Assessment of genetic variability in eggplant (Solanum melongena L.) genotypes for disease resistance and yield parameters

Eggplant is a globally important vegetable crop valued for its nutritional and economic significance. However, its productivity is often constrained by various biotic stresses particularly susceptibility to Phomopsis blight, causing significant economic losses and threatening food security. This study aims to identify genetically distinct genotypes with enhanced disease resistance and yield to support sustainable eggplant breeding efforts. This research evaluated genetic variability among 33 eggplant genotypes, focusing on resistance to Phomopsis blight. The evaluation was conducted during the Spring-Summer and Kharif seasons, of 2022-at the Vegetable Research Farm, Lovely Professional University, Punjab India and laid out in a Randomized Block Design in triplicates. The pooled analysis of variance revealed significant differences among genotypes for key traits. High phenotypic and genotypic variance (>50%) were observed for average fruit weight (g), percent disease index (PDI) for leaf & fruit at 21st day after inoculation (DAI) (%) and percent leaf area diseased (%). High phenotypic (PCV) and genotypic coefficient of variation (GCV) (>20%) were recorded for characters including fruit yield plant-1 (kg), lesion size on fruits (cm2), average fruit weight (g), PDI for fruit at 7th, 14th & 21st DAI (%) and PDI for leaf at 7th, 14th & 21st DAI (%). A narrow difference between GCV and PCV indicated that phenotypic variability was primarily genetic. High heritability (>60%) with a substantial genetic advance (>30%) as a percentage of the mean (GAM) at 5% underscored the potential for improvement through targeted selection, driven by additive genetic effects. These findings provide valuable insights into breeding programs targeting disease-resistant and high-yielding eggplant varieties. Future studies should investigate molecular mechanisms underlying disease resistance to refine breeding strategies.