Partial molecular and biological characterization of grapevine leafroll-associated virus 2 isolates from Argentina

Abstract

Grapevine leafroll disease is one of the most important viral disease affecting grapevine in all the growing regions across the world. One of the viruses associated with this disease is Grapevine leafroll associated virus 2 (GLRaV-2), which has two remarkable properties: high genetic variability (up to date at least 6 different lineages have been reported) and its unique ability among leafroll-associated viral species, to be transmitted by sap inoculation to herbaceous hosts, specifically to Nicotiana spp. The presence of this viral species in Mendoza, Argentina, has been previously reported but there was no knowledge of a possible association between the genetic variability of the isolates of GLRaV-2 and their biological behavior. The molecular characterization of the tandem CP-p19-p24 of the local isolates showed that they belong to four out of the six previously described GLRaV-2 lineages. Using at least one isolate of each lineage, we performed transmission assays to herbaceous host of the Nicotiana genus. Our results showed a differential behavior in some combinations isolate/Nicotiana spp., and an incompatible interaction between GLRaV-2 and two new experimental hosts, N.rustica and N.tabacum cv. Samsun and White Burley