Genetic Analysis of Yield and Associated Traits through Combining Ability and Gene Action in Sunflower (Helianthus annuus L.)

Abstract

Aims: To evaluate the combining ability, determine the nature of gene action governing yield, oil content and associated traits, and identify superior parents and promising hybrid combinations for sunflower (Helianthus annuus L.) improvement. Study Design:  Line × tester mating design. Place and Duration of Study: Oilseeds Research Station, Latur, Maharashtra, India, during kharif 2025 (hybrid development) and rabi 2025–26 (field evaluation). Methodology: Six cytoplasmic male sterile (CMS) lines and seven restorer lines were crossed in a line × tester mating design to generate 42 hybrids. The resulting hybrids, along with their 13 parents and three standard checks, were evaluated in a randomised block design with two replications for ten agro-morphological and quality traits. Data were subjected to analysis of variance, line × tester analysis to estimate general and specific combining ability, and assessment of gene action following the method of Kempthorne (1957). Results: Analysis of variance revealed highly significant differences among the genotypes for all the traits studied, indicating substantial genetic variability. Line × tester analysis showed significant GCA and SCA effects for most traits, with non-additive gene action predominating for seed yield and several associated traits. Among the parents, NDCMS 2A and CMS 597A were identified as good general combiners among the lines, while NDL20, NDL3 and GMU847 were the most desirable testers for seed yield, oil content and associated traits. The crosses NDCMS 2A × NDL20, CMS 597A × NDL20, CMS 597A × NDL3, CMS 852A × GMU847 and CMS 597A × HOCL-20R exhibited desirable specific combining ability effects coupled with superior per se performance, indicating their potential for exploitation in sunflower hybrid breeding. Conclusion: The findings indicated the involvement of both additive and non-additive gene action in the inheritance of yield, oil content and associated traits in sunflower, with the predominance of non-additive gene action for most of the characters. The identified superior combiners and promising hybrid combinations provide valuable genetic resources for the development of high-yielding and high-oil sunflower hybrids and can be effectively utilised in future sunflower breeding programmes.