Introduction of Grapevine virus B and Grapevine leafroll-associated virus 2 testing in sanitary selection of grapevine

Abstract

To introduce testing of Grapevine leafroll-associated virus-2 (GLRaV-2) and Grapevine virus B (GVB) in sanitary selection of grapevine, commercially available antibodies were evaluated and conditions for routine ELISA testing were optimized. Extraction procedure with Granex 91 - special machine, which is used in routine testing in Slovenia, was compared with grinding samples in mortar. Three different extraction buffers were applied in order to overcome the inconvenience of using more than one extraction procedure when testing grapevine material for several viruses in a routine large-scale testing scheme. Results were verified with Western blot and immuno-electron microscopy. The best results were obtained using extraction buffer with unknown composition (pH 9.0) from BIOREBA kit for GLRaV-2. Other extraction buffers gave less positive samples and they are not convenient for routine testing where extraction with Granex is done. Both viruses, GLRaV-2 and GVB were found in Slovenia, but they couldn't be correlated with rougose wood disease that appears on indigenous cultivar Refošk grafted on 'SO4' from collection vineyard in Komen.