Diversity and structure of a sample of traditional Italian and Spanish tomato accessions

Italy and Spain are the countries with the oldest record of tomato cultivation in Europe and arguably, with the higher number of traditional and heirloom varieties. In this work we evaluated the genetic diversity and structure in a sample of 26 cultivated accessions belonging to four traditional tomato types, Muchamiel and De la Pera from Spain, and San Marzano and Sorrento from Italy. The (GATA)4 fingerprinting of the 109 genotypes confirmed the ability of this DNA marker to discriminate tomato plants that are otherwise difficult to distinguish. Furthermore, both the estimated population structure and the genetic differentiation statistics were consistent in indicating that subpopulations are more likely to correspond to farmers' breeding efforts and market specialization than to country-specific groups. Our results provide useful information not only for germplasm description and management but also for current breeding programs in both regions.