialica Beauv. ) in Shanxi Province were analyzed in this paper. The results indicate that a significant difference in their contents exists between the varieties. The contents of protain, lysine and fat in most varieties are 10.00-12.99%, 0.220-0.279% and 4.00-4.99%, averaging 11.45 ±1 .43%,0.240±0.031% and 4.48 ±1.85% respectively. Their average contents in middle Shanxi are the highest, reaching 13.31±1.31%, 0.271±0.027% and 4.97±0.69% respectively. Moreover, there are a lot of high quality materials with high protein, lysine and fat contents, for example, Dai Qinggu, 7465, Daizhou Yellow, 7421, etc. There is a close interrelation among protein, lysine and fat; and high contents of protein, lysine and fat can be probably incorporated in the same genotype. But a negative correlation is significantly shown between protein and the percentage of lysine in protein.Therefore, the content percentage of lysine in protein should not be used when high lysine content breeding target is determined. Instead, the percentage of lysine content in dry weight ought to be adopted. A negative correlation is shown between protein, fat and lysine .while the main characteristics of plant have importance in the following order, growth period dura-tionnumber of seedsseed weightplant height1000 seed weightlength of the main ear

The distant hybridization from maize and diploid perennial teosinte ( Zea diploperennis L.) was conducted for seven years,through twelve generation.Inbred lines which are resistant to diseases and environmental stress and have fine agronomy characters was obtained through selfing and selection.A new hybrid variety called shannong 993 which showed high yield,multiple resistant and high quality characters was developed.This indicated that maize×teosinte( Zea diploperennis L.) is the effective ways to widen germplasm pool of maize and to over come the stasis situation of maize production in China.

The medium and condition of liquid fermentation for biomass production of Bacillus subtilis B0₃ were optimized with mono-factor experiment and uniform design.The most suitable medium for living cell production was formulated with the ingredients:3.0% corn meal,6.0% soybean oil meal and 0.3% K2HPO4·3H₂O.The optimized fermentation process was as follows:the seed culture was cultured for 21-24 h,the pH of production medium was adjusted to 6.0 before sterilization,the fermentation was carried out in 500 mL erlenmeyer flask with 50 mL production medium inoculated with 5% seed culture and incubated at 35℃,180 r/min for 60-66 h.The biomass density of 104.24×108-105.75×108 cfu/mL was obtained with optimized formula,which was over 96% higher than that produced by basic medium and initial fermentation process.

T he nitrate contents in 1 m soiLprofile at stem elongation stage were mainly affected by the nitro-gen amount applied as basaLdressing.And the nitrate contents in soiLprofile at blooming stage and maturing stage were related to the nitrogen amount applied as top dressing at stem elongation stage, as welLas the nitrogen amount of basaLdressing.The differences of nitrate distribution between the treatments at stem elongation stage mainly observed in 0-60 cm soiLprofile, while the differences at blooming stage and maturing stage observed in whole 1 m soiLprofile.Finally, it is found that the apparent nitrogen balance in soi-Lwheat plant system could be maintained when 144-213 kg/ha was applied, but treatment which whole 144 kg/ha was applied as basaLdressing had a highest absorption ratio, and a lowest residuaLratio.

Effects of rice seedling age and transplanting density on the biological characteristics of rice were examined using a rice cultivar,Yangliangyou6,in a field study.When rice seedling age was in the range of 35-55 d and transplanting density was in the range of 1.8×10⁵-3.0×10⁵ hills/ha,leaf area index(LAI) of rice at the mid-tillering stage and panicle initiation stage were decreasing as the increase of rice seedling age,however,increasing as the increase of transplanting density.There were significant differences in productive panicle per m²,total spikelet per panicle,solid spikelet per panicle and yield in the treatments of rice seedling age.Remarkable differences were found in the productive panicle per m² and yield in the treatments of transplanting density.There was also noticeable effect of interaction between rice seedling age and transplanting density.

The waterproof installations were carried out to deal with the content of soluble protein and free proline of different boll weight genotypes and inner positions in cotton under water stress.The results showed that the content of soluble protein at different positions appeared different trends for these genotypes under the two treatments,it illustrate that different position had different capacities of adaptation to drought stress.Under water stress,the soluble protein content which in each positions were decreased in these genotypes at the whole stage,the big-boll and small-boll varieties in lower branch leaves showed less accumulation of soluble protein content,the change of the content of soluble content in middle branch leaves was smaller than the lower one for each genotype which showed that the physiological characters of the branch leaves was more stable in the boll development.Under drought stress,the free proline content at each branch leaves showed more accumulation than the CK,the big-boll variety had more accumulation of the content of free proline in each poison.The free proline content in the lower branch leaves was the most,and then the middle ones,the upper ones was the least.Different varieties had different regulation mechanism in the condition of drought,so free proline can be considered as a physiological index nearly correlative to drought of cotton.

Changes in the contents of betaine, soluble sugars, free amino acids and organic acids in the leaves of the young grapevine plants (Vitis vinifera L.) during water stress were investigated. The results showed that the contents of both soluble sugars and free amino acids increased in the grape leaves under water stress, moreover, that they continuously increased as water stress was developing. Compared with drought-sensitive Red Globe grapevine, the contents of both soluble sugars and free amino acids in the leaves of drought-resistant Long Yan grapevine increased to a greater extent. Under moderate water stress, the contents of inositol, fructose, and glucose + sorbitol + mannitol increased in the leaves of Long Yan grapevine plants, especially, the inositol content enhanced almost 1.5-fold. Throughout water stress, the content of both betaine and organic acids were rather low.

To study the effects of straw mulching on inorganic nitrogen and soil urease in winter wheat field, fixed-plot field experiments were conducted in the growing season of 2006-2007 in Huaxian County,Henan Province.The results showed that content of soil NO₃^--N in 10-30 cm layer of the soil mulched with straw was lower than that in the unmulched soil in late growing period.Straw mulching was favorable to absorption and utilization of soil NO₃^--N of winter wheat.Straw mulching also affected distribution of soil NH₄⁺-N and increased soil NH₄⁺-N content.Since soil urease activity was high in the soil mulched with straw both in early growing period and at maturity of winter wheat, decreasing N appplication rate was reasonable in production practice.However, during the period from earing to grain filling soil urease activity was low and then increasing N application rate was reasonable．

The aim of this experiment was to discover difference of protective enzyme activity and study effects of metabolism assimilation in soybean leaves by spraying different plant growth regulators(PGRs).It was also to provide references for anti-aging and increasing function of metabolism assimilation in the pod filling(R5)stage.Field experiments was conducted the effects of different PGRs on metabolism assimilation and activity of protective enzyme,and Kennong4 variety was selected to avoid the impact of genetic factors in 2006.The results showed that three regulators(SOD simulation material(SODM),Choline chloride(Cc)and Diethyl aminoethyl hexanoate(DTA-6)increased SOD and POD activity with a continuation of spraying time in soybean leaves.SOD activity of DTA-6 was the highest,followed by SODM;POD activity of SODM was the highest,next came Cc.In addition,SODM and DTA-6 also increased the CAT activity of leaves at a certain extent,enhanced soluble proteins,soluble sugar,as well as to nitrate content of free amino acids,and slowed down the increase of MDA.But Cc was not obvious.The above results indicated that it is effective to enhance the antioxidant capacity and slow down the senescence of its leaves,and maintaining physiological assimilation function of its metabolism assimilation and activity of protective enzyme in soybean leaves.

A field experiment with 12 Japonica rices selected of different breeding (two breeding time) time was carried out on the farm of Yangzhou University,Jiangsu province,China.The effects of different N levels including 0,225,300 kg/ha N on rice grain yield,dry matter production,N accumulation and utilization efficiency were analyzed.Results showed that,rice yield increased with the selection time replacement and the performance of yield with two times was different with N application rate increasing.Yield of 83.3% varieties selected early increased with N application rate increasing,while a half of contemporary varieties having higher yield level at 225 kg/ha N level.It indicated that varieties selected early responded more sensitive to N fertilizer than contemporary varieties.Among agronomic traits,plant height and panicle length decreased,grain setting density increased with selection time replacement.Dry matter accumulation,N uptake and utilization efficiency of contemporary varieties were higher than those of varieties selected early.Correlation analysis showed that the relationship between rice yield and dry matter and N accumulation at heading,maturing but jointing stages were significant or highly significant positively.N utilization efficiency was positive significantly correlated with yield,negative with plant height and panicle length,It indicated that rice yield,N uptake and utilization efficiency increased,plant height tended to dwarf type and panicle type evolution from sparse dense to type with the selection breeding time changed.

A comparative study on canopy characters and efficiency for solar energy utilization in peanut at the yields of 8.5 t/ha and 6.0 t/ha was carried out. Results are:A longer duration of maximum leaf area index (LAI) was a marked character in supper high-yielding peanut (SHYP). The leaf area duration (LAD) of SHYP reached 400.1 m2·d/m2, significantly higher than that of HYP. The LAD in yield-forming stage was very important to peanut yield, taking more than 80% over whole growing season. The efficiency of LIR per unit leaf area in SHYP was lower than that in HYP. The dry matter production rate (DMPR) was constantly higher in SHYP compared with that in HYP during whole growing season, especially during late growing season. There was a clear character for SHYP. It was estimated that there existed a high potential in ESEU for peanut production, and the optimum conditions and measures for further increase of peanut yield should be studied in future.

A field experiment was conducted to investigate the effect of freezing irrigat ion with saline water in winter on the dynamics of soil salinity and moisture in coastal saline soil. Four irrigat on amounts (0, 90, 135 and 180 mm)with the shallow brackish groundwater (15 g/L) were exploited in this experiment in winter. Results showed that top soillayer was well desalinized with freezing irrigation in the next spring when soil freezing layer thawed. The desalinizing ratiois 12. 7%, 73. 8% and 80.9% in 90, 135 and 180 mm irrigation treatments, respect ively. However the no irrigationtreatment showed intensive salinization in spring. The possible reason is that the ice layer restrains the freezing and thaw??ing process of the saline soil and the leaching effect of fresh water produced from the melted saline ice.

The research is to study the apoptosis of pigs induced by porcine circovirus type 2??like agent P1. Theapoptosis was detected by TUNEL assay in immune organ samples( tonsil, spleen, superficial inguinal lymph node) of pigsinfected by P1 molecular clone.The results showed that the apoptosis??specific signal was detected in immune organ sam??ples( tonsil, spleen, superficial inguinal lymph node) at 21 and 35 d after P1 infection.The result suggests that P1 appearsto be related to immunosuppression resulted in apoptosis of lymphocyte.

Bearing branch is the basic fruiting units of Chinese jujube.Understanding the biological characteristics and growth of bearing branch is important to improve quality and yield of jujube fruits.Therefore,the concept,the biological characteristics,the sorts and the growthing of bearing branch were summarized.And the relation of bearing branch and fruiting was also reviewed.At last,the main problems which need to study furtherly were also outlined.

Limited irrigation experiment was conducted under field condition with winter wheat. After analyzing the data about the biomass, LAI, the ratio of grain-filling, water use efficiency and evapotranspiration,it was found that the irrigation at the stem-elongation stage was efficient to WUE and crop yield; the sufficient irrigation could increase the biomass but reduce the water efficiency; the soil water consumed by different treatments were different and the maximal difference was 143.3 mm; the ineffective water-consumption through e-vaporation between plants of the different treatments were also different and the maximal difference was 20 mm.

Four typical tobacco soils in South Anhui Province were selected to investigate the dynamic changes of carbon2nitrogen metabolism and total sugar content during the growth and development of flue2cured tobacco. The results showed that the carbon2nitrogen metabolism of tobaccos grown in Alluvial sandy soil and coarse sandy soil presented a similar trend of dynamic change.During the early and middle growth stages of tobacco,both carbon metabolism and nitro2 gen metabolism were at a high level. The activity of nitrate reductase decreased significantly in bottom leaves after trans2 plant for 45 d,and in middle and top leaves after transplant for 60 d. The invertase activity also decreased after peak val2 ues,but its degree of decrease was much less than that of nitrate reductase. The content of total sugar was at the highest level for both sandy soils. For the rice clay soil,the level of carbon2nitrogen metabolism was relatively low at early and middle plant growth stages compared to the Alluvial and coarse sandy soils,and its peak time was much delayed.At late growth stage,the level of nitrogen metabolism was relatively high,but the sugar content was relatively low. For the powder sandy soil,the peak time of carbon2nitrogen metabolism appeared early,and maintained a low level during the whole plant growth season. The sugar content in powder sandy soil was also lower than in sandy soil.

In this paper the ameliorating effects of organic acids added in the nutrient solution on aluminum stress were studied.The results showed that citric acid and malic acid added in the nutrient solution could ameliorate distinctly the inhibition of aluminum on wheat growth,decrease the aluminum (Al) absorption,increase the absorption of calcium(Ca).The ameliorating effects of citric acid was better than that of malic acid.

There was significant difference in the response of different crop varieties to the environmental factors which mainly included light-rate and CO₂ concentrate. It was very necessary to study the response of environmental factors on the winter wheat growth. Field experiments were conducted to study response of light-rate and CO₂ concentrate to photosynthesis on different winter wheat varieties from March to June in 2006. The results showed that photosynthesis parameters of different winter wheat varieties in response to light-rate and CO₂ concentrate presented significant difference. The significant difference of leaf water use efficiency (WUE) in different winter wheat cultivars was observed. Leaf WUE changed with the increase of light-rate and concentrate of CO₂.

To advance our understanding the effects of light regimes on photosynthetic characters and yield components, and comparison the difference between sweet and waxy maize, two genotypes of maize, Xiangbainuo and Yuetian 3, were planted by artificial shading. These two genotypes of maize were raised under three light regimes: 100% of sunlight, 80% of sunlight, and 40% of sunlight for their whole life long. Leaf photosynthetic characters (Pn and Tr), chlorophyll fluorescence parameters (Fv/Fm and Φ_SⅡ), and photosynthetic pigments content (Ch1 a, Ch1 b and Car) were determined. Yield components were also measured. The results showed that rates of apparent photosynthesis and transpiration were reduced significantly by shading, however, there was no significant difference between the two genotypes of maize. Fv/Fm in the two genotypes of maize increased with decreasing light intensity in seedling and grain filling stages. At the same light regimes, Fv/Fm in Xiangbainuo was much higher than that in Yuetian 3 in seedling stage, but lower in grain filling stage. With decreasing light intensity, Φ_SⅡ in both Xiangbainuo and Yuetian 3 increased in seedling stage, decreased in grain filling stage. Bald length was much longer in two genotypes of maize by shading. The main effects of week light regimes leaded Pn and Tr of sweet and waxy maize reducing significantly. There was week light stress on both sweet and waxy maize, thought there was difference between the two genotypes of maize. The significant decreasing of ear length, kernels per row and weight per ear under week light regimes were the main reasons of yield reduction.

