Prevalence of aster yellows (AY) and elm yellows (EY) group phytoplasmas in symptomatic grapevines in three areas of northern Italy

Flavescence doree (FD) and others important grapevine yellows (GY) diseases are known to occur in northern Italy. In this communication we report the results of an extended survey of naturally yellows diseased grapevines growing in three provinces of northern Italy, Vicenza, Brescia and Pavia. The plants were sampled at the end of June and the beginning of August. Direct PCR assay using group-specific primers for universal phytoplasma 16S rDNA amplification or for amplification of 16S rDNA from 16SrI (aster yellows and related phytoplasmas), 16SrIII (X-disease and related phytoplasmas) and 16SrV (elm yellows and related phytoplasmas) phytoplasma groups, and RFLP analysis of amplified DNA, were conducted. Phytoplasmas belonging to group 16SrV were detected only in grapevines in the Vicenza province; whereas, phytoplasmas belonging to group 16SrI subgoup G were found in grapevines in all three provinces.