Identification of phytoplasmas associated with grapevine yellows in Serbia

The molecular identification and characterization of phytoplasmas from infected grapevines in four locations in Serbia are reported. Phytoplasmas were detected and identified by restriction fragment length polymorphism (RFLP) analysis of polymerase chain reaction (PCR) amplified 16S rDNA. Grapevine yellows were associated with three molecularly distinguishable phytoplasmas: Flavescence dorée phytoplasmas (elm yellows group: 16SrV‐C subgroup) were present only in the Župa Aleksandrovac region; Bois noir phytoplasmas (stolbur group: 16SrXII‐A subgroup) were detected in the other surveyed regions; a mixed infection of European stone fruit yellows (apple proliferation group: 16SrX‐B subgroup) and Bois noir phytoplasmas was identified in one sample. A finer molecular characterization by RFLP analysis of rpS3 and SecY genes of Flavescence dorée phytoplasmas from Župa Aleksandrovac confirmed that the Serbian genotype is indistinguishable from a strain from the Veneto region, Italy. Characterization of the tuf gene of Bois noir phytoplasmas showed lack of amplification of samples from Erdevik. HpaII profiles of tuf gene PCR products of samples from Pali and Radmilovac were identical, and were indistinguishable from one of the two profiles produced by samples from Italian grapevines used as reference strains.