多环境下大豆子粒大小性状的全基因组关联分析

为探究多环境下大豆子粒大小性状的分子遗传基础，挖掘与子粒大小性状相关的SNP位点和候选基因，利用150份大豆种质资源在2019年和2020年6个环境条件下对大豆子粒粒长、粒宽、粒厚和百粒重性状进行表型测定，并进行全基因组关联分析。结果表明：在CMLM（压缩混合线性）模型下，在6个环境条件下检测到896个与子粒大小性状显著关联的SNP位点，分布于20条染色体。不同性状检测到72个重叠的SNP位点。检测到39个稳定遗传的SNP位点，贡献率为10.68%~24.93%。通过稳定性与重叠性分析，获得35个稳定表达的SNP位点，贡献率为10.92%~23.16%。在粒宽、粒厚及百粒重性状中同时检测到显著关联的SNP位点最多，位点rs16533609的贡献率最高（16.51%）。根据稳定表达的SNP筛选候选基因，推测Glyma.03G006600、Glyma.04G077100、Glyma.08G203600、Glyma.12G195400、Glyma.17G039800、Glyma.18G202100和Glyma.20G215700等7个基因对大豆子粒大小性状有调控作用。

Genome-wide association analysis of seed size traits in soybean under multiple environments

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 896 SNP 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.18G202100 and Glyma.20G215700 have regulators effect on soybean seed size traits.