'Candidatus Phytoplasma solani' Associated With Grapevine 'Bois Noir' Disease In Azerbaijan

During surveys conducted in the most important viticultural regions, such as Absheron, Ganja and Guba, the white varieties of grapevine (Vitis vinifera L.) dislpaying the yellowing and red varieties with the leaf reddening and leaf rolling symptoms reminiscent phytoplasma infections were collected for molecular analysis. Polymerase chain reaction assays using phytoplasma universal primer pair R16F2/R16R1 followed by primer pair R16F2n/R16R2 in nested PCR confirmed the association of phytoplasmas with symptomatic grapevines. Restriction fragment length polymorphism (RFLP) analyses using RsaI, and TaqI restriction enzymes indicated that grapevine phytoplasma isolates detected in Azerbaijan are belonged to ‘Candidatus Phytoplasma solani’ strain (16SrXII group). To verify the RFLP results, all of the positive samples were subjected to Stolbur group specific nestedPCR test based on stamp gene amplification using the primer pairs Stamp-F/R0 and Stamp-F1/R1. Amplification of non-ribosomal Stamp gene confirmed the results of RFLP analysis. This is the first report of the ‘Candidatus Phytoplasma solani’ causing grapevine ‘Bois noir’ disease in Azerbaijan.