Four serologically unrelated closterovirus-like particles (GLRV-1, GLRV-2, GLRV-3 and GLRV-4) were isolated in our laboratory from leafroll diseased grapevines. Polyclonal antibodies raised against these particles were useful for their characterization and their detection m infected plants.The coat proteins of these four serotypes were characterized by a SDS-PAGE after denaturation, followed by a transfer on nitrocellulose sheet and itnmunoprinting using the specific polyclonal antibodies. The capsid of GLRV-1, GLRV-2, GLRV-3 and GLRV-4 contains a single protein species with molecular weight of about 39 Kd, 26 Kd, 43 Kd and 36 Kd respectively. No serological relation was found between tbese four filamentous particles either by ELISA, immuno electron microscopy or immunoblotting experiments.Serological analysis of many grapevines originating from tbe Middle East and Europe sbowed a ver)' close association between the presence of GLRV-1, GLRV-2, GLRV-3 and GLRV-4 antigens, and leafroll symptoms on Vitis vinifera Pinot Noir. This association was confirmed by testing sytnptomless and diseased grapevines collected in the field, and by serological analysis of heat treated plants originally infected by GLRV-1 and GLRV-3, which are the most widespread antigens detected in leafroll infected grapevines. ZusammenfassungCharakterisierung und serologischer Nachweis von vier mit der Blattrollkrankheit der Rebe assoziierten Closteroviren Vier serologisch nicht verwandte Glosteroviren (GLRV-1, GLRV-2, GLRV-3 und GLRV-4) wurden aus blattrollkranken Reben isoliert. Polyklonale Antikorper, die gegen diese Partikel gewonnen wurden, konnten mit Erfolg zu deren Charakterisierung und Nacbweis in infizierten Pflanzen eingesetzt werden. U.S. Copyrigh, Clearance Center Code Su.e^eni: 093 1 -1 785/90/3003-0205S02.50/0 206 ZiMMERMANN, BASS, LEGIN and WALTER

A new green–grafting technique developed for vegetative propagation (MARTIN et al. 1987) is currently being used for the rapid indexing of grapevine virus diseases. By this method, leafroll, fleck, corky bark, vein mosaic, vein necrosis and graft incompatibility were detected under greenhouse conditions. The symptoms appear sooner than by the usual indexing method involving field planted woody indicators. Another advantage of green–graft indexing is the high saving of space and labour. This, method provides a valuable tool for routine control of the sanitary selection of disease–free grapevines.

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