Chloroplast DNA( ctDNA) come from cytoplasmic male sterile( CMS) it s maim ainer lineof sugarbeet was studied by means of rlom amplied polymorphic DNAs( RAPD).The fingerprints of the~plification by polyme chain reaction(PCR) of random DNA segments was enelysised.

In this paper we summarized the progress on chilling resistance study in cucumber recently.The review was divided into three parts:Effect and injury of chilling on cucumber seedling in different degree and duration of low temperature.Difference of enzyme activation between the donestication and stress of low temperature.There was a suggest on research of chilling stress in cucumber,which was interaction between metaboly and low temperature based on entire plant.Also,low soil temperature should be took into account.

The polysaccharides from Ganoderma lucidum by boiling water method was extracted. These crude extracts were tested for antimicrobial activitiy to three kinds of plant pathogens (Erwinia carotovora, Penicillium digitatum, Botrytis cinerea) and five kinds of food farmful bacteria(Bacillus cereus, Bacillus subtilis, Escherichiacoli, Aspergillus niger and Rhizopus nigricans) with the agar diffusion method. The results showed that the polysaccharides liquid had a powerful inhibiting effect on Erwinia carotovora, a weak inhibiting effect on Penicillium digitatum and nearly non- in?? hibiting effect on Botrytis cinerea for the plant pathogens. For the food harmful bacteria, the polysaccharides liquid had a strong inhibiting effect on Bacillus subtilis and Bacillus cereus, a weak inhibiting effect on Escherichia coli and As pergillus niger, nearly non??inhibiting effect on Rhizopus nigricans. In a word, the antimicrobial activity of polysaccha?? rides from Ganoderma lucidum was higher on bacteria than that of on fungi.

Soluble protein content,soluble sugar content,free proline content,MDA content,SOD activity and POD activity in different time of flower in carrot male-sterile lines and their each maintainerd were studied.The results showed that the soluble protein content in both male-sterile lines and their each maintainerd increased from little bud to blossom stage.The soluble protein content in malesterile lines was lower than that of maintainers'.The soluble sugar content increased with the development of flower,and reached its highest in blossom stage.The soluble sugar content in male-sterile lines was lower than that of maintainers'.The free proline content decreased in male-sterile lines,and increased in their maintainers with the flower development.The free proline content in male-sterile lines was lower than that of maintainers'.SOD activity increased with the flower development.SOD activity incMS was lower than that of maintainers'.Changes of POD activity in flower development stage were:high-low-high.POD activity incMS was higher than that of maintainers.

Simple sequence repeats (SSRs) were used to detect genetic diversity among 66 maize (Zea mays L.) inbred lines, which were widely used in northeast provinces of China. Seventy selected SSR primers gave stable profiles amplified in samples of 66 inbred lines. Seventy primers produced 273 polymorphic amplified fragments. The average number of allele per SSR locus was 3.9 which varied from 2 to 7. The polymorphism information content (PIC) for the SSR loci varied from 0.121 to 0.814 with an average of 0.584. Genetic similarities among the 66 inbred lines ranged from 0.62 to 0.93. The cluster analysis showed that the inbred lines could be classified into 5 distinct clusters. The results were consistent with the groups based on the available pedigree. Most of the parents used in maize commercial hybrids came from opposite clusters.

Assay for salt tolerance and drought resistance of t ransgenic wheat with BADH cDNA by biolist icmethod were conducted under simulated salt/drought stress condition. The results indicated that the t ransgenicwheat has many obvious advantages over its received plant s,such as the more vigorous development of seedlings,the well developed root system and the greater root act ivity under salt/ drought stress condition,as well as theimproved plasma membrane protection of ex cised leaf. The betaine aldehyde dehydrogenase enzyme activity underdif ferent salt concentration is also hig her,and more betaine accumulation under drought condition,than it sreceived plant. This indicated that the int roduction of BADH gene into wheat may affect a series of physiolog icalreaction to adapt st ress condition,this may be one of the reasons for its higher salt/drought tolerance. The w ayto increase crop stress tolerance/ resistance through transgenic method may be effect ive.

In this paper, the accumulating variat ion of protein, fat, seed w eight w ere analyzed at different period of the early and late-maturing variet ies, and the relationship betw een variation and quality w as discussed. The result s indicated that the quickly-increasing period of protein, fat, seed w eight ran through the whole accumulat ing procces, and different variet ies had dif ferent quickly-increasing period. In general, the quickly-increasing period of protein, fat, seed weig ht all w ere in 20-50 days after f low ering.

Trials were conducted in laboratory and field in Beijing region indicated allelopathy of wheat straw on maize. Four phenolic acids as allelochemicals have been identified and quantified in no-tillage with wheat straw mulch. They are ferulic acid ( FA), vanillic acid ( VA), cinnamonic acid ( CA) and p-hydroxyben- zoic acid ( p-HBA). Their average amounts are ( 1. 31-2. 47) × 10^-7, ( 2. 86-3. 77) × 10^-7, ( 1. 53-2. 69) × 10^-7and ( 1. 97-2. 60) × 10^-7mol/ L, respectively, and they reduced slowly in soil. FA, VA and p-HBA were tested in laborotary bioassay for their allelopathic effects on germination and seedling growth of maize. The con- centrations required to reduce growth by 10% of maize radicle of FA, VA and p-HBA, namely ED10, are 1. 14, 3. 57, 6. 30 mmol/ L, respectively.

Effects of different ABA,2,4-D concentrations and ZT and IAA ratio on callus induction and plant regeneration of barley immature embryos,bombed by microprojectile,were studied.The results demonstrated that 1.0 mg/L ABA could effectively inhibit coleoptile growth of immature embryo without negative effects.Frequency of bud differentiation was up to 8%～17% from embryonic callus induced by the treatment of 1.0 mg/L 2,4-D,while few buds induced by 4.0 mg/L 2,4-D.Desirable combination of ZT and IAA for bud differentiation was 1.0 mg/L ZT and 0.1 mg/L IAA.According to optimum hormone concentrations,plant regeneration frequency of bombed immature embryos from six barley varieties were at a range of 2%-8%.

The experiment was carried out in climate chambers to investigate the effectsof high temperature and air hu2midity on reduced glutathione(GSH)content,ascorbic acid(AsA)content,carotenoid content,flavonoid content and antiox2idative enzyme activities in ten hot pepper varieties leaves under both normal and high temperature and air humidity condi2tions during seedling stage. The results indicated that contents of AsA and activities of POD,APXincreased,and contents ofGSH,CAR and activities of DHAR,SOD decreased under high temperature and air humidity stress. There was no regularityof the contents of flavonoid under high temperature and air humidity stress.According to the every index’s the relative val2ue,and then the methodsof subordinate function was used in evaluation for antioxidant activity differencesof hot pepper va2rieties,and the antioxidant activity followed the sequence:I> C>W>D >J > H> F > G> E> K.

An experiment was carried out by a split block design with two factors of compact com hybrids of XY335(high-plant), ZD958(medium-plant) and GY 1(short-plant) as main plot and planting densities of 45 000, 53 250, 61 500, 69 750 and 78 000 plarn/hm²、sub plot to describe the variation of population quality indices, such as yield and yield components, leaf area charges, dry matter accumulation and partitioning, sink source relation, and population uniformity, as affected by hybrid and planting density. It was shosvn that grain number per ear, unifomuty of plant height, dry matter per plant, ratio of seed- set, full degree of sink, grain leaf ratio and yield-leaf ratio arisen from variable coefficient of planting density treatments regularly declined with hybrid plant height reduction. During late grosving stage, change trends of reduction rate of leaf area, relative status and balance relation of source and sink induced by planting density treatments were also varied with the variation of hybrid plant height. High-plant hybrid was shown low for suitable planting density and harvest index, and its population quality was susceptible to planting derv ity increase, however, short plant hybrid was relatively susceptible to planting density with limited individual productivity. Medium plant hybrid was ideal hybrid type for more post silking dry matter accumulation when reasonable planting density sown, high in theoretical yield and adaptation to optimal planting density.

The research progress and value on distant hybridization of plant breeding in recent years was reviewed comprehensively,especially about the reproductive factors which resulted in unsuccessful hybridization and the effective methods to overcome.These included the pre-fertilization barriers such as crossing incompatibility and post-fertilization barriers such as embryo abortion.The morphological,cytological and molecular cytological identification methods for hybridity of distant progeny were reviewed,and a new study field of plant distant hybridization was proposed as well.

We studied the effects of lead stress on chlorophyll content and the activity of antioxidant enzymes in waxy corn seedling leaves. The experiment results showed that with the increase of lead concentration the contents of chlorophyll a,chlorophyll b,and total chlorophyll decreased in waxy corn leaves; and the activities of SOD,POD,CAT first increased then decreased; The treatment of low concentrtion lead stimulated the growth of waxy corn,however the treatment of high concentration lead hold it.

Based on field sampling and laboratory analysis,the content,speciation distribution and availability of selenium in wheat field soils of Hebei were studied. The results showed that Firstly,the total selenium contents were between 0. 061－0. 584 mg /kg in wheat field soils of Hebei and the average value was 0. 341 mg /kg. Secondly,the available selenium contents were between 4. 93－83. 88 μg /kg and the average value was 31. 51 μg /kg.Thirdly,the selenium in wheat field soils existed mainly in the elemental,organic and sulfide bound forms,which accounted for 42. 25%－58. 46% of the total selenium,then in the residue form,which accounted for 28. 28% －40. 99%,and the ammounts of the other forms accounted for 12. 26%－17. 36%. But the soluble,exchangable and carbonate bound forms of selenium only accounted for 8. 12%－10. 37%,which they were available for plants.Forthly,the average availability of selenium was 9. 69% in wheat field soils of Hebei. There was significant positive correlation of the available selenium contents with the total selenium contents,organnic matter,pH and CEC in soils. So in agricultural production,we could increase the available selenium contents effectively by improving soil organic matter.

Leaf head of Chinese cabbage(Brasszca campestrzs L. ssp. pekznenszs)is the main harvesting organ,therefore cytoplasmic male sterility is an effective method in breeding varieties. In order to select and utilize cytoplasmic male sterile type in Chinese cabbage,3 cytoplasmic male sterile types of Chinese cabbage:Ogu-CMS, Pol-CMS and CMS 96 were compared with their maintenance lines on main biological characteristics in this article. Results showed that Ogu-CMS was decreased accompanying to the mufti-backcrossing,and had less combination ability;Pol-CMS was affected by environmental factors. While CMS96 was a new cytoplasmic male sterile type, it was the best among three CMS materials. CMS96 was not only better than maintenance lines in late-bolting at the early backcrossing stage,and produced higher quantity in propagation but also was stable in male sterility and no decrement with mufti-backcrossing,and had better combination ability. Therefore CMS96 showed wide application on breeding new varieties of Chinese cabbage in the future.

Nitrogen fertilizer effects on the grape leaves′ growth and the anatomical changes both of the leaves and roots through different levels of nitrogen fertilizer applications.The results express that the leaves′ length,width and leaf area are increased with the amount of nitrogen fertilizer applications′ increasing,which is also same to the content of chlorophyll,Especially,chlorophyll a increased sharply,while the chlorophyll b didn′t increase in evidence.Then the chlorophyll fluorescence quantum absorptivity is increased strongly,which is same with the chlorophyll a/b′s trend of change.That indicates quantum absorptivity is in relation with the chlorophyll a.Samples are observed by the cross sections,after the staining by DAPI,as the amount of nitrogen fertilizer applications increasing,nucleolus amount of the leaves′ is not changed in evidence,while the nucleolus amount in the root apiex meristem is increased sharply.After the staining by the I2-KI,also the starch content of both the leaves and roots is increased in evidence as the amount of nitrogen fertilizer applications increasing.

Under field condition,effects of shading on stalk mechanical and rind penetration strength were investigated using three maize cultivars differing in lodging resistant ability,i.e.JK519,CS1 and ZD958.The results showed that JK519 with a large spike under thinned planting density was sensitive to shade stress,its plant height and ear height were decreased significantly,and LAI(leaf area index) was also declined.With lower internodes diameter and shorter internodes length at basal stem,the ratio of dry weight to length of internodes was reduced in shading condition.The rind penetration strength of JK519 was decreased by 36.4% and 66.0% under a shading intensity of 30% and 60%,respectively;and field lodging seriously.However,with a shading intensity of 30%,CS1(a compact and tolerant to high density type) was declined slightly in the ear height,LAI and internodes diameter,and its rind penetration strength was only decreased by 5.9%.The rind penetration strength was decreased obviously by 60 % shading intensity,lodging heavily.Meanwhile,the finally maize yield,the number of harvest ear and grain per ear,and weight of 1 000 kernels of three maize cultivars were decreased significantly with increasing shading intensity.The 30% shading intensity should be definite as an appraise and selection condition of the mechanical strength of maize high yield and lodging resistance.

Several physiological indicatrixes of healthy and diseased last expanding leaves were measured after inoculation a week later. With the farther infecting of stripe rust,water content of leaves,relative content of chlorophyll, the efficiency of primary light energy conversion and the potential activities of photo system Ⅱ decrease. The correlation analysis between net photosynthesis rate and severity showed that there was significantly negative correlation between net photosynthesis rate and severity. What's more,the correlation analysis between transpiration rate and severity showed that there was significantly negative correlation between transpiration rate and severity.

Eighteen reproducible and informative SSR primer pairs were selected from the 89 pairs of primers of Medicago truncatula.In 8 genome DNA of Medicago ruthenica.And a representative set of 50 wild Medicago ruthenica genetic resources from Inner Mongolian were analyzed by SSR methodology using the informative primer paris for their diversity of genetic.The results showed a total of 109 alleles were detected with an average of 6.1 alleles per SSR primer pair.According to integrated evaluation,6 SSR primer pair,BI4BO3,MTIC272,MAL369471,MTIC237,MTIC188 and MTIC27 were most effective for genetic diversity studies on Medicago ruthenica.The genetic distances among the germplasms ranged between 0.023 6 and 0.807 5 with their average at 0.177 8.By cluster analysis with sum of squares for microsatellite showed that 50 accessions can be divided into 9 groups with different characteristics which could afford reference in deeper research on Medicago ruthenica.

