Nine genotypes of melon (Cucumis melo L.) were crossed in a half diallel pattern crosses without reciprocals. The parents and their thirty six F1 hybrids were evaluated in complete randomized block design with three replicates for some fruit characters to estimate the general and specific combining ability, heterosis and heritability. There were highly significant differences among all parental genotypes and its hybrids for all studied characters. The values of general and specific combining ability effects were highly significant which indicate the presence of both additive and non- additive types of gene actions in controlling flesh colour, total soluble solids. Moreover, the calculated ratio of GCA/SCA were more than unity which indicate that additive type of gene action were more important in the inheritance of all studied characters. There were highly variation among hybrids for mid and better- parent heterosis in all studied characters. The additive component (D) and dominant components (H1) and (H2) were highly significant, suggesting the importance of both additive and non- additive effects in the determination of the studied characters. The results indicate that the nine parents used in the present study carried more dominant than recessive allels for the studied characters. There were very high broad sense heritability (99, 95, 99 and 99%), while the values of narrow sense heritability were 51, 41, 22 and 61 %, for flesh colour, total soluble solids content, total sugars and total carotenoids, which indicate the large influences of the genetic variance on the expression of these characters. Furthermore, the additive genetic variance components is relatively large comparing to the other types of genetic variance components. |
