A novel procedure for identifying a hybrid QTL-allele system for hybrid-vigor improvement, with a case study in soybean(Glycine max)yield

“Breeding by design” for pure lines may be achieved by construction of an additive QTL-allele matrix in a germplasm panel or breeding population, but this option is not available for hybrids, where both additive and dominance QTL-allele matrices must be constructed. In this study, a hybrid-QTL identification approach, designated PLSRGA, using partial least squares regression(PLSR) for model fitting integrated with a genetic algorithm(GA) for variable selection based on a multi-locus, multi-allele model is described for additive and dominance QTL-allele detection in a diallel hybrid population(DHP). The PLSRGA was shown by simulation experiments to be superior to single-marker analysis and was then used for QTL-allele identification in a soybean DPH yield experiment with eight parents. Twenty-eight main-effect QTL with 138 alleles and nine QTL × environment QTL with 46 alleles were identified, with respective contributions of 61.8% and 23.5% of phenotypic variation. Main-effect additive and dominance QTL-allele matrices were established as a compact form of the DHP genetic structure. The mechanism of heterosis superior-to-parents(or superior-to-parents heterosis, SPH) was explored and might be explained by a complementary locus-set composed of OD+(showing positive over-dominance, most often), PD+(showing positive partial-to-complete dominance, less often) and HA+(showing positive homozygous additivity, occasionally) loci, depending on the parental materials. Any locus-type, whether OD+, PD + and HA+, could be the best genotype of a locus. All hybrids showed various numbers of better or best genotypes at many but not necessarily all loci, indicating further SPH improvement. Based on the additive/dominance QTL-allele matrices, the best hybrid genotype was predicted, and a hybrid improvement approach is suggested. PLSRGA is powerful for hybrid QTL-allele detection and cross-SPH improvement.

利用中国秋大豆(Glycine max(L.) Merr)筛选SSR核心位点的研究

选择中国秋大豆为试验材料 ,对基因组DNA进行SSR标记筛选和鉴定。经过 2 0 0个位点在琼脂糖胶上初筛和 96个位点在变性聚丙烯酰胺胶上复鉴 ,选出 6 0个位点 ,这些位点具有以下特点 :(1)分布在大豆 2 0个整合遗传连锁群 ,相邻位点间平均遗传距离在 5 0cM左右。除连锁群C2 、O上分别有 5个位点 ,G、K、M上分别有 2个位点外 ,其余 15个连锁群均分布有 3个位点 ;(2 )与 96个位点在 80份秋大豆种质检测到种质间遗传关系达到极显著相关 (r =0 .910 ) ;(3)在 80份秋大豆初选核心种质中表现出较高多态性 ,平均每个位点等位变异数为 9.3,多态性信息含量 (PIC)值为 0 .773;(4)在检测的秋大豆绝大多数种质基因组中 ,均为单一拷贝的位点 ,具有较高特异性 ;(5 )在相同的PCR扩增条件下 ,同一位点不同等位变异间易于识别且扩增强度较为一致。这套SSR核心位点的确定为中国大豆核心种质的构建奠定了基础。

大豆(Glycine max(L.) Merr.)叶片抗氧化酶对干旱及复水的响应机制

采用10%PEG-6000模拟干旱胁迫,研究了抗旱品种晋大74与不抗旱品种晋大75两种大豆幼苗在水分胁迫及复水后叶片MDA含量、O2-·含量、SOD、CAT、APX及POD等的活性变化,旨在揭示抗氧化酶对干旱及复水的响应机制。结果表明,在干旱胁迫下,两种大豆叶片MDA及O2-·,含量都高于对照,且晋大75增加幅度显著大于晋大74;复水后晋大74中MDA及O2-·接近于对照水平,表明旱后复水产生了补偿效应。干旱胁迫下,晋大74通过保持较高的SOD活性或较低的APX、CAT降幅以减弱活性氧伤害,而旱后复水过程中晋大74通过维持较高的SOD、APX、CAT酶活性,利用其协同作用有效清除活性氧,避免膜伤害。总之,耐旱品种在干旱及复水过程中具有更强的抗氧化修复能力。

