SELECTION OF PARENTS FOR HYBRID VARIETY DEVELOPMENT IN TOMATO (Solanum lycopersicum L.)

Abstract

The present research program was conducted to study for selecting potential parents to develop hybrid varieties in tomato (Solanum lycopersicum L.). All experiments were conducted at Getco Research and Development (R&D) farm, Atwari, Panchagar. Significant variations were observed in all the 12 traits under study. Fruit yield per plant has significant positive correlation with days to first fruit harvest and number of fruits per plant at phenotypic and genotypic level but based on path analysis, for yield per plant improvement, selection through number of fruits per plant will be effective. Line × Tester analysis was used to select potential parents utilizing general combining ability and per se performance. Five important traits namely Fruit length, fruit diameter, single fruit weight, number of fruits per plant anf fruit yield per plant were considered for this study. Based on the findings of overall ranking of genotypes, GCA and mean, the parents viz. AVTO-1009, AVTO-1130, AVTO-1008, AVTO-1173, TMM and TM-045 were selected from the Line × Tester analysis. These six different parents from 24 genotypes based on GCA and per se performance on combined ranking were used for (6 × 6) diallel analysis. Eleven traits namely days to first flowering, 50% flowering, first harvest, plant height, harvest duration, Fruit length, fruit diameter, single fruit weight, number of fruits per plant shelf life and fruit yield per plant. All the six parents have significant general combining ability in most of the traits and crosses AVTO-1173 × TM-045, AVTO-1009 × AVTO-1173, TMM × TM-045 and TM-045 × AVTO-1009 had at least one good general combiner for parents and had high SCA and reciprocal effects. Broad sense heritability noted highest for days to first harvest, plant height, harvest duration and number of fruits per plant suggesting directional selection could be effective for desired genetic improvement. High heterosis for mid parent heterosis, heterobeltosis and standard heterosis over check variety Mintoo Super and SCA effects for yield and yield contributing traits were significant positive performance for yield and yield components, shelf life and earliness four hybrids viz. TMM × TM-045, AVTO-1173 × TM-045, AVTO-1009 × AVTO-1173 and TM-045 × AVTO-1009 were found to be the heterotic and identified as the promising. Based on the phenotypic traits, consumer preferences, shelf life, market trends, stress tolerance and regional trials two hybrids (TMM × TM-045 and AVTO-1009 × AVTO-1173) among the selected four promising hybrids. Tomato breeding in private sector of Bangladesh, normally parents are randomly selected for hybrid development, but Line × Tester analysis can play an important role in selecting parent for hybrid variety development.