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This special topic selects papers related to maize published in Acta Agriculurae Boreali-Sinica , involving papers on maize genetics and breeding, cultivation, physiology and biochemistry, soil fertilizers, diseases and pests, etc.Click on the relevant paper to open the web page and download the full text. In order to quote and share for readers, each article contains a complete citation format in Chinese and English (including international DOI number) and a proprietary  QR code. Long press the  QR code of the article to open the web page of the article and realize mobile sharing at the same time. Thank you for downloading, quoting, forwarding and sharing.
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  • LIN Jing, LIN Jianxin, ZHANG Yang, LU Heding, CHEN Shanhu, LIAO Changjian
    Abstract (174) PDF (101) RichHTML (39)

    In order to preliminarily explore the key regulatory networks and genes involved in maize cold resistance,identify the key regulatory pathways and genes in response to low temperature stress,which laying a foundation for further research on the molecular mechanism of cold stress resistance.Here,a cold tolerance variety Mintian 6855 was employed to determine the gene expression pattern at 24,48 and 72 hours post low temperature of 5 ℃ stress by using transcriptome technique.The PCA analysis revealed that the repeated samples were well clustered together and significantly separated from CK samples.The results of difference analysis showed that about 4 000—7 000 difference genes expressed after cold stress treatments,while,only about 100—2 000 showed difference expressing among low temperature treated samples,indicating that low temperature was the main factor results in genes difference expressing,and the difference expression genes were mainly responded in the early stage.Meanwhile,KEGG annotation analysis results revealed that the differentially expressed genes were enriched in pathways of plant hormone signal transduction and MAPK,suggesting that these two signaling pathways actively respond to cold stress.In addition,different express genes were also enriched in plant-pathogen interaction as well as circadian rhythm plant,strongly implied that there were overlapping or common regulatory pathways in biological and abiotic stress pathways,while,genes that regulate circadian rhythms also playing a key role in plant adaptation to low temperatures.

  • ZHAI Lichao, ZHANG Lihua, ZHENG Mengjing, LÜ Lihua, SHEN Haiping, YAO Haipo, JIA Xiuling
    Abstract (43) PDF (38) RichHTML (3)

    In order to explore the responses of kernel position effect of summer maize to plant density and its carbon and nitrogen metabolism characteristic,field experiments were conducted during 2020 and 2021 growing reasons at Dishang Experimental Station,Institute of Cereal and Oil Crops,Hebei Academy of Agriculture and Forestry Sciences. Three plant densities(PD1:60 000 plants/ha;PD2:75 000 plants/ha;PD3:90 000 plants/ha)were arranged,with the objectives to study the effect of plant density on grain filling and kernel weight ratio of inferior and superior kernel and its physiological characteristics of carbon and nitrogen metabolism. Compared with the superior kernel,the response of inferior kernel to plant density was more obvious,significant differences in grain-filling rate and kernel weight of inferior kernel were observed since 20—25 d and 30—35 d after pollination,respectively. As the plant density increases,the kernel weight ratio of inferior to superior kernel significantly decreased,PD3 decreased the kernel weight ratio of inferior to superior kernel by 8.45% on average,compared to that of PD1. The single plant dry matter accumulation significantly decreased as the plant density decreased,this was mainly due to the significant decrease of post-silking dry matter accumulation. The analysis of carbon and nitrogen metabolism of kernel showed that the increased plant density exacerbate the difference in starch and protein contents between inferior and superior kernels;and the increased plant density also exacerbate the difference in SPSase,ADPGase and GS activities between inferior and superior kernels,which mainly attributed to the significant decrease in SPSase,ADPGase and GS activities of inferior kernel. In conclusion,the increased plant density exacerbate the kernel position effect of summer maize,this was related to the lower grain-filling rate and kernel weight of inferior kernel since mid-grain filling stage,the lower grain filling rate in inferior kernel under dense planting was not only related to the insufficient post-silking dry matter accumulation,and it was also closely related to the lower activities of SPSase,ADPGase,and GS in inferior kernels.

  • LIU Shuai, XU Xuexin, ZHAO Jinke, QU Wenkai, HAO Tianjia, MENG Fangang, JIA Jing, ZHAO Changxing
    Abstract (50) PDF (34) RichHTML (1)

    In order to explore the effects of the combination of nitrogen application rate and nitrogen application period on the photosynthetic characteristics,senescence characteristics,grain filling characteristics and yield of leaves at ear position of summer maize under the integrated condition of drip irrigation,summer maize variety Zhengdan 958 was selected as the test material.Under the condition of 210 kg/ha,top dressing treatment at jointing stage,belling stage and flowering stage(A1),top dressing treatment at jointing stage and belling stage(A2),top dressing treatment at jointing stage and flowering stage(A3);under the condition of 180 kg/ha,top dressing treatment at jointing stage,belling stage and flowering stage(A4),top dressing treatment at jointing stage and belling stage(A5),top dressing treatment at jointing stage and flowering stage(A6);the traditional border irrigation was set as the control CK,and the total nitrogen application was 240 kg/ha,CK1 was topcoated with nitrogen fertilizer at jointing stage at one time,and CK2 was topcoated with nitrogen fertilizer at jointing stage and belling stage respectively,with a total of 8 treatments.The results showed that compared with CK1,A1 and A4 treatments not only maintained LAI and SPAD values in the late growth stage of summer maize,but also significantly increased the activity of antioxidant enzymes(SOD,POD and CAT),and effectively inhibited the content of peroxide MDA,so as to delay the aging process of its leaves and protect the functional structure of leaf cells.Therefore,the summer maize under this treatment maintained efficient photosynthetic characteristics in its later growth stage,promoted the grain filling rate,and then increased the number of grains per ear and 1 000 grains weight,so that the maize yield was significantly improved.The yield difference between A1 and A4 treatments was not significant difference,but the nitrogen application rate of A4 was reduced by 14.3% compared with A1,which reduced the input of nitrogen fertilizer and saved the input cost.It was the recommended treatment in this experiment.

  • WANG Lijuan, LIU Dan, XU Yongqing, FENG Xu, HE Fumeng, LI Aiyu, WANG Xue, YANG Yan, LI Cuiting, YUAN Qiang, LI Fenglan
    Abstract (29) PDF (9) RichHTML (3)

    In order to further reveal the decomposition process and mechanism of corn straw in the cold area under the application of low temperature straw degrading agent,and provide a new strategy and theoretical basis for the decomposition and comprehensive utilization of straw in the cold area.Corn straw was decomposed by low temperature straw degrading agent and its physical and chemical characters and microbial diversity were analyzed.According to the change of temperature in the fermentation process,the ripening process of corn straw was divided into five stages:initial stage(A1),heating stage(A2),ripening stage(A3),stable stage(A4)and cooling stage(A5).The monitoring results of the physical and chemical properties of corn straw in different maturity stages were as follows:with the extension of maturity time,the fiber bundles on the surface of corn straw were destroyed gradually.After maturity during the cooling stage,the relative content of cellulose and hemicellulose in corn straw decreased to 33.48% and 16.57%,respectively,while the content of total nitrogen and ammonium nitrogen in corn straw decreased at first and then increased,and the contents of organic matter decreased to 149.7 g/kg.The monitoring results of microbial diversity in the fermentation stacks were as follows:Guehomces were the most abundant and dominant species in the ripening process;Pseudomonas and Sphingobacterium were the main genera in the initial and ripening stages,and thermophilic microorganisms played a major role in the heating,stationary and cooling stages of ripening.The changes of physical and chemical properties and microbial diversity in fermentation stack of corn straw after the application of low temperature straw degradation agent in cold area were clarified.

  • ZHAO Changjiang, DU Mengxiang, SONG Juqi, XU Shangyuan, HE Lin, XU Jingyu, YANG Kejun, LI Zuotong
    Abstract (424) PDF (127) RichHTML (213)

    NRL(NPH3/RPT2-Like)is a type of light-responsive protein unique to plants and plays a vital role in the phototropic signal pathway. To reveal the NRL gene maize genome's characteristics and expression,we analyzed them using bioinformatics methods combined with qRT-PCR technology. The property,structure,evolution of their encoded proteins,and growth period tissue expression and stress expression were analyzed. 31 ZmNRL genes identified were located in nine maize chromosomes,encoding protein amino acids 464-749 aa,which predicted to have chloroplast,nuclear and cytoplasmic locations. According to protein conservation,ZmNRL family was divided into four categories. Their gene structure also presented certain conservation,the most contained four exons. Analysis of the cis-elements of gene promoters revealed a large number of abscisic acids,jasmonic acid,light response,and anti-oxidation elements,among which G-box and Sp1 were two types of light-related elements. The expression of ZmNRL family genes in tissues during the growth period showed a temporal and spatial specificity,and the majority expression level was not high. Only ZmNRL2,ZmNRL4,ZmNRL24,and ZmNRL29 highly expressed. Furthermore,the characteristic modules were produced based on the data of the tissue co-expression genes. And the GO enrichment analysis of a particular leaf growth module containing six ZmNRL genes,mainly associated with the plastid organization biological processes and rRNA binding molecular functions. The expression of ZmNRL5,ZmNRL7,ZmNRL12,and ZmNRL19 genes were analyzed by qRT-PCR under salt,drought,high temperature,and Rhizoctonia solani inoculation treatments. The results showed that ZmNRL12 was significantly up-regulated in maize seedlings treated with high temperature,while ZmNRL5,ZmNRL7 and ZmNRL19 genes were down-regulated in drought,salt and pathogen treatments. In summary,31 ZmNRL genes were identified in the maize genome. They not only had apparent specific tissue expression but also participated in biotic and abiotic stress responses.

  • FU Jingfeng, LUO Shangke, CHENG Yi, ZHANG Jun, WEI Sheng, ZENG Tao, CHEN Du, WEI Pengcheng, ZHENG Yingxia, SONG Bi
    Abstract (93) PDF (107) RichHTML (38)

    The objectives of this study were to investigate the effects of nitrogen application rate on the grain yield,nitrogen accumulation and use efficiency of spring maize under different film mulching methods,and to provide a theoretical basis for efficient nitrogen application management of spring maize film mulching in high altitude area of Guizhou.Field trials were carried out from 2018 to 2019.The plots were arranged in a split-plot design.The main plots were assigned to the film mulching methods(wide film and narrow film) to be studied and divided into subplots according to the five nitrogen application levels(0,80,160,240 and 320 kg/ha).To study the effects of different film mulching methods and nitrogen application rates on yield,nitrogen accumulation,transport characteristics and utilization efficiency in different organs of spring maize.Film mulching,nitrogen application rate and their interaction significantly increased the yield of spring maize.The results showed that compared to narrow film mulching,wide film mulching not only increased the yield of spring maize by 17.8%,but also significantly enhanced the nitrogen accumulation and the retransfer of nitrogen accumulated before silking,then significantly increased the grain nitrogen accumulation.Moreover,compared to narrow film mulching,wide film mulching achieved significantly higher NUTE,NUPE,AEN,NPFP and NUE values showing increases of 4.9%,21.4%,23.5%,12.2% and 4.23 percentage points,respectively.Nitrogen application realized the synergistic growth of grain yield and plant nitrogen accumulation of spring maize,and could significantly affect nitrogen absorption,accumulation and transport.As the N application rate increased,the N translocation and the contribution rate of nitrogen transfer from vegetative parts to grain after silking could be effectively promoted,as well as enhanced.However,the nitrogen use efficiency,including the NDGPE,NHI,NUTE,NUPE,NUE,AEN,NPFP of spring maize,significantly decreased by increasing of N application rate.The regression analysis had shown that the optimal yield and nitrogen application rate for wide film mulching were reduced nitrogen application by 55 kg/ha and increased yield by 12.3% compared with narrow film mulching.The combination of wide film mulching and suitable nitrogen application rate was beneficial to the plant accumulation and absorption of nitrogen,so as to achieve high yield and nitrogen productivity,and then achieve the purpose of saving fertilizer and increasing yield.Considering the grain yield,N accumulation,transport and N use efficiency of spring maize,the reasonable N application rate of wide film mulching for spring maize in high altitude and other similar ecological zones in Guizhou was 160 kg/ha,which yield could reach 11 404.3 kg/ha.

