Fine mapping and candidate genes analysis of qHSW11-1，a major quantitative trait locus coordinating hundred-seed weight in soybean

Soybean is an important industrial crop. which can be used for oil extraction, protein extraction and biodiesel production. Hundred-seed weight (HSW) is one of the important factors affecting soybean yield, which is regulated by multiple genes. In this study, based on the chromosome segment substitution lines (CSSLs) population, using the complete interval mapping (ICIM) and bulked segregant analysis (BSA), a QTL locus qHSW11–1 related to 100-grain weight was mapped. The secondary segregating population was constructed for fine mapping, and the interval size was reduced to 0.16 Mb. A total of 21 genes were annotated in the interval. According to gene sequence alignment and real-time quantitative analysis between parents, 4 genes were preliminarily predicted as the key genes affecting 100-seed weight. Haplotype analysis of candidate genes was performed using a germplasm resource population containing 686 soybeans, and excellent haplotypes affecting soybean 100-grain weight were obtained. This study will provide an important reference for the genetic improvement of 100-seed weight in soybean. • Using wild soybean to construct a genetic population, QTL mapping of soybean 100-seed weight. • The QTL of 100-seed weight was fine mapped on chromosome 11 of soybean. • Four functional genes related to 100-seed weight of soybean were preliminarily digging. • Using soybean germplasm resources, the excellent haplotypes of candidate genes were analyzed.