Inheritance Pattern and Combining Ability of Yield and Yield-Related Traits in Gossypium hirsutum L.
Abstract
Gossypium hirsutum L. is a significant fibre crop and is a key element in the textile industry. The present study investigated the inheritance and combining ability of yield and yield related traits in upland cotton in a complete 3 × 3 diallel mating design. The three genetically different parental genotypes Cyto-608, CIM-343 and MNH-1026 were crossed in all possible combinations to generate six F₁ combinations with 9 genotypes; these were then tested for plant height, monopodial branches, sympodial branches, bolls per plant, boll weight, seed cotton yield per plant and lint percentage. Analysis of variance showed significant differences between genotypes for all traits, thus statistically significant variation in the material evaluated was noted. Several traits had significant GCA and SCA effects, indicating a contribution from additive and non-additive genetic effects, per Griffing's Model I analysis. MNH-1026 was superior for a number of traits, but exhibited mixed breeding value for the different traits, with boll number, seed cotton yield, plant height, and lint percentage being superior. Specific crosses also exhibited beneficial SCA effect for certain traits. The differences in the reciprocal crosses were significant for boll number, seed cotton yield, and lint percentage, suggesting direction-specific differences, but the effects cannot be definitely classified as maternal or cytoplasmic inheritance. Interpretation of the relative magnitude of variance components was done in conjunction with statistical significance of GCA and SCA but not as proof of gene action by only the magnitude of the variance components. The overall results suggest that there is a preliminary indication that both additive and non-additive gene effects are involved in the inheritance of yield and yield related traits in the cotton material evaluated. The results are, however, based on only three parents and two replications, and need to be replicated in other genetic material, locations, and growing seasons.