Under conditions of grow thamber, hydroponic culture was employed to investigate the effectsof boron on growth and mineralelt content in mung bean(Phaseolus aureus Roxb.).It was showed that,inhibited growth of mung bean in response to limited supply of boron was accompanied by a decrease in root toshootboronratio.

Magnetic beads enriched method was used to isolate microsatellite DNA from Leuciscus waleckii Dy-bowski genome.We design 105 pairs of primersfrom 160 microsatellite sequence and compose them.

Select two cucumbers which were stable personality and different ecotype.Then mix two positive and negative combinations.The result of joint analysis showed that it was not obvious discrepancy between the positive and negative combinations about ratio of yellow line and fruit length.It showed that yellow line was subjected by nucleus gene.In this paper inheritance of the yellow line and fruit length ratio of cucumber was investigated by joint analysis and the major gene plus poly-genes model of quantitative traits analysis of multi-generation(P1,P2,F1,B1,B2,F2).Another analysis showed that the inheritance of yellow line ratio was controlled by a major gene with additive-dominance effects plus polygene with additive-dominance effects(the D model).Heritability values of the major genes of B1,B2 and F2 population were estimated as 95.8%,93.39%and 14.99%.Heritability values of poly-genes were between 1.36% and 54.04%.The major gene plus poly-genes effect(d)and dominance effect(h)was-41.78 and-35.96 respectively,and the additive-dominance effects of this analysis were both negative with small difference.So the inheritance of the yellow line may be controlled by a major gene with additive-dominance effects plus polygene with additive-dominance effects.

The chlorophyll content of domestic and overseas spring wheat in different ecosystem and its connection with drought resistance have been researched under irrigation condition in different year,the experimental results as the comparison indicated that the chlorophyll content of dry land is lower about 5.37 than that of wet land in the condition of irrigation.Under the dry stress condition,the dry stress treated chlorophyll content went down 2.39 compared with comparison and chlorophyll content of dry land went down 1.89 compared with that of wet land.That also has been found there is less discrepancy among different years of chlorophyll content.Chlorophyll content correlated Δ positively.And chlorophyll content correlated drought resistance tightly.

in vitro screening of resistant mutants of eggplant to Verticillium daliae was studied with Verticillium daliae toxin and tissue culture technology.The induction rate in stem on medium of MS medium+IAA 1mg/kg+NAA 1mg/kg+KT 0.2mg/kg was higher than that of in hypocotyl and cotyledons.The toxin concentration of 15% was considered as the selection pressure of resistant mutants of eggplant to Verticillium dahliae.The resistance of callus to Verticillium dahliae toxin could be improved by increasing the concentration gradually.

There are three major methods that have been usually employed in cotton genetic transformation knowing as agrobacterium-mediated gene transfer, particle bombardment gene transfer and pollen tube pathway gene transfer. In this paper, their basic principles, technical characters, development and application were reviewed.

The results of field investigation and experiment showed that the S. avenae had two kinds of ecotype,i.e.ear-type and seedling-type.The ear-type aphid is only an ecotype adapting high temperature, which has two kinds of typical body color: (1) orange-red, and (2) greenish, Meanwhile there is an intermediate colored one the yellowish-green. The orange-red aphids are produced from the yellowish-green aphids which are from the green ones. The range of optimal temperature is from 15-20℃ for seedling-type aphids, and from 24-26℃ for ear-type ones which are the major type of S. avenae for overwintering (account for 96%).

Effects of different sowing dates on growth,development and the formation of seed yield of P.cornutum were studied from 2003 to 2004,the study were based on the experiment during 1998 to 2002.Used direct-seeding method,the seed was sowed every fifteen days,there were twelve sowing dates in all.The results showed that the initial temperature and effective accumulated temperature were 12.56℃and 69.07℃,respectively.With sowing dates delayed,plant height,number of total leaves,plant extending diameter,stem thick,number of primaries per-panicle,the re-greening rate and seed yield were decreased,and if sowing dates were too late,seedling emergence stage was postponed to next year.The seedling age that could be over-winter and be bolting in next year were exceed 59 days,at the same time morphological index of seedling were 9.6cM plant height,15.5cM extending diameter,5.8 pieces of leaves,over 0.8cM stalk thick.The growth potential and seed yield of biennial seedlings were positively correlated with the growth potential of annual seedlings.The course of growth and development of biennial plant was accord with annual plant,the period of growth development of P.cornutum was divided into vegetative growth stage,dormant period and reproductive stage.The optimum sowing date of P.cornutum for cultivation or harvesting seed were in the mid May in spring,sowing date of over-winter cultivation using germinated seed was in the early October in Inner Mongolia.The study clarified the optimum sowing date of artificial cultivation and the youngest seedling age over-winter cultivation of P.cornutum,it will be useful for artificial cultivation and breeding of P.cornutum.

It was compared protein content and acid composition of blue or purple grain wheat with that of white grain wheat.Qualities value of different blue or purple grain were evaluated.The results showed that comparing with white grain,Blue or purple grain wheat had higher grain protein content,and their acid type were plentiful.Their EAAS and EAAI were very high.Every EAA were plentiful and equilibrium.They had high nutritional value and grain quality.Among these varieties,Wumai 526 with blue grain had best grain quality.

In the experiment,the leaves of maize were dealed with the low concentration filtrate of Bipolaris maydis race C toxin cultivation whose Malondialdenvde content is low.Two pair of homokary maize corn C103 and B37 were used as the test material.The low concentration filtrate of Bipolaris maydis race C toxin cultivation as an elicitor is extensive and can be repeatable.

108 Bacillus strain has been isolated from the roots of cotton, LC-105 strain has been chosen by the antagonistic effect to the cotton wilt and diameter of the antagonistic circle reach more than 20 mm. Antagonistic material has been separated from the metabolism of the strain. Antagonistic material purifying has been done by DEAE-Sephadex iron-exchange chromatography and Sephacryl-S100 gel chromatography. The antagonistic material is proved to be a kind of protein. Electrophoresis pure has been identified by the polyacrylamide gel electrophoresis method.

The field experiment was conducted to LAI, SPAD value photosynthetic (Pn) rate, evaluate fluorscence induction kinetic parameters and grain yield in different sowing date and planting density of two different spike type cultivars during grain filling stage, during 2007 -2008. The results indicated that two different spike type cultvars have shown for LAI smallest was the third sowing date, SPAD value was the first sowing date low. Pn, PS Ⅱ potential activity(Fv/Fo), the maximal quantum efficiency of PS Ⅱ photochemistry(Fv/Fm) and yield were higher in treatment of B_2C_1 for small spike type cultivar (Liangxing99), the same of large spike type cultivar (Zhouyuan9369). October 12 to 19 is the suitable sowing period.

Chloronicotinyl insect icides is a group of new developed insecticides. The survey results indicated that severalinsect have evolved the esisitance to imidacloprid and acetamiprid and so on now. In this paper, the current situationand the latest trends on the study of pest resistance to chloronicotinyl insecticides are reviewed.

Effect of straw returning in field scale on soil organic carbon(SOC) and grain yield was studied to explore more reasonable farming management models,which was helpful to provide a theoretical basis for soil cultivation and sustainable agricultural development in Guanzhong Plain.With the actual situation of agricultural production in test area,the trends of SOC,active organic carbon(AC) content and grain yield in different treatments were examined to clear the effect of straw returning through a comprehensive comparison.After the returning of wheat straw to cropland,the summer maize was grown.The result showed that SOC in topsoil(0-40 cm) have been improved in straw application,and that soil AC and carbon pool management index(CPMI) of 0-20 cm soil layer were slightly lowered in high stubble in field,while soil AC and CPMI were increased through smashing the wheat straw into field,which didn't make their mutation change.Subsequently,the result showed that maize stalks were returned to the field in three models,and that,after the wheat growing season,SOC content in the topsoil has increased significantly through the straw returning treatment,and that,through smashing straw into field twice the SOC content can increase by 1.86 g/kg in 0-20 cm soil and 1.69 g/kg in 20-40 cm soil respectively.And also,the returning of crops stalk to the cropland can increase the AC content in the topsoil strikingly-especially,when wheat straw is smashed into the field,the AC content in the topsoil can increase more strikingly,that is,a average AC content can increase by 0.90 g/kg respectively in 0-20 cm and 0.85 g/kg in 20-40 cm soil;And straw returning significantly increased CPMI,especially through smashing straw into field treatments.Under the conditions of climate in Guanzhong Plain,soil organic carbon condition could be improved significantly through returning straw to field scale,especially,the SOC quality can be improved.Therefore,in the short run,smashing and returning the straw to the field can change the SOC more obviously.For there easily appear seasonal drought in the study area,it was useful to improve water use efficiency in maize growth period effectively to ensure the stable or higher yield trough high-stubble of wheat straw in field.It was the optimal model combination of high stubble of wheat with maize straw smashed into field in a whole rotation period for productive and efficient agriculture in this region,which can make a full use of water and heat resources in Guanzhong Plain.

The research is to study the effects of Chinese yam polysaccharide(CYPS)on antibody and T subpopulations in piglets pheripheral blood in the immune response to PRRSV killed virus vaccine.16 35-day-old piglets were randomly assigned into equal four groups and three groups were vaccinated with PRRSV killed virus vaccine.At the same time,the piglets in groups CYPSH and CYPSL were intramuscularly injected with CYPS at 17.1 or 8.55 mg/kg dosages,group C(control group),with sterile saline,once a day for three successive days,group F(fake group)only injected with saline.At 7,14,24,34,44,54,69,79 day after vaccination,pheripheral blood were sampled for detection of serum antibody titer to PRRSV by ELISA and T lymphocytes subpopulations by cytofluorometry.Results showed that CYPS can boost the proportion of CD3⁺ and CD8⁺ lymphocytes in piglets pheripheral blood after immunization with PRRSV killed virus vaccine,and enhanced antibody titer to PRRSV after 34 days.CYPS is a potential immunostimulatory for PRRSV killed virus vaccine.

To develop DUS testing standards for Pak-choi,we collected and selected 80 Pak-choi varieties,which are landraces with different morphology and ecotype and hybrids in a large planting area in China.On the basis of botanic characters in vestigation,SSR fingerprinting and genetic distinctness of 80 non-heading Chinese cabbage varieties were an-alyzed by a set of SSR markers in this study.Out of SSR primer 131 pairs,20 pairs were screened out with polymorphism among 80 varities and 56 polymorphic bands were obtained.The polymorphism ratio was 73.68%,2.8 polymorphic bands in average and were amplified by a pair of SSR primers.80 varieties could be distinguished by a 5-primer-combination of Na12E02,Na12A08,Ni4D09,BRMS-269 and BRMS-296.SSR fingerprinting mapping for each variety was established.The results from genetic cluster showed that the varieties with similar morphological traits or the same origin have a close genetic base,87.50% of the tested varieties were distinguishable at a genetic distance threshold of 0.36.

We explored the way of biological control by isolating antagonisticmycetes-fungus from pathogenic soil for Sclerotinia sclerotiorum.The result showed that 38 strains were isolated from soil samples derived from Huhhot,Bayannaoer and Baotou regions of Inner Mongolia.We observed that 8 strains,named as F-1,F-3,F-6,F-8,F-11,F-15,F-21,F-25,displayed antagonisms against S.sclerotiorum on the PDA plate.F-6 and F-8 were selected to study their inhibition to S.sclerotiorum growth and effects of their metabolic products on S.sclerotiorum of sunflower.Meanwhile,we examined the cultural and morphological characteristics of F-6 and F-8.Results showed that F-6,F-8 and their metabolic products could inhibit S.sclerotiorum growth on the PDA plate.

在盐碱地上栽植果树，是改良利用盐渍土的综合措施之一。建国以来，我国在盐碱地上兴建了许多大型果园，并且创造了高产典型，丰富了栽培果树的技术措施。如葡萄、枣、梨、苹果和桃等，只要土壤含氯化钠不超过0.13%，都能良好的生长。这就为改良利用盐碱地发展果树生产开辟了途径。近年来，对于在盐碱地栽培果树的研究，在国内外已引起重视。关于土壤盐分与植物生长的关系，土壤盐分对植物影响的生理机制，以及各种植物的耐盐力等，科技工作者从多方面开展研究工作，发表了许多研究报告和论著，这对今后利用盐碱地发展果树非常重要。本文就国内外一些关于果树耐盐力、耐盐生理，以及土壤盐分对果树植物的危害等方面研究成果加以介绍，以供参考。

Taking different extraction solvents to study the bioavailability of various heavy metal elements and correlation between the available concentration and the total in vegetable soil.The result indicates that there was considerable diversity in the bioavailability of different heavy metal elements.The sequence was CdPbHgAsCr,the higher were Cd and Pb,the bioavailability coefficient of them were 43.36% and 6.57%.whereas the lowest was Cr,it was barely 0.15%.It was showed that available Cd and Pb in soil easily transported and accumulated by vegetable,moreover there was potential ecological risk.There was a very notable linear correlation between available Cd and total Cd in vegetable soil of tillage layer,its regression was Y=1.598 9X+0.046(n=108,R=0.866).Available Pb and total Pb exist in linear correlation,the coefficient correlation was 0.769.Available As and total As exist in linear correlation,the coefficient correlation was 0.671.There was no linear correlation between the available concentration and the total with Cr and Hg.Available Cd,Pb and As could be considered as the significant and impersonal indicators of enviornmental stress of heavy metal on soil.

The growth characteristics of two Vibrio parahaemolyticus (V. p for short ) stains were studied by using the method of predicive microbiology. The primary and secondary predictive models of Vibrio Parahaemolyticus were cre?? ated based on their growth conditions at 4- 40. The result showed that the Gompertz model was found to fit with the experimental curves which are typical sigmoidal at fitting temperature and the Monod funct ion were found to f it with the experimental curves at low temperature. The secondary models for the effects of temperaturewere modeled. Data process?? ing of the model has shown the minimum growth temperature, the maximum growth temperature and the optimal growth temperature for two V. p stains. Validation of the models showed that the residual difference of predicted and observed value was within 0.05, and the values of bias factor and accuracy factor were also acceptable statistically. The predictive models are highly reliable. Also, the discussion was given for the application of the predictive model.

The agronomic traits of 86 wheat varieties or lines,which were planted in the garden plot ofthe Life Scion College of Hebei Normal University,were stulie and analyzed.

