Genetic potential of bottle gourd (Lagenaria siceraria (Molina) Standl.): Combining ability, gene action and heterosis analysis

Abstract

An investigation on diallel analysis in bottle gourd [Lagenaria siceraria (Molina) Standl.] was conducted during 2024–25 at the Department of Horticulture, Pandit Jawaharlal Nehru College of Agriculture and Research Institute, Karaikal. To generate F1 hybrids with desirable traits for yield and quality, seven diverse cultivars (PLR 1, PLR 2, Arka Bahar, Arka Shreyas, Kethanur Local, Udumalpet Local and Karur Local) were crossed to produce 42 F1 hybrids. Along with hybrids, parents were evaluated for 18 growth, yield and quality traits. Analysis of variance indicated highly significant differences among genotypes for all the 18 characters studied. Combining ability analysis revealed that both general combining ability (GCA) and specific combining ability (SCA) were highly significant for all characters. For fruit yield vine-1, significant GCA (4.53) and SCA (3.07) effects suggested the involvement of both additive and non-additive gene action. Higher GCA/SCA ratios were recorded for fruit circumference (0.539), individual fruit weight (0.370) and number of staminate flowers vine-1 (0.373), indicating the predominance of additive gene action, while lower ratios for number of fruits vine-1 (0.018) and total sugars (0.027) suggested the importance of non-additive gene action. Among the parents, Kethanur Local exhibited superior mean performance for vine length (13.48 m), number of nodes vine-1 (108.80) and fruit yield vine-1 (8.31 kg), indicating its good GCA. Significant heterosis was observed for yield and its component traits. The hybrid Kethanur Local x Karur Local recorded the highest fruit yield vine-1 (12.19 kg), while Udumalpet Local x PLR 1 produced the maximum number of fruits vine-1 (10.90) with a fruit yield of 10.08 kg. For quality traits, Arka Shreyas x PLR 2 expressed the highest total soluble solids (4.10 °Brix) and Arka Shreyas x PLR 1 recorded the highest total sugars (3.56 %). After considering per se performance, SCA effects and heterosis, the hybrids are arranged in order of their fruit yield as follows: Kethanur Local x Karur Local, Udumalpet Local x PLR 1, Arka Bahar x Kethanur Local and PLR 2 x Kethanur Local. Standard heterosis is one of the best ways to recognise the hybrid Kethanur Local x Karur Local as the one with the most exceptional features further. The results indicated the predominance of both additive and non-additive gene action for most traits, highlighting the scope for exploiting heterosis through hybrid breeding as well as selection of superior combiners in bottle gourd improvement programmes.