野生大豆(Glycine soja)YD63和栽培大豆(G. max)ZD19茎秆解剖结构比较

以野生大豆YD63和栽培大豆ZD19为研究对象,通过组织化学方法观察茎秆解剖结构的差异,分析和阐述这些解剖结构与功能和环境适应性间的关系,旨在为大豆抗逆性研究提供解剖学依据。结果表明:1.野生大豆表皮毛和腺毛多于栽培大豆,且角质层厚度、表皮厚度和表皮比例均大于栽培大豆,表皮和外皮层细胞的木质化和木栓化程度也高于栽培大豆;2.野生大豆皮层、韧皮部、木薄壁组织和髓的比例均大于栽培大豆,茎秆机械强度降低,可塑性升高,抗逆性增强;3.栽培大豆木质部、木纤维和总纤维比例均大于野生大豆,并且表皮细胞壁、韧皮纤维壁、木纤维壁和导管壁厚度均大于野生大豆。栽培大豆组织木质化的比例大于野生大豆,茎秆的机械强度升高,可以更好地维持直立生长和形态构建;4.栽培大豆微管形成层的细胞层数和厚度均大于野生大豆。栽培大豆木质部的比例大于韧皮部的比例,而野生大豆两者比例基本相同;5.野生大豆韧皮部厚壁组织几乎是连续分布,仅在髓射线处中断,而栽培大豆是不连续的,呈片状分布,野生大豆韧皮部厚壁组织的比例大于栽培大豆;6.野生大豆导管壁强度(t/b)2和小导管比例大于栽培大豆,水分运输的安全性较高,但野生大豆木质部的连通性和水分运输的效率低于栽培大豆。

Effects of salinity on activities of H^+-ATPase, H^+-PPase and membrane lipid composition in plasma membrane and tonoplast vesicles isolated from soybean(Glycine max L.) seedlings

The effects of NaCl stress on the H +-ATPase, H +-PPase activity and lipid composition of plasma membrane(PM) and tonoplast(TP) vesicles isolated from roots and leaves of two soybean cultivars(Glycine max L.) differing in salt tolerance(Wenfeng7, salt-tolerant; Union, salt-sensitive) were investigated. When Wenfeng7 was treated with 0.3%(W/V) NaCl for 3 d, the H +-ATPase activities in PM and TP from roots and leaves exhibited a reduction and an enhancement, respectively. The H +-PPase activity in TP from roots also increased. Similar effects were not observed in roots of Union. In addition, the increases of phospholipid content and ratios of phospholipid to galactolipid in PM and TP from roots and leaves of Wenfeng7 may also change membrane permeability and hence affect salt tolerance.

Analysis of QTLs for the Trichome Density on the Upper and Downer Surface of Leaf Blade in Soybean [Glycine max (L.) Merr.]

Trichomes （plant hairs） are present on nearly all land plants and are known to play important roles in plant protection, specifically against insect herbivory, drought, and UV radiation. The identification of quantitative trait loci （QTL） associated with trichome density should help to interpret the molecular genetic mechanism of soybean trichome density. 184 recombinant inbred lines （RILs）, derived from a cross between soybean cultivars Kefeng 1 and Nannong 1138-2 were used as segregating population for evaluation of TDU （trichome density on the upper surface of leaf blade） and TDD （trichome density on the downer surface of leaf blade）. A total of 15 QTL were detected on molecular linkage groups （MLG） A2, Dla, Dlb, E and H by composite interval mapping （CIM） and among all the QTL, qtuA2-1, qtuD 1 a-1, qtuD lb-2, qtuH-2 qtuE-1, qtdDlb-2, and qtdH- 2 were affirmed by multiple interval mapping （MIM）. The contribution ofphenotypic variance of qtuH-2 was 31.81 and 29.4% by CIM and MIM, respectively, suggesting it might be major gene Ps loci. Only 10 pairs of main QTL interactions for TDU were detected, explained a range of 0.2-5.1% of phenotypic variations for each pair for a total of 22.8%. The QTL on MLG Dlb affecting trichome density were mapped near to Rsc-7 conditioning resistance to SMV （soybean mosaic virus）. This study showed that the genetic mechanism of trichome density was the mixed major gene and polygene inheritance, and also suggested that the causal nature between trichome density and other agronomic traits.

Genetic Analysis of Combining Abilities and Heterosis for the Contents of Soybean Isoflavone and Its Components Among the Soybean Varieties [Glycine max (L.) Merr.]