To probe into the morphological and physiological responses of Cucurbita ficifolia B.in response to phosphorus deficiency,the biomass,root morphological characters,P absorption characters and root exudates were determined by using nutrient solution approach in greenhouse.Based on the studies,we expected to lay some theoretical foundations for the improvements of P efficiency and provide materials for such studies.The results showed that on the 21st days after phosphorus deficiency,the shoot biomass of C.ficifolia was significant decreased,root/shoot ratio,root lengths and root surface areas increased,no significant differences were found in root biomass,root tips,root average diameter and root volume between phosphorus deficiency and normal phosphorus status.P uptake rate and P reallocation rate decreased,root P uptake/plant P uptake ratio and P utilization rate increased.The results demonstrated that root lengths and root surface areas increased might be responsible for the efficient P acquisition in C.ficifolia in the phosphorus deficiency environment.On the 21st days after phosphorus deficiency,root exudates of C.ficifolia contained similar chemical compounds as those of normal phosphorus status,which were mainly phenol,aromatic,ester,amine,olefin and alkanes.The components of root exudates of C.ficifolia under phosphorus deficiencywere more than that in normal phosphorus status.The autotoxicosis of C.ficifolia was enhanced in phosphorus deficiency.

To use three kinds of screening plate,and to combine with quantitative degradation test of calcium lignosulphonate,three lignin-degradation strains,TP1,Tf1 and Ls21 were obtained.In order to confirm the degradation effect of the strains,the strain Tf1 (Pleurotus sajor-caju),was selected to do solid substrate fermentation test about the wheat straw and corn straw.And Phanerochaete chrysosporium (BKMF-1767) was made as a reference.The result showed that the degradation rate of Tf1 to the wheat straw and corn was 38.4% and 47.7% respectively,and it was higher than the reference strain (32.2% and 34.6%).This research improves the screening method system of lignin-degrading fungus.There is an important significance to expand the resource of lignin-degrading fungus and exploit the straw resource.

Effect of nitrogen (N) supply on dry matter productivity and nitrogen use efficiency in summer maize (Zea mays L.) hybrid Zhengdan 958 with different plant population was studied. The results showed that the effect of N on grain yield of individual plants, mainly acted through the regulation of kernel number, was more evident in 67500 plants/ha and 82500 plants/ha. Appropriate N could improve the development of apical kernel, and increase kernel number and yield by reducing aborted kernels. N use efficiency could be increased by distributed more N absorbed by plant to kernel. Appropriate N could not only keep leaves with higher photosynthesis ability and provide more assimilate to grain, but also accelerate C-N mobilization from vegetative organs to grain.

A pot experiment was conducted to investigate the effects of different level of phosphate fertilizer application on permeability of membrane and antioxidative enzymes in rice(non-chilling cv. Changbai 9 and chillingtolerant cv. Jijing 81) under low temperature stress. The results showed that as the increasing of P fertilizer application, membrane permeability and MDA decreased and the increased in P-treated rice, but soluble sugar content, proline, peroxidase(POD), catalase(CAT) and superoxide dismutase(SOD) increased and then decreased. Compared with the normal temperature treatment, appropriately increasing phosphorus can improve the content of soluble sugar, praline, add the activity of POD, CAT, SOD, and decline membrane permeability and MDA content in rice under low temperture stress. The increase rates of the soluble sugar, proline, POD, CAT, SOD for P treatment in non-chilling cv. Changbai 9 were higher than those in chilling-tolerant cv. Jijing 81 under low temperature stress. and membrane permeability and MDA content decreased even more. The results indicated that membrane permeability and antioxidative enzymes of rice can be improved by exogenous application of phosphorus, it is beneficial to increase the cold resistance of rice.

Twenty-one Chinese cabbage cultivars were analyzed with Random amplified polymorphic DNA(RAPD). Using 13 arbitrary 10-mer primers, we scored a total of 87 clear and repeatable different fragments for their presence/absence. 39 bands (44.8%)were polymorphic. Primer OPE-01 had the highest ratio of polymorphic, with which 15 Chinese cabbage cultivars could be distinguished. Primer OPE-01 combined with primer OPH-03 and primer OPH-12 could distinguish all of the Chinese cabbage cultivars.

In order to investigate effects of N P K ratio on yield and quality in solar greenhouse cucumber (Cucumis sativas L), the experiment was carried. The results showed that ample phosphorus fertilizer development and improved cucumber's output significantly; Proper N, K and more P improved the soluble protein of fruit. Proper N-P fertilizer cooperated with more K fertilizer improved fruit quality, increased the content of soluble sugar and vitamin C,it also decreased the content of NO₃^-.

A total 252 arbitrary 10-mer primers were used to screen the dominant male genomic sterile and male fertile gene in flax. Two primers were found, S62 and S135, respectively, could produce RAPD markers correlated with dominant genomic male sterile gene, which are S62-500 and S135-350.

The paper conducted a research on the effect of 15 kinds of feed additive of China herbal ontaining Astraglus,Angelica and glycyrrhiza etc. on cow milk yield and duality. The result showed following: in different stages of lactation, feed' additive of China herbal made milk yield increase. When adding feed additive of China herbal, milk yield at earlier,peak and mid stage of lactation increased by 12.2%,24.5% and 3.4%.Because of feed additive of China herbal, contents of milk fat and free fatty acid decreased, but protein content anal content of solid-not-fat increased slightly with small fluctuation in physical index. Thert:fore when feeding cow with feed additive of China herbal, physical and chemical indexes of milk were normal, by assuringhealthy,safe,uncontaminated and natural milk.

The advantages,the prospects of the use of 2n gametes in plant breeding and germplasm enhancement,and the significance of unreduced gametes in plant evolution have been conf irmed. Both spantoneous andinduced 2n gametes were practicaly used in breeding programs of potato,red clove,goose berry etc. with admirableresult. The aim of this paper is to make an up- to- date review of 2n gametes in 4 subtopics. 1) Theg eneral research fields and their recent results; 2) the advances and the achivements of the use of 2n gametes in sexual polyploidization,germplasm utilization,maximizing heterozygosity,vercoming the Endosperm BalanceNumber barrier,breaking self-incompatibility,breeding for True Potato Seed and some else projects; 3) therecent studies on manipulating the efficiency of 2n gametes through recurrent selection,mechanical seperat ing 2n pollen,induced meiot ic mutant orinduction of 2n gametes; 4) the prospects of 2n gamete utilization.

The author proposed a one narrow, two high, and three late cultivation approach for high-yield of summer corn, and conducted related study based on the characteristics of solar energy and heat in Hebei middlesouthern summer corn region. The 'one narrow' means to reduce row spacing; the 'two high' means that the corn hybrid used is tolerant high planting density and high harvest index; the 'three late' means late thinning out of seedling to reach good plant uniformity, late fertilizer top-dressing to improve kernel number per ear and grain weight, and late harvest to achieve maximum kernel plumpness. The result showed that a combination of techniques of the hybrid used better in tolerance to high planting density and harvest index over 0.53, row spacing kept around 50 cm for high density, seedling thinning at 5 -6 leaf stage, and nitrogen fertilizer used 70% of total as basal use and 30% as top-dressing at 13 -14 fully-expanded leaf stage for normal nitrogen quota could obtained high yield. Late harvest is an effective practice for yield increase and the use efficiency of solar energy, heat, fertilizer and soil resources, for harvest delayed to early October could increase 5% -10% of yield.

Potato needs considerable amount of water during its growth.We did experiments on different irrigation methods to compare per Chinese acre water absorption efficiency and economic uutcome.The results showed that production per Chinese acre of dripping irrigation is 61.7% higher than that of spray irrigation and 22.4% higher than that of duct irrigation,Unit area water absorption efficiency and economic outcome:dtipping is 7% and 7% hivhvr than snrav 5% and 22.6% higher than duet.

In order to finding new Bt resource,two hundreds and eighty-fiveBacillus thuringiensiswere isolated from three different soil-type samples.Thirteen of them were shown to be highly toxic to scarabaeoidae larvae.By using of the PCR-RFLP system and SDS-PAGE,the types of gene cry of the 13Bacillus thuringiensisisolates and the expression of insecticidal crystal proteins were analyzed.The result is that twelve of them have thecry8Cagene which coding the crystal proteins kill Scarabaeoidae larvae.FTL53 couldn't be finded any gene.The thirteen Bt strains express 130 kDa protein.This research lays a foundation to find new and high toxin cry gene.

The phenolics content and some related oxidase activities were determined between healthy and browning spot fruits with bagging in Huangguan pears,the results indicated that there were higher phenolics content and activities of POD and PPO,but not significant difference on SOD activity of peel and flesh in serious peel browning fruits than those in healthy ones,and meanwhile,the content of phenolics and activities of POD,PPO and SOD were higher in browning spot zone than those healthy one.After the application of spraying to the fruit surface with 1% CaCl₂,0.1 mmol/L CPZ,0.1 mmol/L TFP,0.5 mmol/L SO and 0.05 mmol/L EB,the content of phenolics was not obviously affected by all treatments,but the peel browning spot was stimulated only by EB,and more,the PPO activity was decreased by CaCl₂,but increased by SO,EB and TFP,as well as was slightly influenced by CPZ.These showed that the occurrence of peel browning was closely related to the marked rise of PPO activity,and Ca²⁺-CaM system and Ca²⁺-ATPase might be involved in this browning process.

According to diallel crossing design, 4×4 combinations from 4 female parents with crack resistance and 3 crack-susceptible male parents and 1 crack-resistant male parent were made. These 16 F₁s and 8 parents were used to study relationship between crack characteristics and fruit skin architecture as well as their heterosis. Experimental results showed that fruit skin of crack-susceptible genotypes was much thinner than that of crack-resistant ones. But there were some crack-resistant genotypes with thin fruit skin. Crack characteristics displayed a strong heterosis but its direction depended on combinations. General combining ability played an important role on crack-resistant time of F₁. The potential of improving crack capacity based on skin architecture was discussed.

On the basis of analysising the integrated necessity of WebGIS( Web Geographic Information Sys-tem) and ES( Expert System), this paper amplifies the structure, implementation and function of the crop man-agement information system based on the combined technology of WebGIS and ES.

Heat tolerances of 8 wheat cultivars were studied.The results indicated that there were larger differences in heat tolerances among cultivars.The heat tolerance was related to leafchlorophyll content, MAD content and canopy temperature of cultivar.Assimilate accumulating after anthesis was directly affected by heat tolerance of cultivar.Leaf membrane thermostability and canopy temperature might be used as selection parameters in wheat breeding for heat tolerance.

After two days of 4℃ treatment at three-leaf stage, the activities of eatalasc, pcroxidase and supcroxidc dismutasc, and permeability of protoplast layer to nonclcctrotes declined, but level of membrane lipid pcroxidation increased in the leaves of cold sensitive inbred line of maize.In the cold resistant line, by contrast, the activities of the three protective enzymes, and permeability and viscosity of protoplast increased, and correspondingly, membrane lipid pcroxidation had no significant change.The results suggested that there ight be a close relationship between the activities of enzymes investigated or protoplasmic parameters and cold resistance of maize.

Based on economy and increment, the article showed the researchful actuality of controlled??release fertiliz??er applied to different crop, then discussed the essentiality of controlled??release fert ilizer applied to summer maize, andmaked mention of the important problem settled next .

Eight different maize hybrids were chosen to study the biological traits which had important influence on maize kernel mechanically harvesting qualities.The quality indicators of corn machinery direct harvesting included kernel crashing rate,grain impunity rate,era losing rate and kernel losing rate.We had analyzed the correlation between grain moisture content and kernel crashing rate,grain impunity rate,era losing rate and kernel losing rate independently.Then we studied the maize plant type biological traits,ear biological traits,yield biological traits and lording biological resistant traits which had important effect on kernel mechanical harvesting indexes.The results showed that different maize varieties had different grain moisture content.Demeiya No.1 had the lowest grain moisture content,whereas Liyu 16 had the highest grain moisture content,followed by Zhengdan 1002.The grain moisture content of Zhengdan 958 was 29.91%,which was in the middle level of the eight different grain moisture contents.We found that grain moisture content,ear height,ear diameter,rind crushing resistance and bract width were significantly correlated with maize kernel mechanically harvesting qualities.To cultivate new maize hybrid which was more suitable for mechanically harvesting,the grain moisture content,ear height,ear diameter,bract width all should be decreased.

Soil biologic amendment (BSA)was applied to the cucumber continuous cropping to control soil2borne dis2 eases and reduce replant diseases of cucumber. The changes of soil microorganism population structure were discussed by different agent. The result showed that total population of cucumber rhizosphere microbes increased remarkably after ap2 plying soil amendment.Number of bacteria and actinomycetes had a drastic variation.Number of fungi increased slightly. The species and amount of the dominant species were changing,beneficial microbes such as Trichoderma and Penicillium were more.Dominant species in rhizosphere antagonism were stronger along with controlling effect increasing. Applying BSA could increase soil microbial diversity and adjust community structure of soil microbial,and had better ecological sta2 bility than fungicide.

The dynamics of the number of microbes in rhizosphere of wheat with different planting densities was studied in this paper. The results indicated that the amount of rhizosphere soil bacteria was attained the higher value in jointing and heading stage.The maximum population of actinomyces and fungi was observed in anthesis stage.The change of bacterium population in the rhizosphere showed a single-peaked curve with the increase in planting density.The maximum populations were observed at planting densities of 150×104/ha or 225×104/ha.The population of actinomyces and the activity of urease and protease had the same trend to that of the bacteria.However,the fungus population decreased with the increase of planting density.The correlation between yield and the microorganism population and enzyme activity in soil showed that the increase in microorganism population would benefit the wheat grain yield.

The reaction to bacterial wilt disease of 79 accessions of 18 Arachis species belonging to 5 sections was evaluated in the years from 2004 to 2006.15 genotypes with high resistance were identified including 3 accession of section Procumbentes,1 of section Erectoides,1 of section Heteranthae,8 of section Arachis and 2 of A.sp.The percentage of accessions with resistance was 19% which was much higher than that of cultivated peanut.The relationship and genetic diversity of 15 Arachis accessions with bacterial wilt resistance were investigated based on SSR markers.The tetraploid species A.monticola was most closely related to the cultivated peanut A.hypogaea among the materials involved in the present study.The diploid species A.duranensis and A.chacoense of section Arachis were also closely related to the cultivated peanut.The DNA molecular characters and fingerprints of the 15 accessions were detected based on SSR products.

Based on the field experiment of cotton irrigation in 2004,the effects of irrigation quantity and frequency of drip irrigation to plastic-mulched cotton at critical growing stage was studied on growth,yield and water use efficiency(WUE).We hoped to find out the optimum irrigation mode which could increase the yield and improve WUE.The results of the experiment showed that the different irrigation modes had significant effect on the cotton yield and WUE.However,different irrigation modes had little effect on the stem height and leaf area at postbudding stage.Cotton which was irrigated two times at bolling stage,10.42mm each time,obtained the highest yield about 4929.0kg/ha and the highest WUE about 0.98kg/m³ respectively.

