Variability, correlations, genetic advance and heritability of physiological and agronomic parameters of Bambara groundnut (Vigna subterranea [L.] Verdc.) genotypes from Burkina Faso

Abstract

Bambara groundnut is a seed legume of the Fabaceae family. It is the second most important food legume in Burkina Faso and is one of the main sources of income for women producers in rural areas. In Burkina Faso, research works on Bambara groundnut carried out to improve the performance of available landraces are very limited. For this purpose, agro-morphological characterization was carried out to contribute to a better knowledge of the diversity as well as the correlations between the characters, their mode of heritability and the genetic advance would make it possible to lay down milestones for a good strategy of conservation and improvement of the plant. Investigations were set up on the experimental site of the University Center of Tenkodogo following a completely randomized block design with four replications. A total of 20 genotypes were evaluated for this purpose. Nineteen (19) agronomic and physiological traits were recorded during the development stages of the plant and after harvest. The descriptive statistical analysis showed that there are strong amplitudes between the minimum and maximum values for all the studied characters. All the characters discriminate the accessions at the 5% threshold, except the plant spread. The cumulative values of the variance of the first four factorial axis (F1, F2, F3 and F4) for the 19 characters studied were 84.424%. The estimation of the genetic parameters showed slightly higher coefficients of phenotypic variation than the coefficients of genotypic variation for each of the 19 traits studied. The small differences between the phenotypic and genotypic coefficients of variation observed for all traits indicate that they are little influenced by the environment. The studied traits expressed a very high broad sense heritability with certain characters (H² ˃30). These high heritability values allow for more reliable responses to selection. Moreover, when heritability is high, the influence of environmental factors acts in a not very significant way on the expression of the characters. The results obtained in this study should be taken into consideration for any Bambara groundnut improvement program in Burkina Faso.