EPPO Global Database

New data on grapevine flavescence dorée and other grapevine yellows

Numerous papers were presented on grapevine yellows during the 14^th ICVG Conference (Locorotondo, IT, 2003-09-12/17). The EPPO Secretariat has extracted the following new data concerning these diseases.

The following table summarizes the current knowledge about grapevine diseases and their associated phytoplasmas observed in different parts of the world.

Disease	Phytoplasma name	Ribosomal group (and subgroup)	Known insect vector	Preferred host plants of vector	Distribution
Flavescence dorée	FD	EY or 16SrV (-C, -D)	Scaphoideus titanus	Vitis	France, Italy, Spain
Palatinate grapevine yellows	PGY	EY or 16SrV	Oncopsis alni	Alnus glutinosa	Germany
Bois noir, legno nero, Vergilbungskrankheit	Stolbur	Stolbur or 16SrXII-A	Hyalesthes obsoletus	Convolvulus arvensis, Urtica dioica, Ranunculus, Solanum, Lavandula	Europe, Israel, Lebanon
Australian grapevine yellows	Candidatus Phytoplasma australiense	Stolbur or 16SrXII-B	-	-	Australia
Australian grapevine yellows	Tomato big bud	FBP or 16SrII	-	-	Australia
Buckland valley grapevine yellows	BVGY	AY or 16SrI-related	-	-	Australia
Grapevine yellows	Aster yellows	AY or 16SrI-A	-	-	Italy
North American grapevine yellows	Western X	W-X or 16SrIII-I	-	-	New York, Virginia

Table adapted from Boudon-Padieu (2003).

First report of Scaphoideus titanus carrying grapevine flavescence dorée phytoplasma in Portugal

In 2001, the presence of S. titanus was reported for the first time in the North of Portugal. Surveys were carried out in 2001/2002 over the whole country to determine its distribution. Preliminary results showed that S. titanus only occurs in the North of Portugal (Trás-os-Montes, Entre-Douro-e-Minho). 54 specimens of S. titanus were collected in vineyards and tested. The presence of phytoplasmas belonging to 16SrV-D was detected in 9 samples. So far, grapevine flavescence dorée phytoplasma has not been detected in samples of grapevine (only phytoplasmas belonging to 16SrI-B), but its presence in the insect vector is a serious concern. Therefore, surveys will continue on the occurrence of such phytoplasmas both in S. titanus and in grapevine in order to prevent possible outbreaks of flavescence dorée in Portugal (de Sousa et al., 2003).

First report of flavescence dorée in Serbia

Symptoms of grapevine yellows have been observed in Serbia (county of Rasina) since the mid-1990s. Symptoms were characterized by leaf roll, red and yellow discoloration, vein chlorosis and necrosis, shortened internodes and lack of lignification. On regional cultivars like Plovdina and Smederevka, symptoms were so severe that some vineyards had to be uprooted. The disease was observed on young plantations as well as in old vineyards. Molecular tests revealed the presence of phytoplasmas belonging to the Elm Yellows group (16SrV-C). The Serbian iolates were most closely related to an Italian isolate of grapevine flavescence dorée phytoplasma from Treviso. As S. titanus was detected in the same area in spring 2003, it can be considered that flavescence dorée occurs in Serbia (Duduk et al., 2003).

Presence of Scaphoideus titanus in Slovenia

This insect has been found in the western part of Slovenia since the mid-1990s where it is relatively abundant. However, grapevine flavescence dorée phytoplasma has never been detected in Slovenia. Only bois noir is present and widespread in all grapevine-growing areas (Petrovic et al., 2003). According to theEPPO Secretariat, this confirms earlier reports of S. titanus in Slovenia.

Grapevine flavescence dorée phytoplasma detected in Clematis vitalba

In Italy, Grapevine flavescence dorée phytoplasma was detected in Clematis vitalba plants growing in the vicinity of vineyards. Infected Clematis plants showed no symptoms. Further studies will be done on insect vectors to better understand the potential role of such plants in the epidemiology of the disease in the vineyards (Angelini et al., 2003).

Sources

Angelini, E.; Squizzato, F.; Lucchetta, G.; Borgo, M. (2003) Identification of a grapevine flavescence dorée-C phytoplasma and two deletion mutants in Clematis (abst. pp 60-61). Boudon-Padieu, E. (2003) The situation of grapevine yellows and current research directions : distribution, diversity, vectors, diffusion and control (abst. pp 47-53) De Sousa, E.; Cardoso, F.; Casati, P.; Bianco, P.A.; Guimarães, M.; Pereira, V. (2003) Detection and identification of phytoplasmas belonging t 16SrV-D in Scaphoideus titanus adults in Portugal (abst. p 78). Duduk, B.; Botti, S.; Ivanovic, M.; Dukic, N.; Bertaccini, A. (2003) Molecular characterization of a flavescence dorée phytoplasma infecting grapevine in Serbia (abst. pp 91-92). Petrovic, N.; Seljak, G.; Matis, G.; Miklavc, J.; Beber, K.; Boben, J.; Ravnikar, M. (2003) The presence of grapevine yellows and their potential natural vectors in wine-growing regions of Slovenia (abst. pp 97-98). Extended abstracts of papers and posters presented at the 14th ICVG Conference, Locorotondo, IT, 2003-09-12/17.