Seed size is a major determinant of grain yield in soybean, however their genetic basis remains largely unknown. In order to delimit map‐based position of a major locus qSS3, we evaluated three mapping populations, including RILs, NILs and a sub‐F₂ in three environments for six seed size‐related traits. For these traits, the kurtosis and skewness ranged between 0.0 and 1.16, while h²_b ranged from 0.75 to 0.96, indicating that this RIL population is suitable for QTL analysis. QTL analysis identified 12 loci which consist of 30 significant QTLs with PVE% and LOD values of 6.6%–26.2% and 2.50–5.61, respectively. Among them, qSS3 was a major and stable locus explaining 7.3%–26.2% of the variation in 5 of the 6 traits, with the respective LOD values falling in the range of 2.72–5.61. Additionally, qSS3 effects were confirmed in NILs and delimited to an interval of ~1,126 kb containing 123 annotated genes. Overall, this study may assist efforts aiming to improve soybean seed traits by identifying valuable genetic resources which can be used in future MAS breeding programmes.

中文翻译：

---

大豆种子大小的主要位点qSS3的遗传分析和基于图谱的定界

种子大小是大豆籽粒产量的主要决定因素，但是其遗传基础仍然未知。为了确定主要基因座qSS3的基于图谱的位置，我们针对三种与种子大小相关的性状，在三个环境中评估了三个图谱种群，包括RIL，NIL和sub-F ₂。对于这些特征，峰度和偏度在0.0到1.16之间，而h ² _b则在0.75到0.96之间，表明该RIL群体适合进行QTL分析。QTL分析确定了由30个重要QTL组成的12个基因座，PVE％和LOD值分别为6.6％–26.2％和2.50–5.61。其中，qSS3是一个主要且稳定的基因座，解释了6个性状中5个性状的7.3％–26.2％变异，各自的LOD值在2.72–5.61范围内。此外，在NIL中证实了qSS3效应，并限定为〜1,126 kb的间隔，包含123个带注释的基因。总体而言，这项研究可以通过鉴定可用于未来MAS育种计划的宝贵遗传资源来协助旨在改善大豆种子性状的工作。