Genetic Variability, Trait Correlation and Path Coefficient Analysis in Bottle Gourd (Lagenaria siceraria L.)

The present investigation was conducted at the Agricultural Research Farm, Suresh Gyan Vihar University, Jaipur to investigate genetic variability, correlation and path coefficient analysis in bottle gourd (Lagenaria siceraria L.) under the semi-arid conditions of Rajasthan. The experiment was laid out in a randomised block design with sixteen treatments and three replications. The results revealed that genotype Arka Bahar emerged as the most promising line for crop improvement, achieving the highest total fruit yield (80.42 t/ha) and yield per vine (14.12 kg), closely followed by DS-4 for vine yield (13.66). The highest values for other traits were recorded among different genotypes, including DS-2 for vine length (18.21 m) and fruit diameter (18.11 cm), Pusa Santushti for developmental duration (requiring up to 79.30 days for first harvest), MS-1 for sex ratio (15.37), RS-2 for fruits per plant (13.27), DS-4 for fruit weight (1.31 kg) and DS-3 for fruit length (40.11 cm). Genetic analysis revealed that fruit diameter recorded the maximum genotypic coefficient of variation (39.76%), phenotypic coefficient of variation (40.40%), and genetic gain (80.63%), followed closely by yield of fruit per vine and vine length. Conversely, vine length exhibited the highest broad-sense heritability (97.87), followed by fruit diameter (96.88), fruit yield (96.57), and yield of fruit per vine (95.88), showing that all these parameters maintain heritability estimates above 93%. Correlation studies indicated that yield of fruit per vine was significantly and positively correlated at both genotypic and phenotypic levels with vine length (rg=0.421), (rp=0.417), number of primary branches (rg=0.837), (rp=0.810), days to first male flower (rg=0.362), (rp=0.349), number of fruits per plant (rg=0.537), (rp=0.412), average fruit weight (rg=0.358), (rp=0.344), length of fruit (rg=0.428), (rp=0.400), and total fruit yield (rg=0.504), (rp=0.496). In path coefficient analysis, average weight per fruit exerted the highest positive direct effect on fruit yield genotypically (0.9098), followed by length of fruit (0.8337), yield of fruit per vine (0.2978), and number of fruits per plant (0.2034). Phenotypically, vine length had the highest positive direct effect (0.48937), followed by length of fruit (0.26651) and average weight per fruit (0.24135). Ultimately, the high heritability associated with substantial genetic gain for critical traits particularly fruit diameter, yield per vine, and vine length indicated that these characters are governed by additive gene action and can be reliably improved through direct selection. Therefore, breeding strategies focusing concurrently on utilizing genotype Arka Bahar and selecting for yield per vine, fruit diameter, and average fruit weight may support genetic improvement in future programmes.