Limited information is available on the distribution of grapevine red blotch virus (GRBV) in grape-growing regions outside
North America. In this study, the presence of GRBV was investigated in 596 grapevine samples coming from different
sources in Northern Italy, including rootstock and table grape accessions from ampelographic collections, and commercial
varieties with red blotch-like symptoms. Only ‘Queen’ and ‘Incrocio Dalmasso VIII-5’ accessions, collected from the
CREA-Viticulture and Enology repository of table grape varieties, tested positive for GRBV. Sequencing of fragments from
replication and coat protein genes revealed that the two accessions were infected with GRBV isolates belonging to two distinct
lineages. While the American origin of ‘Queen’ could explain the GRBV presence in this accession, the viral infection
of the Italian ‘Incrocio Dalmasso VIII-5’ remains an unsolved mystery.
