Genotyping of the F1 population derived by crossing Chardonnay and Tocai friulano to study the suscepitibility and resistance of Flavescence dorée in grapevine

“Flavescence dorée” (FD) occurs in many European viticulture regions, and it is considered one of the most destructive grapevine diseases. Understanding the genetic control of FD susceptibility is a crucial step in managing the disease. Identification of single nucleotide polymorphism (SNP) markers linked to FD resistance can be a powerful tool for the introgression of valuable genes needed to develop resistant varieties. Observations performed in many experimental vineyards revealed differences in resistance to FD among varieties, that appear to have a genetic basis. The cultivar Tocai friulano is less susceptible to FD, and its ability to compartmentalize FD phytoplasmas in the symptomatic portions of the plant was recently demonstrated (Casarin et al., 2023). Moreover, the comparison of the transcriptional changes between Tocai friulano and Chardonnay (highly susceptible) highlighted passive defence strategies in response to the insect vector and/or the phytoplasma infection (Bertazzon et al., 2019). The aim of this study was the genetic dissection of FD resistance revealed by Tocai friulano through the adoption of molecular approaches such as genotyping-by-sequencing (GBS). GBS was carried out on the F1 population derived by crossing Tocai friulano and Chardonnay.