Combining ability for yield and yield related traits and its relationship with gene action in cucumber

Combining ability studies was carried out to estimate general combining ability of 8 parents and specific combining ability of 28 crosses of cucumber for nine quantitative traits in 8 × 8 half-diallel mating design excluding reciprocals. The result revealed that the magnitude of σ2s were higher than the σ2g, predictability ratio (PR) was found to be less than 0.5 and average degree of dominance (ADD) was found to be > 1 for all the traits, indicating predominance of non-additive gene action and scope of heterosis breeding in improvement of different traits. The estimates of gca effects of parents showed that DC-1 was good general combiner for earliness, days to first fruit set, days to first fruit harvest and fruit diameter. For fruit length and average fruit weight, Kalyanpur Green was good general combiner. Pusa Uday showed the highest significant gca effect for number of fruits per plant and total yield per plant and second highest significant gca for average fruit weight. Majority of cross combinations recorded high sca effects and per se performance due to low × low, low × high or high × low parental gca status. The hybrid Pusa Uday × DC-1 exhibited high significant sca effects for days to first female flower opening, days to first fruit set, days to first fruit harvest, average fruit weight, number of fruits per plant and total yield per plant followed by Pusa Uday × Kalyanpur Green, Punjab Naveen × DC-1 for total yield per plant, hence can be further exploited for commercial cultivation after multi-location testing.