Genetic improvement for yield, quality and leaf curl virus resistance in tomato (Solanum lycopersicum L.)

Five superior lines of tomato viz., VRSL-17, VRSL-18, VRSL-20, VRSL-22 and VRSL-40 were crossed with three testers viz., AVTO-1002, AVTO-1130 and AVTO-1314 which were resistant to tomato leaf curl virus in Line x Tester mating design. The resultant fifteen crosses along with eight parents and two checks i.e. US-618 and ArkaVikas were evaluated for yield, ToLCV resistance during late rabi, 2016. Highest fruit yield per plant was recorded in VRSL-22 x AVTO-1002 (3.17 kg) but was on par with VRSL-22 x AVTO-1314 (3.19 kg). With regard to disease reaction, one hybrid has shown highly resistant reaction, eight hybrids were resistant, four hybrids were moderately resistant and two hybrids have shown susceptible reaction under artificial screening. Among fifteen hybrids, no ToLCV incidence was recorded in VRSL-22 x AVTO-1002 (0.00), whereas VRSL-20 x AVTO-1002 and VRSL-22 x AVTO-1314 recorded 3.33% incidence of ToLCV under artificial screening. Combining ability analysis revealed that the magnitude of sca variance was greater than gca variance for the characters like number of primary branches per plant, days to 50 per cent flowering, number of clusters per plant, number of flowers per cluster, number of fruits per cluster, fruit set percentage, number of fruits per plant, days to first fruit harvest, fruit length, fruit diameter, number of locules per fruit, average fruit weight, fruit yield per plant, titrable acidity, ascorbic acid content, lycopene content and ToLCV incidence in field screening as well as artificial screening. This indicated the preponderance of non-additive gene action governing the inheritance of these characters. Hence, heterosis breeding is ideal to improve these traits.