The peroxidase isozymes in one-year-old shoot-bark of ApricotsArmeniaca spp.)were determined via polyacrylamide gel electrophoresis.The experiment results are shown as follows:1.Isozyme band patterns of peroxidase are clear, polymorphic and stable in one-year-old shoot-bark extracts of apricots.It is suitable isozyme as gene marker in apricots.2.Isozyme analysis stands by the points:the evolution mode of Armeniaca spp.is natural geography isolation;A.vulgaris Lam. is the primitive species in Armeniaca spp.;other relative A.mume sieb. have been evolued from A.vulgaris Lam.3.Isozyme of POD is the best gene marker to identify interspecies hybrids. Renyongxinga group of cultivars for sweet kernel products)is the apricot origin from interspecies hybrid between A.vulgarisLain.and A.sibiricaL.)Lam.

玉米矮花叶病自1963年在美国首次报道之后,在世界各地主要玉米产区都已列为一个重要病害。我国自1968年河南省新乡地区辉县一带大发生之后,已逐步扩展到全国各主要玉米产区,先后有北京、天津、河北、甘肃、山东、山西等省市报道该病发生情况，最近在广东省崖县也有发现。

The full-length cDNA sequence of novel peroxidasel gene(designed as GbPODl, NCBI accession humber：FJ599670)were isolated from Ginkgo biloba L.The coding region of the gene is l092 bp long, and its deduced mature protein consists of 329 amino acids with a predicted molecular mass of 35.8 kDa and a pI of 8.10.Phylogenetic tree analysis revealed that GbPODl shared the same ancestor with other PODs, could be classified as type III peroxidase.The resuh of southern analysis showed that GbPODl gene was encoded by a multi-gene family in Ginkgo biloba.The expression analysis by RT-PCR showed that GbPODl expressed in a tissue—specific manner in G.biloba.GbPODl was also found to be up-regulated by MeJA, CuS04, CdCl2, MV, and mechanical wounding.These resuhs indicate that the GbPODl has the potential to play a role in response to heavy metal and wounding against foreign attacks, was amultifunction gene.

This paper reported genetic performance of the basic vegetative growth stage using P₁，P₂，F₁，F₂，BC₁，BC₂ generations from 2 temperate×tropical combinations. The results showed that the performance of the days to anther, days to shed and days to silkhas an earlier tendency for the cross than for the parents in the combination of 340 (temperate line) ×CML322 (subtropical line with insensitive to photoperiod), and inheritance of the basic growth period belonged to the genetic model of additive-dominance. The performance of the basic vegetative stage in the CML312 line with sensitivity to photoperiod is abnormal withhigher CV within the line and F₁. The early tendency ofheterogeneous genotype and the quantitative effect for earlier days to anther, days to shed, days to silk because of the different temperate genetic component ratio in 6 generations were observed.

The pollen abortion processes of cms-T, V and K in wheat with the same nuclear background (83(21)35) were studied cytologically by. light microscopy. It was found that the microsporogenesis of cms-T、V and K were normal. The pollens of cms-T aborted at late microspore stage, mainly in typical and spherical abortion types; those of cms-V aborted at late microspore-2-celled pollen stage, spherical abortion and light-staining abortion were the main types; while those of cms-K aborted at late 2-celled pollen-3-celled pollen stage, light-and blackstaining abortion were the main types.
The abnormal fusion of anther locules was very pApular in cms-T, while the developement of anther wall layers in cms-K or cms-V was normal. The inharmonious relation between nuclear and cytoplasm is the fundamental cause of opllen abortion. The cytological observation can be used as complemental criterion for determining the types of cms.

The effect and mechanism of pyroligneous acid sprinkled on leaves to the yield of panax and content of ginsenoside was studied，pyroligneous acid diluted as 200， 300，4 00 times and pure water as check，4 treatments，3 replicances， 3m² square of each plot，4 insufflations in all period was designed in the experiment，The result shows: the proper diluted pyroligneous acid sprinkled on leaves can strengthen root vigor of panax，improving the absorbing of N， P，K，enhancing the composing of chlorophyl，promoted yield and quality.

The plasmid pMON5122 containing 2,4-DAPG synthesis gene had been introduced into wild strains ofP.f luorescenceby engineering approach.The effects of different heat shock hours,different concentration of CaCl₂and different growth phase ofP.fluorescenceon the transformation frequency were tested,and the control effect on cucumber fusarium wilt disease by engineered strains ofP.f luorescencewas invest igated.The results showed that it was beneficial to the transformation ofP.fluorescencewhen OD₆₀₀was about 0.53 and the cells were treated with 0.025 mol/L CaCl₂and heated for 3-4 min at 42.The results from pot experiment test showed that the control effect of the engineered strains on the cucumber wilt disease was 75.0% and the rate of emergence of cucumber seeds was raised.

Potassium level in previous nutrient solution for muskmelon varied considerably, which influenced plant growth and fruit quality formation. The effects of 120, 240, and 360 mg/ L potassium levels on plant growth, macroelement accumulation, amino acids and aromatic compounds in fruit were studied, in order to optimize potassium fertilizer application. The muskmelon vigorously grew at potassium level of 240 mg/ L in nutrient solution, which was beneficial to macroelement absorption. However, no significant difference in leaves area and fruit weight were recorded among the three treatments. The concentration of TSS, glutamic acid, aspartic acid, alanine, and aroma components concentration were significantly increased in fruit flesh with 240 mg/L potassium level, which should improved the nutrition and taste quality of muskmelon. The excessive potassium level(360 mg/L) reduced fruit quality. Favorable nutrient and taste of muskmelon with medium culture were achieved when potassium level was adjusted to 240 mg/ L. The muskmeklon macxoelement absorption ratio of N, P, K, Ca, Mg was 28: 5: 40: 21: 6 under this potassium level at harvest.

The contents of endogenous hormones in flower buds and leaves,including IAA,Z+ZR,GA₃,ABA of two male sterility lines(CMS and GMS) and their corresponding maintainer lines of Pepper(Capscium annuum L)were assayed using ELISA.The experiment also analyzed the ratio of the endogenous hormones.The results as following:The changing tendency of endogenous hormones contents including IAA,Z+ZR,GA₃,ABA in the flower bud ofcMS and its corresponding maintainer lines consists with the tendency in GMS and its corresponding maintainer lines,that is the contents of IAA,Z+ZR,GA₃ and ABA in male sterile lines are lower than in the maintainer lines.There also have the same contents changing tendency of IAA,Z+ZR,GA₃ and ABA in the leaves incMS and GMS,that is the contents of endogenous IAA,Z+ZR,GA₃,ABA in male sterile lines are higher than in the maintainer lines.The ratio of endogenous hormones including IAA/ABA,(Z+ZR)/ABA,GA₃/ABA in the flower buds has the same changing tendency incMS and GMS,that is the ratio of male sterile lines is lower than of the maintainer lines.In conclusion,the results indicate that the changes of hormones in the regulating male sterile have the same rules and the male sterile of pepper may have same traits in the mechanism of biochemistry and biophysics,although the dominating gene of the GMS andcMS is different.

The nutrient use efficiency in wheat was studied in this article by using split-plot design. The result showed that the wheat yield was significantly depressed under no-till than the conventional tillage. The nitrogen use efficiency under no-till was down by 8. 19 percentage points from conventional tillage,and the phosphorus use efficiency under no-till was down by 0. 64 percentage points. The potassium use efficeincy under no-till was 3. 05 percentage points higher than that under conventional tillage. The nutrient use efficiency was increased by balanced fertilization in two tillages. The N,P,and K content of the wheat straw under no-till was higher than that under conventional tillage,especially the potassium.

We researched the effects of the chemical fertilizer,biological_organic_inorganic compound fertilizer,biological_organic fertilizer and fen manure,which were applied to the cucumber in greenhouse in autumn and spring,on the physiological and chemical characteristics of soil and cucumber.The result showed that using the biological_organic_inorganic compound fertilizer,biological_organic fertilizer and fen manure would have effected on the improvement of the soil physiochemical properties,enforcing the ability of moisture reserve of soil.It indicated that soil bulk density decreased,soil total porosity and soil moisture capacity increased.The most significant effect was found in the treatment of applying of fen manure,with soil bulk density decreased by 4.26%,soil total porosity and increased by 4.68% and 10.7% respectively.The content of soil organic matter,total soil nitrogen and soil available potassium in the plough layer have the most level after utilization of fen manure,but it was also showed that the increased amount of soil total phosphorus,soil available phosphorus and alkali dispelled nitrogen had the highest level after using biological_organic_inorganic compound fertilizer.The fen manure and biological_organic_inorganic compound fertilizer could improve the growth of cucumber and was responsible for improvement of its product,with increasing by 102.8% and 123.1% respectively compared with the treatment of no fertilizer.No differences were found significantly between the treatment of fen manure and the treatment of biological_organic_inorganic compound fertilizer,but there were the significant differences in the other treatments.In addition,applying of fen manure and biological_organic fertilizer,biological_organic_inorganic compound fertilizer may improve the content of vitamin C and reducing sugar in the fruit,meanwhile with nitrate decreased,so they could improve the quality of products.

Effect of Different Nitrogen application on early and middle Growth of Spring Wheat by pot cultivation.The results showed that:nitrogenous fertilizer could promote the growth of spring wheat.Plant height,stem width,tiller number,dry weight of stem and leaf increased 5% to 100% compared with the control treatment,nevertheless it doesn't show a linear relationship between the increase of wheat and the nitrogenous fertilizer applied amount all the time.In tillering and elongating stages,compared with control treatment,applying nitrogen increases the total N content in stem and leaf of wheat.The total P,K content increased first,and then with the increasing of N applied it presented a decreasing trend in stem and leaf.In addition,both of NO₃^-_N content in stem radix and leaf chlorophyll content show a distinct positive correlation with N applied amount,so they can reflect the N supply level of soil.

Fructan is a very important water soluble carbohydrate. The fructan accumulation in plants can improve stress resistance. This paper introduced some knowledge of fructan and reviewed the effect of fructan on plants' stress tolerance. Some mechanism of freezing tolerance or drought tolerance were expatiated at fructan and osmotic adjustment, fructan and membrane and fructosyltansferase activity. In addition, the gene engineering of improving fructan accumulation and correlated quest ion were reviewed.

Resis tance mechanism of 10 wheat variet ies were observed and analysed. The results indicated that there were larger dif ferences in resis tance of wheat characters to wheat midge.Resis tant varieties were related to height of plant, ear length, spikelet densi ty, flag leaf length and width, stem waxnature, grain husk fine hair, hardness, thickness. On the basis of field insect plot appraisal, the biochemical mechanisms of 8 wheat varieties/ l ines resistant to wheat midge(sitodiplosis mose llana Gehin) were studied by chmical analysis methods to e xplore the possible factors contribut ing to wheat midge resistance. Total phenolics, tannins and soluble sugar were the main factors of wheat resistance to wheat midge and thei r rather s trong ef fects appeared at early milky stage. Total phenols was the more important fac tor of these three. Total phenolics and tannins were the substanes of wheat induced resis tance to wheat midge, whi le soluble sugar had no relation to induced resistance.

Chilling-res istant plants regenerated from anther of eggplant s train E-9903 under low temperature s tres scul ture were used as experimental material. DNA was ext racted fr om young leaves using SDS method. Forty 10-base-long oligonucleotide primers were used in polymerase chain reaction. The index of chil ling injury of cellular variation S1 progeny were measured. Results sho wed that polymorphism existed when primer OPK12 was used in polymerase chain reaction.The index of chilling injury of c ellular variation S1 progeny were much lower than that of contr ol strain.

Changes of contents of IAA,ABA,GA₃and ZR in anther at different development stage in Cytoplasmic Male Sterility (CMS)line and its maintainer of Chinese cabbage were investigated by ELISA (enzyme-linked immunosorbent assay).It is observed that changes of contents of IAA,ABA,GA₃and ZR in anther of CytoplamicMale Sterility line were different to its maintainer.At the third stage (the length of flora bud was 2.0-3.0 mm),the contents of IAA,GA₃and ZR incMS and the value of ZR/ABA were remarkably lower than its maintainer.However,the contents of ABA incMS were significantly higher than its maintainer.The microspores have just started to be sterile at this stage.It is concluded that the deficiency of IAA,GA₃and ZR and over product of ABA and breaking of hormonal equilibrium induced male sterility in Chinese cabbage.

Cotton aphid Aphis gossypii (Homoptera: Aphidae) is one of the seriously occurred non??target pests in transgenicBt cotton fields. The activit ies and specific activit ies of midgut digestive enzymes, including proteinase, amy?? lase, trehalase and sucrase, of cotton aphids fed on Bt cotton cv. GK12 for different generat ions were detected with microtiter plate reader, and were compared with those of cotton aphids fed on the non??Bt parental cotton cv. simian 3. Thus the short??term and long??term effects of Bt cotton on the digest ive enzymes of cotton aphids were determined. The re?? sults showed that there were no significant differences in the activities and specific activities of the four digest ive enzymes between the cotton aphids fed on Bt cotton and non??Bt parental cotton, no matter for one to three generations, or for over sixty generations. And there were no significant difference among the cotton aphids fed on Bt cotton for different generations. It indicated that Bt cotton had no significant impacts on the activities of cotton aphid??s midgut digestive enzymes both in the short run and long term.

Determining the leaf moisture potential in 16 tree species collected from Baotou park,correlation of leaf moisture potential and soil moisture content showed that some species were high moisture potential and delayed desiccate species,such as Chinese pine,P.glabra,sophora,Chinese wax,periploca et al; some were sub-high moisture potential and delayed desiccate species,such as flowering almond,privet,Manchu cherry,sorbaria kirilowii,et al.;some were low moisture potential and tolerated desiccate species,such as spruce,rose;some were sub-low moisture potential and tolerated desiccate species,such as arbor vitae,meadow sweet,clove, acacia,hankow willow.

