Molecular characterization of phytoplasmas to trace the epidemiological routes of Flavescence dorée between Vitis spp. and the leafhopper vector

Grapevine Flavescence dorée (FD) is one of the major problems of viticulture in several European countries. FD is associated with phytoplasmas of the 16Sr-V ribosomal group, and is transmitted in a persistent propagative manner by the leafhopper Scaphoideus titanus. FD is epidemic in the Piemonte region of Italy since 1998. In spite of the application of the compulsory control methods (insecticides against the vector, rogueing of infected plants, use of healthy propagation material) the disease is still spreading and represents a serious threat to viticulture. The vector transmits FD phytoplasma (FDp) from vine to vine but can also acquire the pathogen from gone-wild rootstocks and fly to the vineyard, thus spreading the disease. A detailed molecular characterization of the pathogen aimed at tracing its movement between the wild compartment and the vineyard was undertaken in order to provide grounds for designing more effective control strategies. Adults of S. titanus were collected with yellow sticky traps inside the vineyard and in the surrounding wild areas at seven sites of the Piemonte region. %