To explore the impact of organic fertilizer on the physiological growth of flax and the rhizosphere bacterial communities,and to investigate green high-yield cultivation techniques for flax in dryland,a field experiment was conducted using Baxuan No.3 as the material.The study examined the effects of four different fertilization treatments(T0:no application; T1:low quantity of cow manure; T2:medium cow manure; T3:high quantity of cow manure)on the physiological growth changes,nitrogen utilization,dry matter accumulation,and the diversity,community composition,co-occurrence networks,and metabolic pathways of the rhizosphere bacteria of flax,as well as discussing the environmental factors driving the differences in bacterial communities.The results showed that the T3 treatment resulted in higher flax production. Compared to the control, this fertilization condition also had the highest indicators for plant height, capsule fruit number per plant, thousand-grain weight, and nitrogen use efficiency, which form the physiological basis for stable yield following the application of organic fertilizer.The application of organic fertilizer significantly affected the diversity and richness of the rhizosphere soil bacteria of flax,and there were significant differences in the structure of the rhizosphere bacterial community.The population structure of the rhizosphere bacteria of flax was influenced by organic matter,total nitrogen,and available phosphorus.The dominant flora in the rhizosphere of flax was the same across different treatments,but the relative abundance of each dominant flora varied significantly.The rhizosphere of flax was dominated by the phyla Proteobacteria,Actinobacteria,Acidobacteria,Chloroflexi,and Bacteroidetes.The relative abundance of Proteobacteria and Actinobacteria increased with the increase of organic fertilizer treatments,while that of Acidobacteria decreased with the increase of organic fertilizer treatments.WGCNA analysis identified 15 co-expression modules,with the Red and Pink modules showing a significant positive correlation with organic matter content.The application of organic fertilizer increased the complexity of the bacterial network,and seven key OTUs were identified through combined WGCNA analysis.In conclusion,the application of organic fertilizer promoted the growth of flax and altered the structure and network complexity of the bacterial community in the rhizosphere soil of flax.

Soybean P34 protein mainly exists in soybean seeds,and its upstream promoter was likely to regulate the high expression of downstream genes in seeds.In order to further study the tissue expression pattern of soybean P34 protein gene and the regulatory activity of soybean P34 protein gene promoter,qRT-PCR was used to detect the expression of soybean P34 protein gene in soybean tissues.The 5'upstream sequence of soybean P34 protein gene(GmP34P)was cloned.The transcription initiation sites and cis-elements were analyzed by bioinformatics.The expression vector was constructed and the tobacco was transformed by Agrobacterium-mediated leaf disk method to detect GUS expression in transgenic tobacco.The results showed that the expression of P34 protein gene in soybean seeds was significantly higher than that in roots,stems,leaves and flowers.The length of GmP34P sequence obtained by cloning was 1 380 bp.Predictive analysis showed that the transcriptional start site of this sequence was base A at position 1 342,and the sequence contained a variety of cis-acting elements related to high seed expression,such as RY element,Skn-1 motif,2S seed protbanapa,etc.The plant expression vector pCAM-GmP34P containing GUS gene driven by GmP34P promoter was obtained.The positive transgenic plants were screened by hygromycin,PCR and RT-PCR.The results showed that GUS gene expression was extremely significant in transgenic tobacco seeds compared with other tissues by qRT-PCR with positive pCAM-GmP34P transgenic tobacco plants.GUS histochemical staining showed that the GmP34P promoter could regulate the high expression of downstream GUS gene in seeds.

WRKY is a unique class of transcription factors in plants,which plays an important role in plant abiotic stress response,seed dormancy and germination,growth and development,etc.In order to reveal the function and underlying molecular mechanism of GmWRKY44 gene in soybean WRKY transcription factor family,bioinformatics analysis and biology function verification of soybean Williams 82 GmWRKY44 were performed.GmWRKY44 gene was 1 077 bp in length and encoded 358 amino acids;the results of structural prediction and evolutionary analysis showed that,the secondary structure was composed of 23.46% α-helix,4.75% β-fold,58.94% irregular coil and 12.85% extended chain,and the tertiary structure was unified with the secondary structure;It contained a conserved WRKY domain, the zinc finger structure was of the C₂H₂ type, and it belonged to the WRKY IIc subfamily; GmWRKY44 is a homologous gene of Arabidopsis thaliana AtWRKY71 with a similarity of 35.56%, and the two genes had similar gene structures. RT-qPCR analysis showed that GmWRKY44 responded to salt stress and its expression level first decreased and then increased.Under salt stress,the germination rate and root length of wild-type(Col-0)and GmWRKY44 overexpressing Arabidopsis lines were inhibited to a certain extent,but GmWRKY44 overexpressing lines were significantly better than Col-0.In addition,under salt stress,the growth inhibition of GmWRKY44 overexpressing lines was lower than that of Col-0.Physiological index analysis revealed that under salt stress,the overexpression lines of GmWRKY44 exhibited significantly higher activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)than Col-0,while the content of malondialdehyde(MDA)was significantly lower than Col-0.These data indicated that overexpression of GmWRKY44 could improve salt tolerance in transgenic Arabidopsis.

In order to explore new approaches for high-oil peanut breeding and establish a new method for directly developing high-oil peanut germplasm,this study employed in vitro mutagenesis breeding technology to create new high-oil peanut germplasm.Jihua 9 embryo leaflet was used as mutagenic test materials,Jihua 9 and Jihua 54 were used as control test materials,and bleomycin was used as mutagenic agent.The ovules were sterilized and placed in gradient mutagenesis medium and screened for semi-lethal concentrations of bleomycin.After somatic embryos germinated into seedlings,sterile peanut seedlings were used as rootstocks,and transplanted to the field.Bioinformatics analysis of two known regulated peanut fat synthesis genes WRI1 and experimental feasibility validation by the correlation of WRI1 gene expression in grain and crude fat content of mutagenic plants were conducted.The results were best when the bleomycin was 3 mg/L.The crude fat content of IM13-3 was higher than that of Jihua 9(CK₁,test variety control)and Jihua 54(CK₂,high oil variety control).Two WRI1 genes,WRI1X2 and WRI1X1,encoding 366 and 357 amino acids,respectively,were both unstable hydrophilic proteins. WRI1 gene expression and crude fat content were significantly positively associated in grain.Bleomycin was first used as a peanut vitro mutagenesis agent,and IM13-3 was obtained with a crude fat content of 56.64%.It further proves the authenticity of Jihua 9 high oil mutant and the feasibility of peanut in vitro mutagenesis method. The gene expression level of the high-oil mutant WRI1 was determined and was significantly different from the control varieties. Demonstrate the feasibility of breeding methods for in vitro mutagenesis of peanut.

To investigate the function of lysophosphatidicacid acyltransferase 2(LPAT2)in Brassica napus,from which one copy(A07)of BnaLPAT2 was cloned by PCR.we constructed the overexpression vectors p35S∷BnaLPAT2-A07 and the seed-specific expression vector pNapin∷BnaLPAT2-A07,and by utilizing Agrobacterium-mediated genetic transformation method,obtained a total of 15 and 11 transgenic Brassica napus cv.Zhongshuang 6 respectively by PCR positive detection.Real-time Quantitative PCR(qRT-PCR)showed that the transcript levels of BnaLPAT2-A07 in most tissues of T₃ overexpressed rapeseed were higher than that of CK.However,in the seed-specific expression tissues of T₃ transgenic rapeseed,the BnaLPAT2-A07 genes were strongly expressed in the development and maturation stages of silique.Soxhlet extraction results showed that the oil content in the transgenic seeds driven by the 35S or Napin promoter accumulated 1.39 and 2.36 percentage point more oil than control seeds,respectively.The fatty acid components of transgenic rape were detected by gas chromatography.Compared with CK,the content of linolenic acid was increased by 3.13 and 1.47 percentage point,respectively.Taken together,the BnaLPAT2-A07 could promote seed oil synthesis,however,the specific selection function of BnaLPAT2-A07 for linolenic acid needs to be further verified.

In order to investigate the impact of different environments on the symbiotic nodulation ability of soybean-rhizobia and to screen suitable culture conditions for symbiotic nodulation,this study established 10 treatments based on 4 environmental factors(culture temperatures:22,26,30 ℃;culture substrates:vermiculite,vermiculiteand nutrient soil;inoculation periods:0 day post-inoculation,inoculation at 10 days;final bacterial concentration:OD₆₀₀=0.5,OD₆₀₀=0.9,OD₆₀₀=1.3),resulting in 36 different culture conditions.Five nodulation-related phenotypes of soybean-rhizobia were measured under these conditions,including the number of nodules per plant,nodule dry weight per plant,nodule size,SPAD of leaf growth at 10 and 24 days post-inoculation(DPI).Principal component analysis,fuzzy mathematics membership function method,and cluster analysis were employed to comprehensively evaluate and classify the symbiotic nodulation ability of soybean-rhizobia under different conditions.A comprehensive evaluation system for the nodulation ability of soybean-rhizobia was established,and the optimal culture conditions were selected based on the comprehensive evaluation index D value.The results showed that culture temperature was the primary environmental factor influencing the symbiotic nodulation of soybean-rhizobia.The maximum values of the number of nodules per plant,nodule dry weight per plant,nodule size,SPAD of leaf growth at 10 and 24 days post-inocubion corresponded to culture temperatures of 30,26,26,30 and 26 ℃,respectively,under,different culture conditions.Under the culture conditions set,the optimal culture temperature for the symbiotic nodulation of soybean-rhizobia was 26 ℃.Multivariate linear regression analysis and grey relational analysis based on the comprehensive evaluation index D value indicated that nodule dry weight and nodule size had a strong correlation with the symbiotic nodulation ability of soybean-rhizobia,serving as important reference indicators for nodulation ability identification.The results of this study established a comprehensive evaluation system for the symbiotic nodulation ability of soybean-rhizobia,providing a theoretical basis for selecting phenotypes and culture conditions for nodulation ability identification.

