Fungi associated to grapevine trunk diseases in young plants in Asturias (Northern Spain)

Dark discolorations of the vascular vessels of 3-year-old potted plants of Asturian grapevine cultivar (Northern Spain), were observed during pruning. These symptoms can be associated to fungal trunk diseases that, in the last decades, are affecting young vineyards all over the world. Cross sections from root, trunk and canes of 19 young grapevine plants were analyzed for the presence of pathogenic fungi associated with these diseases. Non-pathogenic fungi were isolated from both asymptomatic and symptomatic samples, showing that dark discolorations, in some cases, were a consequence of abiotic causes. Regarding pathogenic fungi, Cylindrocarpon spp. colonies were the most frequent, isolated mainly from roots and from asymptomatic tissue. Botryosphaeria spp. colonies were mostly isolated from trunk and from sec tions with dark discolorations generated by pruning. Phaeoacremonium spp. was isolated from all the organs (roots, trunk and canes). Only one colony of Libertella spp. was isolated. These results suggest the need of a standard protocol, combining treatments and management activities, to be performed in nurseries to limit the spread of these diseases.