  • LI Qiang, KONG Fanlei, YUAN Jichao
    Abstract (528) PDF (48) RichHTML (28)

    To increase crop yields,reduce the application of chemical fertilizers,and improve nutrient utilization efficiency,N-efficient maize cultivars were screened and popularized. An understanding of nitrogen uptake,utilization,and field balance in maize cultivars with contrasting nitrogen efficiency response to N management is essential for efficient breeding and cultivation of maize to produce fodder and bio-energy. To determine the effects of N management on these factors during maize cultivation,a two-year field experiment was conducted in 2015 and 2016 in a subtropical semi-humid climate zone. The results showed that the proportion of N in the stem plus sheath and leaves in ZH311 during VT and R6 was significantly higher than that of XY508. In addition,the N accumulation into grain post-silking(NAG)and contribution of NAG to grain(CNAG)of ZH311 were significantly higher than those of XY508,while the N redistribution rate(NRR)and contribution of NRA to grain yield(CNRA)of ZH311 were significantly lower than those of XY508. The higher proportion of N in the vegetative organs of a N-efficient cultivar,ZH311,led to a significantly higher N accumulation in each stage than that observed for the N-inefficient cultivar XY508. The N accumulation advantage of ZH311 was higher after silking than before silking. The high post-silking N accumulation of ZH311 inhibited the pre-silking N transport that determines the N transport rate and contribution rate to grain of pre-silking N accumulation,which were significantly lower than those of XY508. Meanwhile,the N uptake efficiency,N recovery efficiency,and N partial productivity of ZH311 were significantly higher than those of XY508. Compared with that of XY508,the root system of ZH311 could more effectively absorb and utilize inorganic N in the 40-80 cm soil layer,reduce N deposition,and significantly decrease apparent N losses. The differences in apparent N losses between the two cultivars were mainly elicited post-topdressing. In summary,ZH311 has not only a higher yield per unit area than XY508,but also lower N losses,consequently reducing environmental risks.

  • ZHAO Siqi, QUBI Wuhe, LUO Ting, YU Xuejie, KE Yongpei, GOU Qixian, SHI Haichun
    Abstract (36) PDF (30) RichHTML (26)

    To investigate the physiological and biochemical responses of maize to gray spot stress.Using the natural inoculation method in the field,two inbred lines K365(resistant)and K169(susceptible)and two hybrids Zhenghong 431(resistant)and Zhenghong 532(susceptible)were used as test materials.To study the effects of gray spot disease on leaf photosynthesis,reactive oxygen species content,antioxidant enzyme activity and endogenous hormone content of different resistant maize inbred lines and hybrids.Gray leaf spot stress led to the decrease of net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) of maize leaves, except for Ci, the three photosynthetic indexes of resistant materials did not decrease significantly, specifically, Pn, Gs and Tr of K365 decreased by 24.41%,25.00% and 4.20%, respectively. The Pn, Gs and Tr of positive Zhenghong 431 decreased by 11.53%, 21.43% and 0.06%, respectively, while the three photosynthetic indexes of susceptible material decreased significantly, specifically, Pn, Gs and Tr of K169 decreased 59.32%, 95.28% and 80.18%, respectively. The Pn, Gs and Tr of Zhenghong 532 decreased by 85.39%, 69.60% and 56.77%, respectively;at the same time, the content of hydrogen peroxide (H2O2), peroxidase (POD) activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, salicylic acid (SA) content, and jasmonic acid (JA) in maize leaves were increased under leaf gray spot stress, and the resistant materials could stimulate higher POD,SOD and CAT activities,maintaining a relatively stable H2O2 content,more reasonable regulation of SA and JA content,could maintain the balance of endogenous hormones.Resistant material may through rational accumulation of SA,JA signaling molecules to regulate antioxidant system,late in the disease still maintain a high level of defense enzymes in the body to more effectively remove excess H2O2,at the same time,adjust the blade endogenous hormone balance to make it adapt to the effects of resistant,thus to enhance maize disease resistance.

  • WANG Yongchao, YAN Bowen, CAO Hongzhang, WANG Shancong, MA Mengjin, ZHANG Junjie, GUO Jiameng, WANG Hao, SHAO Ruixin, YANG Qinghua
    Abstract (47) PDF (55) RichHTML (20)

    Increasing the planting density is still the main way to improve the yield of maize,but the group light will be affected by increasing planting density,which leads to premature leaf senescence. Therefore,it is of great significance to study the effect of the mixture of diethyl aminoethyl hexanoate(DA-6)and chloroquine(CCC)on the photosynthesis intensity and time of maize leaves in the process of improving maize yield by increasing planting density. In 2018 and 2019,a maize variety of Zhengdan 958 was used as experiment material in field. Two planting densities were set(6.75×104,9.00×104 plants/ha)and the mixtures with two concentrations(0 mg/L DA-6+0 g/L CCC and 15 mg/LDA-6+2 g/L CCC)were sprayed on the whole plant at 7-leaf stage. The leaf area index,specific leaf weight,leaf photosynthetic performance,antioxidant capacity and yield differences of maize population of different planting densities were studied under the control of compounding agents,in order to provide a theoretical basis for the application of chemical regulators in maize dense planting. Results showed that when the planting density increased from 6.75×104 plants/ha to 9.00×104 plants/ha,the leaf area index of maize was increased,and the specific leaf weight was also increased at the late silking stage. The leaf area index of the low-density group sprayed with the compounding agent was decreased,while the high-density group had no significant change. The specific leaf weight in the plants sprayed with the compounding agent enhanced,but the difference was not significant compared to the control. After dense planting,the SPAD value and photosynthesis intensity of ear leaves significantly decreased,and the chlorophyll fluorescence parameters negatively affected. In the dense planting group treated with the compounding agent,the SPAD value,the net photosynthetic rate,transpiration rate,stomatal conductance,intercellular carbon dioxide concentration of ear leaves were significantly increased overall as well as the maximum fluorescence,variable fluorescence and Fv/Fm,and initial fluorescence decreased. After dense planting,the relative senescence rate of leaves increased,the activity of antioxidant enzymes decreased,while reactive oxygen species and malondialdehyde accumulated excessively,and the content of soluble protein decreased. In the dense planting group treated with the compounding agent,the relative senescence rate of leaves decreased,the activity of superoxide dismutase,peroxidase,catalase and soluble protein content significantly increased,and the content of ROS and MDA significantly decreased on the whole. A negative effect on the agronomic traits of ears could be observed in dense planting,but the yield was not significantly affected due to the increase in density. After spraying the compounding agent,the photosynthetic capacity and time of maize ears promoted,resulting in improvement of ear traits and significant increase of yield. Compared to the high-density group non-treated by compounding agent,the yields of the group treated by compounding agent increased by 14.61% and 6.64% in 2018 and 2019,respectively. To sum up,the compounding agent increased the material accumulation by improving the photosynthetic capacity and time of maize group,thereby increasing the maize yield.

  • LIU Jianling, WU Jing, JIA Ke, LIAO Wenhua, LÜ Yinghua, MA Junyong
    Abstract (330) PDF (23) RichHTML (44)

    This study investigated the dynamics of soil phosphorus,yield responses to soil phosphorus and phosphate fertilizer in winter wheat-summer maize rotation system in the last decades,which was important for the scientific application of phosphate fertilizer in continuous high-yielding cropping.A combined method that included in situ phosphate fertilizer experiment under different soil fertility conditions,the analysis of changes of soil available P since 1978,the response of yield to phosphate fertilizer was used.Average content of soil available P of winter wheat-summer maize rotation area was 22.43 mg/kg,and the soil available P of the piedmont plain of Taihang mountain was greater than the alluvial plain.During 1996-1999,the soil available P content of the the piedmont plain and the alluvial plain was 15.09,11.90 mg/kg in cultivated land,respectively,the application rate of P2O5 in the winter wheat season of the rotation system was 180 kg/ha;the soil P supply capacity for winter wheat in these two regions piedmont were 83.9%,75.8%,respectively,and for summer maize they were 83.3%,89.7%,respectively.Under the condition of winter wheat straw returning,soil P surplus of these two regions was estimated to be 52.8%,55.4%,respectively.During 2010-2012,the soil available P of the piedmont plain of Taihang mountain was 27.22 mg/kg,the application rate in winter wheat and summer maize season were 108,60 kg/ha,respectively.The soil P supply capacity in winter wheat season was 84.6%,90.1% in summer maize season.Soil P surplus was estimated to be 6.7% in winter wheat season,and soil P of deficit was estimated to be 47.1% in summer maize season without straw returning.The application rate of P2O5 for the maximal yield production of winter wheat and summer maize were calculated according to the yield responses of winter wheat and summer maize to the P fertilization rates at multiple sites during 2002-2006 and 2012-2016.For winter wheat they were 107.3,125.1 kg/ha,respectively,and for summer maize they were 52.0,58.9 kg/ha,respectively.The accumulated P increaded the yield of winter wheat and summer maize for excess application 3 time of P fertilizer in 3 years 6 crop.The recommendation of P2O5 rate for winter wheat and summer maize with wheat straw returning were 90-100 kg/ha and 30 kg/ha,respectively,and they were 100-120 kg/ha and 45 kg/ha without wheat straw returning.

  • CAI Fengle, MA Xin, WANG Shuaili, LU Liangtao, SHAO Ruixin, LI Hongping, ZHAO Yali, MU Xinyuan, ZHAO Xia, LI Shuyan, LIU Tianxue
    Abstract (48) PDF (25) RichHTML (16)

    Clarifying the regulation effect of nitrogen on grain development under heat stress at blister stage of maize is of great significance for rational fertilization,relieving the harm of heat and realizing high and stable yields.The effects of amount of nitrogen application(90,180,270 kg/ha,marked as N90,N180,N270)on the grain development and yield under heat stress during blister stage of maize were investigated by using Xianyu 335(XY335)and Zhengdan 958(ZD958)as materials and setting heat treatment(T)and control(CK).The results showed that heat stress broke the balance of endogenous hormones in maize grains, resulting in the decrease of abscisic acid (ABA) content in the grains of N180 and N270 of two maize varieties and auxin (IAA) content in the grains of N180 and N270 of ZD958; Soluble acid invertase activity (SAI) of upper grains was decreased, grain volume expansion and dry matter accumulation were blocked, abortion rate was increased, grain number per ear was decreased, and yield was significantly decreased. The heat-sensitive variety XY335 was more affected by heat stress than the heat-resistant variety ZD958.With the increase of nitrogen application rate,the negative effect of heat stress on corn grains development was intensified.Under heat stress,the ABA/GA3 of XY335 and ZD958 decreased,the IAA and ZR contents increased,the grains volume and dry matter were more severely reduced,the abortion rate was significantly increased by 25.55,29.31 percentage points and 15.45,24.49 percentage points,respectively,the grains number per spike was decreased by 42.89%,52.68% and 20.95%,35.25%,respectively,and yield was significantly decreased by 44.29%,52.04% and 26.41%,39.94% respectively,under medium(N180)and high(N270)nitrogen treatments compared with low nitrogen(N90)treatment.Therefore,reasonable nitrogen application rate(N90)could alleviate the adverse effects of heat stress on corn grain development and reduce yield loss.