In order to study the problem of strong winter/spring Brassica napus seed germination and flowering period under different winter sowing dates.Two strong winter rapeseeds and two spring rapeseeds provided by Gansu Agricultural University were used as materials.The experiment was carried out in the experimental field of Gansu Agricultural University from October 2022 to August 2023.The winter rapeseeds was carried out on October 11,2022.The winter/spring rapeseeds was sown every 20 days from December 10,2022,and the sowing ended on February 8,2023.The flowering period was recorded,and the germination seeds of winter rapeseed were sampled every 20 days to determine their physiological and biochemical characteristics and analyze the expression characteristics of vernalization genes(FLC,VRN2,FRI,FT).The results showed that the flowering period of winter/spring rape seeds was different by 22—34 days.The difference of flowering time between autumn sowing and spring sowing was 4—7 days.The flowering time of winter rapeseed in autumn sowing(October 11 th)was close to that of spring rapeseed under different winter sowing dates(December 10th,December 30th,January 19th,February 8th),and the flowering overlap time was as long as 15—20 days.With the delay of the sowing date,the relative expression levels of FLC,FRI and FT genes in germinating seeds of winter sowing were down-regulated.The relative expression of VRN2 gene was down-regulated in the early vernalization and up-regulated in the late vernalization.The activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)and the contents of soluble protein(SP),gibberellin(GA3)and salicylic acid(SA)in germinating seeds were increased in the early vernalization,but those were decreased in the late vernalization.The contents of malondialdehyde(MDA)and abscisic acid(ABA)were increased in rapeseed germinating with the increase of vernalization time.

This study explored the effects of intercropping and rotation on the growth,yield and quality of continuous cropping peanut,to provide theoretical basis for achieving high yield in peanut production.From 2022 to 2023,sweet potato-peanut rotation system(PSP)and maize-peanut intercropping and rotation system(PMP)were set up in the experimental farm of Henan University of Science and Technology on the basis of continuous cropping peanut for 2 years and 11 years respectively,with continuous cropping peanut as control(CCP1 and CCP2,respectively).The effects of PSP and PMP on photosynthetic characteristics,root characteristics,dry matter accumulation and distribution and yield of peanut were studied.The results showed that compared with CCP1,the leaf area index(LAI)of rotating peanut in PSP system(SRP)was significantly increased by 35.08%—53.68% and 24.32%—33.52% at pod-setting stage(PSS)and full pod maturity stage(PMS),respectively.The SPAD value at PSS and pod bulking stage(PBS)increased by 11.93%—18.55% and 5.95%—9.63%,respectively.Compared with CCP2,the LAI of rotating peanut in PMP system(MRP)increased by 46.81%—57.96% and 27.00%—61.78% at PSS and PMS,respectively.At PSS and PBS,compared with CCP2,the SPAD value of MRP and intercropping peanut(MIP)increased by 3.32%—3.69%,7.50%—8.64% and 5.47%—18.37%,15.73%—31.11%,respectively.At PSS and PBS,compared with CCP1,the net photosynthetic rate of SRP increased by 23.68%—41.31% and 26.52%—32.55%,and compared with CCP2,MRP increased by 12.77%—17.81% and 16.88%—62.07%,respectively.They both significantly improved the root length and root tip number,and promoted the dry matter accumulation and the distribution to pods during PMS,and the yields increased by 31.42%—47.36% and 54.12%—75.09%,respectively.Compared with CCP2,MIP reduced the LAI,net photosynthetic rate,root length,root tip number,as well as dry matter accumulation and yield of peanut under the influence of maize shading.At the same time,the content of peanut oleic acid and oleic acid-linoleic acid ratio was significantly increased after rotation.Among them,SRP increased by 1.63—1.65 percentage point and 6.59%—10.52%,respectively,compared with CCP1,and MRP increased by 1.95—2.82 percentage point and 9.75%—14.16% compared with CCP2,respectively.In summary,sweet potato-peanut rotation and maize-peanut rotation increased the peanut yield compared with continuous cropping peanut,the reason was that sweet potato-peanut and maize-peanut rotation promoted peanut root growth,delayed the leaf senescence,and increased photosynthetic rate,especially the photosynthetic rate during late growth period,which promoted the dry matter accumulation and distribution to seeds.Besides that,they could improve the quality of peanut to a certain extent.

In order to explore the improvement effect of calcium fertilizer and ARC microbial agent on red earth dry land with low-calcium,the peanut variety Xianghua 522 was used as the experimental material,and two levels of calcium hydroxide fertilizer(0,750 kg/ha,code Ca₀ and Ca₅₀)and three levels of ARC microbial agent(0,30,60 kg/ha,code A₀,A₂ and A₄)were set to form six treatments to carry out pot experiment.It measured soil nutrient and soil enzyme activity in 0—20 cm arable layer soil at peanut seedling stage,flowering stage,pod setting stage and pod filling stage,and pod economic characters and yield were measured at harvest.The results showed that:single application of calcium fertilizer and the combined application of calcium fertilizer and ARC microbial agent could significantly improve the pH of soil at all growth stages,but ARC microbial agent had little effect on it.Compared with CK(Ca₀A₀),Ca₅₀A₂ and Ca₅₀A₄ significantly increased the content of hydrolyzable nitrogen in soil in the whole stage and the content of available phosphorus in soil in the first three growth stages;the content of available potassium in soil of Ca₅₀A₄ was higher than CK in general,and it was significant at seedling stage and pod setting stage;compared with CK,Ca₅₀A₀ significantly increased the content of exchangeable calcium in soil in four stages,with an increase of 23.78%—56.21%;the content of calcium ion in soil with calcium fertilizer application was significantly higher than that without calcium fertilizer application(the flowering stage was not significant),and it was little affected by ARC microbial agent;the content of organic matter in soil remained stable in the whole growth stage,but Ca₅₀A₄ and Ca₅₀A₂ were significantly higher than CK in each growth stage.Compared with CK,the soil sucrase activity of soil each treatment was significantly increased in four stages,and the increase was the largest in Ca₅₀A₄,ranging from 50.79% to 162.56%;the protease activity of soil was significantly increased by Ca₅₀A₂ in four stages with an increase of 26.58%—244.63%;the acid phosphatase activity of soil was significantly increased by Ca₅₀A₄ and Ca₀A₂ during the whole growth stage;the catalase activity of soil in all treatments showed a decreasing trend in general.All treatments could increase the yield of peanut pod in different degrees,and the effect of calcium fertilizer application was greater than that of ARC microbial agent,among which Ca₅₀A₄ had the best effect,with the pod weight per plant increasing by 12.29%,mainly increased the pod number per plant and the full pod number per plant.To sum up,the combined application of calcium fertilizer and ARC microbial agent has a good interaction effect on improving soil nutrient content,stimulating soil enzyme activity and increasing peanut yield,and the best effect is 750 kg/ha calcium fertilizer+60 kg/ha ARC microbial agent(Ca₅₀A₄),which can provide a theoretical basis for green and high yield cultivation of peanut.

To explore the planting patterns of mechanical harvesting sesame and achieve goals of high yield,stable yield and deep combination of agricultural machinery and agronomy,the split plot design with two factors was carried out to investigate the effects of different planting pattern and density on the photosynthetic characteristics,biomass,yield and mechanical harvesting characteristics of Yuzhi ND837,in order to provide theoretical foundation and technical guidance for the full mechanization production of sesame.The planting pattern included wide-and narrow-row spacing planting(Z1,wide-row:60 cm,narrow-row:20 cm),banding planting of 4 rows(Z2,line spacing:30 cm,banding spacing:60 cm),banding planting of 8 rows(Z3,line spacing:30 cm,banding spacing:60 cm)and equidistant row planting(Z4,line spacing:30 cm)as primary area.The planting density included 180(M1),225(M2),270(M3)and 315 thousand plants/ha(M4)as vice-area.The results showed that planting pattern and planting density both had significant effects on the photosynthetic characteristics,substance accumulation,yield and mechanical harvesting characteristics of sesame.The net photosynthetic rate(Pn),SPAD value and biomass per plant descended with the order of M1>M2>M3>M4,while the biomass of population increased at first and then descended with the planting density increasing under the same planting pattern.Under different planting patterns,the Pn,SPAD value,biomass per plant and biomass of population all showed Z1>Z2>Z3>Z4.Under the comprehensive effects of planting pattern and density,the Pn and SPAD value of Z1M1 were the highest,and the biomass per plant was also the highest in Z1M1(59.76 g/plant),but the biomass of population and yield were the highest in Z1M3(13 032.97,1 719.87 kg/ha,respectively).The uniformity of plants tended to be the same,the diameter of stem and the ability of capsule formation per plant decreased,but the lodging percentage at maturity also gradually decreased with the increase of planting density(M1>M2>M3>M4).The lodging percentage showed Z1>Z2>Z3>Z4 among different planting patterns.Under the comprehensive influence of planting pattern and density,the lodging percentage of Z3M1(17.51%)was the highest and Z4M4(7.97%)was the lowest.Under the conditions of the experiment,Z1M3 has the biggest yield,and the agronomic traits and mechanical harvesting characteristics at maturity are also better.

