Disease Note

Occurrence of a Necrotic (NL-8) Strain of Bean Common Mosaic Virus in Ontario, Canada. J. C. Tu, Harrow Research Station, Agriculture Canada, Harrow, Ont. N0R 1G0. Plant Dis. 70:694. Accepted for publication 11 February 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-694a.

Two distinct strains of bean common mosaic virus (BCMV)—strain 1 and strain 15—exist in Ontario. In 1982, many diseased white bean (Phaseolus vulgaris L.) plants of the cultivar Sanilac in several fields showed symptoms of vein necrosis in addition to mosaic. The symptoms resembled those of a necrotic strain of the virus. Several isolates were collected from leaves of diseased plants with vein necrosis. Strain determinations conducted in accordance with the differential schemes used by Kelly et al (1) and Provvidenti et al (2) indicated NL-8. Necrotic strains NL-8 and NL-3 were discovered recently in New York and Michigan, respectively (1,2). This is the first field occurrence of BCMV strain NL-8 in Ontario.