In order to know the fertilizer efficiency of sulphate-potassium magnesium in rice,the effects of different applying amount(5 treatments)and period(4 treatments)of sulphate-potassium magnesium on growth,grain yield,and quality of rice were studied using the method of field experiment.The results showed that:the grain yield,crude proteincontent,crude starch content,reduction-type vitamin C content of rice with 1 023.34 kg/ha of sulphate-potassium magnesium application was higher than the other four treatments.The grain yield,crude starch content,reduction-type vitamin C content of rice with all base application of sulphate-potassium magnesium was the maximal.The crude protein content of rice with 50% of base application,20% of applying at the jointing stage,30% of applying at the heading stage was the maximal.The optimal amount of sulphate-potassium magnesium for rice grain yield increasing and quality improving was 1 023.34 kg/ha,and the optimal method of sulphate-potassium magnesium application was at the all base application.The treatment of sulphate-potassium magnesium application with 50% of base applying,20% of applying at the jointing stage 30% of applying at the heading stage,could also significantly improve the rice quality.

For discuss the effect of organic fertilizer on flue-cured tobacco quality,this paper choice several organic matter decomposing products to study the effects of organic acids on the aroma quality of different maturing degree flue-cured tobacco(Nicotiana tabacum L.) leaves through field trial and analysis in laboratory.The result showed that the organic acids were not obvious improvement on the content of the petroleum extraction in middle stalk position leaves with mature,whereas malic acid and oleic acid were significant on the improvement of the major aroma matter contents in tobacco leaves.so promoting favor of tobacco leaves.When the leaves were harvested in over-ripe,in comparison with the ripe harvesting time,humic acid and oleic acid were obvious in improveing the petroleum extraction and furfural,benzaldehyde,solanone,megastigmatrienone,and neopphytidiene,et al.The effect of humic acid on aroma was better than those of oleic.

CMS is one of the most important system for F1 seed production in Chinese cabbage. Concerning the physiological and biochemical mechanisms of CMS, the changes of soluble sugar, soluble protein, amino acids and isozymes in anther at different development stage of Cytoplasmic Male Sterility line and its maintainers in Chinese cabbage have been investigated in this study. It showed that the contents of soluble sugar, soluble protein in CMS were significant lower than its maintainer. No difference was observed in the contents of total free amino acids between CMS and its maintainer. However, the proline content in CMS was significantly lower than its maintainer; Bands pattern differences were observed for 6 kinds of isozymes (AAT, MDH, EST, POD, COD and PPO) in anther at different development stages between sterile and maintainer line.

Research on the relationship between endogenous hormones and tiller activity of main crops of Gramineae was done over two seasons( 1999-2001). The results were as following: The same changes of en- dogenous IAA and CTK contents rose early and then droped, were presented in the tiller process of winter wheat and rice at the early growing stage of maize. Yet, the value of IAA/ CTK descended at the early stage of tiller process, and then ascended at the late stage. At the same time, the number of weekly tiller increment per plant rose quickly early, and then drop late. So, wheat and rice tiller activity was noticeably regulated by the content of IAA and CTK, especially the value of IAA/ CT K. It could be improved or inhibited by a low or high value of IAA/ CTK respectively. It was also found that the dynamic of IAA/ CTK played a rather important role in the early growing stage of maize.

We examined the way which alleviates autotoxicity in tomato.Tomato seedlings were transplanted in perlite as growth substrate.Decomposed tomato root solution(DS) was added to Hoagland solution with or without the addition of activated charcoal or carbonized maize cob.Biomass,photosynthesis and antioxidant enzymes activity of tomato seedlings were systematically investigated.Results showed that DS suppressed the biomass,photosynthesis and chlorophyll contents of tomato seedlings.At the same time the activities of POD,CAT in leaf were increased firstly,then decreased and the MDA content was increased by the treatment of DS.DS-induced growth inhibition and physiological changes,however,were greatly alleviated by application of carbonized maize cob and activated carbon.Similar to activated carbon,carbonized corn cob could alleviate the DS induced inhibition on the growth of tomato seedlings.Carbonized corn cob can be used to prevent the plants from monocropping obstacles.

The content of seed protein, fat and soybean isoflavone were measured, prolamine, gobulin and glufelin in the seed storage protein were ext racted in turn. The results analyzed by SDS-PAGE were as follows: Among the varieties tested, 7 were high in protein, 4 high in fat, 6 high in isoflavone, 2 high in protein and isoflavone, 1 high in fat and isoflavone, 1 high in protein, fat and isoflavone.By SDS-PAGE of seed storage protein, 4 were found to be high quality in protein, and 2 were special varieties for tohu and one for young soybean. Measurement of protein, fat and isoflavone connected with SDS-PAGE could be a handy and quick method for finding varieties that had high quality in protein.

Using potted Jinguang plum seedling as material,the content of osmotic adjusting substance and the diur2nal variation of photosynthesis in Jinguang plum leaves were studied. The results were as follows:with the increase ofdrought stress degree,the relative water content and chlorophyll content in leaves were decreased,but the permeability ofplasma membrane and the content of MDA,soluble sugar and proline in leaves were increased;And with the developmentof drought stress,the photosynthesis rate,transpiration rate and stomatal conductance were declined,and intercellular CO2concentration was raised;The main reason for the decrease of photosynthesis rate were stomatal limitation in light droughtstress,and nonstomatal limitation in severe drought stress.

The resistance to bacterial leaf blight of rice in eight pairs of cytoplasmic male sterile(CMS)lines(line A)and their maintainers(line B)was tested by inoculating 39 isolates(belong to 6 races)of Xanthomonas oryzae pv. oryzae during last two years. According to the difference of lesion length between line A and line B,it was discovered that Gang 46A, Zhenshan 97 A and You 1A were most susceptible to strain Ah28(race 4), and the ZS97A was more susceptible to Ah28 than ZS97B. Comparison of resistance of seven restorers and eight hybrid combinations(F₁)to different races showed that the resistance of hybrid combinations to the disease was not only controlled by nuclear genes, which derived from restorer and CMS line, but had close relation with compatibility of pathogenic race specificity.

Genotypical difference existed in the growth and respiration of total and primary and secondary roots by analysis of pot and tube experiments. The primary roots of early-middle mature genotypes grew quick in the early stage, and senescence quick in the late stage; but late mature ones showed inversely. The amount of root did not directly influence the grain yield.

"The Sethoxydim Resistant varity 528-4 and inresistant varity 528-5 of Jigu 25 were used for material of the experiment,these varieties were all selected and bred by institute of millet crops,Hebei academy of agricultural and forestry science.All organs dry matter accumulation in the course of bearing and yield and weeding control(effect of Jigu 25 by chemical treated and summarized seedling and normal managed were determined and analysised to reveal the physiological mechanism that simplify cultivaled Jigu 25 could not only chemical thin and chemical weed,but also increase yield certainly.The results showed that:The weeding effect of simplify cultivaled Jigu 25 was up to 95%,and yield was increased by 8.73% compared to CK.The physiological mechanism of its output was showed:①simplify cultivation treatment early thinned and weeded,reduced weeds and excess millet seedling in competite nutrients and space,played a role to strong seedlings.②Biomass of simplify cultivation treatment was higher in two key accumulation stages of the jointing to heading,flowering and grain filling to maturity,and growth faster.③Root of simplify cultivation treatment developed better from seedling to jointing than others,it has laid a good foundation for development of vegetative growth and reproductive growth better.After into heading and flowering stage,stem growth peak,stop elongation,then decreased rapidly,indicated that after accessed to reproductive stage,matter of simplified cultivation treatment transformated more and more quickly compared with summarized seedling and normal managed treatment.After the leaf area of simplify cultivation treatment reached the maximum in the flowering period,there was a long period of stability to the high luminous efficiency of photosynthesis,photosynthate into grain more.In the peak period of grain filling to form a dough stage,volume of dry matter accumulation bigger,the speed of accumulation higher,therefore the rate of seed higher. "

The antifungal activities of 126 species of medical plant extracts (MPE) were tested against mycelia growth of Colletotrichum lagenarium and Alternaria brassicae. The result showed that at the concentration 0.01 g/mL, the antifungal rate of 27MPE (for example, Soianum nigrum, Ranunculus ternatus and Eriobotrya iaponica) was more than 50% against at least one tested fungi. The antifungal rate of 6 MPE was more than 50% to both of the tested fungi. At the secondary screening, the tested MPE were diluted to 0.005 g/mL. The inhibitory rate of 11 species to C. lagenarium was more than 60%, the inhibitory rate of 3 species to A. brassicae was up to 40%.

Nitrate is a type of substance easily accumulated in vegetables,especially in leaf vegetables,and poses serious health hazard if ingested excessively.Light is one of the most important environmental factors that influence nitrate content in plants.This review summarized the effects of light on nitrate accumulation in vegetables from the aspect of light intensity,light quality and light duration respectively,expatiated the daily variation in nitrate content in vegetables under traditional lighting mode,and summarized the effect mechanism from the aspect of nitrate absorption and assimilation.

In this paper,we studied nine pieces of soybean cult ivars major planted in Hebei Province,which included high protein content cultivars such as Jidou 12,Jidou 7; high oil content cultivars such as Jihuang 13,nf37 and nf58; both high content of protein and oil cultivars such as Jidou 15,Jian 15; and cultivars without fishy smell such as Wuxing 1,Wuxing 2.Manual rub inoculation with sixstrains of SMV to identify the soybean's resistance degree.The results show that Wuxing 1,Jidou 12 and Wuxing 2 are three good resistant sources to SMV.

Effects of daidzein on the milk yield,components and hormones in milk of cows in late lactation were studied.Four Holstein dairy cows in the 7th month of late lactation were sampled and self-control method was used.Daidzein was added to the concentrated feed at the dose of 10mg/kg during the treatment stage.The results showed that daidzein could lessen the declining tendency of milk yield in late lactation and increased the milk yield to some extent.Lactoprotein was evidently increased(P<0.01) while butterfat was not evidently affected.The level of T₄ in milk was evidently increased(P<0.05);the level of GH,PRL,E₂ and TSH in milk prone to rose while T₃ prone to decreased.It could be concluded that daidzein could indirectly affect milk yield and components of milk by regulating the levels of intrinsic hormones.

Detached leaves in air caused quickly water stress, osmotic adjustment of the leaves were not observed and water potential(ψW,) and turgor potential(ψp)of leaves decreased rapidly, therefore, the net photosynthetic rate (Pn)，stomatal conductance (Gs) and mesophylic conductance to CO₂(Gm) depressed on a large scale in short time, In contrary,soil drought caused leaves producing osmotic adjustment in varying degrees, the water potential decreased more slowly, turgor potential was keeped to some extent，Pn, Gs and Gym decreased slowly, Under two types of drought stress, leaves of Shanhe No, g had greater drought tolerance than that of Zhengyin No,1 due to their stronger water holding capacity and greater osmotic adjustment, Thus, the depression of Pn, Gs andG，m of Shanhe No, 6 leaves was smaller than that of Zhengyin leaves,

The carbohydrate composition containing maltose,sucrose and the mixture of maltose and sucrose respectively in induction medium of wheat anther culture were studied.The callus rate induced in medium using maltose as the sole carbohydrate was found to be the highest,followed by that using the mixture of maltose and sucrose,and the callus rate in that using sucrose medium was the lowest.In the whole carbohydrate experiment,the callus rate increased with the increasing of maltose content.The effects of the carbohydrate on callus rate related to their hybolysis products.Maltose was the best carbohydrate in isolated microspores culture.The microspores incubated in other carbohydrate did not form callus.Some of microspores incubated for 3 days in only maltose medium had viability.It was concluded that high concentration of sucrose,glucose and fructose was toxic to the microspores.The initial concentration of glucose up to 2 0 mmol/L resulted in the microspores death.When high concentration of glucose was added after 1 day incubation with moltose,the microspores was still viable.The viability of microspore increased with the incubation time.

Ef fec ts of mulching wi th liquid-film on the growth of cotton were studied in this paper in 2000 and 2001,using pestresis tant cotton variety of 99B. It was found that it speeded the growth of cotton on the early stage, restrained the vigorous growth in the later period, regulated and optimized the plant types of cotton, and resulted in the early rapid growth and early maturi ty of cotton.

Potato(Solanum tuberosum),also named Irish potato,foreign-poi,is cultivated widely in our province.With high nutritional value,it can be used as materials of light industry.Potato possess high nutrition,extensive adaptation,and high yield besides lower fatty content,which contains protein,carbohydrate,iron and vitamin and theirs content are greater than wheat,ripe and maize,starch 15%-20%,protein 2% fibrin 2% and manifold vitamin.Potato,tolerating store and transportation is important variety of adjusting midseason and low-season.So spreading synthesis technique of poisonfree production,developing vigorously industry of potato have significant effect to composing of improving on food and enriching people's living.

Under high and low fertility conditions, 30main wheat varieties in different periods were selected as mate rials in Shandong Province.The difference of nitrogen absorption allocation and utilization were researched in the different wheat varieties, and the nitrogen??efficient varieties were selected. The results showed that the difference of nitrogen content of whole plant, stem??leaf, glume, and grain among the different wheat variet ies were highly significant. In two fertil??ities conditions, the max than the min increased 22.62% and 42.58%, 58.18% and 78.67%, 70.15% and 59.92%, 24.26% and 42.64%, and the nitrogen content of various organs increased with the improvement of soil fertility. Average nitrogen content of varieties in the high??fertility planted was increased by 12.47%, 30.16%, 12.26% and 5.47% than in the low??fertility.The average nitrogen distribution among varieties in two fertilities conditions: grain were 72.13% and 74??14%,stem??leaf were 21.61% and 18.70%, glame were 6.25% and 7.16%. Distribut ion of glume and grain inthe low fertility conditions increased by 14.56% and 2.79% than in the high fertility conditions, but stem??leaf decreased13??47%. By the UPGMA of Clustering, Clustered Yannong19, Lumai21, Shannong 8355 and Lumai15 four higher NUEand higher UHI varieties. And clustered Jimai20, Zimai12, Shannong12, and Hongyoubao four higher UHI varieties andXiaoyan6, Yannong15 two higher NHI varieties planted suitable for low fertility. Lumai14 and Lumai15 were higher NUE varieties.

Under field conditions, effects of different row spacirgs on matter transforming and grain filling characteristics were studied in Zhengzhou experimental farm of Henan province. The result indicated that row spacing could influence the dry matter production and transforming efficiency. The highest dry matter production came from the row spacing of 15 cm, and the lowest from 30 cm. Spike axis and husk had the lowest contribution rate to grain dry matter accumulation, stalk and sheath the highest, and leaves the middle. The highest total dry matter transforming amount to grain was from the row spacing 20 cm, and the lowest from 30 cm. Besides, grain filling course was imitated by logistic equation. In all, 20 cm row spacing was benefitial to 1 000-grain weight.

