Grapevine Vein Necrosis: Further Data on Etiology and Diagnosis

Vein necrosis (VN), a virus-like disease latent in all European grapevine cultivars and in most American rootstock species and hybrids, induces necrosis of the veinlets on its specific indicator Vitis rupestris times Vitis berlandieri 110 R. Vein necrosis is very common in Tuscany, where, during an indexing trial, 38 out of 62 (61%) putative grapevine clones selected during sanitary improvement programmes in the last few years indexed positive on 110 Richter. The 62 accessions were checked by PCR with two different universal primers (13/14 and RSP5/RSP6) for the presence of Grapevine rupestris stem pitting-associated virus (GRSPaV) and with group specific primers (Groups I, II and III). Primers 5/6 were able to detect all sequence variants and a differential biological behavior was observed among molecular variants. Only group I was highly associated to symptoms expression, groups II an III were not correlated to vein necrosis.