Identification and validation of stable and novel quantitative trait loci for pod shattering in soybean [Glycinemax (L.) Merr.]

Abstract

Pod shattering is an important domesticated trait which can cause great economic loss of crop yield in cultivated soybean. In this study, we utilized two recombinant inbred line populations (RILs, CY, Huachun 2×Wayao; GB, Guizao 1×B13) to identify quantitative trait loci (QTLs) associated with pod shattering in soybean across multiple environments. A total of 14 QTLs for pod shattering were identified in the two RIL populations, which had LOD scores ranging from 2.64 to 44.33 with phenotypic variance explanation (PVE) ranging from 1.33 to 50.85%. One QTL qPS16-1, located on chromosome 16, included a well-known functional gene Pod dehiscence 1 (Pdh1) that was reported previously. Ten new putative QTLs were validated in two RIL populations, and their LOD scores were between 2.55 and 4.24, explaining 1.33 to 2.60% of the phenotypic variation. Of which four novel QTLs (qPS01-1, qPS03-2, qPS05-1, and qPS07-1) could be detected in two environments where nine genes had specific changes in gene expression. Although the nine genes may have significant effects on pod shattering of soybean, their detailed functions still need to be further explored in the future. The results of this study will facilitate a better understanding of the genetic basis of the pod-shattering resistant trait and benefit soybean molecular breeding for improving pod shattering resistance.