Studies on grapevine yellows in Campania (IT)
In Campania, southern Italy, typical symptoms of grapevine yellows e.g. leaf roll, veinal yellowing and necrosis, withering of flower clusters, incomplete lignification of shoots and black pustules along the shoots have been observed. In order to determine the etiology of the disease, affected plants have been tested by using PCR for phytoplasma infection. Phytoplasmas were detected in all tested plants. Further analysis (PCR and RFLP) revealed that the phytoplasmas infecting grapevine in Campania were genetically uniform and similar to the phytoplasma causing Vergilbungskrankheit (VK) in Germany. It can be recalled that VK is thought to be similar or identical to bois noir but distinct from grapevine flavescence dorée phytoplasma (EPPO A2 quarantine pest). Both VK and bois noir are closely related to the stolbur agent. Although, phytoplasmas belonging to the stolbur group have been found on grapevine in other regions of Italy (e.g. in Emilia Romagna), the authors noted that this is the first report of a phytoplasma disease on grapevine in Campania.
Sources
Marcone, C.; Ragozzino, A.; Credi, R.; Seemüller, E. (1996) Detection and characterization of phytoplasmas infecting grapevine in southern Italy and their genetic relatedness to other grapevine yellows phytoplasmas.
Phytopathologia Mediterranea, 35(3), 207-213.