Association mapping of important agronomic traits in Mucuna pruriens (L.) DC.

Abstract

The Mucuna pruriens (L.) DC. can meet three burgeoning needs of tropical agriculture: low-cost protein source, high-value medicinal plant, and an excellent green manure cover crop. But like other underutilized crops, it lacks modern breeding resources. Identifying marker-trait associations (MTAs) can prompt marker-assisted breeding paving a way for development of the improved varieties. Recent studies have demonstrated feasibility of identifying MTAs using a small number of accessions (<100) triggering the hope for resource poor crops. Taking cues from there, we characterized a panel of 70 M. pruriens accessions across two consecutive years and performed association analysis for 16 phenotypic traits using 66 genic-microsatellite markers. The results showed significant phenotypic (P < 0.05) and genetic diversity (Shannon’s information index, I = 0.62) in our germplasm collection. Many of the tested traits were highly heritable (42.86% to 99.93%). A total of 15 MTAs were detected at an adjusted significance level of P < 5.55 × 10-3 for nine economic traits such as – seed length, seed thickness, seed width, hundred seed weight, seed yield per plant, inflorescence length, flower buds per inflorescence, flower length, and petiole length with phenotypic variance explained (PVE) ranging from 14.72 to 31.12%. Their annotation using the Arabidopsis genome database affirmed reliability of our MTAs. This is the first report on association mapping in M. pruriens and results are expected to galvanize marker-assisted breeding as well as mining of candidate genes in this promising legume.