Improper application of soybean fertilizer can lead to late ripening,lodging,worsening of diseases and pests,and a decrease in fertilizer and yield benefits,to improve fertilizer efficiency and fully tap into the potential of soybean yield and quality,therefore,this article investigates the effects of seven fertilization modes F1(basic application of 3 000 kg/ha organic fertilizer+300 kg/ha chemical fertilizer),F2(basic application of 3 000 kg/ha organic fertilizer+150 kg/ha chemical fertilizer+topdressing 150 kg/ha chemical fertilizer),F3(basic application of 3 000 kg/ha organic fertilizer+225 kg/ha chemical fertilizer+topdressing 75 kg/ha chemical fertilizer),F4(basic application of 1 500 kg/ha organic fertilizer+75 kg/ha chemical fertilizer+topdressing 225 kg/ha chemical fertilizer),F5(basic application of 300 kg/ha chemical fertilizer),F6(basic application of 150 kg/ha chemical fertilizer+topdressing 150 kg/ha chemical fertilizer)and F7(basic application of 225 kg/ha chemical fertilizer+topdressing 75 kg/ha chemical fertilizer)on soybean growth,development,photosynthesis,yield,and quality through field experiments using a single factor experimental design.The results showed that increasing the application of organic fertilizer significantly enhanced the dry weight of soybean roots when compared to applying chemical fertilizer alone,applying chemical fertilizer alone with a base to top dressing ratio of 3∶1 was the most beneficial for increasing root dry weight.The combination of organic fertilizer and chemical fertilizer resulted in higher fresh leaf weight,dry leaf weight,fresh stem weight,dry stem weight per plant,as well as higher fresh weight and dry weight per plant when compared to single application of chemical fertilizer,and there were no significant differences in the above indicators among the treatments treated with single application of chemical fertilizer.The combination of organic fertilizer and chemical fertilizer increased the number of leaves per plant and leaf area index of soybean at pod bearing stage and filling stage,under the condition of no organic fertilizer application,the base to top dressing ratio of 3∶1 of chemical fertilizer was beneficial for improving the number of leaves and leaf area index of soybean.Compared to single application of chemical fertilizer,combined application of organic fertilizer and chemical fertilizer increased the photosynthetic rate at flowering and filling stages by 16.69%—21.66% and 14.99%—30.66%,respectively,unreasonable base to top dressing ratio of chemical fertilizer or reducing organic fertilizer dosage could affect the chlorophyll content and photosynthetic rate of soybean in the middle and later stages of growth and development.Increasing organic fertilizer application amount could increase soybean yield and protein content,while reduce fat content,applying chemical fertilizer alone with a base to top dressing ratio of 3∶1 was the most conducive to increasing yield.Therefore,it can be concluded that the combination of organic fertilizer and chemical fertilizer is significantly better than that of single application of chemical fertilizer in improving soybean growth and development,photosynthesis,yield,and quality,in addition,single application of chemical fertilizer performs better with a base to top dressing ratio of 3∶1.

This study investigates the influence of high and low nodule density on the composition and functionality of the soybean rhizosphere microbiome.The study used the wild-type soybean Williams 82 and a high-nodulation mutant(HiN)derived from this line to assess the impact of nodule variation on associated microbial populations.A controlled pot experiment was conducted,comparing the growth of both genotypes at the flowering stage,followed by the collection and high-throughput sequencing of 16S rDNA from the rhizosphere microbes.The high-nodulation mutant exhibited significant increases in plant height,aboveground biomass,and nodule count,with respective enhancements of 41.22%,37.46%,and 119.23% over the wild type.Comparative analyses revealed distinct differences in microbial community structure and composition between HiN and WT,with an elevated relative abundance of Bacteroidetes in the HiN rhizosphere.At the genus level,several key genera,including Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium,Bradyrhizobium,Chryseobacterium,Microbacterium,and Nocardioides,were more abundant in HiN.LEfSe analysis highlighted the enrichment of Actinobacteria and Bacteroidetes in HiN,contrasting with the predominance of Firmicutes in WT.GUS-labeled Bradyrhizobium further substantiated the enhanced capacity of HiN to enrich Bradyrhizobium.Collectively,these findings elucidate the regulatory role of nodule number on the symbiotic interactions within the soybean rhizosphere microbiome.

Germination control is an important basis for promoting rapid emergence and uniform seedlings of Brassica napus.In order to explore the effect of exogenous sucrose on B.napus seed germination and seedling development,it selected the early-maturing rapeseed variety-Xiangyou 420 to conduct germination tests under different conditions and detected the expression changes of moisture,abscisic acid,endogenous sugars and key genes.The results showed that exogenous sucrose delayed the germination initiation process of Xiangyou 420 seeds,improved the uniformity of germination,promoted the cotyledons to turn green and formed true leaves after the cotyledons expanded,inhibited the excessive elongation of the main root and promoted the development of lateral roots.Exogenous sugar first inhibited and then promoted water absorption during the germination process of Xiangyou 420 seeds.It inhibited water absorption within three hours after sowing and released the inhibition of water absorption within six hours after sowing.The ABA content in seeds continued to decrease during the germination process,and exogenous sucrose promoted the decrease in ABA content within three hours after sowing.The total soluble sugar content decreased rapidly within 15 to 18 hours after sowing,and the reducing sugar content increased with the germination process in the early stages of germination.Exogenous sucrose had no significant effect on the changes in total soluble sugar content but inhibited the increase in reducing sugar content within nine hours after sowing and promoted the increase in reducing sugar content 15 hours after sowing.During the germination process,the expression of two sucrose phosphate synthase (BnaSPS) genes decreased significantly during the radicle germination stage and then increased after the cotyledons turned green.Exogenous sucrose inhibited the expression of the two BnaSPS genes before radicle germination, and significantly induced,the expression of BnaC09g37470D gene after the cotyledons turned green.In summary,it preliminarily reveals that exogenous sucrose regulates water absorption at the initial stage of imbibition through osmotic effects,and delays the initiation of B.napus seed germination by regulating endogenous sugar utilization in seeds during the germination stage and sugar conversion in the early stages of seedling development through sugar metabolism,promotes the seed germination process after imbibition,improves the uniformity of seed germination,and promotes the development of seedlings.

The EXORDIUM(EXO) gene was identified in Arabidopsis thaliana as an brassinosteroid(BR)-responsive gene that promotes plant growth by mediating cell expansion.In order to investigate the function of EXO gene in Brassica napus and its expression pattern in different tissues at flowering stage,we used B.napus Zhongshuang 6 as the material,cloned the sequence of the coding region of the EXO gene named BnEXO,and carried out bioinformatics analysis,and used Real-time Fluorescence Quantification to determine the relative expression of BnEXO gene in B.napus in roots,stems,leaves,petals,buds,and pericarps at flowering stage.The results showed that the CDS sequence of BnEXO gene was 945 bp,BnEXO was a stable hydrophilic non-transmembrane protein,which belonged to secreted proteins and was expressed extracellularly,and the secondary structure of the protein was dominated by the random coil.The results of expression analysis in different tissues showed that the expression of BnEXO gene in different tissues was in the order of petals,pericarps,buds,stems,roots and leaves,and the highest expression was found in petals.In addition,20 B.napus EXO genes(BnaEXO),11 B.rapa EXO genes (BraEXO),and 11 B.oleracea EXO genes (BoEXO)were identified in this study based on the protein sequences of eight EXO gene family members in A.thaliana.Most proteins of gene family members were stable proteins,localized extracellularly,with amino acid lengths ranging from 271 to 411 aa,isoelectric point predictions ranging from 5.76 to 9.60,and molecular masses ranging from 28.76 to 46.21 ku.Phylogenetic analysis classified the EXO genes into five subgroups,EXOA,EXOB,EXOC,EXOD,and EXOE,with the least number of members in the EXOB subgroup.Gene structure analyses showed that most members contained only one exon and no intron,and the sequences of EXO gene family members were highly conserved.The results of cis-element analysis of the promoter region of the members in B.napus indicated that the BnaEXO genes play important roles in plant growth and development and in adversity stress.

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

In order to promote the cultivation of lodging resistant varieties of Brassica napus and explore the genetic resources of lodging resistance in the stem of Brassica napus,this study used four lodging resistant and three easily lodging resistant germplasm as materials,and measured the content of five components,including cellulose,hemicellulose,total pectin,protopectin,and lignin,in the lower stem during the flowering period.Transcriptome sequencing analysis was performed on the lower stem of YLS0084(lodging resistant)and YLS1691(easily lodging prone).The results showed that the average content of cellulose and total pectin in the anti toppling material,significantly higher than materials prone to lodging;transcriptome analysis revealed a total of 7 397 differentially expressed genes with upregulation and 9 438 downregulation,which were enriched in pathways such as carbohydrate metabolism,translation,amino acid metabolism,and signal transduction;nine genes related to lodging resistance in rapeseed(BnaA01G0071800ZS,BnaA01G0175700ZS,BnaA01G0205800ZS,BnaA03G0404800ZS,BnaA03G0517200ZS,BnaA05G0431400ZS,BnaA07G0056300ZS,BnaA09G0031300ZS,and BnaC05G0128400ZS)were validated through qRT-PCR,and were significantly upregulated in YLS0084.The results of this study demonstrates that the content of cellulose and total pectin in the stem of Brassica napus has a positive effect on lodging resistance and provides important genetic resources for lodging resistance in Brassica napus.

Modern soybean cultivars typically display yellow to brown pods,while their wild ancestral specie,Glycine soja,possesses black pods.Pod color is an important domestication trait and phenotypic characteristic,which is strongly related to pod blasting habit and avoidance of predation.Two alleles were certified to control the pod color in soybean,among which the brown pod L2 gene has not been identified.In order to identify L2 gene on the soybean genome,and provide a theoretical basis for functional analysis and breeding application of brown pod related genes in soybean.The cultivated varieties Zhonglongyou 203(yellow pod)and wild varieties FF1235(black pod)were used as parents to generate an F₂ segregating population for genetic analysis in this study.The BSA-seq was performed using two gene pools which were constructed by brown pod and yellow pod individuals from the F₂ population,respectively.On this basis,recombinant exchange individuals were analysed.The results showed that brown pod was a quality trait controlled by a pair of alleles in soybean.The brown pod L2 gene was located in the 0—0.75 Mb region of Chromosome 3.By further use of 7 polymorphic InDel markers in fine mapping,the candidate interval was finally delimited between Indel-L2-3 and Indel-L2-6 with 344 kb physical distance.There were 32 candidate genes in the interval,among which Glyma.03G005700 gene was annotated as isopropylmalate polymerase.Glyma.03G005700 gene is highly homologous to the discovered black pod gene L1 (Glyma.19G120400),which may be responsible for converting 4-hydroxypyruvate into eucomic acid and piscidic acid,and may be a key gene in the regulating the formation of brown pod in soybean.

