[Purification, serology and detection of grapevine leaf roll virus]

Closterovirus-like particles associated with grapevine leaf roll disease were purified from stem phloem tissue by differential centrifugation and cesium sulphate-sucrose density gradient centrifugation. The particles were between 660-2000 nm long. Most of them were about 1400 nm long and also decorated by the antiserum against GLRV NY-1 isolate. The purified preparation was tested for their serological relatedness in indirect ELISA. The results indicated that these closterovirus-like particles reacted with serotype II, III and IV of GLRV. The antiserum to NY-1 (type III) reacted more strongly than type IV (to VA-4) and type II. (to 1800 nm). In sodium dodecyl sulfate immunodiffusion test, the extract of diseased petiole reacted with serotype III, IV and II. It is possible to be infected by 2 or 3 closterovirus-like particles in China. We have made antiserum to the purified closterovirus-like GLRV and set up a PAS-ELISA to detect GLRV-free grapevine plantelets. We have obtaimed 21 varieties of GLRV-free and GFLV-free grapevine. They shown high quality and quantity in field test.