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Etiology

Physical and Chemical Properties of Blueberry Shoestring Virus. D. C. Ramsdell, Associate professor of plant pathology, Department of Botany and Plant Pathology, Michigan State University, East Lansing, 48824; Phytopathology 69:1087-1091. Accepted for publication 9 April 1979. 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, 1979. DOI: 10.1094/Phyto-69-1087.

Blueberry shoestring virus (BBSSV) is an isometric virus 27 nm in diameter. The sedimentation coefficient is 120S. Buoyant density of the virions in CsCl is 1.392 g/cm³. In Cs₂SO₄ virions form two bands, at buoyant densities of 1.273 and 1.355 g/cm³. Particles are comprised of 20% RNA and 80% protein. The single RNA component is single stranded, based on thermal denaturation studies. Molecular weights of the RNA and protein subunit are 1.45 × 10⁶ and 30,000, respectively, as determined by polyacrylamide gel electrophoresis. Electrophoretic mobility of the virus at pH 5 in 0.02 M buffer is 0.42 × 10^–3 cm²sec^–1 volt^–1 and the isoelectric point is between pH 4.5 and 4.7. Reversible temperature-dependent self-aggregation of the virus occurs at 20 C but not 4 C. Although apparently serologically unrelated to other viruses, BBSSV belongs with viruses in the southern bean mosaic group, based on the above properties and stabilization by divalent metallic cations. The cryptogram is R/1:1.45/20:S/S:S/Ve, Ap.