Twenty cucumber (Cucumis sativus L.) genotypes were evaluated during the summer of 2022 at the Horticultural Research Centre, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, Uttar Pradesh, to estimate genetic variability and selection parameters for 16 quantitative traits. The experiment was laid out in a randomised block design (RBD) with three replications at 90 × 60 cm spacing. Analysis of variance (ANOVA) revealed highly significant differences among genotypes for all traits, indicating the presence of substantial variability. High genotypic and phenotypic coefficients of variation were recorded for average fruit weight, fruit yield per hectare, vine length and number of fruits per plant, while all traits exhibited high heritability coupled with moderate to high genetic advance as percent of mean, suggesting the predominance of additive gene action. Fruit yield per hectare showed highly significant and positive correlations with fruit yield per plot, fruit diameter, number of fruits per plant, average fruit weight, number of leaves per plant, fruit length and vine length at both genotypic and phenotypic levels, whereas days to first male and female flower anthesis and days to first fruit harvest were negatively associated. Genotypic path analysis revealed high positive direct effects of fruit diameter, fruit yield per plot, days to first male and female flower anthesis, vine length, node number to first male and female flower anthesis, number of fruits per plant and average fruit weight on fruit yield per hectare. Mahalanobis D² analysis grouped the genotypes into five clusters, with maximum inter–cluster distance between clusters III and V, indicating high genetic divergence and suggesting that crosses between these clusters may produce superior segregants for yield and related traits.
