First report of grapevine bois noir phytoplasma in Spain.
During the last 5 years, a grapevine yellows disease was observed on grape cv. Chardonnay in several viticultural areas of Catalonia (northeastern Spain). Flavescence dorće (FD), a phytoplasma disease, was suspected because of the presence of the leafhopper Scaphoideus titanus, the vector of FD, in affected vineyards. In late summer and autumn 1994, when typical yellows symptoms appeared in Catalonia, leaves from symptomatic plants were collected. The primers used were designed for specific amplification of a part of the 16S rRNA gene from all known phytoplasmas. AluI restriction profiles of the amplified fragments showed that the grapevine phytoplasma belonged to the aster yellows (AY) phytoplasma group and was present in all symptomatic plants tested. Further analysis with specific primers indicated that the phytoplasma was most closely related to the stolbur phytoplasma, a subgroup of the AY phytoplasma group, and therefore similar to the phytoplasma associated with bois noir (BN) disease in France. Although the BN and FD phytoplasmas cause similar symptoms, the vector of FD, S. titanus, cannot transmit the BN phytoplasma. This is the first report of grapevine BN phytoplasma in Spain.