Estimation of combining ability, gene action and components of genetic variation in cucumber (Cucumis sativus L.)

Abstract

The study aimed to assess combining ability and understand the genetic control of fruit yield and its component traits in cucumber. Seven parental genotypes were crossed in a half-diallel fashion to produce 21 F₁ hybrids, evaluated in a randomized block design at the Potato Research Station, SDAU, Deesa during summer 2022. Analysis of variance revealed significant gca and sca effects for all traits except moisture content for gca, indicating the involvement of both additive and non-additive gene actions. Parents ACUS- 20-04, ACUS-19-14, and ACUS-19-19 were identified as good general combiners for fruit yield. Non- significant t² values and a unit regression slope validated the additive-dominance model for early flowering and key vegetative traits. For all traits, H1 exceeded H2 and the ratio H2/4H1 was below 0.25, reflecting unequal gene distribution among parents. KD/KR > 1 showed higher frequencies of dominant alleles. Overall, σ²gca/σ²sca < 1 indicated the predominance of non-additive genetic variance in governing yield and related traits. The ratio of σ2gca/σ2 sca being less than unity, which suggested greater role of non-additive genetic variance in the inheritance of these traits. The genetic components of variance and graphical analysis revealed that different type of gene action were involved for fruit yield and components traits in cucumber.