Combining ability and heritability of some tomato (Solanum lycopersicum L.) cultivars

General and specific combining ability (GCA and SCA) were estimated using five tomato cultivars and their F1 hybrids, using diallel cross system without reciprocals. Heritability percentages in narrow sense were, also, calculated for the different studied characters of tomato. The obtained results indicated, generally, that a particular cultivar or hybrid cannot be used to evaluate all studied characters with equal efficiency. However, the best general combiner parent which appeared to have the significant highest positive values of GCA was found to be the cultivar Super Marmand for the characters; plant height, number of flowers per clusters, ascorbic acid content and total soluble solids; the cultivar Edkawy for number of primary branches, number of locules per fruit and fruit weight; the parental cultivar Peto-86 for number of fruits per plants, fruit shape index and pericarp thickness; and Super Strain-B for fruit firmness and total fruits yield per plant. The obtained results illustrated, also, that the best hybrid combinations that reflected the highest positive values of SCA; which means that the parents of this particular cross can combine well to produce a hybrid with high general performances were found to be those of the F1 hybrids Peto-86 × Edkawy for plant height and total soluble solids; CastelRock × Peto-86 for fruit shape index, fruit weight and total fruits yield per plant; Super Marmand × CastelRock for number of flowers per cluster and number of fruits per plant; Super Strain-B × Super Marmand for ascorbic acid and T.S.S.%; and Super Strain-B × Peto-86 for fruit firmness. Narrow sense heritability estimates were found to be in the range from −37.33% (not different from zero) for the number of flowers per cluster up to 86.69% for fruit firmness characters.