Agronomic and morphological diversity of Bambara groundnut (Vigna subterranea (L.) Verdc.) accessions in North-Central Namibia

Abstract

Bambara groundnut (Vigna subterranea (L) Verdc.) is an orphan, underutilised and less exploited crop in Africa and beyond, yet it is an essential traditional crop for subsistence farmers in sub-Saharan Africa. Currently, in Namibia, neither a pre-breeding nor a breeding programme exists for Bambara groundnut. Twenty-five Bambara groundnut accessions acquired locally and outside Namibia were characterised for descriptor state, including possible character diversity on the quantitative descriptors. Square lattice design with three replications was used. Data were analysed using analysis of variance (ANOVA), Pearson correlation moment, Principal Component Analysis (PCA), and cluster analysis. ANOVA indicated significant differences (P < 0.05) among accessions for most of the characters measured, and highly significant differences (P < 0.01) for the number of pods per plant, pod yield, seed yield, plant height, and dry biomass. The dendrogram sub-criterion indicated three clusters, confirming the results of the PCA, which grouped accessions with common descriptors in the same quadrants. PCA biplot showed that the first two components explained 59.55% of the variation. Overall results suggest that the Bambara groundnut accessions evaluated in this study showed high variability, thus can be used as a source of pre-breeding materials to initiate a national breeding programme.