Identification of the phytoplasma associated with Bois Noir disease on grapevine in Spain
In this paper, it is recalled that grapevine yellows has been described in several countries and is not always due to grapevine flavescence dorée phytoplasma (EPPO A2 quarantine pest). In particular, severe damage has been observed in France and is sometimes associated with flavescence dorée, sometimes with another disease known as Bois Noir. Grapevine flavescence dorée phytoplasma (transmitted by Scaphoideus titanus) is NOT reported as present in Spain, but is found in France (Languedoc, Armagnac, Roussillon). Bois Noir (not transmitted by S. titanus) is thought to be a distinct yellows (related to stolbur of solanaceous plants which belongs to the aster yellows group, whereas flavescence dorée is associated with the elm yellows group, see RS 93/178) and has been reported in Jura, Champagne and Bourgogne.
In Spain, symptoms of grapevine yellows have been observed in some vineyards of Cataluña (Vitis vinifera cv. Chardonnay) during these last years. Studies have been carried out in affected vineyards to determine whether S. titanus is present and to identify the causal agent of the disease. The authors have found that S. titanus was present in all vineyards studied in rather high numbers (5-7 insect/plant), and analysis (amplification of the 16SrRNA gene and restriction) of samples collected from affected vines revealed the presence of the Bois Noir phytoplasma. The authors felt that the presence of S. titanus is a threat as it could spread grapevine flavescence dorée phytoplasma if it was introduced into Spain, and they pointed out that this disease is now spreading in Roussillon (French region neighbouring Spain). According to the EPPO Secretariat this is the first report of Bois Noir in Spain.
Sources
Batlle, A.; Larrue, J.; Clair, D.; Daire, X.; Boudon-Padieu, E.; Laviña, A. (1995) Identificación del fitoplasma asociado al Bois Noir de la viña en España.
Phytoma - España, No. 68, 40-44.