Estimation of Heterosis, dominance effect and genetic control of fresh fruit yield, quality and leaf curl disease severity traits of chilli pepper (Capsicum annuum L.)

Abstract

Development of chilli hybrids having high pungency, antioxidant vitamins and appreciable tolerance against leaf curl virus is the present need in major part of the tropics. Five genetically diverse parents were selected out of twenty two genotypes of diverse origin through multivariate analysis. They were crossed in diallel fashion without reciprocals to produce 10 F1 hybrids to determine mode of gene action, extent of heterosis and dominance effect, and to estimate combining ability for 14 quantitative characters. The predictability ratio revealed overwhelming response of non-additive gene action in controlling the expression of fresh fruit yield per plant and most of the yield components, antioxidant vitamins (vitamin C and beta-carotene, a precursor of vitamin A) content of fruit and severity of leaf curl virus disease. The breeding procedures applicable to improvement of studied characters are discussed. The maximum extent of significant heterobeltiosis in desired directions was recorded from hybrids in a five-parent diallel of chilli for fruit yield per plant (71.06%*, significant at the 5% level), PDI of leaf curl virus (−47.61%**, significant at the 1% level), capsaicin content of fruit (46.67%**), beta carotene content of fruit (36.17%**) and vitamin C content of fruit (28.93%**). The study depicted that hybrid vigour is available for commercial production of chilli hybrid, and that isolation of pure lines from the segregating generation of heterotic F1′s is an alternative approach to improve fruit yield, quality and viral disease tolerance. Partial- to over-dominance effects were found to be involved in the inheritance of fruit yield and other horticultural traits. Two inbred lines BCCH Sel-4 and Chaitali were the most promising general combiners for fruit yield per plant and other important traits that could be utilized in future chilli improvement programmes. We could also able to isolate a promising hybrid, BCCH Sel-4×AC-575 on the basis of its per se performance; heterosis manifested in them and the sca effects, and this hybrid could make a dent by fulfilling the major horticultural attributes in commercial chilli growing zones of the tropics.