Phenotypic and genotypic diversity of Bambara groundnut (Vigna subterranea L. Verdc) germplasm in Malawi

Abstract Bambara groundnut ( Vigna subterranea (L.) Verdc) are a neglected and underutilized crop species that is in high demand among Sub-Saharan African smallholder farmers. Despite the high demand, there are no improved varieties available to smallholder farmers in Malawi. This study aimed at characterizing agro-morphological traits and identifying genetic diversity using Diversity Array Technologies Sequence Low Density (DArTseqLD) Single Nucleotide Polymorphism (SNP) markers in order to identify unique traits that can be used in germplasm discrimination for seed production and genomic variation for crop improvement. Forty germplasm were evaluated at the Crops and Soil Sciences Department's farm of Lilongwe University of Agriculture and Natural Resources, Bunda College. From forty germplasm, 188 samples were selected for genotyping using DArTseqLD SNP markers. Data on agro-morphological traits were collected following Bambara groundnut descriptor and subjected to multivariate analysis. Principal Component Analysis revealed a total variation of 53%. The study generated 1048 DArTseqLD SNP markers. Analysis of molecular variance (AMOVA) revealed 84% and 13% variation among and within the Bambara groundnut germplasms respectively, 3% variations was observed among the populations. Cluster analysis based on genotypic data grouped the 188 samples into 9 clusters. Based on phenotypic and genotypic data, it can be concluded that there is a significant degree of variation and genetic diversity in the germplasm evaluated that can be used by farmers in seed production and plant breeders in crop improvement program.