Precisely Positioning QTLs for Premature Senescence Resistance in Asparagus Bean Using a High-density SNP Chip

Premature senescence (PS) is an important adverse agronomic trait of asparagus bean. Since immature pods are the major economic organ for asparagus bean, PS will influence the pod number in late stage which leads to the decline of pod yield and brings economic losses to growers. Using an enlarged recombinant inbred line population (RIL, F6:8) comprising 119 lines from the cross of ZN016 and ZJ282 as materials, the study carried out the quantitative trait loci (QTL) precise positioning of PS resistance traits of asparagus bean based on the high density molecular genetic map with 8,032 SNP loci which was constructed by the 60K high-density SNP chip of cowpea. We positioned the major QTLs for PS resistance of asparagus bean to an about 0.424 cM interval on LG11. Compared with previous results of QTL positioning of the same trait, the coarse positioning results in the early stage of this laboratory were confirmed, and the accuracy of QTL positioning was greatly improved which greatly reduced the distance between the wing markers. This study might provide the basis for molecular marker-assisted breeding and gene cloning against the agronomic trait of PS resistance.