Acquisition of flavescence dorée phytoplasma by Scaphoideus titanus Ball from recovered and infected grapevines of barbera and nebbiolo cultivars

The capability of Scaphoideus titanus in acquiring Flavescence dorée phytoplasma from recovered and infected grapevines of Barbera and Nebbiolo varieties was investigated. Sanitary status of source grapes was confirmed by nested PCR. Leafhopper nymphs were caged on grapes in different viticultural areas of the Piemonte Region. FD isolates from grapes and leafhoppers were characterised by RFLP analysis of partial ribosomal and secY genes. S. titanus acquired FD from infected grapes only, with higher efficiency from Barbera (26%) than Nebbiolo (14%). Recovered plants did not represent a source of inoculum for the vector and therefore do not impact on FD spread.