The ZF-HD (Zinc finger homeodomain)transcription factors,which belong to Homeobox protein family,are unique to plant kingdom and play an important role in the development of flowers and leaves in plants.The Glyma.02g040100 gene,a ZF-HD transcription factor,was isolated from soybean cultivar Kefeng No.1 by PCR method and was named as GmZHD1.Bioinformatics analysis showed that this gene contained 888 bp encoding 295 amino acid residues and the molecular weight of GmZHD1 protein was 32.64 kDa with a theoretical isoelectric point (pI)7.69.Sequence analysis indicated that GmZHD1 possessed two conserved domains,a zinc finger domain and a homeobox domain,and shares highest sequence similarity with FtHB2 (44.4%);The result of subcellular localization indicated that GmZHD1 was located in nucleus;And RT-PCR results showed that GmZHD1 expressed in all tissues detected,and with relatively higher transcript expression levels in flower,seed and leaf.In addition,the GmZHD1 was linked to the plant over-expression vector pBA002 successfully,providing foundation for further study on the function of GmZHD1 in soybean.

The transcription factor BnHY5-2 is associated with plant stress resistance.In order to reveal the response of Brassica napus L.transcription factor BnHY5-2 to salt alkali stress in B.napus,the response of BnHY5-2 to light and salt and alkali was analyzed by transient overexpression,qRT-PCR analysis and subcellular localization.The results revealed that under light conditions,the expression level of the BnHY5-2 gene in B.napus leaves and stems was 29.22 and 3.15 fold higher,respectively,compared to dark conditions.The higher sensitivity to light in leaves suggested that they were the primary site for light signal response.Under light conditions,the expression of BnHY5-2 in leaves and stems was significantly downregulated by 53.1% and 31.0%,respectively,when B.napus was planted in Dalian coastal saline-alkali soil;after applying saline-alkali treatment under dark conditions,the expression of BnHY5-2 was downregulated by 48.2% in the stem,while the difference in expression in the leaves was not significant,indicating organ differences,indicating that the leaves had stricter requirements for light conditions.In B.napus leaves with transient overexpression of BnHY5-2,two out of six genes related to saline-alkali stress(BnNAC32 and BnGS)showed upregulation by 1.25,3.28 fold,respectively,while the other four genes(Bnamy,BnAsp,BnNHX7,BnTPS)were downregulated by 24.8%,25.4%,71.0%,and 82.0%,respectively.Meanwhile,the content of the resistance substance betaine in B.napus increased from 0.256 to 0.573 mg/g,indicating an enhancement by 1.24 fold,suggesting that the overexpression of BnHY5-2 gene could improve the saline-alkali tolerance of B.napus.Subcellular localization results showed that the transcription factor BnHY5-2 was localized in the nucleus and regulates the expression of functional genes.Therefore,BnHY5-2 is not only related to light signaling but also participates in the saline-alkali resistance of Brassica napus L.

In order to explore the effects of saline-alkali stress on the physiological and molecular mechanism of Brassica napus L.,using Huayouza 62 as experimental material.The seedlings of Brassica napus L.were treated with different concentrations of compound salt,compound alkali and compound saline-alkali solution.Physiological indexes such as seed germination rate,chlorophyll content,proline content,soluble sugar content and antioxidant enzyme activity in Brassica napus L.leaves were determined.The accumulation of betaine in rape leaves was determined by high performance liquid chromatography(HPLC).The key enzyme gene choline monooxygenase gene(CMO)in betaine synthesis pathway was analyzed by qRT-PCR technique.The results showed that the degree of damage to seed germination in artificially simulated saline-alkali solution of different concentrations was compound saline-alkali>alkali>salt.Low concentration saline-alkali solution promoted chlorophyll formation in rape leaves,while high concentration saline-alkali solution inhibited chlorophyll formation,saline-alkali stress significantly increased the contents of proline and soluble sugar,and the contents of proline and soluble sugar in high saline-alkali solution(YJ75,saline-alkali 75 mmol/L)for 21 d were 65.99 and 5.21 times higher than those in the control group,respectively,and the content of malondialdehyde was increased by saline-alkali stress.Saline-alkali stress significantly increased the activity of peroxidase(POD).Compared with the control group,the content of POD in high saline-alkali solution(YJ75)increased by 2.26 times after 21 d,and the content of POD reached the highest value on the 14th day after treatment with compound salt and compound alkali,however, the activity changes of superoxide dismutase (SOD) and catalase (CAT) were not obvious, and the role of species in the process of saline-alkali stress was low.Saline-alkali stress significantly increased the expression of key enzyme gene CMO,thus regulating the accumulation of betaine.In summary,the damage degree of saline-alkali stress to Brassica napus L. was compound saline-alkali > alkali > salt.Under high saline-alkali stress,Brassica napus would accumulate a large amount of betaine to reduce the damage.