In order to study the important role of zinc finger protein C₂H₂ in the stress response to soybean cyst nematode disease(SCN),lay an important foundation for further research on anti-soybean cyst nematode.The transcriptome data of SCN3 roots inoculated with Dongnong L-10(SCN-resistant)and Heinong 37(SCN-susceptible)were utilized in the present study,and the differentially expressed gene,GmC₂H₂-2like,was screened out.The localization of this gene was observed under the inverted fluorescence microscope.The gene was bioinformatically analyzed,and its overexpression vector was cloned and constructed to transform soybean hairy roots to study its resistance function against cyst nematode disease.The results showed that GmC₂H₂-2like encoded 410 amino acid residues,with a molecular weight of 45.77 ku,an isoelectric point of 8.73,and 47 phosphorylation sites,and the protein tertiary structure contained four structures,namely,α-helix(25.61%),random coil(57.32%),extended strand(13.66%),and β-turn(3.14%);the results of the subcellular localization revealed that the encoded protein was located in the nucleus;analysis of the overexpressed trans-GmC₂H₂-2like soybean hairy roots revealed that the number of cyst nematodes per unit area of the root tissue was significantly lower than that of the empty vector control,suggesting that GmC₂H₂-2like has the function of inhibiting cyst nematodes.

By screening differentially expressed genes and metabolites in the green and purple leaves of Brassica napus,it lays a theoretical foundation for the analysis of mechanism of anthocyanin synthesis.Phenotypic observation of GL and PL seedlings showed that PL exhibited a mottled distribution of purple when two true leaves were grown(3 weeks),as the purple gradually deepened during development,it gradually became lighter and eventually disappeared after the bolting stage(>16 weeks),while GL leaves remained green throughout the entire period;transcriptome analysis identified 2 523 co-differentially expressed genes at weeks 6,13,and 16,and these differentially expressed genes were significantly enriched in the anthocyanin synthesis pathway.Twenty-four genes related to anthocyanin synthesis were significantly differentially expressed,including 3 MYBL2,1 C4H,1 F3H,2 F3'H,2 TT8,3 DFR,4 ANS,5 UGT,and 3 TT19.The expression levels of these genes in PL leaves were higher than those in GL at 6 and 13 weeks.Eight differentially expressed genes were selected for qRT-PCR validation and the results were consistent with the trend of transcriptome analysis data.A total of 50 anthocyanins were detected in the anthocyanin-targeted metabolome,of which 29 showed significant difference in accumulation;compared to GL,PL had 16 types of anthocyanin accumulation upregulated and 13 types of anthocyanin accumulation downregulated.The up-regulation of TT8 and its target genes(DFR,ANS,UGT,TT19)in early development(6—13 weeks)promoted the accumulation of cyanidin-based anthocyanins and the decrease of petunian-based anthocyanins in PL.The expression levels of differentially expressed genes and metabolites in the anthocyanin synthesis pathway reached significant levels.

To investigate the effect of exogenous melatonin (MT) on salt tolerance of soybean seedlings,and to screen the appropriate application concentration under different salt stress.The soybean variety Tianyou-2986 was used as the test material,and 3 salt concentrations (low salt S₃:3 g/L,medium salt S₅:5 g/L,high salt S₇:7 g/L ) and 6 MT concentrations were set(M₀:0 μmol/L,M₁:25 μmol/L,M₂:50 μmol/L,M₃:75 μmol/L,M₄:100 μmol/L,M₅:150 μmol/L),the morphological parameters,biomass,antioxidant enzyme activity and osmoregulatory substance content of soybean seedlings were analyzed.With the increase of salt stress,the root morphological parameters,biomass,root-shoot ratio,antioxidant enzyme activity and osmoregulatory substance content of soybean seedlings decreased,while the malondialdehyde content increased.Under low salt (S₃) and medium salt (S₅) stress,The number of total length,lateral roots,SOD and POD of 50 μmol/L MT were increased by 52.30%,19.98%,74.10%,40.03% (low salt) and 68.52%,19.24%,81.72% and 37.42% (medium salt),respectively.Under high stress (S₇),75 μmol/L MT increased by 71.17%,19.11%,80.79% and 27.01%,respectively.Under salt stress,exogenous 25—100 μmol/L MT promoted soybean seedling growth and improved salt tolerance to different degrees.The overall evaluation of the affiliation function showed that 50 μmol/L MT was the most effective in alleviating salt damage under low and medium salt stress,and the suitable concentration of MT was 75 μmol/L under high salt stress,and the main reason for the alleviation of salt damage in soybean seedlings was that MT increased the activities of antioxidant enzymes and osmoregulatory substance content,and reduced the content of malondialdehyde,which could alleviate oxidative and osmotic stresses of soybeans under salt stress.

In order to investigate the effect of iron ions on the biological characteristics and pathogenicity of Verticillium dahliae in sunflower,the growth rate,conidial production,number of microsclerotia,crude toxin secretion,cell wall degrading enzymes activity and pathogenicity of V.dahliae were measured after the exogenous addition of iron ions to the culture medium.The results showed that the growth rate and conidial production of mycelium showed an increasing trend after adding different concentrations of iron ions in an exogenous,compared with the control,the growth rate of V.dahliae was the fastest after adding 80 μmol/L of iron ions,and the colony diameter was 68.81 mm with a growth rate of 21.40%;the conidial production was 2.58×10⁷ conidia /mL with a growth rate of 21.13%;the number of microsclerotia also increased with the increase of exogenously added iron ion concentration,and after 5 days of culture,its increase was 51.53% compared with the control.The crude toxin secretion was increased after adding 80 μmol/L of iron ions,and the increase rate was nearly doubled.The activity of cell wall lyase increased with increasing concentration of exogenous iron ions and increased at 80 μmol/L reached the strongest.In addition,the pathogenicity of V.dahliae increased accordingly with the increase in the concentration of iron ions in the medium,as shown by the increase in the disease index from 35.00 to 62.20 when the concentration of iron ions added exogenously from 0 to 80 μmol/L,with a growth rate of 77.71%.In conclusion,the exogenous addition of iron ions not only accelerates the growth of V.dahliae,and promotes conidial production and microsclerotia formation,but also enhances the pathogenicity of V.dahliae.

To clarify the effects of soybean staygreen syndrome on the yield.Different treatments were set up for the main hazard factors that cause soybean staygreen syndrome disease,the resistance of 65 soybean varieties was screened and identified,and the synergistic effect of different hazard factors was analyzed. The results showed that the resistance of different soybean varieties to soybean hazard factors was different,and the number of T2 treated soybean staygreen syndrome sensitive varieties was the smallest,with 53,accounting for 81.54%. The number of soybean staygreen syndrome sensitive varieties of T4 was the largest,with 58,accounting for 89.23% of the total. Compared to the changing range of the control,the average rate of soybean staygreen syndrome with T4 and T5 composite hazard factors (263.87%—281.57%)was larger than that of individual hazard factors (117.82%—151.58%). The effects of treatment of different hazard factors on the main agronomic traits of soybean have reached a significant level. Compared with the control,among the seven major agronomic traits,the 5 treatments of the node numbers of main stem had the smallest change range,with an average of decreasing range 7.71%,and the number of staygreen syndrome pods per plant had the largest change range,with an average of amplification 83.52%. Among the three yield related traits,the 5 treatments with 100 seed weight had the smallest loss rate compared with the control,with an average of decreasing range 8.70%,and the 5 treatments with seed weight per plant had the largest loss rate with an average of decreasing range 52.51%. In short,the results revealed that the effects of treatment of different hazard factors on the yield and main agronomic traits of soybean have reached a significant level,and the seed weight per plant had the largest change compared with the control.

Brassica napus has the potential to tolerate Cadmium(Cd)pollution while producing safely.To provide theoretical support for the ecological restoration and safe utilization of Cd-polluted farmland using B.napus,field plot experiments involved 24 widely grown winter rape varieties were performed in October 2020 at the Agricultural Science Research Institute in Xiangtan City,Hunan Province.Cd accumulation in different tissues of the rape plants grown in low-concentration Cd-polluted farmland(total Cd content 0.54 mg/kg,effective Cd content 0.23 mg/kg)was analyzed.Effective Cd content did not differ significantly among different plots,while there were differences in Cd absorption and accumulation in different tissues of mature rape plants.The highest average Cd content was observed in leaves,followed by roots,stems,and silique walls,while the lowest value was in seeds,which was below the national food pollutant standard(0.1 mg/kg).There was no significant difference in Cd content in roots of different rape varieties,but there were differences in stems,branches,silique walls,and seeds.The transmission coefficients in different tissues of different rape varieties were analyzed,and the results showed that there were differences in transfer coefficients between different varieties.In Qingyou 1,the transmission coefficients in leaves and silique walls were relatively high,but low in seeds.Fengyou 737 and Yangyou 9 had higher transmission coefficients in branches and leaves,and medium values in seeds.The total Cd content in the harvested parts of rape plants was analyzed,and the results indicated that varieties such as Huaza 62 and Qingyou 1 had high total Cd content but low Cd content in seeds.In conclusion,B.napus has the ability to enrich Cd,and varieties such as Huaza 62 and Qingyou 1 have the potential to restore slightly Cd-polluted farmland while ensuring production safety.

In order to have a clearer understanding of the research progress on cold resistance of winter rapeseed in cold and arid regions of China,and to provide theoretical support for breeding and production.The research progress of cold-resistance and cold-resistance breeding of winter rapeseed were summarized respectively from six aspects such as selection index and method,genetic law,breeding method,screening effect,germplasm classification and molecular mechanism research,and four aspects such as breeding method,breeding varieties,cold resistance classification and adaptability screening of varieties.Based on the analysis of the existing problems,six measures were put forward,such as creating germplasm resources by multiple ways,screening out core germplasm by comprehensive evaluation,carrying out research on cold-resistance mechanism and construction of innovation system of molecular design breeding,constructing breeding system and carrying out cold-resistance breeding by multiple ways,improving the adaptability of varieties by comprehensive screening,promoting varieties yield level and improving benefits by carrying out matching cultivation techniques,in order to promote the development of rapeseed production in cold and arid regions of our country.

