Mechanical Transmission, Identification, and Characterization of a Virus Associated with Mottle Leaf in Cherry. D. James, Agriculture Canada, Saanichton Plant Quarantine Station, 8801 East Saanich Road, Sidney, British Columbia, V8L 1H3. S. Mukerji, Agriculture Canada, Saanichton Plant Quarantine Station, 8801 East Saanich Road, Sidney, British Columbia, V8L 1H3. Plant Dis. 77:271-275. Accepted for publication 27 October 1992. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-0271.

A closteroviruslike particle was mechanically sap-transmitted from sweet cherry (Prunus avium) to the herbaceous host Chenopodium quinoa. Successful transmission was achieved by grinding fresh symptomatic leaves of cherry in a buffer containing magnesium, sodium thioglycolate, and nicotine. Stunting and chlorotic spots were observed on the C. quinoa plants 17 days postinoculation. The virus purified from C. quinoa had a modal length of 760 nm, a width of 10.2 nm, and striations 3.1 nm in pitch. The nucleic acid size was estimated at 8.2 kb. The thermal inactivation point of the virus was 50–55 C, and the virus-containing sap remained infectious for only 24 hr when stored at room temperature. Mottle leaf symptoms were observed on Bing cherry slash inoculated with purified preparations of the virus. The virus was subsequently transmitted from the inoculated Bing cherry to C. quinoa, and its identity was confirmed by indirect ELISA and Western blotting using a monoclonal antibody to the virus.