Heterosis and combining ability in hybrids among 12 commercial varieties of sesame (Sesamum indicum L.)

Heterosis and combining-ability effects were studied in the parents and 66 F₁ hybrids from a diallel cross of 12 elite sesame varieties in five different environments in Venezuela. The mean yield of the hybrids was clearly superior to the parental mean in all five locations. There were three heterotic hybrids that showed a higher yield than controls in all environments. The best hybrid in each place yielded significantly better than the best cultivar, the differences ranging from 28 to 109%. Specific combining-ability (SCA) effects were more important than general combining-ability (GCA) in four of the environments. A large genotypexlocation interaction was found for all traits, suggesting that hybrids should be produced for specific locations. ‘Arawaca’ and ‘Piritu’ should be chosen as parents for any sesame-breeding programme in view of their large GCA effects.