In order to explore the effects of growth and aging characteristics of peanut under drought and salt stress,using Huayu 25 as material,potted experiment was carried out to study the change of peanut growth and aging characteristics due to the stress of drought and salt at flowering stage.The results showed that drought treatment (D),salt stress treatment (S),drought and salt stress (DS) increased the content of soluble protein,soluble sugar,free amino acid,proline,O₂^· and MDA. S treatment and DS treatment reduced the activity of SOD,POD and CAT in the leaves,which continued to decrease as time prolonged. But D treatment enhanced SOD and CAT activity in the leaves. After 10 days of rehydration,the content of soluble sugar,soluble protein,free amino acid,proline,O₂^· and MDA of D treatment reduced compared with the numerical values which detected before rehydration.D treatment had no significant difference with CK,including activity of SOD and POD and content of O₂^·,MDA,soluble sugar,free amino acid,proline. However,the difference of the activity of SOD,POD,CAT of DS treatment was significant compared with S treatment,so did the content of O₂^· and MDA.In the harvest time,single plant yield and the kernel rate of D treatment had no significant difference with CK,but DS treatment had significant difference with S treatment. Data from DAT9 showed that drought and salt stress had no significant interaction with soluble sugar,soluble protein,free amino acid and proline content in leaves. However,there was significant interaction of SOD,POD,CAT activity and O₂^·,MDA content between drought stress and salt stress. The interaction between drought stress and salt stress inhibited the activity of SOD,POD and CAT and exacerbated the peroxidation of plant cell membranes. Eventually it decreased the single plant yield and the kernel rate. Therefore,peanuts planting under salt stress should avoid the drought at flowering stage to reduce the harm of salt stress,drought stress and the interaction between salt stress and drought stress.

To study the physiological effects of different degrees of drought on soybean cultivars in different development periods. Two soybean cultivars with different drought resistances were taken as the experiment materials to study the effects of drought stress on the resistance index and physiological characteristics of soybean in different growth periods, and to explore the physiological mechanism of soybean response to different drought intensities at different developing stages in pot culture. Four treatments were set up:continuous mild drought stress (T1), continuous moderate drought stress(T2), drought stress in full seed stage (T3) and without drought stress(CK). The results showed that under drought stress, the chlorophyll contents of both soybean cultivars increased, and Jindazaochun 2 was more obvious at early stage, but it was less than that of Jinda 74 at grain-filling stage. Under continuous mild drought stress and continuous moderate drought stress, the MDA content of Jindazaochun 2 at different growth stages significantly increased, while the POD and MDA contents of Jinda 74 significantly increased under continuous moderate drought stress. At the branching stage, the content of reducing sugar in Jinda 74 decreased significantly during moderate drought. In the Granulation stage, the reducing sugar content of soybean leaves in Jindazaochun 2 was significantly increased, Jinda 74 was only reduced under drought treatment in the Granulation stage. At flowering stage, reducing sugar content reduced in Jindazaochun 2, but increased significantly in Jinda 74. It was found that drought had a great influence on reducing the plant height, node number, stem diameter of both cultivars. The decrease in plant height and stem diameter of Jinda 74 was more obvious. The resistance of Jinda 74 to drought was higher than that of Jindazaochun 2, which was related to the reduction of plant height and water consumption under continuous drought conditions. The results will provide a basis for comprehensive understanding of the soybean resistance to drought stress.

