First report of Grapevine leafroll-associated virus 2 in Russian grapevines (Vitis vinifera).
Grapevine leafroll-associated virus 2 (GLRaV-2), a member of the genus Closterovirus within the family Closteroviridae, is associated with leafroll, young vine decline, graft union-incompatibility, and rootstock stem lesion disease. The survey of a vineyard north of the Krasnodar region was conducted in September 2017. Twenty-six samples (one sample from each vine) with leaf curling, yellow or red leaves were collected from five table Vitis vinifera cultivars: Landish (five samples), Uybilei Novocherkasska (five samples), Kolobok (five samples), Livia (five samples), and Veles (six samples). Based on the results of polymerase chain reaction, two samples tested positive for GLRaV-3, three samples tested positive for Grapevine rupestris stem pitting-associated virus (GRSPaV), and four samples (∼15% of total samples taken) of V. vinifera cultivar Livia tested positive for GLRaV-2. No information was available on the presence of GLRaV-2 in Russia before so further investigations focused on GLRaV-2. Results of polymerase chain reaction assay, virtual restriction fragment length polymorphism pattern, ELISA and pathogenicity test confirmed the presence of GLRaV-2. This is thought to be the first report of GLRaV-2 in grapevines in Russia. Because GLRaV-2 can be transmitted through grafting, this report is important for GLRaV-2 containment by using of virus-free plants for propagation.