Tall Fescue as a Natural Host and Aphid Vectors of Barley Yellow Dwarf Virus in Missouri. K. F. Grafton, Research Associate, Department of Agronomy, North Dakota State University, Fargo 58105. J. M. Poehlman, Professor Emeritus, Department of Agronomy, Om P. Sehgal, Professor, Department of Plant Pathology, and Dale T. Sechler, Professor, Department of Agronomy, University of Missouri, Columbia 65211. Plant Dis. 66:318-320. Accepted for publication 20 June 1981. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-318.

Eighty-one of 136 symptomless tall fescue plants (59.6%) collected from 90 Missouri counties were infected with a virus that was transmitted by Rhopalosiphum padi and produced symptoms typical of infection by barley yellow dwarf virus on Grundy oat seedlings. Purified preparations from the infected oat plants contained discrete isometric particles (diameter, 25–30 nm). R. padi acquired and transmitted the virus to Grundy oat seedlings after feeding on purified preparations. R. padi, R. maidis, and Schizaphis graminum naturally colonizing small grain plants in the field during 1977–1980 were also found to be viruliferous. These results indicate the presence of a large natural reservoir of barley yellow dwarf virus in tall fescue in Missouri and identify three local aphid vectors of the virus.

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