ESTIMATE OF SOME GENETIC PARAMETERS FOR SOME VEGETATIVE AND YIELDING TRAITS IN COMPLETE DIALLEL CROSSES AMONG FIVE INBRED LINES OF CUCUMBER

Abstract

This experiment was implemented in the experimental farm of (Misr hytech seed co. Giza, Egypt) during winter growing seasons 2014 and 2015 to evaluate the inheritance of some cucumber vegetative and yielding traits using a complete diallel cross among five inbred lines. The results showed that the mean square of genotypes, parental inbred lines, crosses and parent vs crosses were significant for the studied traits. The hybrids P2xP4 and P2xP5 exhibited a useful heterosis relative to Mp and Bp for the fruit yield per plant and number of leaves per plant. The mean square of general and specific combining ability was significant for the studied traits. The higher GCA/SCA ratio than the unity of the studied traits indicating to the greatest role of the additive gene action in the expression of these traits. The inbred lines P1 and P 2 exhibited significant positive i g ˆ effects in the traits of number of fruit per plant and fruit yield per plant, so these inbred lines could be act as a good combiner for developing high yielding genotypes. The F1 hybrids P1xP3, P2xP4, P2xP5 and P4xP5 as well as the reciprocal hybrids P4xP1, P4xP2, P4xP3 and P5xP3 recorded a significant positive ij S ^ effect but the reciprocal hybrids recorded a significant rij effect. The results revealed to more than one hybrid distinct in some traits that could be utilized in the greenhouse cucumber cultivation and the future breeding programs.