Genetic analysis of fruit weight and total yield in tomato and development of F1 hybrids for cultivation under leaf curl virus infested conditions

Autumn season crop of tomato (Solanum lycopersicum L.) sown in July in North India fails due to severity of leaf curl virus. Newly developed genetic stocks (14) with variable fruit size and resistance to leaf curl virus were crossed in a diallel mating design and the resulting 91 F₁ hybrids were evaluated to study genetics of fruit weight and total yield and to identify promising hybrids for cultivation under leaf curl virus infestation conditions. Combining ability and components of variation analyses revealed presence of both additive and non-additive gene effects in the inheritance of both the characters. Six parents were observed to be good general combiners for both fruit weight and total yield. Of the 91 F₁ hybrids evaluated, 18 and 17 showed positive specific combining ability (SCA) effects for fruit weight and total yield, respectively. Six hybrids had good SCA effects for both the characters. Of the five hybrids with significantly positive yield heterosis over their respective better parents, three namely 58-18-1-1 x 56-4-6-1, 56-14-6 x 56-12-7-1 and 54-26-1-1 x 57-9-6-1 with high total mean yield and appropriate fruit size have the potential to be commercially cultivated under severe leaf curl virus infested conditions. Two crosses namely 54-26-1-1 x 57-9-6-1 and 58-11-1-1 x 56-12-7-1 have been identified to be pursued further to recover high yielding true breeding lines.