The purpose of this study was to reveal the intercropping advantage of sorghum-soybean intercropping system. Field experiments were conducted in 2018 and 2019 in Fenyang of Shanxi Province. This study included nine treatments, sole-higher sorghum Jinza 22 (G1), sole-lower sorghum Jinza 34 (G2), sole-soy bean(D), 2 rows sorghum and 2 rows soybean(2G1:2D, 2G2:2D), 2 rows sorghum and 3 rows soybean(2G1:3D, 2G2:3D), 2 rows sorghum and 4 rows soybean (2G1:4D, 2G2:4D). Sorghum and soybean yield, land equivalent ratio, water and nutrient use efficiency of different sorghum-soybean intercropping treatments were investigated. The results showed that the 1 000-grain weight and spike weight of sorghum in intercropping system were no significant difference than that of sole sorghum. However, the pods number of soybean had significant difference between different treatments. Compared with sole-soybean(D), the pods number of soybean in 2G1:2D, 2G2:2D, 2G1:4D, 2G2:4D decreased by 37.89%, 32.16%, 22.46%, 21.51%, respectively. The land equivalent ratio (LER) and water equivalent ratio (WER) in the all intercropping system were more than 1, indicating that there were some advantages in land and water use. The nutrient advantage of intercropping system was due largely to a higher total nitrogen accumulation than that of the sole system. Compared with 2G2:2D, the average LER, WER, total nitrogen accumulation of 2G1:2D increased by 8.91%, 8.30%, 4.56%, respectively.The average LER, WER, total nitrogen accumulation of 2G1:4D increased by 10.17%, 9.14%, 4.35%, respectively, than that of 2G2:4D. In the sorghum Jinza 22 and soybean intercropping system, the LER, WER, total nitrogen, phosphorus and potassium accumulation of 2G1:4D were the highest among the intercropping treatments. In conclusion, the LER, water and nitrogen use efficiency by sorghum-soybean intercropping could be improved, and the intercropping advantages of higher sorghum Jinza 22 and soybean were more obvious than that of lower sorghum Jinza 34 and soybean, and the 2G1:4D intercropping system was the suitable combination under the experimental condition.

To investigate the function of soybean GmPP2C89 gene in plant abiotic stress response and adaptation. The expression patterns of GmPP2C89 under NaCl,PEG and mannitol treatments were detected by transcriptome data and Real-time quantitative PCR. Then,the cis-acting elements on the promoter of GmPP2C89 in response to abiotic stress were analyzed,and promoters of different lengths were cloned according to the distribution of cis-elements to construct fusion GUS vectors to obtain the corresponding transgenic Arabidopsis. The response of the promoters to NaCl,PEG and mannitol was analyzed by GUS staining. Transgenic Arabidopsis overexpressing the GmPP2C89 was constructed,and the root length,leaf MDA content and electrolytic leakage,and the expression of salt stress-related genes(SOD,POD,CAT,RD26,RD29A,and RD29B)were measured under normal and NaCl treatment conditions. The results showed that NaCl,PEG and mannitol treatments all led to a significant increase in the expression level of soybean GmPP2C89;the promoter region contained many cis-acting elements such as ABRE,DRE,G-box,MBS,MYB,MYC and TC-rich repeats which were involved in abiotic stress response,and this promoter was more responsive to NaCl treatment. In addition,under the salt treatment,the root length of transgenic Arabidopsis GmPP2C89-OX was significantly greater than that of WT,while the MDA content and electrolytic leakage were significantly lower than those of WT,and the salt tolerance was significantly enhanced;the expression of antioxidant enzyme genes(SOD and POD)and ABA pathway key gene RD29B in GmPP2C89-OX was significantly higher than that in WT. These results indicated that soybean GmPP2C89 was induced by NaCl,PEG and mannitol,and GmPP2C89 overexpression could enhance the salt tolerance of transgenic Arabidopsis by activating antioxidant and ABA pathways.

The plant NADPH oxidase Rbohs(Respiratory burst oxidase homologs) is the main source of reactive oxygen species (ROS),which participate in various physiological processes such as plant growth,development,stress resistance and plant-microorganism interaction.In order to explore the function and mechanism of Rbohs in symbiotic nitrogen fixation,GmRbohL,a member of soybean Rbohs gene family,was cloned in this study.The gene expression pattern,protein subcellular localization and gene function were studied by molecular biology,cell biology and genetics,respectively.The results revealed that: GmRbohL gene was induced by rhizobia and expressed specifically in soybean roots and nodules.Subcellular localization analysis indicated that the gene-encoded protein GmRbohL was a membrane protein.The plant gene silencing (RNAi) vector of GmRbohL was constructed,and the transgenic hairy roots were obtained by the transformation of soybean hairy root mediated by Agrobacterium rhizogenes K599.Gene silencing of GmRbohL resulted in a significant reduction in the number of nodules of transgenic hairy roots,and the production of ROS was also inhibited. Gene silencing of GmRbohL reduced the infection of rhizobia at the stage of root nodule organogenesis,and the expression level of nodulation marker genes also decreased with the decrease of GmRbohL expression.The root nodule tissue sections showed that gene silencing of GmRbohL significantly reduced the number of symbionts in the infected area of root nodules,and the nitrogenase activity of root nodules also decreased accordingly.The above data indicated that gene silencing of GmRbohL significantly inhibits the symbiotic nodulation process of soybean by reducing the production level of ROS.It is speculated that GmRbohL may play an important positive regulatory role in organogenesis of soybean nodules and regulation of nitrogen fixation function.

