EVALUATION OF AGRONOMIC AND NUTRITIONAL TRAITS IN 5×5 HALF-DIALLEL POPULATION OF TOMATO (Solanum lycopersicum L.)

Abstract

The study was conducted through 5×5 diallel cross excluding reciprocals to evaluate the ten F 1 hybrids of tomato for different agronomic traits viz. days to 50% flowering, plant height, number of secondary branches, number of fruits per cluster, number of fruits per plant, single fruit weight, fruit diameter, fruit length, days to first harvesting, yield per plant, shelf life, pericarp thickness, number of locules per fruit and nutritional traits viz. Vitamin-C content, brix percentage, titrable acidity percentage. To develop the F 1 hybrid lines, five parental genotypes were matted in 5×5 half-diallel fashion during the rabi season 2017-18 and then evaluated for their combining ability and heterosis over check variety, BARI hybrid tomato-4 and corresponding better parent at the research farm of Sher-e-Bangla Agricultural University, Dhaka 1207 during rabi season 2018-19. The experiment on evaluation of F 1 hybrids was laid in RCBD design using three replications. The significant differences among the genotypes were obtained for all of the traits studied in the experiment here. The variances for general combining ability (GCA) and specific combining ability (SCA) were highly significant indicating the presence of additive as well as non-additive gene effects in governing the traits. The values of GCA were higher than the SCA values for all the traits except yield trait indicating the superiority of additive gene effects were more prominent for the inheritance of these traits. The parental lines P2 and P4 were proved to be the best general combiner for dwarf plant height, early flowering and early maturity while the parental lines P2 and P3 were proved to be the best general combiner for yield and yield related traits. The tested crosses P2×P5, P1×P3, and P3×P4 showed best specific combiner for yield and yield related traits. Again, three cross combinations viz. P1×P2, P1×P4 and P4×P5 showed best specific combiners for the traits of days to 1 harvesting. Cross combination P2×P5 exhibited highest 49.80% significant heterosis was followed by 40.16% in P1×P2 and 33.80% in P1×P3 over check variety for yield traits. In addition, five cross combinations viz. P1×P2, P1×P4, P2×P4, P4×P5, and P1×P3 showed desirable value for days of 1 st harvesting followed by yield contributing traits. Furthermore, two cross combinations viz. P1×P4 and P4×P5 were best nutritional traits. Considering the performance of SCA effects and heterosis, afore-mentioned crosses could be utilized for developing promising hybrid varieties as well as for exploiting hybrid potency.