In order to cultivate and screen saline-alkali tolerant peanut varieties and expand the utilization area of saline-alkali soil,50 peanut varieties were used as materials,and four saline-alkali gradients,including 0,0.4%,0.8% and 1.2%,were set by potting to screen saline-alkali tolerant varieties. The results showed that under the saline-alkali stress of 0.8% in the germination stage,the seeds of 50 varieties were significantly differentiated in terms of saline-alkali tolerance,and the germination rate and seedling vigor of 8 varieties remained above 90% and 85%. The evaluation results of various physiological indexes at the seedling stage showed that the root indexes and aerial traits did not change much under low concentration (0.4%)saline-alkali stress,but showed different degrees of decline under medium (0.8%)and high (1.2%)concentration stress,and the reduction range was 22%—54% and 30%—56%,respectively. In addition,chlorophyll indexes showed an upward trend with the increase of saline-alkali concentration,with an increase range of 12%—13%. The comprehensive evaluation results of peanut using the excellent index showed that 23,5 and 0 varieties performed excellently under the saline-alkali stress of 0.4%,0.8% and 1.2%,respectively. Correlation analysis revealed that,there was no significant correlation between saline-alkali tolerance stress at the germination stage and the seedling stage,indicating that there were different mechanisms of saline-alkali tolerance during germination and seedling stages. The above results concluded that under the conditions of pot cultivation,moderate concentration (0.8%)saline-alkali was suitable for the screening of peanut saline-alkali tolerance varieties. According to the comprehensive excellence index,five saline-alkali tolerant peanut varieties were selected,namely Jihua 572,Tang 3432,Jinonghua 31,Yihua 16 and Yuhua 191,which provided a basis and germplasm resources for the promotion and cultivation of salt alkali tolerant peanut varieties.

To explore the relationship between agronomic traits and yield of oil sunflowers and select new high-quality and high-yield oil sunflower varieties suitable for climate and planting mode of Hebei Province,genetic diversity analysis,correlation analysis,systematic cluster analysis,and principal component analysis(PCA)were conducted on 14 traits of 39 oil sunflower hybrids.The research results indicated that the coefficient of variation for different traits ranged from 2.50% to 32.37%.Among them,the coefficient of variation of grain weight per head was the highest,at 32.37%,with a variation range of 16.77—113.78 g.The coefficient of variation during the growth period was the smallest,only 2.50%.The yield was extremely significantly positively correlated with 100-grain weight,grain number per head,grain weight per head,grain volume weight,and plant height,and significantly positively correlated with grain area,grain circumference,and grain length;Plant height was extremely significantly positively correlated with 100-grain weight,grain area,grain circumference,grain length,grain width,and grain volume weight,and significantly positively correlated with grain weight per head.PCA divides the agronomic traits of different varieties into four principal components,which could be summarized as grain trait factors,yield factors,growth period and morphology factors,and grain volume weight factors,with a cumulative contribution rate of 81.939%.At a Chi-square distance of 1.05,39 materials were divided into 4 groups,among which group Ⅰ contained 23 materials with excellent grain and yield traits,and was similar to the characteristics of group Ⅰ in the PCA scatter diagram.Based on the above data analysis,from the perspective of selection potential,the impact of traits such as grain weight per head,grain number per head,head diameter,plant height,and 100-grain weight on yield should be mainly considered.

In order to explore the law of nitrogen absorption,transport and utilization of sesame at seedling stage,two sesame varieties with different nitrogen efficiency,including Zhengzhi HL05(ZZ,high efficiency)and Myanmar high yielder(MD,nitrogen inefficiency)were used as materials.The differences in root morphology,nitrogen absorption,transportation and utilization,nitrogen metabolism indices and related gene expressions involved were compared between the two accessions through hydroponics,under normal nitrogen(CK,17.86 mmol/L)and low nitrogen(LN,0.2 mmol/L)levels respectively.The results showed that under different nitrogen concentrations,the root morphological indexes,biomass,nitrogen accumulation,enzyme activities related to nitrogen metabolism and root nitrogen use efficiency of ZZ variety were higher than those of MD on the whole.Low nitrogen stress significantly decreased the biomass,nitrogen accumulation,and leaf nitrogen metabolism-related enzyme activities,increased root morphological indexes,root activity,root-shoot ratio,nitrogen physiological use efficiency,root dry matter use efficiency and nitrogen use efficiency.Among them,the biomass,nitrogen accumulation,transport coefficient,root nitrogen physiological use efficiency and nitrogen use efficiency of ZZ were 2.48,1.08,1.73,2.36 and 2.65 folds of MD,respectively.qRT-PCR results showed that under low nitrogen stress,SiNPF6.3a/b,SiNPF4.6a,SiNRT2.4a/b,SiNRT2.5,SiNPF7.3a/b and SiNPF2.13 genes involved in {{\mathrm{NO}}_3}^{-} absorption,transport and redistribution of the nitrogen efficient variety ZZ in leaves were up-regulated,and the gene expression levels were higher than those of the nitrogen inefficient variety MD.In Conclusion,under low nitrogen stress,nitrogen efficient sesame varieties had more developed roots and higher ability of nitrogen assimilation,transport and redistribution at seedling stage,so as to obtain higher nitrogen accumulation and nitrogen use efficiency.

In order to determine the suitable sowing date of green manure for multiple cropping rape in Hetao irrigation area,field experiments were carried out in Hangjinhou Banner,Bayannur City,Inner Mongolia Autonomous Region in 2019 and Dalad Banner,Ordos City in 2022.There were five sowing dates in Hangjinhou Banner experimental site from July 26th to August 15th,2019,and one sowing date was set every five days,which were sown on July 26th,July 31st,August 5th,August 10th and August 15th,respectively.Similarly,from July 22nd to August 11th,2022,the experimental site in Dalad Banner was set up with five sowing dates,and one sowing date was set every five days to study the effects of different sowing dates on the green manure biomass,nutrient content and nutrient accumulation of rape.The results showed that although the biomass level and climate conditions of the two experimental sites were different,the overall trend showed a decline with the delay of sowing date.Compared with the first sowing stage,the rape biomass in the fifth sowing stage decreased by 90.3% and 75.4% respectively,and the average active accumulated temperature,effective accumulated temperature and sunshine hours in the two-point growth period decreased by 469.9 ℃,409.9 ℃ and 179.1 h,respectively.At the same time,when sowing in the first,second and third stages,compared with the nutrient input (N 27.3 kg/ha,P₂O₅ 34.5 kg/ha),the nutrient input of rape was higher than the input,and the amount of carbon and potassium returned to the field was at least C1 800 kg/ha and K₂O 200 kg/ha.Therefore,considering the biomass of rape green manure and the amount of nutrients returned to the field,rape could be sown early after wheat harvest in Hetao irrigation area,making full use of light and temperature resources to promote rape growth and nutrient accumulation.In order to achieve more than 5 t/ha of rape returning to the field and obtain a higher amount of nutrients returning to the field,at least 1 300 ℃ of active accumulated temperature,1 100 ℃ of effective accumulated temperature and 640 h of effective sunshine hours should be accepted during the rape growth period.

GRAS transcription factors exist extensively in plant genomes and play an important role in both biological and abiotic stress in plants.To study the significant role of the response to stress in soybean cyst nematode (SCN).The susceptible and disease-resistant varieties Dongnong L-10 and Heinong 37 were inoculated with SCN 3 physiological subspecies respectively.After magenta staining was used to confirm the success of insect grafting,transcriptome sequencing was performed on plant roots.A total of 20 candidate genes related to SCN were obtained.The secondary and tertiary structures,phosphorylation sites,hydrophilicity and hydrophobicity,promoter information and gene evolution relationship of encoded proteins were analyzed and studied in bioinformatics.mRNA was extracted from different tissue parts of the plant,including roots,stems and leaves,and reverse transcription cDNA was performed for key candidate genes by RT-PCR.The results showed that the genes in this family were closely related to MYB and MYC transcription factors.The protein encoded by the gene was mainly α-helix and random coil,and the secondary structure and tertiary structure were highly consistent.Protein was a soluble protein,the phosphorylation site was mainly serine.RT-PCR showed that there were certain expression levels in different parts of plant tissues,mainly in roots.The GRAS expression level of resistant cultivars was significantly higher than that of susceptible cultivars under the same soybean cyst nematode stress.GRAS transcription factors were identified as SCN-related resistance genes,providing an important source of genes for resistance to stress response.

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

In order to study the organic acid synthesis mechanism of vegetable soybean and provide a theoretical basis for the quality improvement of vegetable soybean,a natural population containing 264 accessions of vegetable soybean was used as experimental materials.The contents of tartaric acid,malic acid and citric acid in this population were determined by high performance liquid chromatography(HPLC)in 2020 and 2021,respectively,and genome-wide association study was conducted based on the genotype data of this population,SNP loci and candidate genes significantly associated with organic acid content were identified.The results showed that the average content of tartaric acid in 2020 and 2021 populations were 4.13,4.16 mg/g,respectively;the average content of malic acid was 7.26,8.99 mg/g,respectively;the average content of citric acid was 7.12,10.88 mg/g,respectively.Correlation analysis showed that citric acid content of 264 materials showed a significant positive correlation between 2020 and 2021.Significant positive correlation coefficients were obtained for the pairs of malic/citric acids,tartaric/malic acids,and tartaric/citric acids were 0.790^*,0.695^*,0.739^*,respectively.The results showed that there were significant differences among different varieties in the test population,with rich genetic diversity.Six specific germplasm resources with high organic acid contents were selected to provide excellent materials for the improvement and breeding of organic acid varieties of vegetable soybean.Genome-wide association study based on the mixed linear model the number of SNP loci significantly correlated with the contents of tartaric acid,malic acid and citric acid were 54,189,43,respectively,and based on the gene functional annotation information,3 and 5 candidate genes were identified which were significantly correlated with the content of tartaric acid and malic acid,respectively.

