Genotypic Variation in Tomato (Solanum lycopersicum) under Polyhouse-Grown Conditions: A Genetic Diversity Approach

The present investigation was carried out during the 2021–2022 cropping season at Nalegaon, Maharashtra, India (latitude: 18.422146° N; longitude: 76.810104° E). The study aimed to assess the genetic variability and trait associations influencing yield and its contributing components in tomato (Solanum lycopersicum) genotypes. A total of six genotypes were evaluated, including four sourced from the Indian Institute of Horticultural Research (IIHR), Bangalore, and two obtained from the local market.Genetic relationships among the genotypes were analyzed using the Unweighted Pair Group Method with Arithmetic Mean (UPGMA), with a cophenetic correlation coefficient (r) of 0.845, indicating a strong representation of the dissimilarity matrix by the resulting dendrogram. Based on the pairwise Euclidean distance matrix, the greatest genetic dissimilarity was observed between the genotypes ‘Lakshmi’ and ‘Vikas’, while the highest similarity was noted between ‘US440’ and ‘Alankar’, as well as between ‘Lakshmi’ and ‘Apeksha’.The analysis revealed significant genetic variability among the genotypes studied. Principal Component Analysis (PCA) identified plant height (cm), number of branches, number of fruits per plant, yield per plant (kg), pericarp thickness (mm), crop duration (days), and average fruit weight (g) as the most influential traits contributing to genotype differentiation. These findings highlight the existence of substantial genetic diversity and provide a basis for selecting promising genotypes for future tomato breeding programs.