Incidence and distribution of viruses infecting Iranian vineyards.
During February and September 2003, the incidence and distribution of viruses infecting grapevine (Vitis vinifera) in Iran was determined. A total of 238 symptomatic and 1314 asymptomatic leaf samples were collected from 56 different vineyards from 10 Iranian provinces and tested by enzyme-linked immunosorbent assay (ELISA) for the presence of Grapevine fanleaf virus (GFLV), Grapevine fleck virus (GFkV), Grapevine virus A (GVA), Arabis mosaic virus (ArMV), Grapevine leafroll associated virus-3(GLRaV-3), Raspberry ringspot virus (RpRSV) and Tobacco ringspot virus (TRSV). Viruses were found in almost all Iranian vineyards examined. The incidence of viruses in a decreasing order was: GFLV (11.1%), GFkV (8.6%), GVA (8.4%), ArMV (6.6%), GLRaV-3 (6.4%), RpRSV (2.8%) and TRSV (0.35%). GFLV, either alone or in mixed infection in 11.1% of the samples collected nationwide, was the most prevalent virus. In addition, 25 (20%) of 125 symptomatic leaf samples from the Orumeyeh district were shown to contain Tomato ringspot virus. Viruses other than GFLV and GVA are reported from grapevine for the first time in Iran.