Combining Ability and Heterosis Estimates in Sesame

The current work was done during the two successive summer seasons 2013 and 2014 at Shandaweel Research Station, Sohag, Egypt. Eight genetically diverse sesame genotypes namely; Tushky-1, Sohag-78, B-35, Hybrid 31, H.126, Hybrid 155 Family-1, Local-137 and Intro-640 were used for this study. In 2013 season, half diallel cross among parents was done. In 2014 season, the eight parents and the twenty-eight hybrids were planted in a randomized complete block design with three replications. The study aimed to: 1) determine the type of gene effect in inheritance of yield and other traits 2) identify the best general combiners and crosses to be used in sesame breeding programs and 3) determine the percentage of heterosis. Highly significant differences were found among genotypes, parents, crosses and parents vs. crosses for all studied traits, indicating wide diversity among the used parents in this study. Mean squares due to both general and specific combining ability were highly significant for all studied traits. GCA/SCA ratio was less than unity in all studied traits reflecting non-additive types of gene action are having the highest influence on the inheritance of these traits. The two parents B-35 and Tusky-1 could be considered the better parents via estimates of general combining ability for seed yield/plant. However, the cross P X P had the most desirable SCA effects for seed 68 yield/plant and most studied traits. The F cross P X P showed the maximum heterosis percentage of seed 1 2 8 yield/plant over the better parent.