  • JIAO Jinlong, LI Youqiang, WU Ling, SHANG Jing, GAO Shibin, LIU Hailan, WU Yuanqi, LIN Haijian
    Abstract (440) PDF (13) RichHTML (10)

    In order to investigate the effect of fertilizer reduction combined with organic fertilizer on the yield and quality of silage corn and soil nutrient,in 2019 and 2020,the effects of fertilizer reduction and organic fertilizer on agronomic traits,yield, quality,soil nutrient content and fertilizer utilization rate of silage corn were studied.As a result,the yield of silage corn was significantly affected by different fertilization treatments,and the yield of mixed application of organic fertilizer and slow control fertilizer reached 55 084.75 kg/ha,dry matter production reached 24 192.11 kg/ha.There was no significant difference in yield between slow controlled fertilizer constant and slow controlled fertilizer reduction of 20%,that was,excessive fertilization had no significant effect on yield.The accumulation of N,P and K under T2 treatment was 234.83,173.75,35.72 kg/ha,and significantly higher than other treatments.The maximum nitrogen fertilizer productivity of silage corn under T4 treatment was 166.46 kg/kg,and the maximum nitrogen fertilizer utilization efficiency under T1 treatment was 0.80 kg/kg,which indicated that the mixed application of organic fertilizer and inorganic fertilizer could improve the productivity of silage corn.After T4 treatment,the crude fat content of silage corn was the highest,and the application of organic fertilizer could increase the crude fat content of silage corn,and also increase the content of acid washing fiber.The yield of silage maize was correlated with urease,catalase and available phosphorus content,the correlation coefficients were 0.845,0.798,0.784.The results showed that fertilizer reduction and organic fertilizer application in Southwest China could significantly improve the yield and quality of silage corn,which was beneficial to the protection of farmland ecological environment and the sustainable utilization of soil fertility.

  • ZHANG Zongxiang, HUANG Zhengrong, WU Xuefan, LIU Nannan, LI Xiaoxiao, DONG Zhaorong, SONG He
    Abstract (506) PDF (22) RichHTML (19)

    Yield and nitrogen accumulation of maize will decline under soil acidification,but the physiological mechanism is not clear.Field experiment was conducted with four different soil acidity gradients:nautral acid(pH=7,CK),weak acid(pH=6,T1),medium acid(pH=5,T2)and strong acid(pH=4,T3),comparing yield,nitrogen accumulation,grain protein content,nitrogen metabolism-related enzyme activities,gene expression,nitrate nitrogen,ammonium nitrogen,soluble protein,free amino acid content in leaf and stem of maize.The results showed that compared with CK,the yield of T1,T2 and T3 treatments declined by 4.2%,30.7% and 52.3%,respectively.Grain number per spike decreased by 1.8%,28.1% and 42.8%;grain protein content showed a downward trend with T3 treatment significantly reduced by 14.5%.At the big flare stage,with the increase of soil acidity,nitrogen accumulation in leaves showed a downward trend,it was significantly decreased in T2 and T3 treatment by 28.1% and 56.2%,respectively.In stem,the nitrogen accumulation increased firstly and then decreased.Compared with CK,T1 treatment was significantly increased by 33.1%,and T3 treatment significantly decreased by 65.4%.At the big flare stage, the activities of nitrate reductase, glutamate dehydrogenase and glutamate synthase in leaf and stem under T3 treatment were significantly higher than those in CK, while the activities of glutamine synthase in leaf were significantly decreased. The amino acids in stem decreased first and then increased.With the increase of soil acidity,the expressions of ZmGln2 and ZmFd-GOGAT were up-regulated,which promoted the assimilation of NH 4 + released by photorespiration and NH 4 + produced by NO 3 - reduction;the down-regulated expression of ZmGln1.2-ZmGln1.4, ZmNADH-GOGAT2 in leaf and ZmNADH-GOGAT1 in stem decreased the assimilation of NH 4 + released by catabolism.By up-regulating or down-regulating the expression of relevant genes,maize could promote the production of more free amino acids and soluble proteins during nitrogen metabolism to resist acidification stress,but also reduced the nitrogen accumulation,resulting in lower yield and grain protein content.

  • TAI Jicheng, HAN Meiqi, YANG Hengshan, ZHANG Yuqin, MA Jinhui, GUO Xiaoxu
    Abstract (21) PDF (7) RichHTML (8)

    In order to explore a new way to reduce nitrogen and increase efficiency of spring maize,in the agricultural high tech demonstration park of Horqin district,Inner Mongolia,two different ratios of reduced urea gradients and corresponding combined application of urea ammonium nitrate solution(UAN)were set in comparison with conventional topdressing urea(CK1,570 kg/ha)(N1U treatment 225 kg/ha urea + 75 kg/ha UAN and N2U treatment 375 kg/ha urea + 75 kg/ha UAN),the effects of shallow drip irrigation with reduced urea application combined with compared with CK treatment,N2U treatment did not reduce the yield of spring maize when the total nitrogen input was reduced by 25.12%.The total nitrogen input of N1U treatment decreased by 51.42%,and the yield decreased significantly.The total dry matter accumulation of N2U treatment was also significantly higher than that of CK treatment,and increased by 12.84%-16.40% and 6.05%-9.76% at silking stage and mature stage,respectively.Compared with CK,the total nitrogen accumulation in the mature stage increased by 20.55%-42.29%.N2U treatment did not reduce the yield of spring maize under the condition of 25.12% reduction of total nitrogen input,and it was a more reasonable fertilization mode of shallow buried drip irrigation for maize under the same soil fertility in the Xiliaohe plain.

  • ZHANG Panpan, SHAO Yunhui, LIU Jingbao, QIAO Jiangfang, LI Chuan, ZHANG Meiwei, ZHAO Xia, HUANG Lu
    Abstract (390) PDF (41) RichHTML (24)

    This study investigated the accumulation and distribution of dry matter,nitrogen(N)and zinc(Zn)of summer maize under N and Zn fertilization,to provide a basis for reasonable application of zinc fertilizer and combined fertilization.Split-split design was used with three N rates(90,180,225 kg/ha N)as the main factor,two Zn rates(0,4.5 kg/ha ZnSO4·7H2O)as the second factor,two varieties(ZD958 and GSY66)as the third factor.The effect of N and Zn application on the grain yield,dry matter accumulation dynamic and N and Zn absorption,accumulation and distribution of each organ of different maize varieties by field experiment.The results showed that the grain yield achieved 9.77,10.42 t/ha under the N rates of 180,225 kg/ha,respectively,increased by 18.0% compared with 90 kg/ha.The treatment of 225 kg/ha N had the highest plant dry matter accumulation after silking,while the treatment of 90 kg/ha had higher ratio of cob and grain dry matter at the mature stage.Highest N concentration in each organ,Zn concentration in the stem and N and Zn accumulation in the leaf and grain were obtained in the treatment of 225 kg/ha,while highest Zn concentration in the sheath,bract and grain and ratio of grain N and Zn were found in the treatment of 90 kg/ha.No effect was found in the grain yield and dry matter accumulation and distribution under two Zn treatments.Zn application significantly increased N and Zn concentration and accumulation but decreased distribution ratio of grain N and Zn by 6.93,6.86 percentage points,respectively.Relative to GSY66,ZD958 had higher grain yield and dry matter ratio,and increased dry matter by 29.2% at maturity.Besides this,ZD958 decreased grain N and Zn concentration by 8.9% and 5.3%,respectively,but improved grain accumulation and distribution ratio.Correlation analysis showed that grain yield and N concentration in the stem,leaf and grain were significantly positively correlated.There was also a significantly or extremely significantly positive correlation between Zn concentration in the leaf and N concentration in the sheath and grain,between Zn concentration in the cob and N concentration in the sheath,cob and bract.These results suggested that combination of N and Zn fertilizers could increase yield and plant dry matter accumulation,enhance the N and Zn absorption and accumulation in each organ especially grain,but decrease distribution ratio of N and Zn in the grain.

  • SU Gang, WANG Yizhen, GE Junzhu, LI Zifang, ZANG Fengyan, WANG Jinlong, WU Xidong
    Abstract (76) PDF (49) RichHTML (17)

    Field experiments were used to study the effects of green manure rape returning stages and different nitrogen application rates on yield of spring maize and soil nutrients,in order to provide a theoretical basis for higher using efficiency on less application of nitrogen on spring maize in Northern China Plains. The experiment adopted a split plot design. The stages of returning in the main plots were winter fallow field without returning (G0),initial flowering (G1),full blooming (G2),and pod (G3). The nitrogen application rates of split plots were as follows: 0(N0),135(N135),270(N270),405(N405) and 540 kg/ha (N540).During the maize harvest stage,the five-point sampling method was used to measure soil samples to determine the soil nutrients' contents of each plot,and the maize yields with constituent factors.The results showed that compared with G0 treatment,G2 treatment significantly increased the yield by 5.89%,while the G1 treatment significantly increased the yield by 6.37% in 2020,of which the increases of grain number per ear were 5.59% and 8.37%,respectively,but there were no significant effect on hundred-grain weight;the yield of G3 treatment reduced 8.43% due to decreases of the average 2.62% of grain number per ear and 6.40% of the average hundred-grain weight in 2020. The yield increased significantly with the increase of nitrogen application rates. Under the G1,G2 and G3 treatments, the yields of spring maize reached the hightest when nitrogen application rates were N405,N270 and N405 which were 10 961.21,11 253.34 and 10 331.12 kg/ha, respectively.The yields were higher than others with nitrogen application rates of N405 and N270 for 10 961.21,11 253.35 kg/a,respectively. Model analysis showed that the G1 and G2 treatments could ensure the yield was stable above 10 000 kg/ha,while the nitrogen fertilizer application could be reduced by 7.89%—41.45%. In 2020,the G3 treatment could reduce the nitrogen by 10.53% and the yield by 6.27%. Compared with G0 treatment,G1 and G2 treatments significantly increased the average of soil organic matter and alkaline nitrogen content by 8.28%,4.12%,11.17%,and 12.77%,respectively. Soil total nitrogen contents in G1,G2 and G3 treatments increased significantly by 6.01%,5.86% and 8.00% in 2019. Rape returning significantly decreased the soil total phosphorus and available phosphorus contents. There were no significant differences of total potassium content among treatments,while soil available potassium contents of G1 and G2 treatments were higher than G0 treatment,and G3 treatment significantly decreased for 3.41% than G0 treatment in 2020. Each soil nutrients' contents increased firstly and then decreased with the increase nitrogen application rates,the value with N270 was the highest. In summary,returning green manure rape to the field from the initial flowering to the full flowering period can increase the soil organic matter,total nitrogen,alkali-hydrolyzable nitrogen and available potassium content. With the nitrogen fertilizer application reduced by 7.89%—41.45%,the yield can also stable above 10 000 kg/ha,which achieve the goal of stabilizing the production of spring maize and reducing nitrogen and increasing efficiency in the North China Plain.