The genetic analysis of soybean isoflavone content and its components were carried out based on the NC Ⅱ matingdesign in eight soybean varieties. The results showed that the isoflavone contents and its components of soybean seedare quite differences among the tested materials, the contents of isoflavone and daidzein are controlled not only byadditive effects and but also by non-additive effects, while the content of genistin is dominated by non-additive effects,and genistein, glycitin and daidzin are mainly controlled by additive effects. There are significant differences in thecontents of isoflavone and its components among the combinations derived from different parents. Results also indicatedthat the tested traits are negatively heterosis except for the contens of daidzein and daidzin are positively heterosis basedon the data of the GCA and SCA in average heterosis values. In this research we have a suggestion that soybean varietywith high isoflavone should be used as one of the parents in the breeding program, and it is the best choice that thecombinations crossed between two high isoflavone varieties or a high variety and a low one.

Genetic Analysis of Embryo, Cytoplasm and Maternal Effects and Their Environment Interactions for Isoflavone Content in Soybean [Glycine max (L.) Merr.]

Soybean seed products contain isoflavones （genistein, daidzein, and glycitein） that display biological effects when ingested by humans and animals. These effects are species, dose and age dependent. Therefore, the content and quality of isoflavones in soybeans is a key factor to the biological effect. Our objective was to identify the genetic effects that underlie the isoflavone content in soybean seeds. A genetic model for quantitative traits of seeds in diploid plants was applied to estimate the genetic main effects and genotype x environment （GE） interaction effects for the isoflavone content （IC） of soybean seeds by using two years experimental data with an incomplete diallel mating design of six parents. Results showed that the IC of soybean seeds was simultaneously controlled by the genetic effects of maternal, embryo, and cytoplasm, of which maternal genetic effects were most important, followed by embryo and cytoplasmic genetic effects. The main effects of different genetic systems on IC trait were more important than environment interaction effects. The strong dominance effects on isoflavone from residual was made easily by environment conditions. Therefore, the improvement of the IC of soybean seeds would be more efficient when selection is based on maternal plants than that on the single seed. Maternal heritability （65.73%） was most important for IC, followed by embryo heritability （25.87%） and cytoplasmic heritability （8.39%）. Based on predicated genetic effects, Yudou 29 and Zheng 90007 were better than other parents for increasing IC in the progeny and improving the quality of soybean, The significant effects of maternal and embryo dominance effects in variance show that the embryo heterosis and maternal heterosis are existent and uninfluenced by environment interaction effects.

Proteomic Studies of Petal-specific Proteins in Soybean [Glycine Max(L.)Merr.] Florets

A survey of petal-specific proteomes of soybean(Glycine max(L.) Merr[Non-italic].) was conducted comparing protein expression profiles in different petals. Two-dimensional polyacrylamide gel electrophoresis reference maps of protein extracts from standard petals(SP), lateral wings(LW), keel petals(KP), and reproductive organs(RO)(a mixture of stamen and carpel) were obtained. Protein expression in the three petal types was compared using Image Master TM 2 D platinum 6.0 software. This indicated that the proportion of homologous proteins between SP and LW was 59.27%, between SP and KP was 61.48%, and between LW and KP was 60.05%. Within a mass range of 6.5-200.0 ku and pH 4.0-7.0, approximately 590, 646, 544, and 700 protein spots were detected in SP, LW, KP, and RO, respectively. A total of 82 differentially expressed proteins were detected. Sixty-four of these detected spots were differentially expressed and showed more than 2-fold changes in abundance; of these 64 proteins, 26 showed increased expression and 38 showed decreased expression. Among these spots, single organ-specific proteins were also identified.They were ID 49(60.9 ku), ID 45(50.0 ku), and ID 46(40.5 ku) in RO, ID 98(42.0 ku) in SP, and ID 05(29.0 ku) in KP. A total of 14 protein spots from 82 differentially expressed proteins were identified with LC-MS/MS. Further protein identification was conducted using the SwissProt and NCBInr databases. The identified proteins and their putative functions were discussed further. This was the first study reporting the comparison of petal protein profiles of soybean florets using proteomics tools.

