Genetic linkage map construction and identification of QTLs associated with agronomic traits in bambara groundnut (<i>Vigna subterranea</i> (L.) Verdc.) using DArTseq‐based SNP markers

Abstract

Abstract Bambara groundnut [ Vigna subterranea (L.) Verdc.] is an underutilised, protein‐rich and self‐pollinating legume that can withstand high temperature and drought stress and is mainly grown in semi‐arid Africa. In order to dissect the complexity of drought resistance and to use genomic tools for yield enhancement of bambara groundnut in response to drought stress, yield‐related and morphological traits under drought‐stressed (DS) and well‐watered (WW) conditions were evaluated in the F 3 and F 4 segregating generations derived from a cross between two genotypes selected from landraces S19‐3 (originally from Namibia) and DodR (originally from Tanzania). Significant quantitative trait loci (QTLs) for shoot dry weight (SDW) were mapped on LG10 accounting for 15.5% of the phenotypic variation explanation (PVE) under well‐watered conditions and a putative quantitative trait locus (QTL) for the same trait mapped on LG10 with reduced PVE (10.10%) under drought‐stressed conditions in the F 3 segregating population. Significant QTLs associated with the number of seeds per plant (NS), number of double‐seeded pods per plant (NDP), seed weight per plant (SW) and pod weight per plant (PW) were mapped on LG4 (nearest marker: 4181663 and 4175954) with overlapping confidence intervals and explained 21.9%, 21.8%, 23.5% and 19.9% of the PVE, respectively, under well‐watered conditions in the F 4 population, which could be considered as the major QTL involved in the control of these traits. Seven consensus QTLs for yield‐related and morphological traits were mapped on LG2, LG3, LG4, LG7A and LG10. The study provides fundamental knowledge of QTLs associated with yield‐related and morphological traits under drought‐stressed and well‐watered conditions in bambara groundnut, which is also essential for yield improvement of bambara groundnut in response to drought stress.