In order to explore the ecological environment impact on peanut seed flavonoids and polyphenols,and the correlation between their changes with changes of fat and total sugar content,16 widely cultivated peanut varieties which were significantly different in flavonoid and polyphenol content,were planted in several test locations for two years. Total flavonoids content,total polyphenols content,fat content and total sugar content of peanut seeds were evaluated. The results showed that the genotype effect significantly affected the content of flavonoids and polyphenols in peanut seeds.Puhua 23 is a high TFC variety and Yuhua 9327 is a high TPC variety. the effects of ecological environment on the content of flavonoids and polyphenols were significant,and Hefei was the most suitable planting areas for forming flavonoid and polyphenol. The effect of temperature and precipitation was also significant. In addition,the corresponding trend between the secondary metabolites (flavonoids and polyphenols)and primary metabolites (fat, soluble protein and total sugar) among the locations were differentbetween two years.

This study provides a good foundation for further elucidating the function and mechanism of AhPLDα1 and AhPLDα2 in responding to drought stress in peanut.The full-length CDS sequences of AhPLDα1 and AhPLDα2 were cloned from Jihua 4 peanut leaf with ABA treatment using RT-PCR.The AhPLDα1 and AhPLDα2 gene fragments were inserted into the expression vector pBar-F3 by forward ways.These constructs were transformed into Agrobacterium tumefaciens GV3101 by freeze-thawing method and then introduced into wild-type Arabidopsis thaliana using modified floral-dip method.Under the condition of drought,the authors observed phenotypic changes of wild type and transgenic plants.Colony PCR and enzyme digestion results showed that,the plant overexpressing recombinant plasmid pBar-AhPLDα driven by CaMV35S promoter was successfully constructed.Glyphosate resistance screening,PCR detection and gene expression analysis showed that the positive transgenic plants were obtained.Under water deprivation,overexpression of AhPLDα1 and AhPLDα2 in transgenic Arabidopsis plants resulted in significantly enhanced tolerance to drought stress.In conclusion, AhPLDα1 and AhPLDα2 have a certain relation with drought stress signal transduction in transgenic Arabidopsis plants,and are potential candidate genes on the way to modified crop drought resistance.

In order to realize the application of PRPs genes in plant genetic engineering,the GmPRP and SbPRP from soybean were cloned into plant expression vector of pRI101,respectively,and then introduced into tobacco by Agrobacterium-mediated transformation.Two positive transgenic tobacco plants of GmPRP and four positive transgenic tobacco plants of SbPRP were obtained.The transgenic tobacco plants were treated with salt,drought and cold stresses.The results showed that the contents of proline and soluble sugar in SbPRP transgenic plants were significant higher than wild-type plants and the contents of malondialdehyde in SbPRP transgenic plants were significant lower than wild-type plants under salt stress.While the contents of proline,soluble sugar,and malondialdehyde in GmPRP and SbPRP transgenic plants had no significant differences compared to wild-type plants under drought stress.The contents of proline in GmPRP and SbPRP transgenic plants were both significant higher than wild-type plants and the contents of malondialdehyde in GmPRP and SbPRP transgenic plants were both lower than wild-type plants under cold stress.These data indicated that the transgenic tobacco plants constitutively expressing SbPRP showed an increased tolerance to salt and cold stresses and the transgenic tobacco plants constitutively expressing GmPRP showed an increased tolerance to cold stress,which may provide a way toward the application of them.

