Genetic analysis of foliar disease resistance, yield and nutritional quality traits in groundnut

Abstract

A set of 340 diverse groundnut genotypes included in Genomic Selection Panel (GSP) was used to evaluate genetic parameters and trait associations for resistance to rust and late leaf spot (LLS) along with yield and nutritional quality traits. The findings revealed high genetic variability coupled with high heritability and genetic advance as percent of mean (GAM) for resistance to both the diseases and yield traits, whereas low variability for nutritional quality traits with high heritability and low GAM. Disease severity scores for rust and LLS at 90 days after sowing (DAS) were negatively associated with yield, indicating pod yield penalty, thus deploying host-resistance for rust and LLS is a good strategy to plug the pod yield losses and reduce the input cost. It is possible to simultaneously improve the number of pods per plant and hundred kernel mass that contribute to pod yield as no trade-offs were detected between them. The association of oil and protein content with pod yield showed no tradeoffs, suggesting the possibility of simultaneous improvement of pod yield either with high oil or protein content. In breeding programs that target development of groundnut varieties to meet two distinct end-uses, oil milling, and food and confectionery, selection for either high oil (for oil purpose) or high protein and low oil (food/confections) will be efficient, as an inverse association between oil and protein content was observed. The use of disease score at 90 DAS for rust and LLS is effective and optimizes resources to make selection decisions in breeding as positive association among disease severity scores at different periods (75, 90 and 105 DAS) was observed.

Keywords

• groundnut
• heritability
• variability
• correlation coefficient
• foliar disease resistance