Genetic variability, gains from selection and genetic correlations for pod yield and nutritional traits in African landraces of bambara groundnut

Despite numerous studies on heritability and variance components estimates for agronomic traits, though barely for nutritional traits, in bambara groundnut (Vigna subterranea) in recent years, impact of genotypexenvironment interaction on trait variability is still poorly understood. To achieve this and to assess the potential for improvement of seed nutritional attributes without significant reduction in pod yield, 13 agronomic and nutritional traits were evaluated for 40 African landraces of bambara groundnut during 2013 and 2014 cropping seasons. Landracexyear interaction (LYI) effects significantly reduced broad-sense heritability (H) and genetic correlation (rG) between years for pod yield. However, for seed nutritional traits, the effect of LYI was less pronounced, suggesting stability of these traits. The lack of significant genotypic and phenotypic correlation between pod yield and traits such as iron, zinc and protein concentrations of the grain indicated possibilities for the improvement of these nutrients without significant reduction in pod yield. These results highlighted the variability among bambara groundnut landraces in their agro-nutritional traits response to production years, and the need for testing of these landraces using farmers' fields and research stations as contrasting environments.