ArMV (3,4) has a wide host range, infects the seed of many host plants, and is transmitted by the nematode Xiphinema diversicaudatum. The virus causes diseases in many crops such as grapevine, raspberry, strawberry, hop, rose, elderberry, cucumber, lettuce, celery, forsythia, and rhubarb etc. ArMV is more prevalent in Europe than in other continents.
GFLV (3,4) is a grapevine pathogen and is spread by infected propagative material and by Xiphinema index. It is occurring worldwide wherever Vitis vinifera and hybrid rootstocks of grapevine are grown. Different biological strains of the virus cause fanleaf (malformation of leaves and canes) and yellow mosaic diseases of grapevine. Yellowing is most prominent in spring, fading away as the season progresses (heat masking).
Crop losses range from moderate to very high according to the virulence of the virus strain and varietal susceptibility. Fruit quality is also affected.
These reagents allow in a single test (format DAS-ELISA) the detection of both Nepoviruses ArMV and GFLV, recognizing all isolates irrespective of biological strain. The reagents contain a mixture of antibodies to a grapevine isolate of ArMV (P. Gugerli, personal communication) and to an isolate of GFLV from Canda (Vineland Research Station, Ontario; P. Ellis, personal communication).
The coating reagent consists of poly- and monoclonal antibodies, the AP-conjugated antibodies are monoclonal. The ELISA technique is an efficient method for the detection of these viruses in grapevine. However, the virus concentration varies considerably according to the tissue source, the meteorological conditions and thus, the time of the season.
These facts have to be considered for obtaining reliable test results. For testing grapevine tissue, a special extraction buffer «Grapevine» (0.2 M TRIS, pH 8.2) (2, modified) is used; for other plants, the extraction buffer «General» is applied. In grapevines, leaves from young shoots and juicy bark early in the growing season as well as bark (phloem) scrapings from mature canes during dormancy are recommended.
The product was developed in cooperation with the Swiss Federal Research Station Agroscope ChanginsWädenswil (ACW), Nyon, Switzerland; and Phyto Diagnostics Company Limited, North Saanich, BC, Canada.
