Heterosis and combining ability for yield and quality traits in monoecious, gynoecious and parthenocarpic parental lines of cucumber (Cucumis sativus L.) under tropical condition

The present study was conducted to find out high yield and good quality cucumber hybrids which can further be released for cultivation in the tropics under open filed conditions. Therefore, five lines (2 gynoecious, 1 each predominantly gynoecious, parthenocarpic gynoecious and predominantly gynoecious and parthenocarpic) and 11 testers (monoecious) were crossed in a line × tester mating design to develop 55 F₁ hybrids at Vegetable Research Farm, Punjab Agricultural University, Ludhiana. All the 71 genotypes were evaluated during spring–summer 2021 under open field conditions for 11 quantitative traits. Gene action study revealed the predominant role of non-additive genetic variance for all traits except for fruit length. On the basis of GCA (general combining ability) effect, lines PK-1, PBRK-11 and 25–46 VNR and testers Punjab Naveen, Pusa Uday and PMC-1were found to be best for fruit yield, quality and earliness which can be utilized as donor parents in future breeding. The maximum heterobeltiosis was recorded for fruit yield followed by fruit number per plant, fruit weight, fruit length and fruit diameter. The significant and positive correlation between GCA and mean of parental lines was observed for fruit yield, fruit number per plant, fruit length, and days to first fruit picking. Exploitation of the top performing hybrids ‘PK-1 × AVCU-1205, PK-1 × Swarna Ageti, PK-1 × PMC-1 and PBRK11 × Punjab Naveen’, after critical evaluation, could be recommended for commercial cucumber open field production in the tropics. Promising hybrids could also be exploited in segregating generations to identify pure lines having high yield with good fruit quality.