First Report of Blueberry scorch virus in Black Huckleberry in British Columbia.

Blueberry scorch virus (BlScV), an aphid-borne carlavirus, causes a serious disease of highbush blueberry (Vaccinium corymbosum L.) in North America and Europe. Symptoms of BlScV infection on highbush blueberry include necrosis of flower blossoms and young leaves, shoot blight, and chlorosis. Currently, cranberry (Vaccinium macrocarpon L.) is the only other natural host of BlScV. In July 2004, wild black huckleberry (Vaccinium membranaceumL.) was sampled in the Kootenay Region of southeastern British Columbia. Foliar tissues were sampled during 2004 from 11 bushes from a clearing on the side of a mountain near Crawford Bay, BC, Canada and tested by double-antibody sandwich-ELISA using polyclonal antiserum (Agdia Inc., Elkhart, IN). BlScV was detected in 6 of the 11 bushes sampled and in the positive control (BlScV-infected blueberry leaf tissue) and was not detected in the negative control (healthy blueberry leaf tissue). To confirm the presence of the virus, total nucleic acid was extracted from ELISA-positive huckleberry samples according to an established protocol (A. Rowhani et al. Proc. Int. Counc. Stud. Viruses Virus-Like Dis. Grapevine, Extended Abstr. 13:148, 2000). Reverse transcription-PCR was performed using pd(T)_12-18 random primer (Amersham Biosciences, Piscataway, NJ) for reverse transcription and BlScV-specific primers developed against the published NJ-2 sequence of BlScV (GenBank Accession No. NC_003499). Using the forward primer, BS708F, (5'-TCAATCCGTGGTGCTACGAG-3'), and the reverse primer, BS1188R, (5'-ACAGTGCGCAATGTTCCAGT-3'), a 480-bp amplicon was obtained from each of the ELISA-positive samples, while no ampli-cons were observed for the negative control (ELISA-negative huckleberry tissue). Direct sequencing of one selected amplicon revealed 90, 84, and 77% nucleotide sequence identity and 97, 96, and 88% amino acid sequence identity with strains NJ-2, BC-1 (GenBank Accession No. AY941198) and BC-2 (GenBank Accession Nos. AY941199), respectively. BlScV-infected huckleberries were asymptomatic. The presence of BlScV in alternate hosts has implications for disease epidemiology. Testing for BlScV in Vaccinium species in and around commercial highbush blueberry plantings, as well as lowbush blueberry (V. angustifolium Aiton), rabbiteye blueberry (V. ashei Reade), other native Pacific Northwest species (V. ovatum Pursh and V. parvifolium Smith), and ornamental Vaccinium species is warranted. To our knowledge, this is the first report of BlScV infecting black huckleberry.