The low temperature is a major cause of yield loss in Brassica production.The object of this study was to understand the genetic causes underlying cold tolerance and to identify relevant quantitative trait locus.An F₂ population(147 individuals) derived from GZ hui(Brassica napus,high cold tolerance) and 10B(Brassica napus,low cold tolerance) were used as gene mapping population.The two parents and F_2:3 families were used as secondary research material.SSR molecular markers in combination with physiological index and natural conditions of hardiness survey were developped to map QTLs associated with cold tolerance genes.The results showed that 160 SSR primers could amplify polymorphic bands between the two parents among 630 SSR primers,the polymorphism rate was 25.40%;102 SSR primers showed polymorphism between F₂ among 160 SSR premiers with polymorphism rate was 63.75%.A total of 229 loci were finally identified.The genetic map covered 19 linkage groups with 974.70 cM in length,and average destiny was 5.70 cM.Under the condition of natural wintering,relative conductivity,relative water content,SPAD and MDA were measured in F₂ and F_2:3,respectively,and the correlation was analyzed among them showing correlation or significant correlation which indicated these indexes could be regarded as targets to evaluate the cold tolerance in Brassica.Five QTLs were identified associated with cold resistance.There was an overlap area between the QTLs of SPAD and MDA,which could be regarded as a hot area of candidate genes.This research can lay further foundation for fine mapping and cloning of the cold tolerance genes in Brassica napus.

In order to study the genetic characteristic of mosaic-leaf and identify the molecular markers linked to mosaic-leaf in Brassica napus L..In this study,three segregated populations,F₁,BC₁ and F₂,were constructed by crossing two parent lines,2205 (round-leaf) and 1423 (mosaic-leaf).The mosaic-leaf line of two parents and the segregated populations were used to analyze the inheritance of mosaic-leaf;molecular marker technology was used to map the mosaic-leaf gene.The results showed that the leaf morphology of F₁ plants revealed mosaic-leaf phenotype and the separated proportion of mosaic-leaf to round leaf in BC₁ (F₁×2205) and F₂ was fitted to 1:1 and 3:1,respectively,which showed that the mosaic leaf was controlled by a pair of incomplete dominant gene.Meanwhile,637 pairs of SSR primers combined with bulked segregation analysis (BSA) were employed to identify the markers linked to mosaic-leaf gene.As a result,three markers:CB10079,BNGMS114 and BNGMS385,linked to the mosaic-leaf gene were identified.All of them were located in one side of the gene,and BNGMS114 was closest to the gene with a distance of 2.5 cM.The sequences of three markers were submitted to blast with those of B.rapa genome.The results indicated that the sequences of three markers showed good collinearity with those of A10 chromosome.The target gene was located in the downstream section of 15.70 Mb on A10.These results will be useful for MAS and the mosaic-leaf gene cloning.

To establish the protoplast transient expression system of the components of heterotrimeric G protein in Brassica napus, the key factors in protoplast preparation and transformation including explant,flat rolling time and polyethylene glycol(PEG) concentration were optimized.The results showed that the best yield and viability of protoplasts were 10.73×10⁶/mL and 96.4% respectively,with the optimum conditions as 30 days seedling age and 10 min rolling time.The expression of target proteins reached the maximum with 30% PEG.The responses of G protein to ABA were investigated using the protoplast transient system by Western Blot detection.The highest expression levels of BnGA1,BnGB1,BnGG2 and BnRGS1 were observed when the ABA concentration was 100,150,100,50 mmol/L,respectively.

Aquaporins are channel proteins, which located in biological membranes including plasma membrane and tonoplast.It can highly facilitate water transportation across biological membranes.To investigate molecular mechanism of water regulation during seed germination, a tonoplast intrinsic proteins(TIPs)gene fragment TIP4;1 was isolated from Brassica napus seed by RT-PCR.The expression ofTIP4;1 gene during seed germination and stresses treatment was analyzed by quantitative Real-time PCR(qRT-PCR).The transcription levels of TIP4;1 was analyzed during germination, and these results showed TIP4;1 expression levels was scarcely detected in dry seed, but was up-regulated during germination as well as early young seedlings.In addition, expression of TIP4;1 in response to abiotic stress was investigated, and results showed that TIP4;1 gene expression was upregulated under drought, cold and salt stress, suggesting that TIP4;1 may be involved in Brassica napus seed germination and stress response process.Aquaporin regulation mechanism would be further revealed in future, which had realistic significance for solving drought and salt stress problems.

