Study of heterosis and combining ability for earliness and vegetative traits in Cucumber (Cucumis sativus L.)

The present investigation was undertaken to investigate the extent of heterosis and combining ability on earliness, vegetative traits and yield of Cucumber. A field experiment was designed in line x tester mating design with 11 parents (including 8 parthenocarpic lines namely Pant parthenocarpic cucumber-2, Pant parthenocarpic cucumber-3, Nun-3139, Nun-3121, Nun-3141, Infifnity, Isatis, Kian, and 3 monoecious testers namely PCUC-8, PCUC-15, Pant Kheera -1 {also known as PCUC-28}) and their 24 F1 hybrids to work out the heterosis and combining ability for earliness and yield characters. All traits pertinent to earliness and yield showed significant values for heterosis and combining ability. Appreciable heterosis in desirable direction was found over better parent and check parent by the cross PCUCP-3 x PCUC-15 for earliness characters viz. days to first female flower (-71.18 & -70.31), days to first harvest (-3.40 & -22.01) whereas Cross Kian x PCUC-15 showed maximum number of fruits per plant (8.36 & 106.35) and fruit yield (86.34 & 210.74 respectively). The crosses PCUCP-3 x PCUC-15 and Nun-3139 x PCUC-8 showed significant specific combining ability for earliness and yield characters. Cross Nun-3139 x PCUC-8 showed significant yield regarding heterosis and SCA. Regarding general combining ability for earliness parent Isatis and for yield characters parent Kian stood in top. Cross Nun-3139 x PCUC-8 showed Maximum specific combining ability for node number to first female flower (-0.98), number of fruits per plant (3.39) and fruit yield (220.57)