PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Bottle gourd [Lagenaria siceraria (Mol.) Standl.] is a widely cultivated cucurbitaceous vegetable crop in India, valued for its nutritional quality, wide adaptability, and economic importance. To identify superior parents and promising hybrid combinations for yield improvement, the present investigation was conducted to study combining ability for yield and its contributing traits using a line × tester mating design. The experimental material included seven different lines and three testers, which were crossed to create twenty-one F₁ hybrids. These hybrids, their parent plants, and a standard control were assessed in a Randomized Block Design with three replications at the Vegetable Research Farm, Department of Horticulture (Vegetable and Floriculture), Bihar Agricultural University, Sabour, Bhagalpur. Variance analysis showed highly significant differences among genotypes for all examined traits, indicating considerable genetic variability. The variance component estimates indicated that specific combining ability (SCA) variance surpassed general combining ability (GCA) variance for the majority of traits, with the GCA/SCA ratio being below one, except in the case of fruit length. This indicated the superiority of non-additive gene action in the heredity of yield and several yield-related characteristics, emphasizing the opportunity to leverage heterosis in bottle gourd breeding. Among the parents, BRBG-22-1, BRBG-23, BGL-19, and BRBG-41-1 were identified as good general combiners for fruit yield and important contributing characters. Several hybrids exhibited significant and desirable SCA effects for earliness, growth, fruit traits, and yield. Notably, the crosses BRBG-21-2 × Swarna Sneha, BRBG-41-1 × Narendra Rashmi, and BRBG-23 × Rajendra Chamatkar emerged as superior specific combiners for fruit yield per vine. The study emphasizes the importance of non-additive gene action and identifies promising parental lines and hybrid combinations that can be effectively utilized in future bottle gourd hybrid breeding programmes.