To investigate the reasonable amounts of NPK fertilization on peanut in the rotation of peanut and rye during one year,the effects of the different applying amounts of NPK fertilizers on the yield and quality of peanut,the SPAD value and the gas exchange parameters of the leaf of peanut in pod setting stage,and the soil nutrients in the harvest stage of peanut,and the grass yield and the nutrients accumulation above ground of rye were studied by the combining methods of the field investigation and the laboratory analysis.The results showed that the pod yield,the hundred pods weight and the hundred grains weight of peanut,and the grass yield and the protein yield of the following rye were all improved with the increase of NPK fertilizers amounts.However,the excessive fertilization of NPK would cause the increment of the pod yield of peanut being not significant.And the protein content,the fat content,the O/L value of the peanut grain increased significantly when the NPK fertilizers amounts were added to a certain level.And improving the NPK fertilizer levels not only could enhanced significantly the chlorophyll content,photosynthetic efficiency of peanut pod leaf,but also could significantly improve the Alkaline P,Alkaline K content in soil except for the SOM content,alkaline hydrolysis nitrogen content.The C,N,P and K nutrients of rye accumulated with the increase of the fertilization level,and the maximum amounts of the accumulated nutrient was C,and the mini was P.And the reasonable applying amounts of NPK were N 56.25 kg/ha,P₂O₅ 243.75 kg/ha,K₂O 187.50 kg/ha respectively.In conclusion,the rational application of NPK fertilizers can increase the yield,quality and photosynthetic efficiency and nutrients content in soil.

To assess the peanut rhizosphere bacteria community structure in response to salt stress at different development stages, the peanut variety Huayu 25 was used as experimental material, and a pot experiment was set with three salt concentrations to study the effect of salt stress on peanut yield and analyze the changes of microbial community structure of peanut rhizosphere at flowering and harvest stage under salt stress by high-throughput sequencing technology. The results showed that the rhizosphere microbial composition of peanut were basically similar under different salt stress treatments, but the diversity and richness significantly varied between flowering and harvest stage. Under higher salt stress, the diversity and richness of rhizosphere bacterial community were increased at the flowering and needling stage but decreased at the harvest stage. The dominant bacteria phyla of all soil groups were Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria, Verrucomicrobia, Bacteroidetes, and Patescibacteria. The relative abundance of Cyanobacteria, Gammaproteobacteria, Verrucomicrobiae and Bacteroides significantly increased under salt stress, especially at the flowering and needling stage. Hierarchical clustering revealed that the microbial community diversity was markedly altered by the salt concentrations and growth stages, samples of the same growth period were clustered into one group under salt stress. KEGG functional prediction analysis indicated that sequences related to carbohydrate metabolism, amino acid metabolism, energy metabolism, and metabolism of cofactors and vitamins were enriched, whereas that of signal transduction mechanisms, lipid metabolism, replication and repair, xenobiotics biodegradation and metabolism, metabolism of other amino acids, and folding, sorting and degradation were decreased. Among them, salt stress increased the abundance of functional groups involved in substance and energy metabolism, membrane transport, translation, replication and repair, and signal transduction, but decreased the 100 fruit weight and 100 kernel weight of peanut resulted in the decrease of peanut yield. Therefore, salt stress had a great impact on the peanut rhizosphere bacterial community structure and peanut yield. The salt tolerance of peanut could be enhanced by improving soil microbial environment. The results provided a theoretical basis for the development of peanut production in saline-alkali areas.

To explore the effect of different maize and soybean sowing dates on soybean yield,dry matter accumulation and partitioning ratio,provided reference to increase crops yield in maize-soybean intercropping system.The field experiment was conducted with three maize sowing dates:early seeding(A1:May 15 th),middle seeding(A2:May 30 th),late seeding(A3:June 14 th),and three soybean sowing dates:early seeding(B1:May 30 th),middle seeding(B2:June 14 th),late seeding(B3:June 29 th).In maize middle seeding, the soybean growth rate after blooming was 33.2% significant higher than maize late seeding; dry matter accumulation per plant and pod distribution rate of soybean were 32.4%, 17.9% and 26.3%,23.9%significant higher than maize late seeding in R4, R6; soybean yield was 75.7%significant higher than maize late seeding.Compared with soybean middle seeding under maize middle seeding treatment, the soybean dry matter accumulation per plant and pod distribution rate were 195.4%,58.5% and 33.9%, 26.7%significant higher than soybean late seeding in R4, R6; soybean yield was 128.7%significant higher than soybean late seeding. It turned out that sowing maize and soybean simultaneously significantly improved the growth rate after soybean blooming,increased dry matter accumulation per plant,pod distribution rate and yield in maize-soybean intercropping system.

