Multilocus sequence typing confirms the close genetic inter-relatedness between three distinct flavescence doree phytoplasma strain clusters and group 16SrV phytoplasmas infecting grapevine and alder in Europe

ABSTRACT Vineyards of southern France and northern Italy are affected by the flavescence dorée (FD) phytoplasma, a quarantine pathogen transmitted by the leafhopper of Nearctic origin Scaphoideus titanus . To better trace propagation of FD strains and identify possible passage between the vineyard and wild plant compartments, molecular typing of phytoplasma strains was applied. The sequences of the two genetic loci map and uvrB - degV , along with the sequence of the secY gene, were determined among a collection of FD and FD-related phytoplasmas infecting grapevine, alder, elm, blackberry, and Spanish broom in Europe. Sequence comparisons and phylogenetic analyses consistently indicated the…