Effect of Different Potting Mixtures on Growth and Yield of Soybean （Glycine max L.） and Soil Microbial Activity

Soybean （Glycine max： Fabaceae） is a mycotrophic （mycorrhizal） crop grown commercially for human consumption. Seven different fertilizer mixtures, namely cow dung, coir dust, mush room medium waste, saw dust, compost, decaying leaves and field soil with standard dose of NPK （control） were used for this experiment. The variety used was PM 25. Soil microbial activity was measured using CO2 evolution method. The experiment was carried out as a complete randomized block design with five replicates at the rate of eight plants per replicate. Average number of leaves on 25-day and 45-day old plants, shoot-length, root-length, number of pods per plant, wet weight of pod per plant, dry weight of pod per plant, plant wet weight, plant dry weight and seed dry weight per pod were measured. All management practices were conducted according to recommendations of the Department of Agriculture from seed germination to harvesting. Data were analyzed using SAS program （9.1.3）. Highest number of pods/plant （100, 124, 102, 106） and dry-seed-weight in g/plant （12, 14.8, 12, 12） were recorded in those grown in cow dung, compost, decaying leaves and inorganic mixture （control） whereas the lowest pod production （8.7 pods/plant） and seed dry weight （1.0 g/plant） was recorded in saw dust. Instead of inorganic fertilizer there is possibility to use organic potting mixtures like compost and decaying leaves which gave a significant difference in crop productivity as compared to other treatments. Significantly highest mean microbial activity was observed in potting media filled with coir dust.

垄作和覆膜下盐碱地水盐运移和大豆产量的变化

选择河北省黄骅市中度盐碱土区布置夏播大豆[Glycine max(L.)Merr.]田间试验,共设平播(对照)、平播覆膜、垄作及垄作覆膜4个处理,研究垄作和覆膜对土壤水盐运移和大豆产量的影响。结果表明,与传统平播方式相比,平播覆膜处理对土壤水盐运移和大豆产量的影响不显著;垄作处理能显著改变土壤水盐分布,特别是大豆生长中后期降雨量开始减少后,垄作定植沟会产生叠加集雨效果,显著提高大豆生长中期0~20 cm和20~40 cm土壤含水量,减缓作物生长后期向表层返盐进程,有效降低土壤表层盐分含量,对保障大豆植株生长和产量均有一定的促进效果,可增产27.2%;垄作覆膜处理效果与垄作处理类似,覆膜措施影响不显著。垄作技术可以作为滨海盐碱地夏播大豆种植的农耕措施。

大豆对胞囊线虫(Heterodera glycines Ichinohe)1号和4号生理小种抗性的遗传分析

大豆胞囊线虫(Heterodera glycinesIchinohe)是我国大豆的全国性主要病害之一。1号和4号生理小种是黄淮地区的优势小种。以Essex×ZDD2315、Peking×ZDD2315、PI88788×ZDD2226、Peking×ZDD2226的P1、P2、F1、BC1F2为材料,用主基因+多基因混合遗传模型分析大豆对胞囊线虫1号和4号生理小种抗性的遗传机制。结果表明,ZDD2315、ZDD2226对1号生理小种的抗性受主效基因控制,未发现多基因效应,且与Peking存在相同的抗病基因;抗性遗传表现组合特异性,Essex×ZDD2315组合为3对加性主基因遗传模型,主基因遗传率72.02%,PI88788×ZDD2226组合为2对显性上位主基因遗传模型,主基因遗传率62.33%。对4号生理小种的抗性为主基因+多基因混合遗传模型,Essex×ZDD2315、Peking×ZDD2315、PI88788×ZDD2226等3个组合为3对主基因+多基因遗传模型,主基因遗传率分别为67.76%7、2.46%和53.25%,多基因遗传率分别为24.48%、21.31%和35.77%;Peking×ZDD2226表现为2对主基因遗传模型,主基因遗传率45.40%。抗性基因表现为隐性,育种上可以在早代选择。培育多抗品种应以抗4号生理小种为主要目标进行基因聚合。

盐酸环丙沙星对大豆早期生长发育的影响

目的:探究盐酸环丙沙星类抗生素残留对农作物生长发育的毒性作用。方法:设置系列浓度梯度的盐酸环丙沙星,研究其对大豆萌发及其幼苗生长发育的影响。结果:在0~100 mg/L的浓度条件下,大豆种子的发芽率、发芽指数和活力指数均随盐酸环丙沙星浓度的增大均呈下降趋势。当盐酸环丙沙星浓度为5 mg/L时,发芽势最高,与对照组相比无显著差异;当盐酸环丙沙星浓度>5 mg/L时,随浓度升高发芽势不断下降。在96 h内,5 mg/L组的大豆总长度均高于其他组,但随着时间延长,大豆总长度随盐酸环丙沙星浓度的升高而降低,其中100 mg/L抑制作用最明显,总长度最短。与对照组相比,大豆幼苗鲜质量和各类叶绿素含量均随盐酸环丙沙星浓度的增大而减少。结论:环境中的高浓度的盐酸环丙沙星会抑制大豆的萌发及早期生长发育。

