Wineberry latent virus was obtained from a single symptomless plant of American wineberry (R. phoenicolasius) originally from the USA. On graft inoculation WLV infected, without distinctive symptoms, several R. spp. including those used as indicators for known R. viruses. It was not seed-borne in wineberry.
WLV was mechanically transmitted to several herbaceous spp. but induced local lesions in only a few; it was weakly systemic in some Chenopodium spp. Infective C. quinoa sap lost infectivity after diluting to 10-4, heating for 10 min at 70 deg C, and storage for 8 days at 18 deg or 32 days at 4 deg . Sap from infected plants contained flexuous filamentous particles c. 510 X 12 nm. WLV was partially purified by extracting infected C. quinoa leaves in 0.05 M tris-HCl buffer (pH 7) containing 0.2% thioglycerol and 10% (v/v) chloroform, and concentrating virus by precipitation was 7% (w/v) polyethylene glycol (PEG, mol. wt. 6000) and 0.1 M NaCl. The virus was then pelleted through a 30% (w/v) sucrose pad containing 7% PEG + 0.1 M NaCl and finally sedimented through a sucrose density gradient. These preparations had A260/280 ratios of 1.26, contained end to end aggregates of WLV particles and formed a partly polydispersed peak in the analytical ultracentrifuge. WLV did not react with antisera to 4 potexviruses, or to apple chlorotic leaf spot or apple stem grooving viruses.