Genetic dissection of yield-related traits in response to drought stress in common bean

Abstract

Drought stress severely impairs common bean production. For facilitating drought-resistance breeding in common bean, molecular markers were identified in a genome-wide level marker–trait association study. A panel of 210 common bean accessions showed large variation in 11 agronomic traits at the adult stage (plant height, pod number per plant, seed number per pod, seed number per plant, seed yield per plant, pod length, harvest index, pod harvest index, days to maturity, hundred-seed weight, and seed yield) under two water conditions. The coefficient of variation ranged from 6.21% for pod harvest index to 51.00% for seed number per plant under well-watered conditions, and from 4.05% for days to maturity to 40.72% for seed number per plant under drought stress. In a genome-wide association study, 119 quantitative-trait loci were associated with drought resistance, including 41 adjacent to known loci. Among these loci, 12 were found to be associated with at least two traits. Three major loci were identified at Pv01 and Pv02. A set of candidate genes were found that encode MYBs, AREBs, WKRYs, and protein kinases. These results reveal promising alleles that control drought resistance, shedding light on the genetic basis of drought resistance and accelerating future efforts for drought resistance improvement in common bean.