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 an d 66 F-1 hybrids from a diallel cross of 12 elite sesame varieties in five different environments in Venezuela. The mean yield of the hybrid s was clearly superior to the parental mean in all five locations. The re were three heterotic hybrids that showed a higher yield than contro ls in all environments. The best hybrid in each place yielded signific antly better than the best cultivar, the differences ranging from 28 t o 109%. Specific combining-ability (SCA) effects were more important t han general combining-ability (GCA) in four of the environments. A lar ge genotype x location interaction was found for all traits, suggestin g that hybrids should be produced for specific locations. 'Arawaca' an d 'Piritu' should be chosen as parents for any sesame-breeding program me in view of their large GCA effects.