<div>Background: Two-seed pod length and width (TSPL and TSPW, respectively) are the traits underlying seed size, which is an important factor influencing soybean yield. 
 
Methods: A population comprising 213 chromosome segment substitution lines from a cross between &lsquo;Suinong14&rsquo; (SN14) and ZYD00006 was used for a quantitative trait locus (QTL) analysis. The QTLs were identified on the basis of the phenotypes from 2016 to 2019. Additionally, IciMapping 4.2 was used to analyze the phenotypic and genetic data. Genes were annotated using the KEGG and Phytozome databases. 
 
Result: Five QTLs for TSPL and four QTLs for TSPW were identified. One QTL on chromosome 17 was detected for TSPL in 2017 and 2018 as well for TSPW in 2018 and 2019. Analyses of the additive &times; additive epistatic effects of QTLs revealed six stable loci pairs for epistatic effects on the two traits. On the basis of an alignment of the parental gene sequences and the gene annotation information, Glyma.04G188800, Glyma.11G164700, Glyma.13G132700, Glyma.17G156100 and Glyma.13G133200 were selected as candidate genes for TSPL, whereas Glyma.13G174400, Glyma.13G174700, Glyma.16G012500, Glyma.17G156100, Glyma.19G161700 and Glyma.19G161800 were selected as candidate genes for TSPW. These results may be relevant for future attempts to modify soybean seed traits.</div>

Identification of QTLs Associated with Two-seed Pod Length and Width in Soybean