Gene Action of Shelf-Life and other Fruit Quality Traits in a Cross Between a Regular Cultivar and Alc Mutant of Tomato

Abstract

Prolonged shelf-life and good quality fruit are crucial attributes for the marketing of tomato (Solanum lycopersicum L) and thus a major focus for breeding. This study was carried out to explore gene effects, heritability, heterosis and inbreeding depression for shelf-life, fruit quality and some quantitative traits of tomato using six generations derived from a cross between CSIR/CRI-P002 (P1) an adapted variety with good yield and short shelf-life, and Alc-LA3134 (P2), a ripening mutant tomato with long shelf-life but low yield. The P₁ , P₂ , F₁ , F₂ , BC_1.1 , BC_1.2 generations were subjected to generation mean analysis. Mean performance of the F was higher 1 than the mid-parent for all traits except total soluble solids (TSS). Additive and dominance variances were higher than environmental variance for all traits. Apart from shelf-life, the simple additive-dominance (three-parameter) model was inadequate for explaining the gene action for the traits. Using the six parameter model, additive, dominance and epistatic gene effects were found to be significant for most of the studied traits. Duplicate epistasis was detected for all the traits except shelf life. The fixable and non-fixable gene effects exhibited by the traits can be improved through pure line breeding and heterosis, respectively.

Keyword: Additive, Non-additive, Genetic variability, Heritability, Inbreeding depression