Determination of Agro-Morphological Characteristics in Local Tomato (Solanum lycopersicum L.) Genotypes Collected from Central Anatolia Region

In this study, 116 tomato genotypes collected from the Central Anatolia region were subjected to agro-morphological characterization and association analysis. For agro-morphological characterization, observations and measurements were carried out on 30 traits (18 qualitative and 12 quantitative) determined according to the criteria specified by UPOV and IPGRI. The 116 genotypes were evaluated in terms of morphological and quality traits, and the sources of variation were revealed through Principle Component Analysis (PCA), clustering, and correlation analyses. According to PCA results, the first two components, explaining 31.4% of the total variance, highlighted clear relationships between fruit size and structural traits (average fruit weight, fruit width, fruit length, and number of locules) and quality parameters (SSC, fruit and flesh colour, colour values, and fruit firmness). Cluster analysis based on the heat map grouped the genotypes into four main clusters: small and firm-fruited genotypes (Group 1), genotypes with vigorous plant growth and large fruits but low sugar content (Group 2), high-quality genotypes with intense colour, firmness, and high SSC representing the highest market value (Group 3), and genotypes with intense red colour but low firmness and susceptibility to blossom-end rot (Group 4). Correlation analyses revealed a clear trade-off between fruit yield and quality traits, indicating that larger and more locule-rich fruits may have lower dry matter content. Overall, the findings demonstrated that PCA and clustering analyses effectively distinguished the differences among tomato genotypes, and these results provide important contributions both to the selection of genotypes with high market value and to guiding breeding programs focusing on either yield or quality improvement.