Genetic variability, heritability and genetic advance studies in summer squash (Cucurbita pepo L.)

The enhancement of any crop relies on the degree of genetic variability present in the gene pool. For breeders to develop effective breeding programs, it is imperative to comprehend the nature and extent of genetic variations within the germplasm. Present investigation was conducted at Vegetable Experimental field, SKUAST-Kashmir, Shalimar Srinagar during Kharif, 2023 to investigate several aspects of genetic variability including mean, range, PV, GV, PCV, GCV, heritability, genetic advance and GAM (genetic advance as percent of mean) among 30 genotypes of summer squash. Observations were recorded for traits including growth, yield and quality parameters. The experiment was laid out in Randomized Complete Block Design (RCBD). The Analysis of variance revealed significant differences among different genotypes for all the traits studied. For each character examined, it was found that the estimates of Phenotypic coefficient of variation (PCV) was slightly greater than Genotypic coefficient of variation (GCV) indicating little influence of environment on the expression of characters. Highest PCV and GCV was exhibited by total carotenoid content (54.90, 54.81), fruit yield/ha (33.86, 29.90), fruit yield/plant (30.28, 26.32) respectively. High heritability coupled with high genetic advance as percent of mean was observed for most of the traits indicating the traits studied were mainly controlled by additive gene effect and hence selection of these traits may be effective. Selecting superior parents for the development of commercial varieties/hybrids in is facilitated by all these factors.