SOME PROPERTIES OF CHERRY RASP LEAF VIRUS
Cherry rasp leaf virus (CRLV) was prepared from infected cucumber cotyledons by homogenizing in borate-EDTA buffer, clarifying the extracted sap by adding 15 percent ammonium sulfate and purifying by alternate low- and high-speed centrifugation. Yield of virus was low when tissue was frozen and when the sap was clarified by adjustment to pH 5 or with chloroform or butanol. Purified preparations showed three opalescent bands in sucrose density gradient tubes and three schlieren peaks in the analytical ultracentrifuge. Preparations had three components sedimenting at 56, 96, and 128 S; these are probably top (T), middle (M) and bottom (B) components, respectively. These components contained 30 nm diameter isometric particles; only particles in the T component were penetrated by negative stain. Two RNA species, with estimated mol. wts. of 2.0 and 1.5 million were detected when mixtures of M and B components were electrophoresed on polyacrylamide gels. The viral protein also separated into two bands with estimated mol. wts. of 24000 and 22500. The maximum titre of rabbit antisera obtained after two intramuscular injections was 1/1280. CRLV did not react with antiserum against tobacco ringspot, tomato ringspot, cherry leaf roll, peach rosette mosaic, raspberry ringspot, tomato blackring, strawberry latent ringspot or arabis mosaic.
Stace-Smith, R. and Hansen, A.J. (1976). SOME PROPERTIES OF CHERRY RASP LEAF VIRUS. Acta Hortic. 67, 193-198