Genetic variability and character association studies in bottle gourd germplasm

Abstract:

Bottle gourd breeders face a recurring problem: fruit yield per vine varies two-to three-fold across apparently similar accessions, yet which morphological traits actually drive that variation remains unclear. This research evaluated 48 bottle gourd accessions at the Abeokuta research farm across two summer seasons (2022, 2023) to quantify genetic variability, heritability, genetic advance, and character association for eight quantitative traits. Analysis of variance detected significant differences (p<0.01) for all traits. Yield per vine showed the highest phenotypic and genotypic coefficients of variation (PCV = 41.2%, GCV = 37.8%), followed by fruits per vine (PCV = 38.6%, GCV = 34.8%) and fruit weight (PCV = 32.4%, GCV = 29.1%). Broad-sense heritability was highest for yield (84.2%) and fruits per vine (81.3%), with genetic advance as percentage of mean of 71.4% and 64.7% respectively. Yield per vine correlated strongly with fruits per vine (r = 0.84) and fruit weight (r = 0.81). Path analysis identified fruits per vine as having the largest direct effect on yield (0.58), with fruit weight second (0.46). The combination of high heritability, high genetic advance, and strong positive correlation with yield points to fruits per vine and fruit weight as the primary selection criteria for bottle gourd improvement in West African agro-climates.