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Poster: Diseases of Plants: Disease Detection & Diagnosis


Survey of Arabis Mosaic and Grape Leaf Roll Associated virus in Maryland vineyards.
R. POKHAREL (1) (1) Maryland Dept of Agriculture, U.S.A.

Arabis mosaic virus (ArMV) and grape leaf roll associated virus (GRLaV) cause significant crop loss in grapes. However, their natural incidence in Maryland vineyards is not known, and several growers have reported symptoms similar to those caused by these viruses. To find their distribution, 15 vineyards were surveyed during August to September 2015 in Maryland. Up to six varieties per vineyard were examined for virus symptoms. Up to five samples (symptomatic, if present) were collected from each variety. Two hundred seventy samples were tested for each virus group, including the three most symptomatic samples per variety. These samples were tested using a double-antibody sandwich (DAS)-enzyme-linked immunosorbent assay (ELISA) kit developed by Bioreba for GRLaV, and by Agdia for ArMV. Three groups of GRLaV (GRLaV- 1+3 and GRLaV- 2) were tested in two groups. Forty percent of vine samples collected were symptomatic for GRLaV and 29% were symptomatic for ArMV. Only ten percent of samples were found positive for ArMV. Similarly, only 1.1% of samples tested were positive for (GRLaV 1 + GRLaV 3) and 1.5% of samples were positive for GRLaV-2. This result indicated that many plants exhibiting symptoms similar to GRLaV and ArMV were negative for these viruses. This may be because symptoms observed in the field were produced by causes other than the virus tested. Further testing of such vines for other virus and virus-like pathogens may help growers to manage this problem.