Vol. 8, Special Issue 11, Part E (2024)

The primary objective of the present investigation was to better understand the type of gene action in tomato for diverse quantitative traits. Fourteen diverse lines of tomato were crossed in half diallel fashion and the hybrids were evaluated in polyhouse at SKUAST-K, Srinagar. The analysis of variance for all the fourteen quantitative traits revealed significant mean squares. The greater magnitude of dominance variance than the additive variance for all the traits and greater magnitude of dominance component than its corresponding additive component indicated major role of the former in the inheritance of the traits under investigation. The net dominance effect component (h²) revealed absence of high dominance effect in heterozygote and absence of directional dominance for all such traits. However, for PH, NFPP, FS and FYPP, high dominance effect in heterozygote and presence of directional dominance was observed. The F value indicated higher frequency of dominant alleles in the parents for traits viz., DFFS, PH, FlPT, AFW, FS, FYPP and PT and equal frequency of dominant and recessive alleles in DFFR, DuM, DuF, FrPT, NFPP, NLPF and NSPF. The [(H₁/D)^1/2] revealed over dominance range for all the traits under investigation. The H₂/4H₁ indicated the asymmetrical distribution of alleles with positive and negative effect in the parents for all the traits. KD/KR revealed excess of dominant genes in parents as compared to the recessive genes. The h²/H₂ depicted the less proportion of dominance gene groups and probably one gene group control these traits. The low narrow sense heritability [h² (n.s.)] revealed non-additive gene action for all the traits. The study highlights the importance of both additive and non-additive gene action involved in the inheritance of different growth, yield and quality traits. The findings aligned with previous studies, reinforcing the absence of epistasis and emphasizing the potential of using selective mating designs to achieve desirable crop improvements.