VIEW ARTICLE

Etiology

Characterization of a California Isolate of Sorghum Yellow Banding Virus. V. A. Klaassen, Department of Plant Pathology, University of California, Davis 95616; B. W. Falk, Department of Plant Pathology, University of California, Davis 95616. Phytopathology 79:646-650. Accepted for publication 20 October 1988. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/Phyto-79-646.

A small isometric virus was isolated from sudangrass (Sorghum sudanense) in the Imperial Valley of California. The sap-transmissible virus was found to infect a narrow range of the gramineous hosts tested. The virus was not serologically related to several other small, well-characterized isometric viruses that infect the gramineae, including panicum mosaic virus, St. Augustine decline virus, and several members of the sobemovirus group. However, it did react with antiserum to sorghum yellow banding virus, a newly discovered and uncharacterized virus affecting commercial sorghum and sorghum × sudangrass hybrids in Texas. The virions are isometric, approximately 25 nm in diameter, and have an estimated S_20W of approximately 109. They contain a single species of single-stranded RNA of approximately 1.5 × 10⁶ and a single capsid protein of approximately 29,000 MW. Two prominent double-stranded RNAs were isolated from infected Zea mays. These were approximately 3.0 × 10⁶ and 0.6 × 10⁶ MW and hybridized with cDNA prepared against the virion RNA.