First detection of Tomato black ring virus (TBRV) in a French vineyard

Aim : Grapevine plants from the Bordeaux wine region (France) showing symptoms of fanleaf degeneration, but negative for the two main fanleaf viruses were screened by ELISA for other nepoviruses that could explain the symptoms. Methods and results : ELISA tests were performed over a 3-year period (2009-2011) on leaves and woody canes. A total of 665 grapevine plants grafted with Merlot, Cabernet franc and Cabernet-Sauvignon, were found free from Grapevine fanleaf virus (GFLV) and Arabis mosaic virus (ArMV) but infected with Tomato black ring virus (TBRV). The Longidorid nematode species Longidorus attenuatus, known as the TBRV vector in grapevine, was detected from soil samples collected in the infected area. Conclusion : Both the virus and its vector might have originated from a vegetable garden established prior to vine planting, considering that the TBRV-infected area with the most fanleaf degeneration symptoms co-localizes with this previous garden. Significance and impact of the study: This is the first record of TBRV infection in a grapevine plot in France.