  • HE Jing, DONG Jianxin, CONG Ping, SONG Wenjing, MA Xiaogang, GUAN Ensen, WANG Dahai
    Abstract (72) PDF (24) RichHTML (18)

    To investigate the effects of different maize straw carbon addition on soil organic carbon and fertilizer improvement,it focused on an in-situ soil column incubation experiment was established on tobacco fields.Four treatments were set,including none straw addition(CK),conventional straw(RS),decomposed straw(DS)and straw biochar(BC).The organic carbon components and structure,soil physical and chemical properties,and enzyme activities of the 0-20 cm soil layer of tobacco field treaded by the four treatments were characterized and analyzed.One-year incubation results showed that:Compared with none straw addition,the three forms of straw carbon addition all significantly increased the content of total organic carbon(TOC)and microbial biomass carbon(MBC)in the soil.Compared with none straw addition,treatments of conventional straw and decomposed straw significantly increased soil dissolved organic carbon(DOC)content,while straw biochar treatment significantly increased particulate organic carbon(POC)content(42.40%).The three forms of straw carbon addition all significantly increased the microbial biomass carbon/total organic carbon ratio and promoted the turnover of soil organic carbon.The functional group structure of SOC was analyzed by 13C nuclear magnetic resonance.The results indicated that conventional straw and decomposed straw treatment increased the relative content of Alkoxy carbon(O-Alkyl-C)and Carbonyl carbon(Carbonyl-C)(labile carbon component),while straw biochar treatment increased Alkyl carbon(Alkyl-C)(recalcitrant carbon component),Alkyl carbon/Alkoxy carbon(A/OA)and Hydrophobic-C/Hydrophilic-C(Hydrophobic-C/Hydrophilic-C).Different forms of straw carbon had significantly different effects on soil nutrients and enzyme activities,straw biochar treatment significantly increased by 65.72%,19.93% and 5.77% for the content of available potassium(AK),ammonium nitrogen(AN)and nitrate nitrogen(NN),respectively.Conventional straw and straw biochar treatments significantly increased the activities of sucrase(Su)and urease(Ur).The three forms of straw carbon all had a significant effect on the activity of phosphatase(Ps).Redundancy analysis showed that C/N ratio(C/N),cellulase(Ce)and total nitrogen(TN)were the main factors affecting the organic carbon content,while cellulase,pH,and available potassium were the main factors affecting the organic carbon structure.Overall,the application of maize straw biochar had significant advantages in improving organic carbon content and stability,nutrient content,and enzyme activity in a short term.In the comprehensive soil fertility evaluation,straw biochar had the highest score with 0.57.Maize straw biochar was an effective measure to improve the organic carbon level and soil fertility in the tobacco planting soil.

  • JIA Liqiang, LIU Xun, DING Bo
    Abstract (154) PDF (75) RichHTML (17)

    In order to study the role of ZmbZIPs in the stress tolerance of maize,using maize inbreed line Zheng 58 for exprerimental material,expression analysis of 9 ZmbZIPs were performed under 200 mmol/L NaCl,20% PEG6000,4 ℃ low temperature and nitrate or ammonium deficiency stresses.Evolutionary tree analysis indicated that 9 ZmbZIPs were divided 3 subgroup.RT-qPCR analysis showed that 8 ZmbZIPs were detected in maize tissues,whereas ZmbZIP80 were not,indicated it could be pseudogene.Under simulated salt,drought,low temperature and nitrogen stress conditions,8 ZmbZIPs exhibited different expression pattern in response to various stresses,ZmbZIP37 and ZmbZIP53 were induced while ZmbZIP49 and ZmbZIP79 were downregulated obviously under NaCl stress,ZmbZIP37 and ZmbZIP53 of leaves significantly suppressed under nitrate deficit stress while ZmbZIP42 and ZmbZIP49 were upregulated in responsive to ammonium deficient stress.The result indicated 8 ZmbZIP played widely roles against stress conditions.Expression pattern of 9 ZmbZIPs gene differed in different tissues or under various adverse stresses.The study can offer scientific data for further reveal ZmbZIP biological function.

  • ZHANG Qian, ZHAO Qiu, XIANG Chunyang, SHI Xinqian, DU Jin
    Abstract (71) PDF (35) RichHTML (8)

    In order to promote the planting of winter green manure in North China,a long-term field experiment was adopted,and the winter idle field was used as a control.Four winter green manure treatments were set up,Orychophragmus violaceus,Viciavilosa Roth,Lolium perenne L.and Brassica campestris L..The effects of different winter green fertilizers on soil organic phosphorus and phosphorus content and corn phosphorus absorption were studied.The results showed that in the past 7 years of different winter green manure treatments,the change trend of soil total phosphorus and available phosphorus content was the same.Compared with other treatments,vetch increased the soil total phosphorus the most,with an average annual growth rate of 8.07%,winter rape increased soil availability compared with other treatments.The phosphorus content was the most,with an average annual growth rate of 48.34%.Different winter green manures and spring corn rotations had different effects on the organic phosphorus content of various forms in the soil.In 2019,the highest active organic phosphorus content was ryegrass treatment and winter rape treatment,both of which were 12.64 mg/kg;moderately active organic phosphorus content the highest was the winter rape treatment(41.64 mg/kg),the medium-stable organic phosphorus content was the highest in the ryegrass treatment(18.73 mg/kg),for the high-stability organic phosphorus,the winter rape treatment was significantly higher than other treatments.The treatments of February orchid,vetch and ryegrass were significantly lower than the treatments of winter fallow and winter rape;the rotation of winter rape and spring maize could promote the conversion of organic phosphorus to active and medium active organic phosphorus in the soil.After 7 years of winter green manure,the phosphorus content(0.39 mg/kg)of corn kernels treated with winter rape was the highest among the treatments.The order of correlation coefficients between the phosphorus content of corn grains and various forms of organic phosphorus was MLOP(0.952**)>LOP(0.816**)>MROP(0.122)>HROP(-0.064).

  • FAN Fangfang, JIAO Xiaoyan, LIU Jiaqi, GUO Jun, WANG Jinsong, WU Ailian, BAI Wenbin, PING Junai
    Abstract (83) PDF (21) RichHTML (3)

    To study the decomposition characteristics of sorghum and maize residues and the functional diversity of microbial community in straw decomposition,under different residual types(sorghum stalk-leaves,maize stalk-leaves,sorghum root,maize root),soil type(cinnamon soil,yellow loam soil),nitrogen treatment(adjust C/N ratio,not adjusted),the culture experiment method was used to explore the decomposition characteristics of residues under different decomposition conditions,and to analyse the metabolic functional diversity of microbial community used the BIOLOG-ECO plates method in straw decomposition process.The results showed that the decomposition rate of sorghum and maize residues was faster in the early stage than the late stage.The residual dry matter degradation rate and CO2 release rate had the following pattern of decomposition rate was shown,sorghum stalk-leaves>maize stalk-leaves>sorghum root>maize root,under the same soil and nitrogen treatment.According to the second experiment, the dry matter degradation rates of sorghum stalk-leaves and maize stalk-leaves were 55.50% and 48.00%,respectively,however,the dry matter degradation rate of sorghum root and maize root were 31.25% and 16.75%,respectively at 60 d of incubation,under the condition of cinnamon soil+N treatment.The degradation rate of hemicellulose and cellulose in root were lower than that in stalk-leaves,under the same soil and N treatment conditions,the decomposition of hemicelluloses and cellulose was decreased by 23.70,18.80 percentage point,in sorghum root treatment than sorghum stalk-leaves treatment at 90 d of incubation,under the condition of cinnamon soil+N treatment.The microbial metabolic activity of straw was the highest at 30 d and lowest at 90 d during decomposition.The metabolizable ability of microbial community of straw decomposition to amines and phenolic acids was lower on the 1st day of decomposition,and the metabolizable ability to carbohydrates,amino acids and polymers was significantly decreased on the 90th day,compared with 30 d.Collectively,the decomposition of sorghum residues was easier than maize,and adjusting C/N ratio could accelerate the decomposition of residue to a certain extent.The microbial metabolic diversity was the highest at 30 d under the experimental conditions.

