Tanzanian Strain of Bean Common Mosaic Virus. M. J. Silbernagel, Research Plant Pathologist, USDA, Agricultural Research Service, Washington State University, Irrigated Agriculture Research and Extension Center, Prosser 99350. L. J. Mills, WSU Research Technologist II, and Wei-Young Wang, Graduate Research Assistant, Washington State University, Irrigated Agriculture Research and Extension Center, Prosser 99350. Plant Dis. 70:839-841. Accepted for publication 2 April 1986. 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, 1986. DOI: 10.1094/PD-70-839.

A strain of bean common mosaic virus (BCMV) isolated from seed of Phaseolus vulgaris produced in Tanzania was found to be similar pathogenically and serologically to temperature-insensitive (TI) strains found initially in Europe and recently in the United States. This is the first report of a strain of BCMV from Tanzania. The Tanzanian strain (TN-1) induced typical mosaic mottle on cultivars with the recessive ii gene but caused lethal systemic vascular necrosis (black root) on many resistant cultivars with the dominant II gene at normal (23–27 C) growing temperatures. The combination of the dominant II gene and unidentified presumed-recessive genes gave complete protection to both the mosaic mottle and the systemic necrosis phases of TN-1.