Combining Ability for Yield, Percent Oil and Related Components in Safflower

General and specific combining ability variances and effects for nine characters related to yield and adaptability in safflower were studied in a diallel cross based on 8 parents in 1978 and 11 parents in 1979. Significant general and specific combining ability variances were present for all variables examined. However, additive genetic variancea were preponderent for plant height, flowering time, branch number, seed size and oil percent while non-additive variance was larger for yield and its principal components. The influence of environment were more pronounced on the additive than on non-additive component of genetic variation for all characters. Maternal influences were nearly non-existent for seed weight, oil percent and significant but less important for others. None of the parental lines proved best combiners for all the important attributes. Irrespective of the characters, parental performance servedas agood measure of their relative combining ability. Crosses between genetically diverse parents manifested substantial heterosis associated with large positive specific effects for yield and its components. The most productive and heterotic hybrid in the material outyielded the best standard check by as much as 42% in experiment 1 and 70% in experiment 2. The studies highlighted the utility of population breeding approaches and development of hybrids for attaining rapid and sustained genetic improvement in the yield potential of safflower.