Assessment of Genetic Variability, Heritability and Expected Genetic Advance in Summer Squash (Cucurbita pepo L.)

Abstract

An economically significant cucurbit crop prized for its culinary, medicinal and nutritional qualities is summer squash (Cucurbita pepo L.). For efficient selection and breeding of superior cultivars, it is essential to comprehend the degree of genetic variability, heritability and genetic advancement among genotypes. Using 40 different genotypes arranged in a randomized complete block pattern with three replications, the current study was carried out at the Vegetable Experimental Farm, SKUAST-Kashmir, Shalimar, during Kharif 2024. To separate phenotypic and genotypic variability, data on 22 morphological, yield and quality variables were collected and examined. Wide genetic diversity was confirmed by analysis of variance, which showed highly significant variations between genotypes for all variables using ANOVA. PCV values were marginally greater than GCV, indicating little environmental influence, according to estimates of the phenotypic and genotypic coefficients of variation. Fruit yield per plant, fruit yield per hectare, rind thickness, 100-seed weight, flesh thickness, fruit length, vitamin C content, total sugars, dry matter content and crude fiber all showed high heritability and high genetic advancement as a percentage of the mean. The fact that additive gene action essentially controls these features emphasizes how direct selection may be used to improve them. Interestingly, genotypes SKUA-SQ-5, SKUA-SQ-34, SKUA-SQ-17, SKUA-SQ-24 and SKUA-SQ-27 produced the highest no. of fruit per hectare. Overall, the results highlight the significance of utilizing the genetic diversity now in place to create commercially viable, high-yielding, nutritionally enhanced summer squash cultivars in temperate climates.