  • LI Wu, LI Chunyan, LI Guangyu, LIANG Minyi, LI Yuliang, WEN Tianxiang, TU Panfeng, LIU Jianhua
    The aim of this work was to evaluate the effects of γ-aminobutyric acid(GABA)on waxy maize yield formation and its photosynthetic physiology, for guide the application of chemical control technology to improve the yield of waxy corn.The waxy maize varieties Yuecainuo 2, Yuebaitiannuo 7, and Jingkenuo 928 were used as materials, the effects of root application of GABA treatment(RS)on yield and photosynthetic physiology of waxy maize were studied, the root irrigation of water was taken as control(CK).Compared with CK, RS treatment increased naked ear yield of waxy maize varieties(1.62% -4.97%), the bract leaves yield of waxy maize varieties was reduced(16.52% -23.09%), among them, the naked ear yield and the bract leaves yield of Yuebaitiannuo 7 changed significantly. RS treatment improved the net photosynthetic rate and transpiration rate at both filling stage and mature stage, improved the leaf aging index at mature stage. The spike length, number of grains per row, and number of grains per spike were increased to some extent.The heading stage, powder period, and the spinning stage were advanced 1-2 d.The CAT activity in functional leaves was significantly improved under RS treatment but the MDA content in in functional leaves was significantly decreased under RS treatment. A significant positive correlation was observed between naked ear yield and fresh bracts yield, ratio of fresh bracts to ears and leaves, spike length, number of grains per row, number of grains per spike, and leaf aging index at filling stage(P<0.05).Root application of GABA treatment during booting stage can improve the naked ear yield of waxy maize varieties by regulating growth, photosynthetic physiology, yield formation, and the ratio of fresh bracts to ears and leaves.
  • YNAG Guankai, WU Yufang, CAO Hanghang, WANG Xiaodong, ZHANG Xueyan
    To investigate the effects of corn straw as the main component of the cultivation substrate on crop growth and fruit quality under brackish water and fresh water irrigation. Four treatments were designed, including the pure corn stalk(S-control), biochar(SB), S added with earthworm compost(SE), biochar and earthworm compost(SBE).Brackish water and fresh water irrigation were applied with each of the four substrate treatments, respectively, leading to a total of eight available treatments. The results showed that with same cultivation substrates, irrigational water had insignificant effect on the relative growth rates of plant height and stem volume at seedling stage. Compared with fresh water irrigation, brackish water irrigation had more positive effect on increasing the relative growth rate of plant height at later stage in SE treatment groups, with a 79.49% more increase in the relative growth rate. However, there were no significant differences in total biomass and root shoot ratio between SE-treated plants irrigated by fresh water and those irrigated by brackish water Brackish water irrigation promoted photosynthetic rate and transpiration rate compared to the fresh water irrigation in the S and SB treatments. Moreover, transpiration rate was reduced in SE, WUE was increased in SBE and SB. SB had the best effect of alleviating brackish water stress. Under the same culture substrate, brackish water significantly increased the soluble solid content compared to fresh water irrigation, and the highest soluble solid content was detected in SB, which was increased by 5.56%. SE and SB treatments significantly increased soluble sugar content in brackish water compared with fresh water irrigation by 53.84% and 50.15%, respectively, but there was no significant difference in yield. Compared with S treatment, SE increased transpiration rate under fresh water irrigation and had the highest Fv/Fm. SBE decreased the root-shoot ratio and SB increased the water use efficiency under fresh and brackish water irrigation. Compared with S treatment, SB treatment had the most significant effect on increasing soluble solid under brackish water irrigation, while SE treatment had the most significant effect on decreasing organic acid content and increasing soluble sugar content. Therefore, adding biochar and organic matter under different water irrigation can promote tomato growth, alleviate salt stress and improve fruit quality.
  • ZHAO Changyun, ZHANG Qiming, SHI Haichun, YU Xuejie, DONG Li, XIA Wei, KE Yongpei
    In order to explore the influence of mitochondrial complex activity on the fertility of C-type male sterile lines in maize under different nuclear backgrounds, and to clarify its relationship with anther abortion. Plant mitochondrial respiratory chain complex enzyme linked immunoassay kit was used to determine the activities of 5 mitochondrial complex in different stages of anther development, using homogeneous heterogenic male sterile lines K932S and K169S, restorer line K932R and maintainer line K169 as materials. Results showed that in addition to the period of pollen mother cell complex Ⅱ, Ⅳ, the remaining period of sterile cytoplasm complex Ⅰ, Ⅱ, Ⅳ activity under the background of K169 nuclear was significantly higher than K932, most of the time the activity of complex Ⅲ, Ⅴ, on the other hand, when there was a restoring genes but K932R might change the part of the activity of sterile cytoplasm during different mitochondrial complex. The activity of sterile cytoplasmic complexes Ⅱ, Ⅲ and Ⅴ was significantly lower than that of normal fertile cytoplasm at the diad stage, while the activity of five complexes at most other stages was the opposite. It can be seen that the nuclear background have a significant effect on the activity of different mitochondrial complexes of CMS-C in maize at different anther development stages. Under the same nuclear background, the activity of cytoplasmic complexes Ⅱ, Ⅲ and V at the diploid stage was significantly lower than that of normal cytoplasm, which might be closely related to CMS-C drug abortion.
  • CUI Rong, WANG Tianye, WANG Chengyu, LI Jinxiu, ZHANG Xinyu, LIU Shuxia
    The purpose of this study was to explore the effects of different drought stress levels on maize growth traits and yield in the semi-arid region of Northeast China, and to lay a theoretical foundation for further research on the physiological mechanism of maize drought resistance.Three kinds of maize varieties with different drought tolerance were selected and five water gradients of normal water supply(CK), light drought(LS), moderate drought(MS), severe drought(SS)and lethal(S)were set at maize jointing, tasselling and filling stages, respectively. The effects of different drought stress on the growth traits and yield related indexes of three maize varieties were comprehensively analyzed. The plant height, ear position and dry matter weight of maize decreased with the increasing of drought degree, but the stem diameter had no significant difference with the increasing of drought degree. The plant height, ear position and dry matter accumulation of maize variety Jinqing 707 was the highest, followed by Nendan 19 and Fudan 16. During tasselling stage, the spike characters of maize changed most obviously under drought stress, and the maize yield was the lowest under severe drought, and no yield under continuous drought.Under the same drought degree, the worse the drought tolerance of maize varieties, the greater the yield reduction. The specific performance of maize yield is Jinqing 707 > Nendan 19 > Fudan 16.A comprehensive analysis of multiple indicators shows that tasselling stage is the key period of water requirement of maize, which is easily affected by drought stress. At the same time, it is pointed out that drought stress or serious degree of drought stress in tasselling stage is the main factor leading to the decrease of maize yield.
  • LU Baishan, DONG Hui, SHI Yaxing, ZHAO Jiuran, XU Li, LIU Hui, ZHANG Cuifen
    The purpose of this study was to investigate the difference of antioxidant capacity among different varieties of fresh corn, and to select fresh eating corn varieties with strong antioxidant capacity, 19 different varieties of fresh eating corn, such as Jingzinuo 219, were used as experimental materials, Six physiological indexes of fresh eating corn were determined, including anthocyanin content, oligomeric proantho cyanidins(OPC), reduction capacity, flavoid content, hydroxyl radical scavenging rate and total phenols(TP).The comprehensive evaluation and classification of antioxidant capacity of fresh corn varieties were carried out by using membership function analysis and cluster analysis:there were differences in antioxidant indexes among different varieties of fresh corn. Among the single indicators:The anthocyanin content of Heizhenzhu was the highest (1 809.12 mg/kg), and that of other varieties was between 1 482.75-12.49 mg/kg;the oligomeric proantho cyanidins in Heinuo 5008 was the highest, which was 0.47 mg/g, while that of the other varieties was between 0.24-0.10 mg/g;the hydroxyl free radical scavenging rate of Zhuozihuaqingsutianyumi was the highest, which was 0.96%, and the other varieties were between 0.95% and 0.79%;the flavonoid content of Jingzinuo 219 was the highest, which was 1.28 mg/g, and the other varieties were between 1.23-0.12 mg/g;the reducing ability of Zhuozihuaqingsutianyumi was the highest, 445.87 U/g, and the other varieties were between 335.41 and 85.47 U/g;the content of total phenol in Zhuozihuaqingsutianyumi was the highest, which was 54.67 mg/g, and the other varieties were between 52.19-21.02 mg/g. Through the comparison of the comprehensive evaluation D value of six physiological indexes of the fresh eating corn varieties, it was found that the comprehensive D value of antioxidant capacity of Zhuozihuaqingsutianyumi was the highest, D value was 0.87, followed by Jingzinuo 219(0.67)and Heizhenzhu(0.66), and the comprehensive evaluation D value was above 0.60. Cluster analysis was carried out by using the D value of comprehensive evaluation of anti oxidation ability, the cluster results could reflect the antioxidant capacity of fresh corn varieties, among them, Zhuozihuaqingsutianyumi, Jingziluo 219 and Heizhenzhu had strong antioxidant capacity and good stability.
  • AN Hongzhou, GAO Zengyu, LI Kuiying, HE Jianhan, WU Yuhua, ZHANG Quanguo
    In order to clarify the characteristics of nitrogen efficiency differences among different maize inbred lines, select excellent nitrogen efficient germplasm, improve the nitrogen use efficiency of maize, and lay the foundation for the research of maize nitrogen efficient breeding. Average yield and nitrogen efficiency as the evaluation index, and combined with second level traits such as tasselling stage, anthesis stage, maturity stage, plant height, ear position to calculate correlation among traits and investigate the nitrogen use efficiency of 25 maize inbred lines, which were core germplasm or self-breeding maize inbred line materials used in Huanghuaihai. Correlation analysis results showed that ASI and average yield were extremely significantly positively correlated to nitrogen efficiency in two treatments. Plant height was significantly correlated to nitrogen efficiency in low nitrogen and extremely significantly positively correlated in high nitrogen conditions. The three traits could be used as indicators for evaluating the nitrogen efficiency of maize inbred lines. The results of analysis of variance showed that the ASI, average yield and plant height were significantly difference in genotype and nitrogen supply environment under low and high nitrogen conditions. Based on analyzing the average yield, ASI and plant height of maize inbred lines under high and low nitrogen conditions, three maize inbred lines such as Zheng 58, WK858 and 9058 were identified as donor parents improving the nitrogen use efficiency of maize. This study enriched the nitrogen-efficient germplasm resources, evaluated the nitrogen use efficiency of different maize materials, revealed the degree of response of different materials to nitrogen, provided materials for nitrogen-efficient breeding and theoretical basis and technical support for inbred lines selection and fertilizers rational utilization.
  • DONG Li, SHI Haichun, ZHAO Changyun, YU Xuejie, KE Yongpei
    In order to explore new maize dwarf resources and study their genetic characteristics to provide a new material basis for maize dwarf breeding.The dwarf mutant K718d obtained from spontaneous mutation,and the wild-type K718 were used as materials to compare their phenotypic differences and the sensitivities to exogenous hormones;the genetic model of dwarf trait was analyzed based on the reciprocal F1,BC1,BC2 and F2 populations obtained from K718d mated with 5 high stalk inbred lines,the dwarf gene was mapped by BSA-SSR marker method,and the gene alleles were identified by allelic hybridization.The results showed that the plant height,ear height,number of internodes and internode length of K718d were reduced by 48.23%,75.57%,30.83% and 65.92% respectively compared with that of K718,and ear length was shortened by 28.57%,the yield was reduced by 36.44%,the differences reached extremely significant levels;the mutant K718d was not sensitive to GA3 and IAA.According to the experimental results of the two ecological sites,the reciprocal F1 populations were high stalks;the separation ratios of high plants and dwarf plants in the BC1 and F2 populations were accorded with 1:1 and 3:1 respectively,but the BC2 populations were high stalks;which indicated that the plant height of K718d was controlled by one pairs of recessive nuclear genes.The dwarf gene d718 was located between the SSR markers umc2569 and umc1278 on chromosome 1,and the genetic distances were 1.0,2.5 cM respectively,which was a br1 allele.The results lay the foundation for the further fine mapping and cloning of d718.
  • FAN Yafang, GAO Julin, SUN Jiying, LIU Jian, SU Zhijun, WANG Zhigang, YU Xiaofang, HU Shuping
