PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Sponge gourd [Luffa cylindrica (L.) Roem.] is an important cucurbitaceous vegetable crop cultivated worldwide during the summer and rainy seasons. The crop exhibits considerable genetic variability for growth, flowering, yield, and fruit quality traits, providing substantial scope for genetic improvement through breeding. The development of high-yielding and early-maturing hybrids using diverse parental lines is considered an effective strategy for enhancing productivity and meeting the increasing demand for this crop. An experiment was conducted to estimate heterosis for the yield characteristics of sponge gourd. A total of twenty-seven F₁ hybrids were developed using a line × tester mating design. These hybrids, along with nine lines, three testers, and one commercial check, were evaluated in a randomized block design with three replications during summer 2025 at Vegetable Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand. Heterosis was calculated from the mean values of the F₁ hybrids across three replicates. The best heterotic cross for fruit yield per plant was Pusa Sneha × Kashi Divya. This cross also exhibited significant heterosis for days to first male and female flower, days to first harvest, vine length, flesh thickness, and number of fruits per vine. Cross Pusa Sneha × Kashi Divya (112.28%), Kashi Shreya × Swarna Prabha (42.42%), and Pusa Sneha × Pant Chikni Torai-1 (38.39%) were found to be the best heterotic combinations as they exhibited significant heterosis percentage for fruit yield per plant over the commercial check (Pusa Chikni). The crosses Kashi Kalyani × Pant Chikni Torai-1 and Kashi Shreya × Swarna Prabha were found to be the most promising for earliness as they showed significant negative heterosis over mid-parent, better parent and commercial check.