Cultivated and Wild Grape Germplasm Collection

A germplasm collection of 51 cultivated (V. v. spp. sativa) and 44 wild-type (V. v. spp. sylvestris) female grapevines was sorted at the FEM grape repository (ITA362), located in San Michele all'Adige, Italy (S1 Table). The sativa accessions were chosen within a genetic core collection (G-110) that retains 100% of SSR and SNP loci diversity present in the source collection [30 (link)]. The wild individuals, mostly originating from the Italian Peninsula, were selected within the sylvestris accessions of the same repository previously clustered through a hierarchical STRUCTURE analysis [30 (link)]. Young leaf tissue of one field grown plant per accession was harvested and stored immediately in sterile tubes at -80°C for DNA extraction and successive analyses. Total genomic DNA was isolated from freeze-dried tissue after grinding with the MM 300 Mixer Mill system (Retsch., Germany) using the DNeasy 96 plant mini kit (QIAGEN, Germany). DNA concentration and purity were checked both by the Synergy HT Multi-Mode Microplate Reader (BioTek) and the NanoDrop 8000 UV-Vis Spectrophotometers (Thermo Scientific).