Combining ability and gene action studies for different yield contributing traits in cucumber

Abstract

Combining ability and gene action were studied in diallel design (without reciprocal) using six genotypes namely Khira-75, UHF-CUC-1, UHF-CUC-2, UHF-CUC-3, Poinsette and PI-618860. Its information is important for making breeding plans, general combining ability (GCA) studies revealed that P1-618860, UHF-CUC-1, UHF-CUC-2 and Khira-75 were observed to be good combiners for a number of traits, including yield per plot and per hectare. However, the estimates of specific combining ability (SCA) showed the highest desirable SCA effects in crosses Khira-75 × PI-618860, UHF-CUC-1 × PI-618860 and UHF-CUC-3 × PI-618860 for earliness and other desirable traits including yield per plot and per hectare. Predictability ratio and average degree of dominance was observed to be less than 1 for most of the horticultural and yield contributing traits indicating the importance of non-additive components of variance for improvements of these traits. The results indicated the importance of heterosis breeding for effective utilization of non-additive genetic variance in cucumber.