In order to reveal the protective mechanism of exogenous Brassinolide on the photosynthesis of maize seedlings under drought stress,this experiment used the Zhuyu 309 as test materials and adopted the solution culture method,studying the changes of growth parameters,chlorophyll content,photosynthetic parameters,chlorophyll fluorescence parameters and D1 protein content of maize seedlings that used 20% PEG-6000 to simulate drought stress after exogenous Brassinolide (BR) pretreatment. Compared with that of drought stress,the results of corn seedling which after the BR pretreatment showed that its height increased by 45.87%,the root length increased by 20.56%,the total dry matter accumulation increased by 8.01%,the relative water content increased by 4.50%,chlorophyll a content increased by 26.32%,and photosynthetic parameters (Pn,Gs,Ci,Tr) increased by 9.57%,38.23%,30.19% and 28.12% respectively,the activity of photosynthetic system Ⅱ (Φ_PSⅡ) increased by 20.48%,and the maximum photochemical efficiency increased by 0.66%. Photosynthetic system Ⅱ absolute electron transport rate (ETR (Ⅱ) and the relative electron transport rate of photosynthetic system Ⅱ(rETR(Ⅱ)) were increased by 20.40% and 31.02% respectively. The content of D1 protein increased by 37.34% (P <0.05). The results showed that BR treatment under drought stress condition could improve the growth and development of maize seedlings,alleviate the damage of photosynthesis system,promote the stability of D1 protein and improve the adaptability of maize seedling to drought stress.

WRKY transcription factor plays an important role in plant response to abiotic stress and regulation of resistance gene expression. In order to reveal the role of a soybean transcription factor GmWRKY58 in response to abiotic stresses.The full length of GmWRKY58 cDNA was cloned from soybean,and the amino acid sequence,physiological and biochemical characteristics and evolutionary relationship were deduced. Subcellular localization and the changes of gene expression under different tissues and abiotic stress were studied. The results showed that GmWRKY58 had a 954 bp length open reading frame and encoded a total of 317 amino acids. Subcellular localization results showed that GFP signals combined GmWRKY58 was only detected in the nucleus. Real-time RT-PCR analysis showed that GmWRKY58 was expressed in soybean roots,stems,leave,flowers and pods,and the expression in each tissue of roots,stems and leave was significantly higher than flowers and pods. In soybean roots, GmWRKY58 gene can be significantly induced by abiotic stress factors such as high salinity,drought,low nitrogen and iron deficiency.Under high salt stress, GmWRKY58 gene expression was increased by more than 187.4 times. Moreover,this gene just slightly induced by other abiotic stresses shch as SA,low temperature,low phosphorus and low potassium. The results indicate that GmWRKY58 plays an important regulatory role in abiotic stress process of salt,drought,low nitrogen and iron deficiency in soybean.

To overcome the difficulty of soybean's production in Shanxi Province,the relationship between main agronomic characters and yield of 18 new soybean varieties with different ecological types was studied,so as to provide theoretical basis for breeding for high yield and super high yield.The cluster analysis was used to classify the ecological types.The principal component analysis and correlation were used to evaluate the agronomic characters.The results showed that the 18 varieties were divided into 4 categories with cluster analysis in the Euclidean distance at OD=5.54:The first kind was the multi-branch pods type; The second was the middle branch pod type; The third was the lanceolate leaves less branching pod type; The fourth was oval leaves less branching pod type. The yield of soybean germplasm of different ecological types was significant positively correlated with branch number and three pods number, and highly significant positively correlated with plant weight, two pods number, pod weight, grain weight, stem weight, total pods and total number of grains. The yield of soybean germplasm with different branch types varied with the density, and the highest yield reached different points. The yield of multi-branch type increased-decreased-increased with the increase of density, and reached the highest point when the density was 240 000 plants/ha. The yield of medium branch type showed a trend of ascending-descending-ascending-descending with the increase of density, and reached two peaks at the density of 120 000, 210 000 plants/ha, and reached the highest point at 120 000 plants/ha. The yield of small branch type of conifer and elliptical leaf showed a descending-ascending-descending change with the increase of density, the highest point was reached when the density of elliptical leaf type was 150 000 plants/ha, and the highest point was reached when the density of conifer leaf type was 180 000 plants/ha. High-yield and super-high-yield soybean breeding should pay attention to the application of multi-pod materials and reasonable density of soybean materials of different ecological types.

