SPET genotyping of over 15,000 accessions of tomato reveals the genetic structure and history of the tomato germplasm at world level
Résumé
Tens of thousands tomato accessions are conserved in genebanks all over the world, constituting a valuable source of genes of interest for tomato breeding. Genetic characterization of such large collections can improve their management. The G2P-SOL project has carried out the largest-scale tomato genotyping to date, by designing a 5k probe Single Primer Enrichment (SPET) tomato platform, and used it to genotype a collection of over 15,000 accessions from worldwide genebanks. Besides wild species, the main genetic groups found were: wild S. lycopersicum var. cerasiforme (SLC) from Meso-and Southamerica, early vintage cultivated tomatoes, that genetically are closer to SLC than to the bulk of S. lycopersicum var. lycopersicum (SLL), vintage tomatoes, mainly from Spain, early improved materials with no introgressions, and more recent materials that do include wild species introgressions. The structure of the early vintage 36 accessions mirrored the early history of the cultivated tomatoes. They were widely spread across Meso-and South America, probably because they were the cultivated tomatoes in those regions before the Spanish arrival. Interestingly, they were also found in other geographic regions controlled or influenced by the Spaniards during the between XVII, and XVIII centuries, such as the western Pacific (mainly the Philippines) and the Mediterranean. History has left many marks in the tomato genomes. For instance, the Italian San Marzano is genetically closer to a population of ovoid brasilian early breeds that genetically are better characterized as SLC than to most European vintage tomatoes, that are SLL.
Domaines
Génétique des plantes
Licence : Domaine public