Combining Ability and Heritability for Capsaicinoid Content in Field-Grown Tunisian Hot Pepper Varieties (Capsicum annuum L.)

In Tunisia, pepper (Capsicum spp.) is consumed for its fruits, which are used either fresh or dried. The genetic resources of pepper are important as a natural source of capsaicinoids, which confer hotness to its fruits. Fifteen F1 hybrids and six parental genotypes were used to assess combining ability and heritability for capsaicin, dihydrocapsaicin, nordihydrocapsaicin and total capsaicinoid in green pepper fruits (Capsicum annuum L.). The mean squares for general (GCA) and specific (SCA) combining abilities were highly significant for these characters, suggesting the importance of both additive and non-additive gene effects. However, additive gene action was more important, as GCA estimates were much higher than SCA effects. Among the parental genotypes, ‘Rouge Long’ and ‘Piment Sesseb’ and ‘Chaabani’ were good general combiners for capsaicin, dihydrocapsaicin, nordihydro-capsaicin and total capsaicinoid, respectively, and could be used to improve these traits in pepper breeding programmes for the accumulation of favorable genes. They also showed the highest per se performance (0.67mg.g?1, 1.09 µg.g?1, 0.32 mg.g?1 and 2.08 mg.g?1 respectively) for these quality traits. The narrow sense heritability estimate for total capsaicinoid, was relatively high (45%) indicating that the environment had a less pronounced effect on this trait.