Assessment of Combining Ability and Gene Action for Yield and Yield-contributing Traits in Sunflower (Helianthus annuus L.)
Abstract
Aims: To evaluate combining ability, determine the nature of gene action governing yield and yield-contributing traits, and identify superior parents and promising hybrid combinations in sunflower (Helianthus annuus L.). 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, together 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. The data were subjected to analysis of variance, line × tester analysis to estimate general and specific combining ability, and assessment of gene action following Kempthorne (1957). Results: Significant variation was observed among the 58 genotypes for all ten traits studied, indicating sufficient genetic variability for effective selection and hybrid development. Combining ability analysis revealed significant GCA and SCA effects for most traits, with SCA variance exceeding GCA variance and indicating the predominance of non-additive gene action. CMS-249A and CMS-47A exhibited desirable GCA effects for several yield-related traits, whereas EC-601924 and EC-601751 were superior restorers. The hybrid combinations DSP-11A × EC-601924, CMS-249A × RHAGPR-3, and CMS-10A × EC-601751 expressed high SCA effects together with desirable performance for yield and related traits, indicating their suitability for hybrid breeding. Conclusion: Both additive and non-additive genetic effects contributed to the inheritance of yield and yield-contributing traits, although non-additive gene action was predominant. The identified superior parents and hybrids may be utilised in sunflower hybrid-breeding programmes to develop high-yielding hybrids.