Grapevine rupestris stem pitting-associated virus is linked with grapevine vein necrosis

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 of its specific indicator Vitis rupestris x Vitis berlandieri 110 R at the abaxial side of the leaf blade. VN is very common in southern Italy, e.g. 109 out of 218 of the putative grapevine clones selected during sanitary improvement programmes in the last few years indexed positive in 110 R. As assessed by ELISA, the same vines had a very low rate of infection (< 4 %) by major detrimental viruses (GFLV, GVA, GVB, GLRaV-1, GLRaV-2, GLRaV-3, GLRaV-7, GFkV) commonly looked for during selection. When the VN-positive 110 R indicators were checked by PCR and Western blot for the presence of Grapevine rupestris stem pittingassociated virus (GRSPaV) a strikingly high association (98 %) was observed between this virus and VN symptoms. Likewise, all 72 mother plants of Vitis rupestris used as indicators in indexing trials and recently discovered to be infected by GRSPaV, induced VN reactions after grafting onto 110 R. By contrast, no VN reactions developed in 110 R top-grafted on a single GRSPaV-free V. rupestris. Moreover, GRSPaV was consistently detected in the symptomatic lower leaves of the shoots of infected 110 R vines, but not in the symptomless upper leaves of the same shoots. These findings strongly suggest that GRSPaV is involved in the aetiology of VN

Study of the Relationship Between Grapevine Ruspestris Stem Pitting Associated Virus Molecular Variants and Vein Necrosis

Grapevine rupestris stem pitting associated virus (GRSPaV), is the putative causal agent of rupestris stem pitting (RSP) a component of the rugose wood disease of grapevine. Recently, a strikingly high association has been detected between GRSPaV and vein necrosis (VN), suggesting that 110 Richter (110 R) is the best indicator of GRSPaV infection. In the present study, we investigate the occurrence of molecular variants of GRSPaV in grapevine accessions previously indexed for vein necrosis on 110 R. 100% of the VN infected accessions results positive to GRSPaV by RT-PCR using primers 13/14. Using group specific primers, group I was detected in all the 22 accessions infected with VN, 11 times in mix infection with group III, 3 times with group II, and twice as a single infection. Unexpected results were observed with group II, in fact this group is present in 6 accessions negative to VN and to GRSPaV with primers 13/14. No single infection was, however, recorded for group III, the only available indication is its exclusive presence in VN infected accessions. This work confirms the association between GRSPaV and vein necrosis

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 × 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 necrosi

Grapevine rupestris stem pitting-associated virus isolate CC17-10, 28 kDa coat protein gene, complete sequence

Genbank accession number: HQ39673

Grapevine rupestris stem pitting-associated virus isolate SMH22-13, 28 kDa coat protein gene, complete sequence

Genbank accession number: HQ39674