    Twenty-one maize inbred lines were used to study the effects of potassium fertilizer on stem phenotype,stem lodging resistance,ear traits,yield-related traits and grain quality of maize inbred lines with different yield types.The results showed that compared with 0K,the stem diameter of high-yield,middle-yield and low-yield maize inbred lines under 45K treatment increased by 14.21%,11.60% and 8.41%;the bending strength of stem increased by 30.58%,27.52% and 24.59%;the ear diameter increased by 3.61%,2.57% and 1.72%;the ear tip barrenness decreased by 10.19%,7.41% and 4.81%;the 1000-grain mass increased by 4.97%,3.55% and 2.23%;the yield increased by 7.50%,5.57% and 4.45%;the grain protein content increased by 0.62,0.40,0.20 percentage points respectively.Application of potassium fertilizer could improve maize stem morphology and mechanical index,improve maize lodging resistance,promote maize plant growth and development,and then affect maize yield and quality.The results showed that high-yield type>middle-yield type>low-yield type of maize inbred lines with different yield types.The increase of plant height,ear height,stem diameter,stem puncture strength,stem compressive strength,stem bending strength,grain number per ear and 1 000-grain mass,as well as the decrease of ear tip barrenness of maize inbred lines could significantly improve maize yield. Therefore,the above indexes can be used as screening indexes of yield of maize inbred line under potassium fertilizer application.This experiment provided a theoretical basis for breeding high-yield and high-quality maize materials,selecting suitable basic materials for studying the physiological characteristics of maize inbred lines with different yield types,and provided a reference basis for high-yield and high-efficiency maize breeding and rational utilization of potassium fertilizer in China in the future.
  • YI Qiang, YANG Zebing, TAN Jiaying, HOU Xianbin, LIU Yinghong, BAI Guangxiao, HUANG Yubi
    Mining the loci for stem diameter(SD) under different planting densities in maize could improve maize high-density tolerance and lodging resistance. SD was measured from 301 recombinant inbred lines(RIL) derived from the cross between the maize foundation parents Ye 478 and R08 under low(57 000 plants/ha) and high(114 000 plants/ha) planting densities in Jinghong, Yunnan Province, in 2014 and 2015. Quantitative trait loci(QTL) analyses were conducted by using inclusive composite interval mapping in QTL ICIMapping V4.1. QTL and environment interaction was analyzed by using the mixed-model-based composite interval mapping(MCIM) of QTLNetwork 2.0.The results showed that the difference of parental lines indicated Ye 478 did not differ for SD between two densities, but SD in R08 significantly decreased as the plant density increased. Considerable SD variation was observed in the RIL population. The range of phenotypic variation was decreased as the plant density increased. Heritability for SD in the RIL population under high and low planting densities were 48.01%, 65.03%, respectively. Correlation analyses revealed that SD was significantly correlated with plant height, ear height, and ear weight per plant(0.29> r ≥ 0.13, P <0.01), but had no significant correlation relationship with ear tip-barrenness and barrenness rate across both densities. QTL mapping by using joint analyses across both environments detected seven minor QTL for SD, with a range from 3.68% to 6.91%, and four QTL were observed under high density, namely qSD1-1, qSD3-1, qSD4, and qSD6. Only qSD6 was found across both planting densities. None of the four QTL(qSD1-1, qSD3-1, qSD3-2, and qSD4) was presented in the previous studies regarding QTL mapping for SD. Only one pair of loci for additive and additive interaction was found under high planting density. These results suggested different genetic regulations for SD across low and high densities. Among these QTL, qSD6 was simultaneously found across both densities and in the F2:3 population from the same cross reported in the previous study. Moreover, the QTL segments stated above are well descended and transmitted from Ye 478 and its descendants, which could be used for marker-assistance selection(MAS) in maize breeding.
  • DONG Jiaxi, TIAN Xiuping, ZHAO Qiu, SHI Xinqian, YUAN Miaomiao
    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.
  • YAN Ting, LI Xia, CAO Yue, WU Bohan, WANG Jing, ZHANG Manman
    In order to reveal the effect of DNA methylation under drought stress toward rice with high expression of C4-PEPC (PC), germination test, hydroponics experiments and pot experiments respectively were used in this study. By introducing different concentrations of DNA methylation inhibitor (5-Azacytidine, 5-azaC), the drought simulation treatments combining with the inhibitors were used for the stages of seed germination, seedling and late growth, respectively. The changes including germination rate of seed, the relative water content, malondialdehyde content, proline content, soluble sugar, soluble protein content, PEPC activity and the gene expression levels of related genes, C4-PEPC genes, SnRK1s gene, and methyltransferase 1 genes of rice leaves at seedling stage, the photosynthesis characteristics of flag leaves at flowering stage were measured, and their yield component were investigated after harvest as well. The results showed that:In bud and seedling stages, the effect of 5-azaC on drought stress present dose effect in rice as following:promoting under low concentrations and inhibiting under high concentrations, the concentrations of the bud stageOsMET1b on this concentration of 5-azaC, and the expression of C4-PEPC in PC also presented the dose effect. In brief, DNA methylation was involved in rice drought response, but the effects were different in different growth stages, and sugar signal might enhance drought tolerance of PC by participating in DNA methylation.
  • PANG Na, CHENG Song, ZHANG Shuimei, YUAN Jingchao, LIU Jianzhao, LIU Songtao, REN Jun, LIANG Yao, CAI Hongguang
    To investigate the effects of chemical fertilizer combined with different kinds of organic amendments on soil fertility and spring maize yield in mollisol, which provides theoretical foundation for protection and utilization of mollisol.Five treatments i.e., chemical fertilizer alone(NPK), NPK plus corn stalk(NPK+ST), NPK plus cow manure(NPK+NF), NPK plus chicken manure(NPK+JF) and NPK plus pig manure(NPK+ZF) were selected from a field experiment to monitor contents of soil organic carbon, active organic carbon, available nutrients, and soil enzyme activity at 0-20 cm, 20-40 cm soil layer after five amended years, as well as the annual change in maize yield. The results showed that compared with NPK treatment, NPK+NF and NPK+ZF significantly increased soil organic carbon content at 0-20 cm soil layer by 11.5%, 11.1%, respectively, the application of NPK plus organic amendments significantly increased active organic carbon content at 0-20 cm soil layer with the range of 18.3%-39.2%.Compared with NPK treatment, soil available phosphorus and potassium contents at 0-20 cm soil layer were significantly increased in NPK+NF, NPK+JF and NPK+ZF treatments with the range of 1.19-3.02 times, 14.0%-19.6%. In relative to NPK treatment, cellulase activity at 0-20 cm, 20-40 cm soil layer were significantly increased in NPK+ST, NPK+NF and NPK+ZF treatments with the range of 15.7%-29.3% and 19.4%-41.7%, NPK+JF and NPK+ZF significantly increased the urease activity at 0-20 cm soil layer by 16.0% and 12.1%, the activity of invertase and phosphatase at 0-20 cm and 20-40 cm soil layer was significantly increased in organic amended treatments, with the range of 47.3%-126.0% and 19.0%-31.4% in invertase activity, respectively, and NPK+ZF treatment had greater phosphatase activity than others in both soil depths. During the five years, the average maize yield was increased under combined application of chemical fertilizer and organic amendments in the range of 4.82%-11.70%, as compared with NPK, and the highest average yield was found in NPK+ZF treatment. Therefore, organic amendments could effectively improve the level of soil organic carbon nutrient supply, and enzyme activity in topsoil of mollisol, and subsequently increase the maize yield.
  • LI Moxiao, BIAN Zhe, ZHOU Qihui, LIU Yuwei, GONG Xiaodong, GU Shouqin, HAN Jianmin
    In order to clarify the function of the StRTG2 gene of Setosphaeria turcica and its expression pattern in different developmental stages of the pathogen, the amino acid sequence encoded by the yeast ScRTG2 gene was used for BlastP, and the homologous gene sequence in Setosphaeria turcica was obtained, and named it as StRTG2;The whole genome DNA and cDNA of wild type 01-23 of Setosphaeria turcica were used respectively as a template to clone the gene;Use bioinformatics technology to analyze the physicochemical properties, domain prediction, and subcellular location prediction of StRtg2;Use MEGA 7.0 to analyze the evolutionary relationship of Rtg2;Amplify the ORF sequence of StRTG2 to construct a prokaryotic expression vector of the gene. After transforming into E.coli BL21, IPTG was used to induce express;Finally, the RNA-Seq database was used to analyze the main growth and development stages of the StRTG2 gene (hyphae, conidia, germ tubes, appressorium and invading nails). The main results were as follows:The gene was cloned and found to be 1 695 bp in length without introns;the protein encoded by the gene was composed of 564 amino acids, with a theoretical isoelectric point (pI) of 6.96, and had a typical Ppx-Gppa conserved domain. The cell location prediction results showed that the protein was distributed in all parts of the cell, and the possibility of being distributed in the cytoplasm was the greatest;The analysis of the evolutionary relationship of the protein showed that the StRtg2 protein had the highest homology with the homologous protein of Stemphylium lycopersici, followed by Saccharomyces cerevisiae;Prokaryotic expression of the gene, SDS-PAGE gel showed that the size of the protein was 62 ku, which was in line with the expected size;Analysis of the expression pattern revealed that the gene was expressed in the 5 stages of pathogen development, among them, the expression of the germ tube and the invading nail period was significantly reduced. This research can lay the foundation for further analysis of the function of StRTG2 gene.
  • XU Chen, BIAN Shaofeng, ZHAO Hongxiang, ZHANG Lihua, YAN Weiping, LI Yanlu, WANG Junpeng, ZHANG Zhian
    In order to systematically study the physiological response mechanism of maize to different cultivation patterns in semi-arid area, and provide effective cultivation patterns for western semi-arid area of Jilin Province. Field experiments were conducted to set up three cultivation patterns:control pattern (CK), farmers' habit pattern (T1) and optimized cultivation pattern (T2). The effects of cultivation pattern on yield formation, growth and development, leaf physiological characteristics and resource utilization of maize were studied. The results showed that the dry matter accumulation of T2 treatment significantly increased at mature stage (R6) (P<0.05), leaf area index (LAI) significantly increased at R3 and R6 stages (P<0.05). There was no significant difference in plant height between T1 and T2 treatment (P>0.05), but the plant height of T2 treatment was higher than that of T1 treatment. The net photosynthetic rate (Pn), stomatal conductance (Gs) and apparent mesophyll conductance (AMC) of T2 treatment increased significantly compared with CK and T1 treatments at R1 and R3 stages (P<0.05), while stomatal limit value (Ls) decreased significantly at R3 stage (P<0.05). The maximum photosynthetic efficiency (Fv/Fm), actual photosynthetic efficiency (ΦPSⅡ), photochemical quenching coefficient (qP) and electron transfer efficiency (ETR) of photosystem Ⅱ increased significantly at R3 stage (P<0.05). The activities of glutamine synthetase (GS) of T2 treatments were significantly higher than that of CK and T1 treatments at R3 stage (P<0.05), and the activities of glutamate dehydrogenase (GDH) were significantly lower than that of CK and T1 treatments (P<0.05). The yield, grain number per ear, 100-grain weight, light use efficiency, water use efficiency and fertilizer use efficiency of T2 treatment were significantly higher than those of CK and T1 treatment (P<0.05). According to the comprehensive analysis, the yield, growth and development, resource utilization efficiency, photosynthetic physiological characteristics and nitrogen metabolism enzyme activities of maize in semi-arid area were better by using the optimized cultivation pattern (T2 treatment). This cultivation pattern was more suitable to be popularized and applied as an optimized cultivation pattern of maize in semi-arid area of western Jilin Province compared with the traditional farmer pattern.
  • SHI Xinqian, XIANG Chunyang, ZHAO Qiu, DONG Jiaxi, YUAN Miaomiao, TIAN Xiuping
    In order to improve the availability of soil phosphorus and reduce the input of fertilizer phosphorus in North China, the effects of different spring Brassica campestris L. overturning on soil phosphorus supply capacity and phosphorus uptake of subsequent corn were studied. The results showed that, compared with fallow fields in spring, overturning spring Brassica campestris L. could significantly increase the phosphorus content of the soil(P<0.05) and increase the phosphorus supply capacity of the soil. Among the tested corn varieties, Zhongyoufei 1804, Zhongyoufei 1901 and Zhongyoufei 1907 had higher biomass and higher phosphorus content in hectares of plants, the total phosphorus, available phosphorus, and alkaline phosphatase content in the soil after overturning were higher than the remaining other tested varieties (Zhongyoufei 1, Zhongyoufei 2, Zhongyoufei 1802, Zhongyoufei 1903, Zhongyoufei 1904, Zhongyoufei 1906). After overturning the spring Brassica campestris L., the 100-grain weight and yield of subsequent corn were both higher than contrast. Moreover, the 100-grain weight and yield of corn under the treatment of Zhongyoufei 1804((44.60±1.89)g, (15 321.82±2 150.29)kg/ha), Zhongyoufei 1901 ((44.81±0.68)g, (15 634.70±1 201.92)kg/ha) and Zhongyoufei 1907((43.69±1.78)g, (12 931.07±2 787.86)kg/ha)were significantly higher than other treatments. Therefore, Zhongyoufei 1804, Zhongyoufei 1901 and Zhongyoufei 1907 were selected as suitable spring Brassica campestris L. varieties for planting in North China.