Genome-wide association with transcriptomics reveals a shade-tolerance gene network in soybean

Shade tolerance is essential for soybeans in inter/relay cropping systems.A genome-wide association study(GWAS)integrated with transcriptome sequencing was performed to identify genes and construct a genetic network governing the trait in a set of recombinant inbred lines derived from two soybean parents with contrasting shade tolerance.An improved GWAS procedure,restricted two-stage multi-locus genome-wide association study based on gene/allele sequence markers(GASM-RTM-GWAS),identified 140 genes and their alleles associated with shade-tolerance index(STI),146 with relative pith cell length(RCL),and nine with both.Annotation of these genes by biological categories allowed the construction of a protein–protein interaction network by 187 genes,of which half were differentially expressed under shading and non-shading conditions as well as at different growth stages.From the identified genes,three ones jointly identified for both traits by both GWAS and transcriptome and two genes with maximum links were chosen as beginners for entrance into the network.Altogether,both STI and RCL gene systems worked for shade-tolerance with genes interacted each other,this confirmed that shadetolerance is regulated by more than single group of interacted genes,involving multiple biological functions as a gene network.

Soybean Response to Weed Residues in the Soil

Soybean production systems that return plant residues to the soil surface are gaining in popularity. As these practices become more widespread, more crop and weed residues are being introduced into the upper soil profile. Greenhouse studies were conducted to determine the effects of varying concentrations of Palmer amaranth and pitted morningglory plant residues (aboveground portion of the plant) on soybean production. The study was arranged in a completely randomized experimental design with five treatments and five replications. Palmer amaranth and pitted morningglory residues were incorporated into soil at 20,000, 40,000, 80,000 and 160,000 ppm. Inert plastic residue at the same residue levels was included as a check. Soybean dry weight, leaf area and leaf tissue nutrient content were recorded during the study. A decrease in soybean dry weight and leaf area was observed as Palmer amaranth residue in the soil increased. Palmer amaranth residues of 160,000 ppm and 80,000 ppm in the soil significantly reduced soybean dry weight by 69% and 59%, respectively, and soybean leaf area by 60% and 57%, respectively. In contrast, pitted morningglory and inert plastic residues had no observable effect on soybean growth and development. This study demonstrated Palmer amaranth residues in the soil impacted early season soybean growth and development.

汉川市带状复合种植模式下不同品种大豆玉米产量及效益分析

为了探索汉川市带状复合种植模式下不同品种大豆[Glycine max(L.)Merr.]、玉米(Zea mays L.)的产量及效益表现,分析了多个品种大豆、玉米在该模式下的产量、经济效益、社会效益。结果表明,大豆品种中豆63和玉米品种汉玉919在经济效益上表现优异。

Sampling Survey and Identification of Races of Soybean Cyst Nematode (Heterodera glycines Ichinohe) in Huang-Huai Valleys

Soybean cyst nematode （SCN Heterodera glycines Ichinohe） is one of the most important nationwide soybean diseases in China. A total of 38 soil specimens or locations in the area was sampled and tested for SCN races during 2001-2003 for the inspection of race distribution in Huang-Huai Valleys. A map of race distribution was constructed according to the data from both the present study and the published reports cited. Three areas, namely, the area of southeast to Jinan in Shangdong Province; the area of northern Henan Province and its border region to south of Hebei Province; and the area of Luohe, Zhoukou of Henan Province and Fuyang of Anhui Province mainly infested with Race 1 were identified. Race 4 was predominant in Shanxi Province, Beijing and the adjacent area of Henan, Shandong, and Anhui provinces, and the delta of Huanghe River in Shandong Province. Race 2 was mainly found in Liaocheng, Dezhou of Shangdong Province and Shijiazhuang of Hebei Province, and Jiaozuo and Huojia of Henan Province. Race 7 was distributed in the west part of Jiaodong Peninsula of Shandong Province and Kaifeng, Huaxian, Wenxian of Henan Province. Race 5 was found and scattered in Hebei and Henan Province. Race 9 was found in Shangqiu of Henan Province, which was reported for the first time in China. It can be seen that Race 1 and Race 4 were the two predominant races in Huang-Huai Valleys, and that research should focus on developing resistant cultivars of these races. There might exist other races in an area with some predominant races. The race substitution in the past decade was not obviously found, therefore, the results should be meaningful to future breeding for resistance to SCN in Huang-Huai Valleys.