In order to promote the further promotion of green manure planting in Tianjin, a field experiment was adopted, and 9 spring Brassica napus L. varieties were overturned with spring fallow fields as a control to study the effects of different spring Brassica napus L. on soil potassium content and maize nitrogen metabolism.The results showed that there were differences in the biomass and nutrient content of different spring Brassica napus L. varieties. Among them, Zhongyoufei 1901(7 716.50 kg/ha), 1804(6 577.02 kg/ha), and 1907(6 457.03 kg/ha) had higher biomass and nutrient content.The change trend of soil total potassium and available potassium in 2019 was the same as 2020. Among them, the content of total potassium and available potassium in the soil under the treatment of spring Brassica napus L. of Zhongyoufei 1901, 1804, and 1907 was higher than that of other tested varieties in different periods, and the total potassium and available potassium content of soil in 2020 were higher than those in 2019.The potassium uptake by the whole plant of maize and the total potassium uptake by the hectare of the three varieties of maize were higher than those of other tested varieties. Compared with 2019, the potassium uptake of the whole plant of maize treated with different spring Brassica napus L. in 2020 increased by 15.70%-24.34%;the NR and GS activities of the ear leaves in different spring Brassica napus L. treatments increased by 2.16-14.22 nmol/(min · g), 0.99-2.30 μmol/(h · g), respectively. The top 3 NR and GS activities of the maize ear leaves were the same as the potassium uptake of the whole maize plant. Compared with spring fallow, spring Brassica napus L. treatments' yield of maize increased by 10.02%-33.47%, which was 1.09-1.41 times of the spring fallow, and the highest yield in two years was 15 700.94 kg/ha (2020 Zhongyoufei 1901). It could be seen from the path analysis that the nitrate reductase activity of the leaf at the ear position had a direct effect on the protein content of corn grains.In the indirect effect, leaf protein content contributed the most to maize grain protein through leaf nitrate reductase activity.Correlation analysis showed that there were significant and extremely significant positive correlations among Brassica napus L. total potassium, soil potassium, maize potassium uptake, key enzymes in maize leaf nitrogen metabolism, maize leaf protein content, and maize grain protein content.

To explore the effects of different soil compaction on the growth and activity of peanut root,determine the required compaction suitable for the growth of peanut,provide a theoretical basis for the breeding and cultivation of new varieties of high-yielding peanut.Used Qinghua 7 which was high-yield peanut varieties as the material,a method using barrel planting set soil bulk density was 1.1,1.2,1.3,1.4,1.5 g/cm³ 5 treatments,studied the effects of soil compaction on the growth and activity of peanut root.The results showed that in peanut root development period,soil bulk density too large was not conducive to the expansion of root elongation and surface area,and with the growing process to promote the greater impact,soil bulk density too small,then the root length and surface area decline too fast,in peanut root recession period.The suitable soil bulk density (1.2 g/cm³) could not only guarantee the development of root elongation and expand root surface area,but also delay the root length and surface area of root decline.Soil bulk density too large or too small was not conducive to accumulation of the root dry matter weight, increasing of the root volume and root activity. With the increase of soil bulk density,the root diameter increased. So the bulk density within 1.2-1.3 g/cm³ range was conducive to peanut root growth and activity increase.

In order to explore the effects of brassinolide(BR) on seed germination and seedling physiological characteristics of maize under low temperature stress, the maize hybrids Tiannong 9 and Tianhe 1 were used as the materials to study the changes of agronomic traits and physiological properties after their seeds were soaked or sprayed with BR. The results showed that exogenous BR treatment could effectively alleviate the inhibition of maize growth under low temperature stress. The best treating concentration was 0.1 mg/L BR, which increased the germination rate, the biomass of overground and underground parts, the SPAD value, the activities of SOD, POD and CAT, and the contents of proline, soluble sugar and soluble protein, while decreased the MDA content and the relative conductivity in maize seedlings. Compared with the low temperature control, the maize hybrids Tiannong 9 and Tianhe 1 treated with exogenous BR of 0.1 mg/L initial germination rate increased by 18.89 and 11.10 percentage points respectively, the final germination rate increased by 6.67 and 18.89 percentage points, their aboveground dry weight increased by 55.92% and 49.15%, their underground dry weight raised by 38.79% and 14.26%, their relative electrical conductivity decreased by 7.33% and 6.80%, their CAT activity increased by 110.58% and 120.43%, and their proline content increased by 66.59% and 54.63%, respectively. It suggested that the relieving effects of 0.1 mg/L BR treatment on the two maize varieties under low temperature stress were different, Tiannong 9 being better than Tianhe 1. The maize varieties with different cold resistances had different adaptability to different BR concentrations.