Multilocus sequence typing of phytoplasmas associated with Flavescence dorée disease in Tuscany vineyards identifies a highly homogeneous lineage in the subgroup 16SrV–C

Flavescence dorée (FD) is the most threatening grapevine yellows (GY) disease in Europe. Despite strict control measures, alarming signs of spread viticultural areas continue to be detected. FD attributed infection by phytoplasma strains an incidentally cited species, ‘Candidatus Phytoplasma vitis’. In 2017, a GY field survey was carried out traditional viticulture Tuscany, central Italy. (FDp) detected 85 symptomatic vines, accounting for 17% total 500 samples screened. The FDp-positive vines were scattered 50 vineyards across seven Tuscan provinces, indicating distribution FDp has further extended and southwestern parts Tuscany including Florence Livorno. Multilocus sequence typing 15 representative from six affected revealed that constitute highly homogeneous lineage within subgroup 16SrV–C (FD-C). Single nucleotide polymorphisms (SNPs) identified 16S rRNA, rp, secY genes lineage. Such SNP markers provide clues understanding genetic relationships among different lineages present Europe are useful searching potential vectors reservoirs involved region.