大豆R6期籽粒氨基酸含量的全基因组关联分析

为解析大豆R6期籽粒氨基酸含量的遗传机制,本研究利用264份大豆种质资源材料在2020年和2021年测定了与菜用大豆食味品质相关的精氨酸、丙氨酸、谷氨酸和天冬氨酸含量,并进行全基因组关联分析(GWAS)。结果表明,2年共检测到89个与大豆R6期籽粒4种氨基酸含量显著关联的SNP位点,其中有5个标记能同时被2年或2个性状重复检测到,分别为S03_40647948(Chr.3)、S05_2727464(Chr.5)、S10_4122977(Chr.10)、S17_34559022(Chr.17)和S19_48541685(Chr.19),单个位点可以解释11.25%~28.19%的表型变异解,其中Chr.17上的标记S17_34559022在2020年和2021年被共同检测到与谷氨酸含量显著关联,属稳定遗传的位点。共挖掘出9个候选基因,其中ZIP蛋白(zinc finger family protein)、转录因子bHLH(bHLH DNA-binding superfamily protein)、生长素反应蛋白家族(auxin-responsive protein family)和天冬氨酸蛋白酶家族蛋白(aspartyl protease family protein),可能是影响菜用大豆氨基酸代谢的重要基因。本研究挖掘到的5个氨基酸含量主效SNP位点和9个候选基因,有助于解析大豆R6期籽粒氨基酸含量的遗传基础及其调控机制,为菜用大豆食味品质遗传改良奠定了基础。

大豆诱变育种技术的研究进展

随着经济的发展,人们对大豆需求量及品质要求越来越高,培育高产量、多抗性、优质大豆品种迫在眉睫。然而受生态条件的限制,优质大豆种质资源材料匮乏,遗传背景狭窄,而且大豆自然变异过程繁琐且漫长,仅依靠大豆自发突变获得优质遗传材料十分困难,因此利用诱变技术创制优质、高产、多抗新种质是发展大豆产业的有效手段之一。诱变育种技术与常规育种相比,更有利于提高基因变异频率,扩大育种选择范围,高通量筛选有益突变,促进优良性状重组等,能够在短时间内获得性状丰富的突变体,解决种质资源遗传基础狭窄的瓶颈问题,广泛应用于优良性状的大豆新品种选育。本文概述了化学诱变、物理诱变的原理、种类及特点,总结归纳了国内外大豆种质创新中常用的诱变方法和技术优势,展望未来大豆诱变育种技术的应用前景,为大豆育种实践提供参考与启发。

外源褪黑素对铜胁迫下大豆幼苗生长及生理特性的影响

【目的】研究在铜(Cu)胁迫下,褪黑素对大豆Glycine max(Linn.)Merr.生理特性的影响,为缓解重金属胁迫提供一定的参考。【方法】采用盆栽试验,选用Cu敏感品种‘桂早1号’和耐Cu品种‘巴西13’,在0.5 mmol·L^(−1) Cu胁迫下,施用100μmol·L^(−1)褪黑素,探究褪黑素对大豆生理指标(根长、株高、鲜质量、叶绿素相对含量和Cu含量),超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性,丙二醛(MDA)、可溶性糖和可溶性蛋白含量的影响。【结果】Cu胁迫下喷施100μmol·L^(−1)褪黑素显著提高了2个大豆品种的根长、株高、鲜质量和叶绿素相对含量。Cu胁迫下施用褪黑素显著降低2个品种地上部、地下部Cu含量,‘桂早1号’降低25.01%、18.40%,‘巴西13’降低26.84%、20.28%。Cu胁迫下施用褪黑素,‘桂早1号’的地上部POD活性和‘巴西13’的地下部CAT活性显著提高,分别为56.84%和48.35%;‘桂早1号’和‘巴西13’地上部SOD活性分别显著提高19.07%和7.30%;地上部MDA含量分别显著减少8.05%和26.56%。单施褪黑素和Cu胁迫下施用褪黑素对2个品种可溶性蛋白含量无显著影响;而Cu胁迫下施用褪黑素,‘桂早1号’和‘巴西13’地上部可溶性糖含量分别显著提高149.70%和58.75%。【结论】适宜浓度的褪黑素可以通过提高植株抗氧化酶活性,抑制膜脂氧化,减少对Cu的吸收和增加渗透调节物质等方式缓解Cu胁迫对大豆生长发育的影响。