Combining ability analysis and gene action estimates of selected physiological traits under heat stress in chickpea (Cicer arietinum L.)

During the last decade increasing events of heat stress put serious challenge for global food security. Heat stress causes detrimental effects on overall plant growth and thus, limit crop yield including chickpea worldwide. Given the importance of ‘physiological trait breeding’, elucidation of gene action of important physiological traits playing critical role in adaptation plant under heat stress could be one of the important options for tailoring heat stress resilient chickpea genotypes. Therefore, in the current investigation following diallel analysis, a total of six parents and their all possible F₁ combinations excluding (reciprocal crosses) were used for estimating gene action of six important physiological traits and one phenological and one yield traits by planting the F₁ seeds in normal sown (NS) and late sown (LS) conditions. Genetic analysis suggested presence of both additive and non additive genetic variance for the studied traits under both conditions. However, preponderance of additive gene action was recorded based on the results of higher general combining ability (GCA) variance than specific combining ability (SCA) variance, with predictability ratio > 0.5 for most of traits under both conditions. Results of estimates of GCA effect suggested KWR108 and ICCV92944 parents were the better general combiner for the studied traits under both conditions. Similarly, DCP92- 3 ×ICC4958, and KWR108 × ICC4958 cross combinations were the most appropriate combination for the given traits. Thus, parents with high GCA effect and cross combinations with high SCA effect could be potentially incorporated in breeding programme for improving heat stress tolerance in chickpea.