Bambara groundnut (Vigna subterranean (L) Verdc.) is a grain legume underutilized in Africa. The objective of this study was to determine the extent of phenotypic and genotypic variability of the introduced accessions and the relationship between the traits, which would aid in the selection of elite accessions. A field trial was conducted in Tepi, southwestern Ethiopia, during the 2021/22 cropping season. 276 Bambara groundnut accessions were studied in an alpha lattice design with two replicates. Data were collected on 19 agro-morphological traits. The phenotypic coefficient of variation for days to flowering ranged from 6.53% to 81.49% for grain yield, while the genotypic coefficient of variation ranged from 6.55% to 53.64%. Heritability ranged from 6.969% for pod width to 99.816% for leaf length. Mean genetic advance ranged from 4.74% for pod width to 93.14% for pod weight. Grain yield correlated positively and significantly with plant height, number of branches per plant, leaf width, number of pods per plant, seed weight, and hundred seed weight at the genotype level. Cluster analysis revealed significant differences among accessions, which were then divided into five groups. The first six principal components with eigenvalues greater than one explained 73.35% of the total variation among accessions of tested traits. Grain yield was positively and significantly correlated with plant height at the genotype level.

Keywords: Bambara groundnut, phenotypic variability, Genetic variability