Natural Infection of Potatoes (Solanum tuberosum) by a Legume Strain of Cucumber Mosaic Virus. P. A. Somerville, Postdoctoral Researcher, Department of Plant Pathology, University of California, Davis 95616. R. N. Campbell, D. H. Hall (deceased), and A. Rowhani. Professor, Extension Specialist, and Postdoctoral Researcher, Department of Plant Pathology, University of California, Davis 95616. Plant Dis. 71:18-20. Accepted for publication 25 August 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0018.

During the 1984—1985 season, potato plants with severe chlorosis, mosaic, shortened internodes, deformed leaves, and knobby tubers were observed in three fields in Kern County, California. A virus, designated CMV-Py, was recovered from leaves of these plants and from sprouts of knobby tubers collected in these fields. The virus was tuberborne and produced host reactions typical of cucumber mosaic virus (CMV) in all hosts except legumes and potatoes, which were systemically infected. CMV-Py was identified as an isolate of CMV on the basis of serological reaction with antiserum to a nonlegume strain of CMV and the detection of double-stranded RNAs corresponding to CMV RNAs 1, 2, 3, and 4 in extracts of CMV-Py-infected plants. Furthermore, it was identified as a legume strain of CMV on the basis of systemic infection of legumes.