Heterosis, combining ability and genetics for vitamin C, total soluble solids and yield in tomato (Lycopersicon esculentum) at 1700 m altitude

A study was conducted on a 15 x 15 diallel set of tomato excluding reciprocals to find out the extent of heterosis, combining ability and nature of gene action for yield with two important quality traits: ascorbic acid (vitamin C) and total soluble solids (TSS). Significant differences among genotypes were obtained for all three traits. Positive high significant heterosis was found for yield (41.97, 157.84 and 28.94%), for ascorbic acid (16.68, 54.57 and 161.33%) and for TSS (25.97, 11.93 and 19.02) over the top, the better parent and the commercial control respectively. The magnitude of variance due to general as well as specific combining ability were highly significant indicating the importance of both additive and non-additive gene action. However degree of dominance (o(-2) g/o(-2) s) revealed the prevalence of a non-additive gene effect. Cross combinations Arka Vikas x Sel-12 (13.19), KS-10 x Pant T-3 (1.66) and EC 8 18703 x EC 13042 (0.88) were best specific combiners for ascorbic acid, total soluble solids and yield/plant. Predominance of non-additive gene action plays a greater role in the inheritance of ascorbic acid and total soluble solids in tomato under hill conditions.