In the papeR，a field expeRiment was conducted to study the effects of diffeRent light intensities ( 55%，70%，5% and 100% of full sunlight) on the plastid pigment and its degRaded pRoducts in flue-cuRed tobacco． The Results showed that the contents of chloRophyll and caRotene in the flue-cuRed tobacco leaves at diffeRent positions weRe the lowest in CK( 100% light intensity) ． With the decRease of light intensity， the chloRophyll content of leaves at uppeR and middle positions incReased fiRst，and then decReased，but incReased by degRees in loweR leaves， while the caRotene content in leaves of all positions incReased fiRst，and decReased subsequently． The degRaded pRoducts of caRotene and the neophytadiene weRe all higheR in CK than in shading tReatments． The aveRage content of neophytadiene in uppeR，middle and loweR leaves foR the thRee shading tReatments was 13． 59%，19． 99% and 5. 66% loweR than the CK， Respectively，while the aveRage content of degRaded caRotene pRoducts decReased 6． 70%， 8． 08% and 83% Respectively． The Results indicated that shading tReatment incReased the contents of chloRophyll and caRotene in eveRy position of flue-cuRed tobacco leaves，while decReased the contents of degRaded caRotene pRoducts and the neophytediene．

Solution culture and sand culture were employed to investigate the N on plant growth, nitrogen metabolism as well as rhizosphere pH for oat. The influence of N一N，N0₃一 results showed:supplied with both N forms, the oats grew obviously better than that with either, and with increase of N/Nratio in cultural zosphere whereas media，oat plants growth especially roots growth was improved; acidity greatly, the pH value of oat rhizosphere was it increased when supplied plants with N0₃一N. decreased nitrogen forms also affected the oat rhi-when supplied plants with NO₃-N.

The effect of phosphate fertilizer and manure on soil test phosphorus and phosphorus leaching in different phosphorus levels soil was studied.Soil column was used in the experiment of simulation.The results showed that the content of CaCl₂P,Olsen-P and soluble phosphorus in leaching water of soil were all increased significantly after applying phosphate fertilizer and manure in different phosphorus levels soil.The content of the various forms of phosphorus in the soil could be increased by improving soil phosphorus levels.This content was also increased significantly by the increasing phosphate fertilizer and manure.Maximum phosphorus absorption capacity(Qm)and phosphorus sorpt ion index(PSI)were decreased after applying phosphate fertilizer and manure.The degree of phosphorus sorption saturation(DPS)was increased with the increase of the rate phosphate fertilizer and manure.The degree of phosphorus sorption saturation could be increased by improving soil phosphorus levels.The main conclusions were that the degree of phosphorus sorption saturation and the rate of leached phosphorus from the soil were increased with the increase of the rate phosphate fert ilizer and manure in different phosphorus levels soil,however,the phosphorus sorption index was decreased.There was high correlation between the rate of leached phosphorus from the soil and soil test phosphorus.The soil test phosphorus could be increased by increasing phosphate fertilizer or manure and soil phosphorus levels.

Flow cytometric (FCM) analytical technique and chromosome counting were used for the detailed ploidy identification in population of anther culture derived pepper plants. Results revealed ploidy diversity in regenerated plants. The different ploidy in organs (eg. Leave and root tips) of the same plant was observed, and this phenomena showed the importance of determining ploidy level by different samples. Chromosome deletion was observed in some cells of haploid or double haploid plants. The coincidence between FCM and chromosome counting was high up to 0.95 in our experiment. We also discussed about the phenomenon of peak distortion in FCM analytical technique. These observations and results are significant for the haploid breeding, germplasm innovation and cytogenetic researches.

The sensitivity to a trazine was observed in 24 wheat varieties lines with the concentration of 3000 mL/ha 40% atrazine solution. The varieties showed different responses to the application of atrazine . Some of them were of tolerance with most plants growing normally and/or slightly injured. Others were susceptible to atrazine, most of the plants were severely injured and even died. The remaining varieties were classified to medium susceptible or medium tolerant. Investigation indicated that the roots of wheat were more severely damaged than the top parts. Response to atrazine, which had not relation with cytoplasm, was controlled by a single nuclear gene, as revealed by segregation ratios of the susceptible plants to the tolerant ones in F1, F2 and BC1 hybrids between different response varieties. The sensitivity was recessive, whereas the tolerance, dominant. The effects of atrazine on immature embryo culture were also noticed. High concentration (100 mg/L) of atrazine that added to the media reduced the callus induction, yet low concentration (25mg/L) did not substantially influence the callus induction in the present study. Atrazine had some effects on callus developing state during subculture regardless its concentrations in media.

Total nineteen maize inbred lines including three new lines and sixteen elite lines were chosen and their genetic differentiation revealed by quantitative and AFLPs data were studied. The results show that cluster analysis were some consistent with their pedigree based on quantitative and AFLPs, but the AFLP was more compatible, all the parents of strong heterotic combination were divided into different group or sub-group;21-ES and A318 had much differentiation with other elite inbred lines on quantitative traits and AFLPs, so they were both classified into different two groups which included only one inbred line. The genetic distance based on the quantitative and AFLPs had a positive correlation with yield mid-parents heterosis of F1.

A new physiological race of leaf mould (Fulvia fulva (Cooke) Ciferri) 1.2.3.4.9 was detected by continuous investigating and sampling from tomato production in Beijing area for several years. The new race has higher virulence and can attack the popular tomato varieties with the resistance to leaf mould, although it is not dominant race in tomato production up to now. So the tomato breeders have to pay more attention to the new mutation of the fungus.

In order to study the genetic relationship and use resourses rationally in breeding,systemic clustering analysis was conducted based on 10 agronomic traits of 84 germplasm resourses in Brassica napus.The results showed that 84 cultivars (lines)were devided into 4 classes.Class Ⅱ included 75 cultivars (lines)and was devided into 2 subclasses again.Subclass Ⅱ -1 and Ⅱ -2 were devided into 3 and 4 groups respectively.4 classes had quite different agronomic traits.Growth period of subclass Ⅱ -2 was 197.4 days only longer than class Ⅳ, but it′s yield per plant was highest. Specific materials such as long pod,big grain,early material and big density of pod were found in resoures.

Three varieties heat resistant character and maehanism were studied, The result showed:under high temperature, the hard-pulp tomato cultivar(Mantian2180) had the strong growing power, the higher frution rate, the better good character and the hihger yield, so it was suitable cultured in summer. Its thermo-resistant mechanism showed that chorophy content were higher in hard-pulp tomato euhivar after heat stress. The membrane structure damage was lighted by increasing its activities of SOD and POD. The resistance of plant was enhanced by increasing its proline cotent. All of these changes can relieve damages caused by high temperature.

The contents of anther released ethylene of isonuclear alloplasmic lines on Mo17 nuclear background with three male sterile cytoplasm T,C,Tang Xu(S) and normal cytoplasm(N)line during the stage of microsporogenesis and development were studied.It was found that at the 1-2 stage(s)before the microspore abortion happened,the released ethylene contents from male sterile anthers were significantly higher than that from normal cytoplasm line.The study of exogenous application of plant growth substances demonstrated that ethrel could remarkably induce the abortion of microspore and pollen of male fertile materials.It was also found that the abortion stage of male sterile lines was partially delayed by the external application of CoCl 2 which is a kind of inhibitor of ethylene synthesis.The possible regulatory role of ethylene on CMS in maize was also discussed.

In order to determine the effect of water stress by PEG on three varieties of Isatis indigotica from different regions,the activity of anti-oxidative enzymes of seedling leaves and root vigor were assessed by measuring physiological characters.The results showed that physiological and biochemical indexes of root changed greatly under-0.4 Mp of PEG.The activities of anti-oxidative enzymes including SOD,CAT and POD increased in early and middle stage of water stress,and decreased in final period.The root vigor decreased with the increase of degree and time of water stress.The drought tolerance of the variety from Anhui province was better than that from Shanxi Province and Shaanxi Province.

Effects of low temperature,high temperature,sugar-free,colchicines and mannitol pretreatment were studied on the survival rate of microspores in 4 radish cultivars.The result show that microspores had high survival rate under 4℃ after 3 days treatment,while 36℃ treatment reduced the survival rate.The media with sugar,mannitol and colchicines enhanced the vigor of microspores.And the concentrations of mannitol and colchicines had different effects on 4 radish cultivars.

To investigate whether tolerance to cadmium (Cd) stress of rice seedlings could be enhanced or not by exogenous salicylic acid (SA), rice seedlings were grown in half concentration of Kimura Solution B, CdCl2.500 mol/ L and 300mol/ L SA(SA1), or 500mol/ L SA(SA2) was added to the solution, and the free Salicylic acid as control (CK). Under Cd stress condition, the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), chloro??phyll content and the photosynthesis rate of rice leaves were greatly decreased, andcontent of MDA in rice leaves weregreatly increased. But after SA was added to the nutrition solution with Cd, the act ivities of SOD, CAT and POD in riceleaves were greater than that with Cd stress, and the rate of reactive oxygen production, the content of H₂O₂ and MDA was decreased, the content of chlorophyll greatly decreased. All these results indicated that the tolerance to cadmium stress of rice seedlings could be increased by exogenous SA through its effects on the activities of antioxidant enzyme.

The virus-eliminating technology with shoot-tip culture and rapid propagation of two local famous elite garlic varieties in Hebei province were studied.The results indicated that the best induce medium for bud propagation was B₅+0.1mg/L NAA+3mg/L 6_BA.The numbers of hormone and nutritious and the period cultured were different in different varieties.The garlic shoot-tip with some bud scale is better for culturing.It can increased the survival rate of virus eliminating seedling and propagate rate.The period of virus eliminating garlic be transplanted plant effect the yield and significant different in two varieties.

In response to the less precipitation and the increasing shortage of water resources in North China,the identifying methods and the evaluating index for drought-resistant and high-yielding crop variety identification were discussed.The first relevant local standard about identification of drought-resistant crops in China was put forward to make the crop breeding procedures perfect.Hebei Province first developed the method in China that new crop varieties,especially in wheat and corn,attend drought-resistant tests while attending regional tests.Drought Resistant Index(DRI) has become the indicator and standard in drought-resistant identification of wheat and rice in the country.

Pot and field experiments were conducted to investigate the effects of Bio- organic- inorganic compoundfertilize on the growth, yield, and quality of flue- cured tobacco.The results showed as follows: compared to the contrast ofcommon fertilizer that contains the sameNPK quantity, in disposal AA, AB, and AB, the plant heights were more 11. 2- 11. 4 cm, the maximum leaf area was more 51. 71- 146. 02 cm2, and the number of leaves were more 1. 2- 3. 4, the content ofchlorophyll and activity of roots were speeded in the previous period, and fell more quickly in the latter period, especially indisposal AB. In the mature period, the shoot dry matter weights increased by 16. 96%, 22. 38%, 19. 44%, K content wasadded by 11. 05%,12. 27% and 7. 36%.The N content declined a little, Schmuck number and sugar/ nicotine were moreharmonious. In the field,The field experiments keeps the same with test result trend cultivated in a pot.

In comparison with CK, NPKM increased soil total P content by 52.2%, and that in the treatment of NPK + straw increased by 18.85%, NP, PK and NPK treatment increased by 17.87%, 15.88% and 14.89%, respectively. Above soil total P increases were also higher than those with the treatment of N only or NK. Compared with CK, soil available P increased by 10-fold and 3-fold with the treatment of NPKM and NPK + straw, and 3 -5 fold with NP, PK and NPK. Therefore, application of chemical fertilizer alone without organic manure can keep the balance of K input and output. Addition of NPK along with pig manure and straw increased soil available K by 16. 0% and 11.4% respectively, compared with CK. The available K declined year by year in the treatments without K fertilizer. Changes of soil slow-released K followed similar trend to the available K. Therefore, long-term application of ehemieal K fertilizer or its combined application with organic materials can not only meet the K demand by crops.

The trial in peanut fields in Kaifeng city,Henan province and Qingdao city,Shandong province of China,showed that nematode isolations of Rhabditis(Oscheius) spp could control grub damage in peanut production.The effect rate was up to 96%,16% higher than that of chemical pesticide,50% phoxim solution.The rate of no damaged peanut legume had been kept up to 97% in the treatments of Rhabditis nematodes(91.2% in the contrast of phoxim solution,51.6% in the contrast of tap water).The yield in the nematode treatments was 242 kg/667m²,126 kg/667m² higher than that of in CK with tap water.The rate of increased yield was 90% in the nematode treatments,20%higher than that of in CK with phoxim solution.There was no significance difference between number 1^# and 2^# isolations of Rhabditis(Oscheius) spp to suppress the grub damage in peanut production fields.There was significant difference at 1% level between the nematode treatment and CK treatments,concerning the ratio of grub damage reduced down and peanut yield raised up.The data of this preliminary study indicated that some nematode species or isolations in the genus of Rhabditis(Oscheius) may have potential possibility to be considered as bio-control agents.

The experiment was carried out by the method of comparative physiology,which was conducted to study on the formation of the population and correlation of the source-sink in different variety sugar beet,and the infection of the development of source-sink on the yield formation.The results showed that LAI and LAD of the sugar beet could be used as the important index of distinguish the size and capacity of the source.The assimilation capability of LAD could influence the potential of the sink of the earthnut straightly,the larger LAD could restrains the expands of the earthnut in the evening and even influences the formation of the yield and quantity of the sugar beet.It indicates the connection of fertility sugar beet with high sugar beet at the moment.The peak value of LAI present at the root and sugar increasing stage.The highest LAI should over 4.3.If it reaches the highest peak,it could keep at the comparatively steady persistent period about 20 days.And the LAI should keep at about 2.4 in the evening of sugar content accumulated stage.The colony LAD should arrive at above 19.3 m²·d in the root and sugar increasing stage,then it presents decline slowness in the end.The results above can offer the theoretic gist for directing improving the sugar beet′s producing quality-yield practice.

Microspore culture was carried out in hybrid plants between a high generation inbred line 91-112 and a DH line T12-19, which are high resistant and susceptible to TuMV, respectively. The survive frequency of regenerated plants and seed set of DH plants were highly improved by successive subculture during summer, low temperature treatment after domestication and transplanted in greenhouse. A DH population with 146 lines was obtained.

The measurement and analysis of different cotton varieties root development at low moisture showed that,habrid Bt cotton root grows faster in the early season but decrease faster in the later,normal Bt cotton root grows slowly in the early seson the early mature cotton is between the two types,the resistant to drought cotton keeps a steady growth and decrease.

