Line X tester analysis for hybrid performance, heterosis and combining ability in tomato (Solanum lycopersicum L.)

Abstract

Bacterial wilt resistant determinate lines (7) and indeterminate testers (4) alongwith 28 hybrids developed as per line x tester mating design were evaluated alongwith standard check Avtar (7711) in Randomized Block Design with three replications at the Experimental Farm of Department of Vegetable Science and Floriculture, CSK HPKV, Palampur during summer-rainy season of 2009 and 2010. Observations were recorded on incidence of bacterial wilt disease, fruit yield and component traits. The analysis of variance indicated significant differences among treatments for marketable yield and other component traits in all the environments. The hybrid L4 x T3 (BWR-5 x 16-B) surpassed all the hybrids and the standard check in all the environments and recorded 2.21 kg marketable fruit yield per plant in comparison to 1.04 kg per plant in the standard check Avtar (7711). Line x tester analysis revealed significant differences due to lines, testers, line x tester interactions. Interactions of lines, testers and line x tester with environment exhibited significant differences for most of the traits indicating the importance of testing parents as well as hybrids across environments. Non-additive gene action was higher for the traits days to 50 per cent flowering, marketable yield per plant, pericarp thickness, plant height and harvest duration which reaffirm the importance of hybrids in tomato. Additive gene action was higher for the traits days to first harvest, gross yield per plant, fruit weight, fruit shape index, locules per fruit and TSS, which could be exploited by developing superior pure lines/inbreds through hybridization and biparental matings. The lines 7-2 (L7) and BWR-5 (L4) and the testers 16-B (T3) and CLN 1314G (T4) proved to be the most potential parents whereas L4 x T3 (BWR-5 x 16-B) as the most promising hybrid combination.