Genetic Diversity Analysis and Comprehensive Evaluation of Phenotypic Traits in 364 Cherry Tomato Germplasm Resources

To analyze the genetic diversity of phenotypic traits in cherry tomato germplasm resources, conduct a comprehensive evaluation, and screen for superior cherry tomato materials. This aims to provide a basis for the selection, utilization, and breeding of core cherry tomato germplasm.

This study utilized 364 cherry tomato germplasm resources from domestic and international sources as experimental materials, measuring 41 phenotypic traits. Employing multivariate statistical analysis methods including genetic diversity indices, correlation analysis, principal component analysis, systematic clustering, and membership function analysis, the research conducted genetic diversity analysis, cluster classification, and comprehensive evaluation of cherry tomato germplasm phenotypes.

The coefficient of variation (CV) for 364 cherry tomato phenotypic traits ranged from 9.72% to 45.18%, with the highest CV observed for single fruit weight. Genetic diversity indices ranged from 0.14 to 2.17. The results of the correlation analysis indicate that significant or highly significant correlations exist between quantitative traits. Principal component analysis extracted 13 principal components with a cumulative contribution rate of 70.525%, representing most trait information of cherry tomato germplasm. Through cluster analysis, the test materials were classified into eight categories. Based on the systematic clustering results, the test materials were divided into eight groups. GroupⅠ comprises 29 materials suitable as parental lines for high-yield breeding. GroupⅡ includes 25 materials that can be utilized as fresh-market varieties. GroupⅢ contains only one material, T12, exhibiting unique characteristics. GroupⅣ, comprising 27 materials, is suitable for developing varieties with excellent commercial traits and storage/transport tolerance. GroupⅤ, with 75 materials, serves as a key resource for improving fruit flavor and breeding high-sugar varieties. GroupⅥ, containing 49 materials, exhibits a high sugar-to-acid ratio and favorable taste profile, holding significant value for fresh-eating flavor enhancement. GroupⅦ comprises 150 materials, the largest group, demonstrating significant potential for early-maturing breeding. GroupⅧ contains only 8 materials with distinctive fruit shapes, suitable for developing specialty fresh-eating varieties or for processing into sauces. Comprehensive evaluation using weighted membership functions selected the top 29 cherry tomato germplasm materials based on overall phenotypic performance, identifying 23 key trait indicators.

The 364 cherry tomato germplasm resources showed extensive phenotypic variation and genetic diversity. They were classified into eight groups by cluster analysis, with 23 key indicators identified via principal component analysis, and 29 germplasm materials with superior comprehensive traits selected through membership function analysis.