To investigate the molecular genetic basis of seed size in soybean under multiple environments and to explore SNP loci and candidate genes associated with seed size traits, germplasm of 150 soybean resources was used for phenotypic determination of seed length, seed width, seed thickness and 100-seed weight traits under 6 environments in 2019 and 2020, and genome-wide association analysis was also conducted. Results showed that 896SNP loci, distributed on 20 chromosomes, were detected significantly associated with seed size traits under 6 environments using CMLM（compressed linear mixed model） method. Seventy-two SNP loci were detected 3 or more times for different traits. SNP loci were detected in two or more years for the same trait, with a contribution rate of 10.68%-24.93%. Thirty-five stably expressed SNP loci were acquired with a contribution rate of 10.92%-23.16%by the analysis of stability and overlap. The most significantly associated SNP loci were detected simultaneously in seed width, seed thickness and 100-seed weight traits, with the highest contribution of 16.51% for rs16533609.Based on the screening of candidate genes by stably expressed SNP, it was hypothesized that the seven genes Glyma.03G006600, Glyma.04G077100, Glyma.08G203600, Glyma.12G195400, Glyma.17G039800, Glyma.18G202100and Glyma.20G215700 have regulators effect on soybean seed size traits.

研究采用芽期耐盐性状差异显著的东农46和L-100杂交衍生的包含127个家系的F2:12和F2:13重组自交系群体为试验材料,调查耐盐性状:吸胀率(IR)、发芽指数(GI)和发芽率(GR),计算3个相对耐盐指数:相对吸胀率(STIR)、相对发芽指数(STGI)和相对发芽率(STGR),利用QTL IciMapping 4.1.0.0软件对3个相对耐盐指数作QTL分析.结果表明,共检测到12个加性QTL,贡献率为4.88％～15.91％,2个位点有重叠区间,3个性状表型贡献率最高QTL分别为qSTIR-9-1(15.91％)、qSTGI-2-1(10.21％)和qSTGR-20-1(12.23％),共检测到108个上位性QTL,贡献率为0.55％～26.59％.该耐盐性状QTL为分子辅助培育抗盐大豆品种奠定基础.

大豆是重要的粮油作物,而我国大豆主要依靠进口,提高大豆产量对保障国家粮油安全意义重大.为定位大豆产量相关性状,本研究以产量差异显著的东农42和东农50作为杂交亲本,构建了包含168个家系的重组自交系(recombination inbred lines,RILs)群体,对其进行全基因组重测序,构建高密度遗传图谱,并利用R/qtl软件的复合区间作图法(composite interval mapping,CIM)结合两年六点的大豆产量相关性状表型数据,进行QTL定位.结果表明:利用测序获得的660316个SNP标记构建了一张分布在20个连锁群的包含6227个bin标记的大豆高密度遗传图谱,总图距和平均图距分别为2739.15 cM,0.44 cM.在12个染色体上定位到22个大豆产量相关性状QTL,四粒荚数、单株荚数、单株粒重和百粒重性状定位到的QTL分别为5、4、5和8个.在3号和19号染色体上各有一段基因组区域在两年间重复定位,涉及6个主效QTL,分别为qNFSP-19-1(22.976％)、qNFSP-19-2(11.977％)、qNFSP-19-3(17.203％)、qHSW-3-1(11.346％)、qHSW-3-2(11.346％)和qHSW-3-3(11.175％),加性效应值均为负值.在3、7、11、12和20号染色体上新定位到7个产量相关性状QTL,其中表型贡献率最高的为qHSW-3-3(14.276％),包含具有重复定位区间的qHSW-3-2和qHSW-3-3.与前人定位的结果相比,更多QTL极大地缩短了定位区间,表明本文报道的高密度遗传图谱更准确,可以为大豆产量相关性状的精细定位、候选基因的挖掘及分子标记辅助育种奠定基础.

研究以150份大豆种质为试验材料开展2年3点试验,在收获期测定抗倒伏相关性状,并利用RTM-GWAS方法作关联分析,共检测到99个显著关联SNP位点,其中48个效应显著位点,解释0.28％～3.38％表型变异;89个与环境互作显著位点,解释0.53％～7.04％表型变异;其中,21个位点主效表型变异解释率高于1％;与6个倒伏相关性状显著关联SNP位点中,与茎粗显著关联SNP位点最多,与抗倒指数显著关联SNP位点最少;获得22个有功能注释基因,根据基因表达量和基因功能注释,推测3个基因(Glyma.18G149700、Glyma.04G244100、Glyma.18G011400)可作为与大豆抗倒伏相关候选基因.