To investigate the mechanism of chitosan promoting nodulation in vegetable soybean under salt stress,the effects of exogenous chitosan on sucrose metabolism and root accumulation in vegetable soybean under NaCl stress were explored.Effects of chitosan on nodulation,the accumulation of sucrose and reducing sugar in leaves and roots,as well as sucrose metabolism-related enzyme in vegetable soybean under NaCl stress were studied by using the vegetable soybean variety Nippon Green and the fast-growing rhizobia HH103 symbiosis as the test material in an artificial climate chamber.The results showed that the number of root nodules and fresh weight of root nodules in vegetable soybean were significantly decreased under the NaCl stress(T2)(P<0.05),with an average decrease of 36.06% and 29.91% in each stress period,respectively;the sucrose content of leaves and roots was significantly increased(P<0.05),and the reducing sugar content was significantly decreased(P<0.05);and the activities of sucrose synthase(SS)and sucrose phosphate synthase(SPS)were increased,while the activities of neutral convertase(NI)and acid convertase(AI)were decreased.The number of root nodules and fresh weight of root nodules significantly increased(P<0.05),after chitosan treatment(T3)in all stress periods,with average increases of 26.87% and 25.63% of T2;the sucrose and reducing sugar contents and sucrose metabolism-related enzyme activities of leaves and roots increased significantly compared with T2(P<0.05),with average increases of 11.32%,21.32% and 10.22%,11.11%,respectively.That chitosan could promote the nodule formation of vegetable soybean by inducing the high level of sucrose metabolism in the leaves and roots under NaCl stress and accelerating the transfer of sucrose to roots,which may be one of the important reasons for chitosan to improve the nodule formation ability of vegetable soybean under NaCl stress.

Heavy metal pollution in soil has seriously affected the development of agriculture and the safety of agricultural products in China.Phytoremediation is a widely concerned soil remediation method,and rape is an ideal remediation plant.In order to screen rape breeding materials suitable for using as remediation plants.The pot experiment was carried out.With 100% nutrient soil environment as a control,three polluted soil environments(Ⅱ(25% contaminated soil,75% nutrient soil), Ⅲ(50% contaminated soil,50% nutrient soil), Ⅳ(75% contaminated soil,25% nutrient soil)with different proportions of contaminated soil were set up.The physiological characteristics and gene expression differences of three different hybrid types of Brassica napus,159-6(Self crossing species),Fengyou 520(Hybrid),and 159-6×Fengyou 520(Triple cross),were studied under different ratios of heavy metal polluted soil environments.The results showed that under different ratios of heavy metal contaminated soil,159-6×Fengyou 520 had the highest fresh and dry quality and was higher than control group I.Under 25% polluted soil environment,159-6 had the highest chlorophyll content,while the rest had 159-6 chlorophyll content×Fengyou 520 had the highest chlorophyll content.Except for Fengyou 520 with the highest soluble protein content in a 50% polluted soil environment,the rest were 159-6×Fengyou 520 had the highest soluble protein content.Under 50% and 75% polluted soil environment,159-6×Fengyou 520 had the highest SOD activity,with MDA content lower than 159-6 and Fengyou 520;four genes related to heavy metal resistance(BnaA08g04000D,BnaA09g24330D,BnNRAMP1,and BnPri-miR167a)were identified in 159-6×The expression levels in the leaves of Fengyou 520 were higher than those of 159-6 and Fengyou 520;Bna0280620 and Bna049040 genes in 159-6 under 75% polluted soil environment×The expression level in the leaves of Fengyou 520 was also higher than that of Fengyou 520 and 159-6.159-6,Fengyou 520 and 159-6×Fengyou 520 could grow and develop normally in polluted soil environments with different ratios;Sanjiao rapeseed 159-6×Fengyou 520 performs better in environments containing 50% and 75% polluted soil.The study was carried out from the genotype and biological characteristics of breeding materials,and the differences between conventional materials and hybrid materials in heavy metal resistance and between different hybrid types were analyzed.It was found that hybrids were better than conventional materials,while three hybrids were better than hybrids.

To investigate the function and possible molecular mechanisms of soybean GmGRAS69 gene,which belongs to the GRAS transcription factor family,in plant drought stress.Sequence conservation and evolutionary relationship between soybean GmGRAS69 and GRAS members of other species were analyzed by amino acid sequence alignment and phylogenetic tree construction.Quantitative Real-time PCR was used to detect the expression pattern of GmPP2C69 in soybean roots and leaves treated with PEG.Then,GmPP2C69 overexpression vector was constructed,and then wild-type Arabidopsis was transformed by Agrobacterium-mediated floral dip method.The growth phenotypes of wild-type and transgenic Arabidopsis were observed under normal culture and drought treatment.The fresh weight per plant,relative water content of leaf,soluble sugar content of shoot,antioxidant enzymes(SOD,POD and CAT)activities and corresponding antioxidant enzyme gene expression levels were measured.The results showed that GmGRAS69 was significantly up-regulated in both roots and leaves of PEG-treated soybean plants,and the response was more significant in roots.In addition,GmGRAS69-overexpressed Arabidopsis was successfully obtained,and the drought tolerance of the GmGRAS69-overexpressed plants was significantly enhanced compared with WT.Under drought treatment,the fresh weight,leaf relative water content and soluble sugar content of GmGRAS69-overexpressed plants were significantly higher than those of WT.The activities of antioxidant enzymes SOD,POD and CAT and the expression levels of corresponding genes SOD,POD and CAT were also significantly higher than those of WT.The results showed that the expression of GmGRAS69 was up-regulated under drought stress,and the transgenic plants were enhanced drought tolerance by activating SOD,POD and CAT antioxidant enzyme encoding genes,enhancing antioxidant enzyme activities and increasing soluble sugar accumulation.

FLK(Flowering Locus KH Domain)plays an important role in flowering time regulation,and its function has been characterized in Arabidopsis.In order to identify the function,GmFLK was isolated from soybean Williams 82 and the encoded protein was predicted by structural and bioinformatics analysis.The subcellular localization of this protein was examined in tobacco leaves and the expression pattern of this gene was analyzed in soybean.The results showed that the GmFLK was 6 806 bp in length,containing 6 exons and 5 introns.The CDS was 1 341 bp,encoding 446 amino acids.The molecular weight of the protein was 47.031 ku,and the isoelectric point was 5.46.GmFLK protein contained three structures,α-Helix,β-Strand and Coil,which had 24.44%,14.80% and 60.76%,respectively.Phylogenetic analysis revealed that GmFLK had a close relationship with Glyma.03g248200,followed by Medicago Medtr7g115340,Arachis hypogaea ArahyQL2VNI, ArahyUPVY9X,and Arabidopsis AtFLK.Subcellular localization analysis showed that GmFLK protein was expressed in the nucleus,cytoplasm and cell membrane.GmFLK promoter contained 10 types of cis-acting elements,and 6 types were considered to be involved in photoperiod response.In addition,GmFLK was expressed in flower,leaf,root,seed and stem,and GmFLK showed relative high expression levels in leaf and seed,and relative low levels in flower.The expression patterns of GmFLK under long day and short day photoperiod conditions were similar.However,GmFLK showed different expression levels throughout the day and night,and exhibited low expression level after 4 h,lights-on,and high expression level after 0 and 12 h,lights-on.In summary,our study reveals that GmFLK might be a key factor involved in flowering time regulation.

Abiotic stresses such as drought and soil salinization seriously affect the growth,development and yield of crops.GmRPK2 gene was cloned and constructed into the overexpression vector,then the vector was transformed into Arabidopsis thaliana and the homozygotes was screened.Under PEG,NaCl and ABA stress,the resistance of GmRPK2 overexpression Arabidopsis was tested.The results showed that the germination rate of the overexpressed Arabidopsis seeds was significantly lower than wild type.The elongation of the overexpressed Arabidopsis seedlings roots was also shorter than that of wild-type.In the stress resistance test of Arabidopsis plants,it was found that after salt stress and drought stress treatment,the inhibition of transgenic Arabidopsis plants was more obvious than that of wild-type Arabidopsis plants.The stress resistance test at adult stage showed that the growth inhibition of overexpressed Arabidopsis was more obvious under salt and drought stress.In order to explore the internal mechanism of the reduction of its stress resistance,the physiological indexes of GmRPK2 overexpressed Arabidopsis were detected.The results showed that,the chlorophyll content of overexpressed Arabidopsis was significantly lower,the malondialdehyde and conductivity were obviously higher,and the DAB staining was deeper than that of the wild type.After drought stress treatment,the contents of proline and soluble sugar of overexpressed Arabidopsis were obviously lower than those of wild type,and the water loss rate was obviously higher.The results of RT-PCR showed that GmRPK2 overexpressed in Arabidopsis obviously inhibited SAD1,P5CS1 and ADH1 expression.It was preliminarily speculated that it might inhibit the transmission of stress signals by inhibiting the expression of these genes.Therefore,GmRPK2 gene may affect the stress resistance of Arabidopsis by inhibiting CDPK stress resistance signal transduction pathway,reducing proline accumulation and weakening ABA signal transduction pathway.

To elucidate the genetic mechanism and identify quantitative trait loci(QTL)for Aluminum(Al)tolerance in sesame.We investigated the response of Al stress using sesame landraces Jinhuangma(JHM)and Zhushanbai(ZSB)with different concentrations of Al³⁺ and confirmed a suitable Al³⁺ concentration for stress.Three traits including relative root length(RRL),relative shoot length(RSL)and relative fresh seedling weight(RSW)were evaluated in a recombinant inbred line(RIL)population with 180 lines that derived from two parents that contrasts for Al tolerance(ZSB and JHM).Quantitative trait loci(QTL)mapping were conducted by using a high resolution genetic map containing 1 354 bin markers through composition interval mapping(CIM)method.Significant positive correlations were observed among the three traits.A total of 7 QTLs were detected on 6 chromosomes(Chr2,Chr4,Chr6,Chr10,Chr11 and Chr13),including 3 RRL related QTLs,2 RSL related QTLs and 2 RSW associated QTLs.Among them,two QTLs associated with RRL and RSW were mapped to the overlapped interval on chromosome 2.Putative candidate gene analysis revealed that 15 genes may be related to Al tolerance.These genes mainly involved in metal transport and detoxification,transmembrane binding of metal ions,GDSL-motif lipase,peroxisomal catalase and metabolism and detoxification of toxic substances in organisms.

