Assessment of genetic variability in bambara groundnut (Vigna subterrenea L. Verdc.) using Morphological Quantitative traits

Abstract

Bambara groundnut is one of the neglected and underutilized legumes in the African continent. It is a major source of protein and is grown commonly by resource poor farmers at subsistence level. In South Africa, the crop is used for food and the enhancement of soil fertility. Information on genetic variability among available local accessions of Bambara groundnut will increase the efficiency of the improvement programme in South Africa. Field experiments were conducted at the ARC-Roodeplaat Vegetable and Ornamental Plant Institute research farm in 2011-2012 cropping season to estimate the level of phenotypic variability among 20 Bambara groundnut accessions. The experiment was laid out in a randomised complete block design with three replications. Eighteen phenotypic markers were recorded. Analysis of variance for the phenotypic traits revealed that differences among accessions were highly significant for all traits. This indicated that quantitative morphological traits differed among the accessions studied. The results of the principal component analysis showed that the first 7 principal components contributed 83% of the variability among the accessions evaluated. Leaf area index, pod mass and dry weight are highly associated with the first principal component, while estimated leaf area, actual leaf area, number of pods and fresh weight of Bambara groundnut contributed more to the second principal component. The genetic distances of the accessions varied from 0.86 to 1.79. These phenotypic markers can therefore serve as useful tools that can be exploited for use in future breeding efforts