Evaluation of Genetic Variability, Heritability and Genetic Advance in Cauliflower [Brassica oleracea var. Botrytis L.] Genotypes

Abstract

Exploring genetic variability within the available germplasm is a fundamental prerequisite in any plant breeding program, as it facilitates the selection of superior genotypes. Key genetic parameters such as heritability and genetic advance are valuable tools for breeders in identifying genotypes that exhibit desirable characteristics. To enhance the genetic potential of cauliflower, a comprehensive assessment of genetic variability, heritability, and genetic advance was undertaken using the existing germplasm. The investigation was conducted during the winter season of 2024–2025 at the Main Experiment Station, Department of Vegetable Science, ANDUAT, Kumarganj, Ayodhya (U.P.). Thirty-two cauliflower genotypes were evaluated in a Randomized Block Design with three replications to estimate the extent of genetic variability, heritability and genetic advance for nineteen quantitative and qualitative traits. The analysis of variance revealed significant differences among genotypes for all the characters studied, indicating substantial genetic variability in the germplasm. The phenotypic coefficient of variation (PCV) was found to be higher than the genotypic coefficient of variation (GCV) for all traits, suggesting environmental influence on trait expression. High PCV and GCV were observed for traits such as leaf width, stalk width, curd yield per plot and net curd weight, indicating potential for effective selection. Genetic advance in per cent of mean were found to be high (>20%) for several traits, particularly leaf width (24.10), curd yield per plot (22.28) and stalk width (21.29). Moderate genetic advance in percent of mean (10 to 20%) were observed for traits such as net curd weight (16.65), total soluble solids (16.13), ascorbic acid (15.79), gross plant weight (15.75), days to curd initiation (14.24), stalk length (13.42), curd polar diameter (12.76), leaf length (11.90), days to curd maturity (11.78), curd equatorial diameter (11.50), number of leaves per plant (10.88) and dry matter content (10.58). The high heritability coupled with high genetic advance as a percentage of the mean was recorded for ascorbic acid, curd yield per plot, leaf width and total soluble solids, suggesting additive gene action and effectiveness of direct selection. Among the genotypes, NDC-23-21 and NDC-23-16 were identified as superior based on curd yield per plot. Traits including net curd weight, gross plant weight, days to curd initiation, and curd yield per plot exhibited high heritability coupled with high genetic advance as a percentage of the mean. The combination suggests that the inheritance of these traits is primarily controlled by additive gene effects, and hence, direct selection for these traits is likely to result in significant genetic improvement. The findings highlight the potential for genetic improvement through targeted selection.