In order to investigate the optimal staining conditions for soybean seed viability determination and the changes of important physiological indexes during seed germination stage,single factor and orthogonal tests were used to design and screen the optimal combination of Triphenyltetrazolium chloride(TTC)for soybean seed viability determination.The changes of germination rate and endogenous cell wall hydrolase of soybean seeds under different germination conditions were also analyzed.Univariate analysis showed that the presence or absence of imbibition treatment was critical for seed staining,and low concentration(0.1%)TTC solution significantly reduced the seed staining rate.The results of multi-factor orthogonal test showed that the optimal dyeing conditions of soybean seeds were as follows:imbibition time 6 h,TTC concentration 1%,dyeing temperature 35 ℃,dyeing time 60 min.The dyeing rate of seeds in this combination was 98.5%.Germination rate test showed that light and dark conditions had no significant effect on germination process.Seed germination was inhibited under more water and promoted under less water.In a certain temperature range,low temperature delayed the germination process of seeds,but increased the final germination percentage of seeds.The activities of cellulase,polygalacturonase and β-galactosidase did not change significantly when seeds germinated under light and dark conditions,while the activities of xyloglucan endoglycosylase under light were significantly higher than those under dark conditions.The activities of cellulase and polygalacturonase did not change significantly when seed were imbibed in various water content.The activity of β-galactosidase increased gradually with the increase of water,while the activity of xyloglucan endoglycosylase showed an opposite trend.It is noteworthy that the activities of four cell wall hydrolases in soybean embryos were significantly elevated with the increase of germination temperature.In conclusion,TTC staining results have important practical significance for the rapid determination of soybean seed viability and the improvement of soybean seed quality testing technical regulations.Exploring the activity of cell wall hydrolase in soybean seeds under different germination conditions will help to reveal the mechanism of seed germination in dicotyledons.

In order to explore the effect of phosphorus solubilizing and potassium solubilizing fungus Aspergillus niger Z8 on soybean seed germination and seedling growth,the biomass,physiological effects,soil enzyme activity and soil microbial changes of soybean seeds and seedlings after inoculation with Aspergillus niger Z8 were measured.The results showed that Aspergillus niger Z8 had no significant effect on the germination rate of soybean seeds,but could increase the biomass of soybean sprouts,and the overall effect of K3 treatment group was better;when the concentration of bacterial solution was 1.0%,the plant height,fresh weight,dry weight and root length increased,and the content of photosynthetic pigment in soybean seedling leaves was higher.At this time,the cell volume in root tip elongation zone increased,indicating that it had the best growth potential;the results of pot experiment showed that inoculating Aspergillus niger Z8 could significantly increase the plant height(19.44%-33.47%),root length(19.95%-33.50%),fresh weight(26.67%-86.67%),dry weight(25.00%-87.50%),soluble sugar(31.67%-47.83%),soluble protein(21.70%-35.86%).The inoculation of different treatments can increase the chlorophyll (T4>T3>T2>T1>CK), superoxide dismutase (T4>T3>T1>T2>CK),catalase(T4>T3>T2>T1>CK)and peroxidase(T4>T2>T3>T1>CK)were higher than those in the control group. At the same time, soil sucrase (T4>T3>T2>T1>CK), urease(T4>T3>T2>T1>CK),catalase(T4>T2>T3>T1>CK), acid phosphatase activity (T2>T1>T3>T4>CK), neutral phosphatase(T2>T4>T1>T3>CK)and alkaline phosphatase (T4>T3>T2>T1>CK)were increased content.It had a significant promoting effect on the number of soil microorganisms,increasing the number of bacteria by 6.03%-32.66%,fungi by 22.22%-62.22% and actinomycetes by 0.67%-20.32%.In conclusion,T4 treatment group had the best promoting effect on soybean growth.Aspergillus niger Z8 had good promoting function,which can be used as a biological fertilizer for soybean planting,and is of great significance for reducing the application of chemical fertilizer and sustainable agriculture development.

In order to explore the major metabolites and the key anthocyanin synthase(ANS)genes which affecting the seed testa color in peanut,here,5 peanut varieties(lines)with different seed testa color were employed to determine the main anthocyanin metabolite,expression pattern of ANS family genes as well as their correlations in seed testa. The results showed that a total of 19 anthocyanin glycosides which belonged to 3 categories were detected in the seed testa of 5 peanut varieties(lines). Meanwhile,a total of 17 anthocyanin glycosides were found in the black seed testa,while only 4 anthocyanin glycosides were detected in white seed testa,indicating that the number of anthocyanin glycosides were gradually increased accompanying the deepening of seed testa color. In addition,the expression analysis of the 5 ANS genes showed that only Ahy_Scaffold1g106620 was highly expressed,while,the other 4 genes were almost not expressed or had a low expression. Furthermore,the expression level of Ahy_Scaffold1g106620 was significantly increased accompanying the deepening of seed testa color,suggesting that Ahy_Scaffold1g106620 was a key gene in regulating of anthocyanin synthesis. Further correlation analysis revealed that Ahy_Scaffold1g106620 was significantly and positively correlated with 12 of the 19 glycosides with correlation coefficients ranged from 0.54 to 0.82. However,Ahy_A02g006729 showed significant correlation with only 3 anthocyanin glycosides,and the other 3 genes had no correlation with anthocyanin content in seed testa. These results demonstrated that Ahy_Scaffold1g106620,a member of ANS gene family,was the vital regulatory gene in accumulating anthocyanin. In summary,all these results preliminarily discovered the main metabolites and key regulatory genes of ANS family that affect the seed testa color in peanut.

In order to clarify the similarities, differences and biological functions of Nodule inception(NIN)genes, which expressed core transcription factors NIN involved in all the biological processes from rhizobia infection to root nodule formation and nitrogen fixation in soybean, and integrates nodulation and autoregulation of nodulation signals to dynamically control the number of nodules, methods of bioinformatics were used to analyse the phylogeny, protein sequence, gene sequence and promoter elements of the four GmNINs, and Real-time PCR were carried out to verify the tissue expression pattern.The results showed that the four GmNINs proteins with similar protein sequences belonged to the specific NIN protein family in Legumes, located in the nucleus, had multiple phosphorylation sites and similar core tertiary structure with significant difference in corner. Acorrdingly, the above results indicate that the four GmNINs proteins may be redundant in core functions, but have differences in specific expression patterns.Analysis of the upstream-3 kb promoter sequence of GmNINs showed that the promoter sequence of GmNINs contained many elements such as ABRE, DRE1 and other elements related to stress and hormone response, except NBS and CYC elements.Transcriptome analysis and Real-time PCR results showed that GmNINs were highly expressed in nodules and inhibited in high nitrogen condition; they responded to salt and drought stress of varying degrees, among which GmNIN2a and GmNIN2b were more sensitive and significant in responding to abiotic stress, and GmNIN2a and GmNIN2b may play an important role in the process of plant response to abiotic stress. In short, the results revealed that GmNINs not only regulate the nodule number of soybean and nodulation, but also participate in the process of root response to abiotic stress. The discovery of this regulatory mechanism provides essential clues for breeding new varieties with high quality and high yield.

In order to explore the effect of low temperature during the flowering period in Brassica napus,Brassica napus L.GZhui(strong resistance to winter cold)and 10B(weak resistance to winter cold)were used as test materials,low-temperature stress (14 h, 12 ℃ at daytime; 10 h, 2 ℃ at nighttime) to these materials for 1, 2, 3, 4, 5 d, and normal environment(14 h,22 ℃ at daytime;10 h,18 ℃ at nighttime)as control,determine the changes of physiological indexes in bolting stem leaves and lower leaves under low-temperature stress,as well as pollen viability and stigma receptivity after the opening of flower buds of different length.The research results showed that the leaves of the two materials were slightly wilted after low-temperature treatment,and there was no obvious damage to the shape of the plants in all treatments,the changes of various physiological indexes of leaves after low-temperature treatment were more complicated,and the three antioxidant enzymes were sensitive to peroxidase(POD),and most of the antioxidant was significantly increased,lower leaves more than bolting stem leaves.The content of soluble sugar(SS)in osmotic adjustment substances changed significantly,GZhui increased significantly.Malondialdehyde(MDA)content increased significantly,10B more than GZhui,and the lower leaves and bolting stem leaves showed different performances.For flower buds larger than 6.0 mm,the pollen viability of the two materials was little affected by low-temperature treatment for 4 days.For less than 3.0 mm of flower buds,the development stopped and eventually died for more than 4 days of cold stress,and the pollen viability decreased significantly after 2—3 days of stress.After the flower buds of all levels,less than 6.0 mm were under low-temperature stress,the pollen viability of GZhui was higher than that of 10B,and the difference was obvious with the flower buds of 3.0—6.0 mm,so it was considered that the 3.0—6.0 mm flower buds could be used as an indicator for identifying different varieties of low-temperature tolerance during flowering.The performance of stigma receptivity was consistent with the trend of pollen vigor.The stigma receptivity of flower buds larger than 3.0 mm was not affected within 3 days of low-temperature treatment,and the receptivity of stigma more than 4 days of treatment was reduced;the flower buds smaller than 3.0 mm,the receptivity of stigma decreased to varying degrees within 3 days of low-temperature treatment.These results indicated that flower buds(smaller than 3.0 mm)were more sensitive to low temperature,resulting in reduced pollen vitality and stigma receptivity,and even abortion.

