Usefulness of combining ability and gene action studies for parthenocarpic gynoecious hybrid development in cucumber

The present investigations were aimed to estimate combining ability, gene action and proportional contribution of lines, testers and their interactions for yield and its contributing traits in F1 population of 48 crosses, developed by crossing 16 lines (8 parthenocarpic gynoecious) and 3 testers during the year 2011. Parents (16 lines and 3 testers) and their 48 F1 hybrids were planted in randomized complete block design during the year 2012 for their comparative evaluation. Experimental results revealed that among the parents, lines LC-1-1, CGN-20953, CGN-19533, Gyne-5, CGN-22930 and LC-2-2, and the testers K-75 and Poinsette were found superior on the basis of GCA effects, while the cross combinations CGN-19533 × K-75, CGN-20953 × Poinsette, LC- 1–1 × K-75, Gyne-5 × K-75 and LC-2-2 × Poinsette were found superior based on SCA effects. Gene action studies indicated that the estimates of σ² SCA were higher in magnitude as compared to σ² GCA (average), thereby indicating the predominant role of non-additive gene action governing these traits. Further, proportional contribution of lines × testers interactions was found higher than the individual contribution of lines and testers for fruit breadth (44.99%) and yield per plot (39.45%) and yield per ha (39.45%). Therefore, heterosis breeding could be exploited commercially for the development of stable parthenocarpic gynoecious hybrids in cucumber.