Gene effects for fruit yield and its component traits in cucumber (Cucumis sativus) using generation means

Abstract

Generation mean analysis in cucumber (Cucumis sativus L.) was carried out during 2006–07 to study gene effects for fruit yield and its components in interacting and non-interacting crosses using 3-parameter model and 6-parameter model, respectively. For this purpose, six promising parents selected out of 17 genotypes were crossed in a half-diallel fashion to generate 15 F1s. Top five high-yielding F1s were advanced to F2s, B1s and B2s. The estimates of gene effects obtained through analysis of six generations revealed preponderance of both additive and dominance effects for fruit weight, fruit length and fruit diameter. Epistatic interactions were observed for earliness, number of fruits/plant and yield/plant. However, scaling test was non-significant for fruit weight and length in all the five crosses showing absence of epistasis in the control of these characters. Some crosses showed duplicate type of interaction while others showed complementary epistasis. For instance, for fruit yield/ plant, CRC 8 × Pusa Uday and CHC 2 × DC 1 showed complementary epistasis, which would increase the heterosis in positive direction. The magnitude and direction of the gene effects varied from cross to cross. Thus, characters such as fruit weight and fruit length which are governed by entirely additive components could be improved through individual selection while for days to first female flower opening, days to first fruit harvest, number of fruits/plant and fruit yield/plant showing predominant dominance gene effects and interaction effects, biparental mating and recurrent selection would exploit both additive and non-additive type of gene effects efficiently.