In order to study the effects of straw returning on soil active organic carbon components and carbon cycle related enzyme activities in rice-rape rotation farmland of Chengdu Plain,we carried out 3-year straw returning field experiment(2017—2020),including no straw(CK),chemical fertilizer alone(NPK),50% straw returning and chemical fertilizer(SR1),100% straw returning and chemical fertilizer(SR2),200% straw returning and chemical fertilizer(SR3).We measured soil physical-chemical properties,soil organic carbon content(SOC),soil labile organic C fractions,carbon cycle related enzymes,and their correlations.The results showed that straw returning could effectively improve soil physical-chemical properties,soil available nitrogen,phosphorus and potassium contents.Compared with CK treatment,straw returning treatments significantly increased SOC,ROC,DOC,and MBC contents by 5.05%—8.55%,18.40%—36.80%,35.76%—66.93% and 27.20%—52.10%,respectively.In general,higher returning dosage resulted in higher C content.On the other side,compared with CK and NPK,straw returning treatments significantly increased soil cellulase,β-glucosidase,catalase,polyphenol oxidase.The activities of soil cellulase,β-glucosidase,and polyphenol oxidase under SR2 treatment were the highest,which were significantly higher than SR1 treatment by 16.25%,8.49%,and 14.69%,respectively.The catalase activity of SR3 treatment was the highest,which was significantly higher than that of SR1 treatment by 25.10%(P<0.05).There were significant positive linear correlations among soil SOC,labile SOC fractions,and carbon cycle related enzyme activities.Consequently,full straw returning has been proved of the most efficient way of improving active organic carbon components,carbon cycle related enzyme activities,and promoting the improvement of soil quality in rice-rape rotation farmland of Chengdu Plain.

To screen out new candidate rapeseed varieties suitable for production in South China region,field trail data of fourteen early-mature rapeseed new varieties in China's regional trial was first analyzed by AMMI models,and then the relationship between G×E interaction and climate factors in eight experimental sites were investigated by GGE biplot method. Then biomass and photosynthetic parameters during wintering were also investigated in a representative variety. This analysis allowed a deeper understanding of the influence of climate factors and physiology on yield formation,by which new varieties with better adaptation can be identified and used in agricultural production. The results showed that the mean yield of 14 varieties varied markedly,with S0013 ranking the highest(2 191.021 kg/ha)and 282081 the lowest (1 328.512 kg/ha, only 60% of the previous one). Combined ANOVA indicated that the majority of variation was from the environment effect(82.27%)and the least from the genotype effect(4.93%). Moreover,variation from genotype×environment interaction(G×E)was also very significant,although it only accounted for 10.17% of total variation,most of which(92.63%)could be further dissected by AMMI model. It seemed that yielding ability was mainly affected by climate factor such as rainfall,while yield stability was largely determined by temperature. For yield stability,the fourteen varieties were ranked,from high to low,as Qianza ZW9001>Qianza J9002>C868>05V11>Qianza J9001>WB203>Chuanza 09NH014>S0013>Yunyouza No.2>Za 1613>08SH60>282081>Ronghua 906>131(CK). Among these,S0013,C868 and WB203 had the highest yield,while 282081 the lowest. The discriminating power for experimental sites were listed,in descending order as Yuxi>Baoshan>Ji'an>Nanchang(Yichun)>Guilin>Changsha>Anshun. Moreover,the biomass of YG131 during wintering was the highest in Guilin. Meanwhile,photosynthetic parameters such as Pn,Tr and Ci were also high and positively correlated with plot yield,suggesting that active photosynthesis promote yield formation. Taken together,the comprehensive evaluation of field performance for new rapeseed varieties in Chinese national field trial through AMMI model and GGE biplot can provide valuable information for the breeding of early maturing rapeseed varieties and the selection of idea experimental sites.

In order to explore the control effect of nitrogen fertilizer on soybean cyst nematode disease,pot experiment and field experiment were carried out to analyze the effect of nitrogen fertilizer on the egg hatching,nematode development of soybean cyst nematode and the yield of soybean. Four nitrogen application levels were set as 0.016,0.032,0.048,0.064 g/kg soil,respectively,to analyze the effect of soil eluviating solution and root exudate solution on egg hatching. In the field experiment,four nitrogen application levels were set as 22.50,56.25,67.50,78.75 kg/ha,respectively,to analyze the effect of nitrogen fertilizer on the development of nematode. Treatment without nitrogen fertilizer was used as a blank control in all experiments. The results of pot experiment showed that both soil eluviating solution and root exudate solution could significantly improve egg hatching inhibition rate of H. glycines after nitrogen fertilizer application. The soil eluviating solution of 0.032,0.064 g/kg soil had the best inhibition effect on H. glycines egg hatching,reaching at 34.21% and 29.31%,respectively,the root exudate solution of 0.064 g/kg soil had the best inhibition effect on egg hatching of H. glycines,reaching 55.09%. The field experiment showed that proper application of nitrogen fertilizer could significantly decrease cyst number but increase soybean yield. Treatment with 56.25 kg/ha nitrogen fertilizer had the best control effect on nematodes and the highest yield of soybean,with cyst number decreased by 25.29% and the yield of soybean increased by 14.75%. However,the number of nematode in the control increased by 30.77%. Therefore,application of nitrogen fertilizer is an economical and safe control method to improve the yield and quality of soybean.

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

Zinc finger proteins are transcription factors widely studied in eukaryotes,and play important roles in plant growth and development,and responses to stresses.In order to deeply understand the gene function of zinc finger protein in soybean,the full-length CDS sequence of GmZAT12 gene was cloned from Shangdou 1201,and the characteristics of coded protein by this gene was predicted by bioinformatics analysis.The subcellular localization of GmZAT12 protein was detected by the tobacco epidermal injection system, and the expression pattern of GmZAT12 gene in different tissues of soybean and abiotic stress was analyzed by Real-time PCR (qRT-PCR) technology. The results showed that GmZAT12 CDS contained 516 bp,encoding 171 amino acids and the molecular weight of the protein was 19.264 28 ku with a theoretical isoelectric point(pI)of 9.02.Its main components were random coils and α-helices and it contained 20 phosphorylation sites, mainly serine phosphorylation sites.Sequence analysis indicated that GmZAT12 possessed two conserved C2H2 zinc finger domains.The result of subcellular location indicated that GmZAT12 protein was localized in the nucleus.The results of qRT-PCR showed that CmZAT12 gene expressed mainly in roots,leaves and seeds of soybean,while low expression in flower and stem, and was induced by high temperature,low temperature,NaCl and ABA.The fact implied that this gene might be involved in abiotic stress signaling pathways.

To characterize the genomic structure of Cowpea mild mottle virus (CpMMV)Jiangsu isolate and clarify its taxonomic status and evolutionary characteristics,4 pairs of specific primers were designed and the genomic fragments were amplified using cDNA obtained from reverse transcription of total RNA of a soybean sample collected from Jiangsu as a temple.The amplified products were cloned and sequenced,and the obtained fragments were assembled to get the full genomic sequence.Sequence analysis revealed the genome of Jiangsu isolate were 8 194 bp in length,containing 6 ORFs and 2 untranslated regions(UTRs):5' UTR(72 nt)and 3' UTR(117 nt).Among the six proteins encoded by CpMMV,CP shared highest amino acid sequence identities with other isolates(96.5%-100.0%),while RdRp(81.1%-98.2%),TGB1(81.0%-97.0%)and TGB3(80.9%-95.6%)shared relatively low sequence identities,indicating CP might be a conservative gene and RdRp,TGB1,TGB3 might show good diversity in different isolates.The phylogenetic analysis based on the whole genomic sequence revealed that Jiangsu isolate was clustered with other CpMMV isolates in a branch and it shared highest nucleotide sequence identities with 2 Chinese isolates(98.2% with Anhui isolate,96.0% with Hainan isolate),compared with other foreign isolates such as the United States,Brazil,India,Mexico,Kenya and so on(<82.7%).These results clarified the genomic structure of Jiangsu isolate,which shared similar character with other CpMMV isolates and phylogenetic analysis revealed Jiangsu isolates clustered with other isolates from China with higher sequences identities,compared with foreign isolates.

To further understand the role of the promoter in the regulation of the expression of the Brassica napus FIL gene(BnaFIL),it used the DNA extracted from the leaves of Brassica napus as a template based on the genomic data of Brassica napus.For cloning,the length was 1 326 bp.Using PlantCARE online analysis software to perform bioinformatics sequence analysis on the promoter sequence,the results showed that the sequence contained some conserved DNA modules involved in the photoreaction and essential elements for core promoters such as CAAT-box and TATA-box.Expression related cis-acting regulatory elements CAT-box and photosensitive response elements.Replace the CaMV35S promoter on the pBI121 plant vector with the promoter sequence,fused the promoter with the GUS gene to obtain the pBnaFIL-GUS expression vector,and transfer the vector into Arabidopsis thaliana by the method of Agrobacterium inflorescence.Flower promoter recombinant plasmid-positive transgenic lines and late flower promoter recombinant plasmid-positive transgenic lines.After that,GUS staining analysis was performed on the transgenic Arabidopsis plants,and the expression effect of the promoter was tested.Finally,the GUS gene expression was found in different transgenic Arabidopsis plants.The results showed that there were differences in promoter expression between early-flowering materials and late-flowering materials.The promoters of early-flowering materials could drive gene expression better than those of late-flowering materials.It was inferred from this that the driving effect of the promoter regulates the early and late flowering of rape,resulting in different expression effects of the FIL gene in different materials.

To clarify the lignin accumulation ways in the stem of soybean variety,and further understand the relation between the lignin accumulation and lodging resistance of soybean plant,which could give the theory evidence for plant phenotype regulation and new soybean variety breeding under different planting densities,Charleston,a representative variety with determinate growth habit,was selected in current study and were planted with two densities of 20,35 plants/m².The lignin content in the elongation zone(EZ)and the secondary cell wall maturation zone(MZ)at the third internode of Charleston's stem were measured and the activities of key enzymes such as 4-Coumarate:coenzyme A ligase(4CL)and phenylalanine aminotransferase(PAL)and cinnamate dehydrogenase(CAD)involved in the lignin synthesis were determined at two different densities.The results showed that lignin content in the stem of Charleston under low density was higher than that under high density.The content of lignin in single internode(stem 3)of Charleston under both high and low density treatments was MZ>EZ.4CL,PAL and CAD activities in low density Charleston stem were higher than those in high density of Charleston and in accordance with gene expression levels.The key genes for lignin synthesized were distributed in soybean genome in different gene families.Moreover,different enzyme gene in one gene family showed different expression style in the same section.Same results could be observed in different organ for one gene.