STUDIES ON NEWLY PRODUCED CUCUMBER HYBRIDS (CUCUMISSATIVUS) IN EGYPT

Abstract

A complete diallel cross among five inbred lines of cucumber was evaluated for some important traits. The results showed that the mean squares, genotypes, parental inbred lines, crosses and parent vs crosses were significant for all studied traits. The F1 crosses P2×P4 and P2×P5 (HTCU111×HTCU682 and HTCU111×HTCU621) exhibited useful heterosis relative to mid-parent and better-parent for fruit yield/plant and number of leaves/plant. The mean squares associated with general and specific combining abilities were significant for all traits, GCA/SCA ratio was high than unity for all traits, indicating that greatest role of the additive type of gene action in the expression of these traits. P1 and P2 (AVCU011001 and HTCU111) exhibited significant positive general combining ability effects for number of fruits/plant and fruit yield/plant indicating that this inbred line could be considered as good combiner for developing high yield genotypes. Four F1 crossesAVCU011001×HTCU416, HTCU111×HTCU682, HTCU111×HTCU621 and HTCU682×HTCU621(P1×P3, P2×P4, P2×P5 and P4×P5) as well as the reciprocal crosses HTCU682×AVCU011001, HTCU682×HTCU111, HTCU682×HTCU416 and HTCU621×HTCU416 (P4×P1, P4×P2, P4×P3 and P5×P3)expressed significant positive specific combining ability effects and reciprocal rij effects, respectively. The highest estimate of heritability was 98.64% for TSS,whilehighest heritability in narrow sense was 79.4% for number of fruits/plant. The phenotypic correlation for number of fruits/plant had significant positive correlation with fruit yield/plant and number of fruits/node, also the genotypic correlation forfruit yield/plant, significant positive correlation with number of fruits/node.