Grapevine leafroll-associated virus 7

Grapevine leafroll-associated virus 7 was originally identified in Albania in a symptomless white-berried grapevine cultivar, accession AA42 (Choueiri et al.1996). Cabernet Sauvignon indicators graft inoculated with buds from accession AA42 showed mild leafroll symptoms, hence the leafroll virus designation for the newly discovered virus. Several researchers have reported that GLRaV-7 infection causes no or uncertain leafroll symptoms (Al Rwahnih et al. 2012a; Avegelis and Boscia 2001; Morales and Monis 2007). In no case has GLRaV-7 been associated with symptomatic infection in which the presence of other coinfecting viruses has been ruled out (Al Rwahnih et al. 2012a). Reynard et al. (2015) have determined that the AA42 accession, in which GLRaV-7 was originally reported, was coinfected with GLRaV-4. Thus, the leafroll symptoms associated with the AA42 accession may have arisen from a coinfection of GLRaV-7 with GLRaV-4.