CYNOSURUS CRISTATUS A NEW HOST OF WHEAT DWARF VIRUS IN THE CZECH REPUBLIC
J. Ripl, J.K. Kundu
Wheat dwarf virus (WDV, genus Mastrevirus, family Geminiviridae) has a wide host range among Poaceae (Vacke, 1961). Grass species such as Briza media, Poa pratensis, Poa compressa, Bothriochloa ischaemum, Brachypodium pinnatum, Anthoxanthum odoratum, Agrostis capillaries, Phleum pretense, Dactylis glomerata, Lolium perenne, Trisetum flavescens, Cynosurus cristatus, Deschampsia cespitosa, Alopecurus pratensis, Arrhenatherum elatius, Poa trivialis, Apera spica-venti, Elymus caninus, Festuca arundinacea, Bromus inermis, Elytrigia repens and Echinochloa crus-galli were tested for the evaluation of the host range of two WDV strains: WDV-W and WDV-B. Three seedlings of each grass species were exposed to adults of viruliferous leafhopper vector Psammotetix alienus which were removed from the plants after three weeks. Subsequently, non- viruliferous P. alienus were left for acquisition feeding on the infected grass species for seven days, and were then transferred to healthy wheat and barley plants. The leafhoppers from the grasses inoculated by the WDV-W and WDV-B were transferred to wheat and barley plants, respectively. Samples from grasses and cereals (wheat and barley) were collected 30 and 70 days post inoculation, respectively, for WDV detection by DAS-ELISA (Sediag, France). WDV was detected in two A. spica-venti and C. cristatus plants inoculated by each of the WDV strains and in one L. perenne plant inoculated by WDV-W, as well as in wheat and barley plants. The rest of the grass species remained virus-free. Hence, our results confirm two earlier reported WDV hosts, i.e L. perenne (Vacke, 1971) and A. spica-venti (Vacke and Cibulka, 1999) and identify C. cristenus as a new WDV host. To the best of our knowledge this is the first report of C. cristanus as a host and potential reservoir of WDV in agroecosystems.