Incidence of 14 grapevine viruses in Korean vineyards

The incidence of grapevine virus infections in Korean vineyards was investigated from July to October, 2020. A total of 177 petiole samples were collected from two or three different cultivars in each of four different regions; these were examined by reverse transcription-polymerase chain reaction assay for the presence of 14 major viruses. The overall occurrence of grapevine viruses was 91.0%, and the level of incidence was high irrespective of region or cultivar. The predominant viruses were grapevine leafroll-associated virus 3 (80.2%), grapevine fleck virus (70.6%), and grapevine rupestris stem pitting-associated virus (49.2%). Most grapevines were infected with multiple viruses, suggesting that Korean vineyards are likely to suffer economic losses resulting from viral diseases. This is the first extensive survey performed in Korea to observe the outbreak status of diverse grapevine viruses; surveys of this type can provide important information for the management of grapevine viruses in Korea.