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Etiology

A Carlavirus Associated with Blueberry Scorch Disease. Robert R. Martin, Research scientist, Agriculture Canada Research Station, 6660 NW Marine Drive, Vancouver, British Columbia; Peter R. Bristow, Associate professor, Department of Plant Pathology, Washington State University, Western Washington Research and Extension Center, Puyallup. Phytopathology 78:1636-1640. Accepted for publication 27 June 1988. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1988. DOI: 10.1094/Phyto-78-1636.

Blighting of blossoms and a few leaves during peak bloom were the primary symptoms of a newly recognized disease of highbush blueberry (Vaccinium corymbosum) in Washington. Marginal chlorosis of leaves produced on older wood and overall reduction in plant vigor were additional symptoms observed on diseased bushes. The cultivars Berkeley, Atlantic, Collins, Herbert, and Pemberton were particularly susceptible. Blight symptoms were produced on previously healthy plants after they were graft-inoculated with wood from diseased plants. Bundles of viruslike particles in leaf tissue were associated consistently with infected plants and were present in previously healthy plants after they were graft-inoculated from infected plants. Viruslike particles purified from infected Pemberton blueberry plants were 690 nm long × 14 nm in diameter; the coat protein had a relative molecular mass of 35,200 daltons and a single RNA molecule of 8,400 bases. Antiserum prepared against these viruslike particles distinguished between diseased and healthy bushes in the field by enzyme-linked immunosorbent assay (ELISA). In indirect ELISA, the purified viruslike particles reacted with antisera to nine different carlaviruses but not with antiserum to turnip mosaic virus, a potyvirus. Association of these particles with diseased bushes leads us to believe that these viruslike particles are probably the causal agent of this newly recognized disease of highbush blueberry, for which we propose the name blueberry scorch disease. For the purpose of this paper, we refer to the virus as blueberry scorch virus (BBScV), recognizing that the virus may be a new member of the carlavirus group or a strain of a current member of this group.