  • JIA Liqiang, ZHAO Qiufang, CHEN Shu
    In order to study the role and function of DNA-binding with one finger (DOF) proteins in maize growth and development, the expression profiles of 10 ZmDOFs genes in different tissues or in response to various abiotic stresses have been carefully studied using qRT-PCR. The result of the phylogenetic tree and gene structure analysis showed that 10 ZmDOFs divided into three subclasses. The result of qRT-PCR revealed that 10 ZmDOFs exhibited obvious expression preference or specificity in different organs, 7 ZmDOFs high expression in tassels, 2 ZmDOFs in young embryo after pollination 15 days and 1 ZmDOF in root, indicating the important roles in the processes of maize growth and development. Results by qRT-PCR revealed the altered expression pattern of most of ZmDOFs in response to salt or osmotic stresses, indicating these gene involved in the regulation of salt or osmotic stress response pathway. ZmDOF3 was up-regulated by at least 5-fold under NH4+ depletion treatment, while ZmDOF23 and ZmDOF46 reduced by 90% under NO3- depletion treatment, indicated these genes were involved in nitrogen homeostasis or signaling pathway.
  • HUANG Shaohui, YANG Junfang, YANG Yunma, JIANG Rong, HE Ping, JIA Liangliang
    In order to explore the effects of nutrient expert (NE) management on nitrogen (N) use efficiency and soil organic carbon (SOC) sequestration in the wheat-maize rotation system and improve its management practices, a long-term experiment was set up in 2009 to compare NE management with farmer's practice (FP) management. Through 9-years experiment, the crop yield, N use efficiency, SOC content, SOC sequestration rate and SOC sequestration efficiency were measured and analyzed. The advantages of long-term NE management in wheat-maize crop rotation system were evaluated. The results showed that long-term NE management reduced the amount of N fertilizer application rate, compared with FP management, but maintained the crop yields (no significant difference with FP). Compared with FP management, the average accumulative recovery efficiency of N, agronomic efficiency of N, and partial productivity of N in NE management system increased by 7.4 percentage points, 39.7%, and 28.4% in maize production system, and increased by 8.0 percentage points, 28.9%, and 32.8% in wheat production system, respectively After 9-years experiment, both NE and FP increased the SOC contents, with NE management increased faster than FP. The annual SOC contents rise rates of NE treatment in 0-5 cm, 5-10 cm and 10-20 cm soil profile were 0.28, 0.27, 0.34 g/(kg·a), respectively, which were 7.7%, 68.8% and 126.7% higher than those of FP treatment. The average annual carbon input of NE and FP treatment from straw returning were 8.5, 8.7 t/(ha·a), respectively, and the SOC sequestration rates were 1.35, 0.68 t/(ha·a),respectively, and the SOC sequestration efficiencies were 18.6% and 0.4%, respectively, which shown a significant difference. NE management could improve N use efficiency and increase SOC sequestration. Long-term NE management is one of the important measures for fertilizer saving, efficiency strengthen and SOC pool richen in wheat-maize rotation system. It would play a crucial role in ensuring food security and realizing agriculture green development.
  • WEN Youwei, WU Xiuju, LI Aiyu, LIU Dan, WANG Lijuan
    In order to find a way to alleviate the stress of heavy metal cadmium in maize, this experiment used rare earth lanthanum to reduce the physiological and biochemical reactions of cadmium stress in maize, and combined with transcriptome analysis to study its mitigation mechanism. The experiment found that:Cd2+ treatment would inhibit the normal growth of the root length and aboveground part of maize seedlings, and this inhibitory effect would become more obvious with the increase of Cd2+ concentration. Low concentration of La3+ solution (10, 20 mg/L) would promote the growth of corn seedlings to a certain extent, while the higher concentration of La3+ solution (40 mg/L) would inhibit the growth of corn seedlings. Spraying lanthanum solution would improve the growth of corn seedlings under Cd2+ stress, and the activities of SOD, POD and CAT would significantly reduced compared with cadmium stress, but they were still slightly higher than the control. Transcriptome analysis of cadmium-stressed maize root samples was carried out using a second-generation sequencing technique. The cadmium treatment was used as a control to analyze the differentially expressed genes. It was found that the differential genes were mainly enriched in four pathways:Starch and sucrose metabolism,amino sugar and nucleotide sugar metabolism,plant hormone signal transduction,phenylpropanoid biosynthesis.Through experiments, it concluded that spraying lanthanum solution could alleviate the cadmium stress on corn seedlings, but it cannot restore it to its normal state.Through transcriptome sequencing,we hypothesize that the reason for the mitigation of heavy metal stress by rare earths may be related to the related genes of the above four pathways, and provide candidate molecular resources for the subsequent research on the response of rare earths to heavy metal stress.
  • YUE Runqing, LIU Lu, TIE Shuanggui, XU Xinzhi, CHEN Nana
    In order to breeding maize inbred lines with favorite pest resistant.The modified insect resistant gene Cry1Ab-t was constructed into the plant expression vector pCAMBIA3300m and transferred into the hybrid maize HiⅡ immature embryo with the Agrobacterium-mediated method. The positive transgenic plants were obtained by bar screening and PCR detection.RT-PCR, test strip and ELISA methods were used to detect Cry1Ab-t gene expression in transgenic maize,and the insect resistance was evaluated. The results showed that one hundred and sixteen seedlings were obtained after selecting with bialaphos sodium, and eighty-two seedlings of them were positive by PCR analysis and detection of the Cry1Ab-t gene and bar marker gene. RT-PCR, BT-Cry1Ab/Ac test strip and ELISA methods were used to detect Cry1Ab-t gene expression in transgenic material YA108 with good growth, Cry1Ab-t gene was expressed at transcription and translation level. The results of insect identification indicated that the non transgenic maize filaments were seriously infested by corn borer. However, the transgenic maize YA108 had a high level of insect resistance and stable insect resistance. The non transgenic maize was bitten seriously in the late stage of silking, and there were many boreholes in the stem and mold in the wound, while the transgenic maize YA108 was not damaged. After field inoculation, YA108, the Cry1Ab-t transgenic maize, had good resistance to Asian corn borer in both leaves and filaments. It could kill the larvae of Asian corn borer in a short time and reduce the mildew caused by insect pests to a great extent. The results of indoor and field indirect insect identification showed that the resistance rate of YA108 was detected to be Class 1 at each generation, showing high resistance level to Ostrinia furnacalis.
  • XIANG Xiaoling, CHEN Songhe, GAO Rencai, WU Dongming, CEHN Yanqi, YANG Hongkun, FAN Gaoqiong
    In order to study the effects of maize straw returning and nitrogen application on the growth and nutrient absorption of summer maize in wheat-maize rotation system, the experiment was started from 2015 to 2019 and carried out in Renshou County, Sichuan Province.The summer maize variety was Zhenghong No. 6. The experiment was laid out in a split-plot design, with wheat season maize straw returning or not as the main factor and nitrogen level(0, 120, 180 kg/ha) as the sub-plot. After wheat harvest, summer maize was directly planted in each plot, and nitrogen application amounts were 225 kg/ha. The results showed that the soil organic matter content increased by 34.1% after wheat harvest. Similarly, total nitrogen, alkaline hydrolysis nitrogen, available phosphorus and available potassium increased by 6.64%, 7.34%, 16.2%, 14.3%(2-years mean value), respectively. Under the treatment of straw returning, the biomass of the later maize increased by 34.7%(2018), 38.8%(2019), and the yield increased by 65.7%(2018), 30.7%(2019);the biomass of the later maize improved by 29.9%, 36.7% under the treatment of 120, 180 kg/ha, respectively, and the yield increased by 41.5%, 59.4%. By maize straw returning, the uptake of nitrogen, phosphorus and potassium in the above-ground of the later maize increased by 47.2%, 58.8%, 45.0% respectively(2-year mean value). With the increase of nitrogen application rate, the absorption amount of nitrogen, phosphorus and potassium of later maize plants showed an increasing trend. In conclusion, the winter wheat-summer maize rotation planting mode in the southwest hilly region, long-term return of maize straw could improve soil fertility, improve the yield and nutrient absorption of the later maize, which was a green and resource efficient production mode in the southwest hilly region.
  • ZHANG Meng, ZHANG Hanhan, XU Min, HE Huan, WU Xueyi, Lü Yingying, ZHANG Enying
    The ZmAGP2 gene encoding ADP large subunit of glucose pyrophosphory is involved in the synthesis of corn starch,thus affecting the yield and quality of corn. Maize yield traits are controlled by multiple genes,and its genetic mechanism is very complex. This study aims to fully explore the excellent allelic variation of genes closely related to yield traits through gene sequence variation analysis,which provides a theoretical basis for improving the molecular level of maize breeding. The ZmAGP2 genes sequences of 103 inbred test populations were captured and sequenced using NimbleGen platform. ClustalX 2.0,DnaSP 6.0 and other software were used to analyze the nucleotide polymorphism of the target gene,and the neutral evolution test and haplotype analysis of the mutation site were carried out. The full-length sequence of 4 111 bp was obtained by resequencing the ZmAGP2 genes of 103 maize inbred lines. After nucleotide polymorphism analysis,a total of 112 mutation sites in the full-length sequence were detected,all of which SNP,nucleotide polymorphisms in 5' UTR segments were significantly higher than those in other segments. Polymorphism in the CDS region of the gene drived the ZmAGP2 gene into eight haplotypes encoding five different ZmAGP2 proteins. Neutral test did not detect obvious manually selected signals. The ZmAGP2 gene showed high variation,which accorded with the neutral evolution model hypothesis,was not subject to obvious artificial selection,and the protein sequence changed,which indicated that the sequence variation of the gene causes the change of the protein sequence,which lead to the change of the function of the gene.
  • ZHAO Changyun, SHI Haichun, XIA Wei, CAI Lin, YANG Shu, YU Xuejie, KE Yongpei
    Studying the improvements of different donors and different back-cross times plays an important role in maize back-cross breeding. 36 back-cross improved lines were obtained by backcrossing 0-5 times and selfing 8-3 times,using maize inbred lines K11 and K62 as recurrent parents and three inbred lines as donor parents respectively. The 3×38 incomplete two-row hybrid model was used to analyze the combining ability and heterosis performance of main traits in back-cross improved lines.Donors A3 and B1 performed better than the other 4 donor parents on improving GCA,SCA and heterosis of yield,indicating that different donors presented different effects on improving the combining ability of different traits;In terms of the back-cross time,the improvement of 0-5 back-crosses on the GCA and SCA of yield was not obvious,0 and 1 back-cross performed better on improving the heterosis of yield.Choosing an appropriate donor parent was of vital importance when using back-cross to improve the quality of maize inbred lines,and the back-cross time should not exceed twice in back-cross breeding process;The GCA of yield of 10 improved lines,such as A3-1 and B1-1,were significantly higher than corresponding recurrent parents,which presented excellent potential of high-yield breeding.
  • XU Tianjun, Lü Tianfang, ZHAO Jiuran, WANG Ronghuan, CAI Wantao, LIU Yuee, XING Jinfeng, CHENG Guanglei, ZHANG Chunyuan, ZHANG Yong, LIU Xiuzh
    The yield and quality of silage corn are closely related to the harvest time. The plant,ear and grain related silage quality indexes at the stage of 1/2 kernel milk line were studied to provide instruction for determining suitable harvest time and variety selection in silage corn production. The experiments were conducted in Tongzhou experimental base of Beijing Academy of Agriculture and Forestry Sciences in 2018 and 2019. Totally 40 specific silage corn and dual-purpose corn varieties were selected and sampled at the stage of 1/2 kernel milk line. 5 plants for each plot were selected and the fresh weight of stems,leaves,sheaths,ears (without bracts),bracts,rachises and grains of the plant were weighed. The whole plant was baked in 105℃ oven for 30 minutes,and then dried at 60℃ to constant weight,the dry weight was weighed and then used to test the starch content. The result showed that:There were significant differences in the ratios of ear and kernel fresh weight to plant fresh weight(FWe/FWp,FWk/FWp),and that of kernel dry weight to plant dry weight(DWk/DWp) among different silage corn types and varieties at the stage of 1/2 kernel milk line. The ratios of FWe/FWp,FWk/FWp and DWk/DWp for all the tested varieties averaged 30.2%,20.9%,41.1% and ranged 25.5%-35.7%,16.2%-26.4%,33.6%-48.0%,respectively,with the dual-purpose type were 1.5,3.8 and 5.6 percentage point higher than that of specific silage type. The average plant water content of all the varieties was 68.8% (ranged 63.1%-73.6%),with the specific silage and the dual-purpose type was 70.1% and 67.3%,respectively. The average kernel water content of all the varieties was 39.0% (ranged 35.4%-43.6%),with the specific silage and the dual-purpose type was 39.6% and 38.3%,respectively. The average plant starch content of all the varieties was 30.9% (ranged 25.3%-35.6%). JKQZ368 was the highest (32.9%) and DJJ23 was the lowest (25.3%) among the specific silage varieties; JK968 (35.6%) and JNK728(35.6%) were the highest,and MC859 was the lowest(28.3%) among the dual-purpose varieties. The average plant starch content of the specific silage varieties was 29.6%,which 2.9 percentage point lower than that of the dual-purpose varieties (32.5%). At the stage of 1/2 kernel milk line,the average plant and kernel water content of all the varieties was 68.8%,39.0%,and the average starch content was 30.9%; the ratios of FWe/FWp,FWk/FWp and DWk/DWp for all the tested varieties averaged 30.2%,20.9% and 41.1%. During the suitable harvest period,the ratio of FWe/FWp of specific silage/dual-purpose corn varieties was ≥ 30%(the ratio of FWk/FWp was ≥ 20%,and that of DWk/DWp was ≥ 40%),the dry biomass content was ≥ 30% and the starch content was ≥ 30%. So,we suggested that the ratio of FWe/FWp could be used as a simple index for evaluating the quality of silage maize.