In this research,The response of photosynthetic character of prunus armeniaca to soil drought stress were studied.The results show that net photosynthet ic rate(Pn),transpirat ion rate(Tr)and stomatal conductance(Cs)decreased with the increases in drought stress.Compared with control(CK),decreases of intercellular CO₂concentration(Ci)under mild and moderate stress and increase under severe stress were fonnd.The test of respone of photosynthesis to temperature exhibited the decline of Pn and increase of Tr under higher temperature,and water use efficiency(WUE)decreased.The stress effects of drought were aggravated under higher temperature on photosynthesis.The diurnal variation curves of Pn,Cs and WUE were double-peak types under different water stress,but the curves of Pn and Cs were changed to single-peak types under severe stress.The conclusion is that the photosynthesis of Prunus armeniaca exhibits a certain adaptability to drought stress.

A field expeRiment was conducted to study the effect of chemical feRtilizeRs application combine with manuRe with diffeRent combined Rate on soil NO - 3 -N and NH + 4 -N as well as tomato yield and quality． The Results indicated that soil NO - 3 -N contents incReased with chemical feRtilizeR contents incReased． And soil NH + 4 -N contents showed the similaR tends． The total nitRogen and oRganic caRbon contents in soil changed significantly at tomato haRvest stage． The sequence fRom higheR to loweR was high manuRe feRtilizeR tReatment， low manuRe feRtilizeR tReatment and chemical feRtilizeR tReatment． The mineRalization and immobilization of soil nitRogen， total nitRogen，oRganic caRbon and tomato yield get favoRable effect when the combined Rate of oRganic nitRogen and chemical nitRogen was 3∶ 2． HoweveR， statistical Results indicated theRe weRe no obvious Relativity between the content of soluble sugaR，oRganic acid and Vc in diffeRent feRtilizeR tReatments． Which maybe impact by diffeRent tomato yields． The nitRate contents in tomato fRuits decReased with the incRease of manuRe feRtilizeR Ratio． The nitRate and nitRite concentRations in tomato fRuits weRe loweR than the Chinese standaRd in all the expeRiment tReatments．

The rice cultivars and lines which attended regional trials and represented the current situation of rice breeding in Northeast Region of China were selected as material to analyze genetic diversity and genetic relationship be2 tween different provinces and cultivars on rice by SSR markers. As a result,only 303 alleles were detected in 103 poly2 morphic loci with the average number of 2194 and the distribution of alleles was uneven. So the genetic diversityof rice in Northeast Region of China was narrow,significantly lower than others rice regions. The analysis of genetic diversity be2 tween different chromosomes showed that the polymorphic loci distribution of Chr. 6,Chr. 9 and Chr. 11 was evener and the polymorphism information content was also more than others chromosomes. The homozygosity of three provinces,Hei2 longjiang was highest,Jilin was secondary and Liaoning was lowest. The degree of genetic diversity was in order of Hei2 longjiang >Jilin >Liaoning. The result of genetic cluster analysis indicated that there was the closer genetic relationship between Heilongjiang and Jilin,correspondingly Liaoning was more different.

Microplitis tuberculiter ( wesmael) can parasitize in the young larvae of Spodoptera exigua (H×bner) and Pseudaletia separata ( Walker). Researches on developmental durations, accumulated tempera- ture and developmental zero of Microplitis tuberculifer Wesmael by Pseudaletia separata ( Walker). The result showed that developmental zero and accumulated temperature of egg-larva, pupae were 12. 1 × and 115×15 day- degree, 8×47 × and 99×47 day-degree. With the increasing of temperature its developmental duration become shorter. Its developmental temperature was 23-27 ×. Under 25 × condition developmental durations of one generation was 14×64 day.

General use analysis of primershas the vital significance to reduce their development cost. 41 pairs primers coming from the wheat gene set were selected in this experiment, and general use was carried on analysis among four species in different genus of Pooideae. In the barley, the oats, the triticale and three awn grass, the success ratio of these primers respectively was 73.2%, 82.9%, 87.8%and 85.4%, and some primers even still appeared specificity strip bands in particular plant, These results indicate that the SSR marker coming from the wheat gene set is highly transferable among species in different genus of Pooideae.

The experiment was carried out to study the effect of grafting cultivation on eggplant resistance to Verticillium Wilt and production in the field and the fruit qualities.The results showed:The survival rate of the grafted eggplant was more than 88.50%.Of the four rootstocks,the strongest resistant variety to Verticillium Wilt was Tolubamu.Of 20 stions,the synthetical index of Tolubamu/KuaiYuanQie was the best,whose rate of infection was 41.76% lower than that of the control.And its total yield increased by 75.42%.The main fruit quality indexes of the grafted plant didn't decrease.

Wheat were cultivated in hydroponic culture solution with 100 μmol/L Cu2+ and 100 μmol/L Cd2+separately,the concentration of copper and cadmium,malonaldehyde,phytochelatin and glutathione in roots and leaf were investigated.The results revealed that under stress the concentration of copper and cadmium increased gradually,especially in roots the concentration increased remarkably,75 fold growth approximately,but in leaf the increase was slowly,2-5 fold approximately.The content of cadmium is higher than copper in leaf and roots.Lipid peroxidation in leaf was stronger than that in roots.Under heavy metal stress the concentration of glutathione in leaf was higher than that in roots,while phytochelatins in leaf was lower than that in roots.

A field experiment was conducted to evaluate radiation resource utilization of colony in different planting densities of a winter wheat cultivar Shixin828. It was studied under four different density levels(210 × 104 (D1) , 270 × 104(D2) ,330 × 104 (D3) and 390 × 104 (D4) basis seedlings per ha) . The results indicated that the dsnsity could remarkably influence the radiation utilization. The D3 treatment had the rational size of colony and Leaf area index and had apparent advantages in Light distribution,coefficient and radiation use efficiency of total biological yield at late growth period,with the grain yield and radiation use efficiency of grain yield of it being higher than that of the others significantly. The D1 and D2 treatments had apparent advantages in light transmission rate and net assimilation rate,but it had less Leaf area and dry matter accumulation as a result of less colony; Leaf area index and photosynthetic potential of the D4 treatment was higher than that of the others significantly,but it had apparent disadvantages in net assimilation rate,extinction coefficient and radiation use efficiency of total biological yield at late growth period with close microclimate as a result of great colony; both above reducing yield and radiation use efficiency of grain yield. The winter wheat had the best Light distribution,assimilative capability and suitable dry matter accumulation, with nutriment transporting to grain and its radiation use efficiency of grain yield being up to 0. 572% ,by rational ap-plication of planting densities.

To investigate the effect of different water condition on water use of wheat-corn,application of the straw-mulching,nutrition water-retaining agent and different irrigation were carried out to research the wheat-corn growth,yield,soil moisture and water utilization.The result indicated that rational irrigation plays an active role to wheat population dynamics developing and improve wheat spike length,plant height,spike grains,1 000 grains weight and yield.The highest wheat yield was 1 200 m³/hm² of supplement irrigation,it increased 11.83% comparing to CK.The worst one was 2 400 m³/hm² of supplement irrigation,it minus 1.0%.The more important thing was the irrigation of wheat could affect the corn yield,which of them improves 7.31% to 16.15% comparing to CK,and the best one was 1 800 m³/hm² of supplement irrigation.The result of wheat-corn yield stated the best volume of complement irrigation was 1 200 m³/hm² to 1 800 m³/hm² under the application of straw-mulching and nutrition water-retaining agent for wheat-corn two crops harvest system in mid-production irrigated zone in Henan province.The changes of soil moisture stated progressively that the straw-mulching and nutrition water-retaining agent application could improve and compensate soil moisture and affect the tendency of crop growth and development in a year.The result of soil nutrition changes stated it's necessary to apply phosphate and ium fertilizer and add straw recession volume for autumn crop.

Though years survey and investigation of plot test and high yielding cultivation,the yield constituting index was done.The result show that the big spike variety should aim at the spike weight,but its rate of bearing is low,so raising the seeding quality to get the wanted spike number per 666 7 m 2 is the right way;the many spike variety should aim at the spike number,but the rate of bearing is large,so reducing the seeding quality to keep it from get down while getting the wanted number is the right way;the middle spike variety should aim at the spike weight,the middle spike variety has the high proposibility to get high yielding so the breeding of super high yielding should choose the middle spike variety.

The allelopathy of corn and wheat straw aqueous extracts on seed germination and the growth of cucumber, lettuce and eggplant was investigated by means of bioassay in laboratory. The results showed that the effects of straw aqueous extracts on vegetables seed germination had many forms:inhibit effects, promotion effects, promotion/inhibition double effecs and no siginificant effect. Corn straw aqueous had significantly inhibited vigor index, root length and fresh weight of seedling of cucumber, and seedling height and dry weight was increased at lower conentration and decreased at higher concentration. Corn straw aqueous significantly inhibited seed germination and root growth of lettuce and eggplant, and had promotion/inhibit double effecs on seedling height and fresh weight. Wheat straw aqueous increased seedling height and fresh weight of cucumber, and decreased vigor index and root length of lettuce, and had promoted/inhibited effect on root length, seedling height and fresh weight. Wheat straw aqueous significantly decreased eggplant seed germination rate, and had promoted/inhibited effect on root length, seedling height and fresh weight. According to sensitivity index, the allelopathical effect of corn straw aqueous extracts was stronger than that of wheat straw aqueous extracts on tested vegetables. The allelopathical sensitivity to straw aqueous exracts was different among the tested vegetables, with lettuce being the most sentitive, eggpant being more sentitive and cucumber being the least sensentive.

General situation,the main type and characteristic of circulation on rural land contractua management right in Bayannaoer Municipality are summarized in this study;the problems presented during circulation are summed up, and pertinence suggestion are Enhancing the propaganda work,improving cognition of the peasants,strengthening the management of circulation of rural land contractual management right according to law,standardizing the procedure of circulation,encouraging and supporting the orderlyciroulation of rural land contractual management right to promote the moderately scale management of land.

Effects of salicylic acid on chilling??resistance of hot??pepper were researched by spraying SA in the present study. The results showed that suitable SA concentrat ion ( 2. 0 mmol/ L) decreased damage and wilt rat io of hot??pepper seedlings, increased act ivity of POD and CAT, and chlorophyll content, dropped MDA content at low temperature, and the chilling resistance of hot??pepper was improved. Metabolism of hot??pepper was disturbed, so its chilling resistance fell when SA concentration was above 2.0 mmol/ L. 2.0 mmol/ L of SA was the optimum concentration among all the treat??ments.

Two types of wheat male sterile lines,1B/1R type and non-1B/1R type,and their male maintainable lines were selected to study the agronomical characters,disease resistance,photosynthesis rate and activities of SOD in anthers.The results showed that T.spelta 1BS chromosome made the male sterile lines of Non-1B/1R type produce less haploid and higher plant height than that of 1B/1R type,and there were no significant difference on the disease resistance and agronomical characters between two types of wheat male sterile lines;The male sterile lines of Non-1B/1R type were with higher photosynthesis rate than that of 1B/1R type.There were little difference of SOD activities between two types,which were all with tendency of decrease.There was difference of SOD activities between two types of male maintainable lines.The key period of microspore abortion of two types of male sterile lines was similarly from dinucleate stage to thinucleate stage.

Leaf mould (Fulvia fulva Cooke Ciferri) is one of the serious diseases on tomato under protective cultivaion (greenhouse and plastic house) . In the program of tomato breeding for resistance to leaf mould, it is important to determine the extent of physiological races of leaf mould. Between 1984 and 1990, the races 1. 2 and 1. 2. 3 were found in Beijing. The gene Cf₄ was immune from those races. So a resistant variety (F1) Shuang Kang. 2 with Cf 4 was first introduced in tomato production. In 1990, that hybrid was attacked by the new races of 1. 2. 4, 2. 4 and 1. 2. 3. 4. Another hybrid Jia Fen. 15 with Cf₄ and Cf₅ was developed. It was resistant to the new races found in 1990. Although the six races had no obvious difference in virulence from those races in 1990, the virulence of a few isolations strengthened in a certain degree. The gene Cf₅ came to show no more immunity. Occassionally, a little amount of the mould could be found on the host plants with Cf₅. The breeders have to pay more attention to this matter.

A diallel cross involving 6 wheat parents was made by using Griffing methods to study the genetic model of grain protein and other main quality characters.The genetic parameters of the traits involved were estimated.The results indicated that (1) the inheritance of grain protein content,test weight,dry gluten content,wet gluten content,falling number and sedimentation value fit the model of additive dominance.(2)The high value of falling number was related to recessive genes,and the low value was related to dominant genes.The high value of grain protein content,test weight,wet gluten content,dry gluten content and sedimentation value were related to dominant genes,and the low value was related to recessive genes.(3)Except that the inheritance of sedimentation value performed over dominant gene,the rest were mainly controled by the additive gene,and also the mean dominant degree (H₁/D)were less than 1,and performed partial dominance.(4)Except the falling number,the narrow heritability of the rest traits performed higher.It indicated that they could be selected in early generations.

The author summarized the researches of metabolic rule of plastid pigment and its relationship with tobacco quality, and elucidated the influencing factors of content and composition of plastid pigment and its degrading productsfrom different aspects, such as type and mvariety, ecoenvironment, cultivation measures, metabolic enzymes and genet ic en?? gineering, and finally made a conclusion that the degradation process of plastid pigment, and the relat ionship between aromatic style and plastid pigment as well as its degrading products, chemical regulation should be emphasized in the future.

Fertilization effect on vegetables nutritious component was studied through trials conducted using cucumber,tomato,spinach and carrot.The results showed that the optimum treatment was the combination of half worm manure(56 250 kg/ha) with 50% NPK,which increased the content of vitamin C,soluble sugar,soluble protein and pectin and reduced the content of nitrate,tanin and cellulose of four kinds of vegetables.Compared with the urea treatment,the content of vitamin C in carrot,soluble protein in spinach and the ratio of sugar and acid increased by 61.34%,5.87% and 41.09% respectively.Meanwhile,the nitrate content reduced by 9%.

"A field experiment was conducted to study the effects of different nitrogen application on Winter Wheat yield,nitrogen use efficiency and nitrate-N accumulation in sandy soil.Under optimized fertilization,total N application reduced 30% than conventional fertilization and phosphatic and potassic fertilizer application were not changed.The result showed that the difference of winter wheat yield was not significant between optimized and conventional fertilizing application.Nitrogen use efficiency of Winter Wheat was increased by 5.25%-10.02% significantly for the optimized fertilization than for conventional fertilization.And the remains of NO-3-N in 0-120 cm soil layer were decreased by 66.87,98.87,66.61,42.01 kg/ha under optimize fertilization,optimizing fertilization + organic manure,straw counters-field + optimization fertilization,slow accused of fertilizer than under conventional fertilization respectively."