Prevalence of Viruses Infecting Autochthonous Grapevines in Tunisia

The incidence of virus infections was conducted in the grapevine germplasm collection at the Institut National de la Recherche Agronomique de Tunisie. In this grapevine collection, 162 different autochthonous cultivars were maintained, including numerous spontaneous ecotypes coming from different Tunisian grapevine growing regions. All accessions were sampled and analyzed by DASELISA for the presence of Grapevine leafroll associated viruses 1, 2, 3 (GLRaV-1, -2, -3), Grapevine fanleaf virus (GFLV), Grapevine fleck virus (GFkV) and Arabis mosaic virus (ArMV), using commercial polyclonal antisera. Almost all the major grapevine-infecting viruses assayed, except for ArMV, were detected in the tested cultivars. Conversely, all the wild grapevine accessions were found to be free from the same viruses. Out of 141 cultivars submitted to DAS-ELISA, 40.4% were infected with at least one virus. GLRaV-3 was the prevailing virus (23.4%), followed by GLRaV-1 (19.6%), GFkV (9.2%), GLRaV-2 (4.2%), and GFLV (1.4%). Cultivars collected from northern regions (61.4%) were more infected than their homologues from southern regions (19.7%).