Comprehensive Assessment of Genetic Variability and Trait Associations Governing Processing Quality in Tomato

Abstract

Aim: To assess genetic variability, heritability, and genetic advance for key yield and processing-related fruit quality traits in tomato, along with the association patterns among these traits, was investigated through correlation studies. Study Design: Randomized complete block design with two replications Place and Duration of Study: At the College of Agriculture, Navile, Shivamogga, during summer 2024. Methodology: Twenty tomato genotypes were evaluated for yield and fruit quality traits relevant to processing. Results: Analysis of variance showed significant differences among tomato genotypes for all traits, indicating substantial variability in growth, yield and quality attributes. High genetic variability, heritability, and genetic advance for ascorbic acid, lycopene, ripening index, pericarp thickness, fruit firmness, fruit weight, and locule number. In contrast, plant height and fruit yield showed moderate heritability, influenced more by environmental factors. Quality traits such as total soluble solids, titratable acidity, and pH exhibited high heritability but moderate genetic advance, suggesting potential for gradual improvement. Correlation analysis revealed strong positive relationships among key yield traits. Days to fifty per cent flowering correlated with days to maturity, plant height, total soluble solids, ripening index, and fruit number. Fruit weight and diameter were negatively correlated with flowering time but positively associated with yield and cluster size. Processing quality traits were interconnected: total soluble solids strongly correlated with lycopene and ripening index but negatively with titratable acidity, pH, and fruit size. Lycopene content was inversely related to ascorbic acid, pulp recovery, and locule number. Ascorbic acid was positively correlated with fruit pH but negatively with fruit count, whereas pericarp thickness increased firmness, pulp recovery, and fruit weight but reduced ripening rate and fruit number. Conclusion: Study of genetic parameters describing variability revealed the potential for gradual improvement. Correlation results highlight key trade-offs between yield and quality traits crucial for breeding processing-oriented tomato genotypes.