First report of Nepovirus myrtilli in the EPPO region
Blueberry leaf mottle virus (Nepovirus myrtilli, BLMoV, EPPO A1 List) is an extremely damaging virus to Vaccinium spp., only known to occur in Canada, the USA and South Korea. During a study in 2019-2023 to determine the presence of BLMoV in Türkiye, 316 blueberry leaf samples were collected from commercial orchards of highbush blueberry (Vaccinium corymbosum) and lowbush blueberry (Vaccinium arctostaphylos) as well as asymptomatic wild blueberries (Vaccinium myrtillus) growing around commercial orchards, from the provinces of Antalya (Mediterranean region), Bursa and Istanbul (Marmara region), Kayseri (Central Anatolia region) and Rize and Sakarya (Black Sea region). Samples were tested by DAS-ELISA and RT-PCR. Eight of the 316 samples tested positive for the presence of the BLMoV by RT-PCR. This included one V. corymbosum showing interveinal chlorosis in Istanbul province, six V. corymbosum plants (three of which were symptomless and three showed reddening symptoms) in Sakarya province, and one V. myrtillus showing reddening symptoms in Rize province.
Caglayan et al. (2025) note that highly susceptible cultivars of V. corymbosum (Jersey and Rubel) are not commonly grown in Türkiye. The authors also suggest viral symptoms reported here may be caused by other viruses as many sampled plants showed viral symptoms but tested negative for BLMoV, and some BLMoV-infected plants were asymptomatic. So far, studies on viral diseases of Vaccinium in the country only detected blueberry mosaic associated virus (Ophiovirus vaccinii, BlMaV – EU RNQP).
The authors underline the need to take immediate actions to prevent further spread of BLMoV because it is transmitted naturally through pollen and honeybees.
The situation of Blueberry leaf mottle virus in Türkiye can be described as: Present, not widely distributed.
This is the first report of BLMoV in the EPPO region and the first report on Vaccinium myrtillus, which is a native species in the region.
Sources
Caglayan K, Tunc B, Akkan R, Taş V, Roumi V (2025) Occurrence of blueberry leaf mottle virus (Nepovirus myrtilli) in Türkiye. Journal of Plant Diseases and Protection 132(2), 79. https://doi.org/10.1007/s41348-025-01071-8