New virus disease of barley in Switzerland
A new virus disease of barley has recently been observed in Switzerland. Unusual symptoms of a yellow disease were seen in 1991 in winter barley in three localities near Friburg, and more recently in two other places near Burgdorf (Canton of Bern). The disease appears in patches and differs from barley yellow dwarf by the absence of dead or severely stunted plants and by a very bright and homogeneous yellows on all organs of the diseased plants. It is not yet possible to evaluate the incidence of this disease on quality and yield of barley crops.
By using electronic microscopy, virus particles were constantly observed in samples from symptomatic plants. Immunological and biological tests were also carried out. The causal agent has been characterized as a nepovirus. Up till now, nepoviruses were not reported as pathogens of Gramineae. This new virus appears to be related to arabis mosaic nepovirus (EU Annex II/A2). Concerns about the virus transmission by nematodes and seeds are raised, but further studies are needed to clarify the issue. The author has proposed to call the disease 'jaunisse de l'orge' (barley yellows).
Sources
Gugerli, P. (1996) Identification d'une nouvelle virose de l'orge. Communiqué de presse. Station fédérale de recherches en production végétale de Changins, 1260 Nyon, CH.
Plant Protection Service of Switzerland, 1996-08.