Heterosis and combining ability in forage pearl millet (Pennisetum glaucum L.) under stress and non-stress environments

The present investigation was undertaken for genetic analysis of forage yield and quality traits in pearl millet (Pennisetum glaucum). A set of 15 CMS lines and 4 populations as testers were crossed in all possible combinations to obtain 60 top cross hybrids. The hybrids were evaluated for general combining ability (gca), specific combining ability (sca), heterosis over two environments viz., water stress and irrigated. Analysis of variance for quality characters revealed significant differences due to genotypes, environments and significant genotype x environment interaction for all quality traits. The variance due to gca and sca were significant and varied with change in the environment for all quality traits. The computed variance ratio (σ²sca/σ²gca) revealed the predominance of non-additive gene action in the inheritance of quality traits. The line 05111A was found best general combiner for higher quality under both the environments. Among testers, Giant bajra was best combiner for quality under both environments. The top cross hybrids 91777A × RBC-2 and 01555A × RBC-2 were good specific combiners for high protein and fiber content. Hybrids 220A × Giant bajra, 01555A × NDFB-2 and 408A × GFB-1 exhibited high positive significant heterosis under both the environments. The existence of significant heterotic effect over commercial check also suggested the presence of non-additive gene action and dominance for quality traits.