Incidence of Grapevine Fanleaf Virus (GFLV) and Grapevine Leafroll-Associated Viruses (GLRaV 1−3) in Vojvodina Province

Summary During May and June of 2021, a total of 123 grapevine leaf samples were collected and analyzed for infection by grapevine fanleaf virus (GFLV) and three viruses from the grapevine leafroll-associated virus complex -1, -2 and -3 (GRLaV-1, GRLaV-2 and GRLaV-3, respectively). The samples were collected from commercial vineyards, small backyard vineyards and grapevine nurseries located across the entire Vojvodina Province (Bačka, Banat and Srem). OEPP/EPPO sampling protocols were followed during the sampling of leaf tissues showing possible virus infection symptoms. Among the 123 samples, 47 were collected from Bačka region (Bačko Gradište − 11, Bečej − 10, Temerin − 15, Vrbas − 1, Hajdukovo − 10), 50 from Banat region (Srpska Crnja − 10, Vojvode Stepe − 10, Čoka − 10, Uljma −20) and 26 from Srem region (Šid − 6, Banoštor − 10, Sremski Karlovci − 10) and serological ELISA tests were performed for virus detection. GFLV was detected in five samples (4.06%), GLRaV-1 was detected in six samples (4.87%), while GLRaV-2 was not detected in any of the analyzed grapevine samples. GLRaV-3 was present in five samples (4.06%). When infection rates were examined in relation to cultivars, GFLV was detected in Cardinal, Zalagyöngye, Black Muscat, Italian Riesling and Dornfelder. GRLaV-1 was detected in cultivars Cardinal, Black Muscat, Italian Riesling and Merlot, and GRLaV-3 in cultivars Othello and Italian Riesling. Based on these results, it can be concluded that GFLV and GRLaV-1 and GRLaV-3 are present in vineyards across Vojvodina Province and affect different grapevine cultivars. To effectively control virus infections and their spreading, continuous monitoring of these viruses and their vectors is required along with the planting of healthy propagation material.