  • SUN Lei, WANG Lihua, GAO Zhongchao, TONG Yuxin, ZHANG Lei, CHANG Benchao, WANG Shuang
    In order to study the effects of bio organic fertilizer,silicon calcium fertilizer and zinc fertilizer on emergence,growth and yield of maize. We took of Demeya 1 as experimental materials,experiments were carried out in randomized complete block design with 3 replications. Set up two sowing dates,the first stage of sowing corn was fertilized,and the second stage was not fertilized. Then studied emergence rate,biomass,root growth,physiological characteristics,growth and yield of maize. The results showed that under low temperature condition,the seedling emergence rate could be increased by each optimized fertilization,the seedling emergence rate of T2,T3 and T4 treatments on the 4th,6th and 8th days were significantly higher than T1 treatment. The fresh weight of T2,T3 and T4 treatments were 1.77,2.26 and 2.07 times as big as T1 treatment,respectively. The soluble protein content of T2,T3 and T4 were 1.19,1.95 and 2.09 as big as T1 treatment,respectively. And root length,root surface area,root volume and superoxide dismutase content were increased by each optimized fertilization. The POD content of T4 treatment was lower than that of T1 treatment,the POD content of other treatment was higher than that of T1. The proline content of T2 treatment was lower than that of T1 treatment,and the proline content of other treatment was higher than that of T1 treatment. All fertilization increased the height of ear,the plant height of T3 was higher than that of T1,and plant height of T2 and T4 was slightly lower than that of T1. The yield of maize was increased by the optimized fertilization. The effect of T3 treatment (450 kg/ha total bio organic fertilizer) on improving the injury of low temperature to seedlings and promoting the growth of maize was better.
  • HUANG Ziyuan, WANG Tianye, WANG Chengyu, BAI Yichen, WU Yangsheng, LIU Shuxia
    In order to explore the different fertilization treatments to improve the soil moisture status and the mechanism of maize yield preservation in the semi-arid area of Northeast China,it provides a theoretical basis for the technical measures of drought resistance and yield increase of maize in the semi-arid area of Northeast China. This study used field tests to set four treatments:farmer habits(CK),single application of straw(S),combined application of chemical fertilizer and organic fertilizer(NPK+M),and combined application of chemical fertilizer and straw(NPK+S). Effects of different fertilization treatments on soil physical and chemical properties,corn physiological indexes and yield indexes. The results showed that fertilization could increase the content of N,P,K and organic matter in the soil,reduce the soil pH,and organic and inorganic fertilizers combined with the best application effect. The moisture content of different soil layers in the soil was little affected by the fertilization treatment,but from the data obtained from the experiment,in the 0-20 cm soil layer,the organic and inorganic fertilizers combined with the application of the treatment of the soil moisture content,field water holding capacity, the saturated water content reached the maximum value. Reasonable application of organic and inorganic fertilizers could promote plants to absorb nutrients more balancedly,increase the net photosynthetic rate,stomatal conductance,and chlorophyll content of corn leaves,reduce the moisture lost by evaporation,and then promote the increase of fresh and dry weight of plants. The combined application of organic and inorganic fertilizers had the effect of increasing the length of corn ears,the number of rows of grains,and the weight of thousand kernels,and increasing the yield of corn. Compared with the habits of farmers,the application of organic fertilizer and inorganic fertilizer on the soil in the semi-arid area of Northeast China could effectively improve the soil nutrient status,increase the soil moisture content of different soil layers,increase the water storage capacity of the soil,and increase the index of corn photosynthetic traits,promote the growth and development of corn,improve the yield index,and then increase corn yield. Combined application of organic and inorganic fertilizers is a technical measure suitable for drought resistance and yield maintenance of maize in arid areas.
  • LI Jin, LIU Xiaoli, LI Wenguang, LIU Zhenhua, YANG Zhenping, HUANG Chunguo, SUN Min, GAO Zhiqiang
    In order to explore the best distribution method of fertilizer in the winter wheat-summer maize rotation system under the fixed total input.While ensuring food production,promote the rational use of chemical fertilizers and provide a theoretical basis for scientific fertilization for agricultural production.A field experiment was carried out in winter wheat replanted summer maize field in Yuanqu County.The experiment was designed as two-factor split plot.The main-plot was wheat/maize two-season fertilizer distribution ratio,with three levels of 126/294,210/210,294/126 kg/ha and sub-plot was the ratio of wheat season basal fertilizer and jointing top dressing,and the 6 levels were 10:0,7:3,6:4,5:5,4:6,3:7.After the wheat was harvested,summer maize was replanted.Samples were collected during the harvest period for yield and yield composition.The results showed that when the fertilizer amount in wheat season was 126 kg/ha and corn season was 294 kg/ha,both crops could get high yield,and the difference in wheat yield reached a significant level(P<0.05).The annual output increased by 12.98%,4.25%.Different base dressing ratio management had different effects on wheat.The 6:4 management method was beneficial to the formation of ears.Yield increased by 12.86% compared with no top dressing treatment.Under this management method,fertilizer partial productivity was also higher.Correlation analysis showed that increasing the ratio of topdressing in wheat season was beneficial to increase the 1000-kernel weight of corn.Under the conditions of this experiment,the best ratio of base to dress in the wheat season was 6:4.It was suggested applying N 420 kg/ha with 3:7 nitrogen distribution ratio between winter wheat and summer maize would gain the highest yield.
  • NIU Xiaoxiao, LI Xiaobo, SUN Yi, MA Hailin, ZHANG Jie, LIU Yafei, HAO Yaoshan, CUI Guimei
    Maize stalk rot is not only widespread in China,but also a worldwide disease,which seriously affects the yield and quality of maize. Its distribution and loses caused by the disease,its pathogenic microorganisms and their identification and the evaluation for resistant germplasm resources are briefly discussed. It is indicated that the linkage between the resistance evaluation and breeding is not sufficiently close. The research progresses in genetic regulation and molecular biology of the disease resistance in maize are introduced,and some reference suggestions for further research are put forward.
  • XU Lina, YAN Yan, MEI Peipei, CHEN Shilin, HUANG Shoubing, WANG Pu
    To elucidate the difference of light and humidity distribution at different heights in the canopy between suitable for harvesting and common maize cultivars, a field experiment with two maize cultivars(Zhengdan 958, the common cultivar; Lishou 1, suitable for harvesting cultivar) and four planting densities(45 000,60 000,75 000,90 000 plants/ha) were conducted in a randomized block arrangement. The canopy transmittance and relative humidity at different heights of canopy, dry matter accumulation, leaf area index, empty stalk rate and grain yield were analyzed. Results showed that the relative humidity of canopy bottom and panicle level of two cultivars increased with planting density, and Lishou 1 was lower than Zhengdan 958. The leaf area index of Lishou 1 was lower than Zhengdan 958 and comprehensibly the light transmittance was higher than that of Zhengdan 958 at each planting density. There was no significant difference of dry matter accumulation between two varieties at different levels before the middle of filling stage. The accumulation of dry matter for Lishou 1 was significantly lower than Zhengdan 958, but the redistribution of dry matter was higher at maturity. Lishou 1 had a low empty stalk rate and high yield at high-density(90 000 plants/ha). Therefore, Lishou 1, suitable for machine-harvested corn variety, shows advantages in reasonable canopy light distribution, good microenvironment and smooth material production transshipment. Moreover, individual plant can make full use of limited resources with density increase. Lishou 1 can reach high yield with strong density tolerance and low empty stalk rate.
  • LIU Xinmeng, CHEN Geng, WANG Zhiguo, HE Yunhan, LI Wei, WU Yue, YANG Deguang
    In order to improve the nitrogen use efficiency and corn yield during the whole growth period of maize, it provides a reference for the high-yield nitrogen fertilizer operation model of maize in Heilongjiang Area. Ratio (CK:blank control; T1:50% base fertilizer+50% flowering fertilizer; T2:30% base fertilizer+40% jointing fertilizer+30% flowering fertilizer; T3:20% base fertilizer+60% jointing fertilizer+20% flowering fertilizer; T4:10% basal fertilizer+60% jointing fertilizer+30% flowering fertilizer) on the change of soil inorganic nitrogen content, nitrogen balance, nitrogen accumulation at different growth stages, nitrogen use efficiency and corn yield. The results showed that compared with the control group, T2, T3, and T4 effectively increased the inorganic nitrogen content of the soil plow layer during the filling stage and the mature stage; in terms of nitrogen balance, T2, T3, and T4 were significant difference than the T1 treatment. Reduced the apparent nitrogen loss, of which T4 apparent nitrogen loss was the lowest; compared with T1, reducing the ratio of nitrogen to topdressing significantly increased the nitrogen accumulation during the flowering-maturity period, and the nitrogen accumulation during the filling-maturity period T4 was the highest treatment; compared with T1, T2, T3, and T4 significantly increased the nitrogen absorption and utilization rate, agronomic utilization rate and partial productivity of maize, and the increase ranges was 16.66%-22.47%, 17.80%-35.76%, 4.93%-9.90% (Xianyu 335) and 6.55%-24.46%, 8.23%-36.94%, 2.02%-5.44% (Tiannong 9); reducing the ratio of nitrogen fertilizer to topdressing (T2, T3, T4) yields significantly higher than the traditional nitrogen application treatment T1, T3 had the highest yield, which was 9.90% (Xianyu 335) and 8.86% (Tiannong 9) compared with T1. In summary, under the experimental conditions, when the total nitrogen application rate was 210 kg/ha, 20% basal fertilizer+60% jointing fertilizer+20% flowering fertilizer was the best nitrogen basal dressing ratio.
  • JIN Heyu, ZHANG Mingchao, CHEN Guanglei, ZHOU Jinquan, ZHU Yiyong
    In order to clarify the agronomic traits, yield, nitrogen absorption and utilization efficiency of waxy maize in Jiangsu area under nitrification inhibitor (2-chloro-6-(trichloromethyl)pyridine, CP) under field test conditions, soil ammonium nitrogen and nitrate nitrogen effects, using waxy corn variety Suyunuo No.5 as the test material, setting five treatments:a non-nitrogen control (N0), farmers' conventional nitrogen application (N, taking the local high-yield corn nitrogen application as a reference), farmers' conventional nitrogen inhibitor (N+CP), nitrogen reduction 25% (-25%N), nitrogen reduction 25%+nitrification inhibitor (-25%N+CP). The results showed that:under the condition of reducing nitrogen by 25%, the combined application of CP treatment could significantly increase the yield of waxy corn. Compared with-25%N treatment, the-25%N+CP treatment increases by 15%-17%, and-25%+CP after treatment, the part of agronomic characteristics and yield of waxy corn were not significantly different from the farmers' conventional nitrogen application; the content of ammonium nitrogen in the soil after the combined CP treatment was higher than the corresponding non-CP treatment, and the N+CP treatment was higher than the N treatment 179%-224%, the nitrate nitrogen content was reduced by 35%; the ammonium nitrogen content in the soil treated with-25%N+CP was 202%-261% higher than-25%, and the nitrate nitrogen content was reduced by 30%-36%;CP application could increase the nitrogen accumulation of waxy corn, nitrogen fertilizer had partial productivity and agronomic efficiency of nitrogen fertilizer, among which-25% N+CP treated waxy corn had the highest nitrogen and phosphorus utilization efficiency. Considering comprehensively improving the efficiency of nitrogen absorption and utilization while maintaining the yield of waxy corn, it was recommended to reduce the application of chemical nitrogen fertilizer by 25% and apply nitrification inhibitors, which can provide a basis for achieving the goal of ″reducing nitrogen and increasing efficiency″ of waxy corn in agricultural production.