VIEW ARTICLE

Etiology

Cytopathology and Properties of Cherry Leaf Roll Virus Associated With Walnut Blackline Disease. G. A. de Zoeten, Department of Plant Pathology, University of Wisconsin-Madison, Madison 53706; J. A. Lauritis(2), and S. M. Mircetich(3). (2)Plant Stress Laboratory, Plant Physiology Institute, Science and Education Administration, U.S. Department of Agriculture, Beltsville Agriculture Research Center, Beltsville, MD 20705; and (3)Agricultural Research, Science and Education Administration, U.S. Department of Agriculture, University of California, Davis 95616. Phytopathology 72:1261-1265. Accepted for publication 26 February 1982. 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, 1982.. DOI: 10.1094/Phyto-72-1261.

A virus, associated with walnut blackline disease was purified from the herbaceous host Phaseolus vulgaris ‘Pinto’ and compared with cherry leaf roll virus (CLRV). Virus particles were isometric and approximately 26 nm in diameter. Virus preparations were unstable, but generally consisted of a middle (102–116S) and a bottom (129–133S) nucleoprotein component. The buoyant density was 1.465 g/cm³ at 24 C. In both walnuts and herbaceous hosts, virus particles occurred in a linear row within cell wall protrusions, paracrystalline arrays within phloem elements and in spiral arrangements in apparent replication complexes. This virus presents one of the few cases in which virus particles and host cytopathology can be studied within the infected tree (walnut). On the basis of its properties and cytopathology the virus associated with walnut blackline disease is considered to be the walnut strain of CLRV (CLRV-W).