Genetic Diversity of Flavescence Dorée Phytoplasmas in Vineyards of Serbia: From the Widespread Occurrence of Autochthonous Map-M51 to the Emergence of Endemic Map-FD2 (Vectotype II) and New Map-FD3 (Vectotype III) Epidemic Genotypes

Flavescence dorée (FD) is a European quarantine disease of grapevine caused by FD phytoplasma (FDp) transmitted the leafhopper North American origin Scaphoideus titanus. The affects most important viticultural regions Europe and all wine-growing Serbia. Unlike insect vector, pathogen native to associated with several wild host plants among which alder trees as main source two out three map genetic clusters variants (Map-FD1 FD2). Heretofore, FDp epidemic in Serbian vineyards was thought be monotypic, i.e., single genotype Map-FD3 cluster, M51, correlated clematis natural plant. This study aimed provide data on diversity, through vmpA gene typing, insights into ecological properties epidemiological cycles driving outbreaks Serbia today. Map genotyping 270 isolates collected from 2017 2019 confirmed M51 autochthonous widespread wine producing dominant districts (75%, 202/270 isolates), except north where multiple M12 were recorded (54 isolates). Tree heaven reported new plant reservoir for vineyards, hosting genotype, along clematis. An outbreak endemic M144 documented samples east (5 correlating previous findings same In addition, infections five genotypes (M150-M154) central Serbia, thus indicating high potential outbreaks. typing placed VmpA-III Vectotype III. Finally, we found direct evidence that at least genotypes, M89 M148, Map-FD2/VmpA-II have escaped alders propagated grapevine-S. titanus pathosystem (Vectotype II). Our confirm complexity cycle unique, Balkan epidemiology sourced endemically.