VIEW ARTICLE

Etiology

Beet Western Yellows Virus—A Major Component of Some Potato Leaf Roll-Affected Plants. James E. Duffus, Plant pathologist, U. S. Department of Agriculture, U. S. Agricultural Research Station, P. O. Box 5098, Salinas, CA 93915; Phytopathology 71:193-196. Accepted for publication 14 July 1980. 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, 1981. DOI: 10.1094/Phyto-71-193.

Beet western yellows virus (BWYV) has been isolated from potato stocks with typical potato leaf roll (PLR) symptoms. Virus isolates from potato, that induce leaf rolling, interveinal chlorosis, petiole epinasty, and reduction in leaf size in Physalis floridana and interveinal chlorosis on Capsella bursa-pastoris have been shown to be strains of BWYV. Isolates differing in host reaction and serological characteristics have been found in individual potato plants indicating a complex etiology for the PLR syndrome. In addition to potato, and other solanaceous hosts, one isolate has been transmitted to and recovered from species in the Boraginaceae, Chenopodiaceae, Compositae, Cruciferae, Leguminosae, Malvaceae, and the Portulaceae. The BWYV isolates induce primary leaf roll symptoms in PLRV-free and virus-free potato cultivars, indicating that these isolates might easily be confused with “typical” PLRV. Preliminary serological data indicate that there are several serotypes of BWYV in potato that differ from each other and from PLRV in serological reactions. This evidence suggests that serological testing for PLRV occurrence would probably give misleading information. The broad host range of these BWYV isolates raises questions about the reinfection of virus-free potato stocks from infected wild hosts in “isolated” areas.