1. Plant virus investigation in the Institute of Botany Vilnius, Lithuania Juozas Staniulis Head of the Plant Virus Laboratory Institute of Botany Zaliuju Ezeru 49, LT-08406, Vilnius, Lithuania E-mail: fitvirus@botanika.lt

2. Staff of the Plant Virus Lab.: Dr. Habil. Juozas STANIULIS – woody plants, el. microscopy Dr. Habil. Meletėlė NAVALINSKIENĖ– ornamental plants Dr. Marija SAMUITIENĖ – ornamental plants Dr. Rasa JOMANTIENĖ – phytoplasmas Dr. Irena ZITIKAITĖ – vegetables Dr. Laima URBANAVIČIENĖ – cereals Dr. Deividas VALIŪNAS – phytoplasmas Methods used: –Plant indicators, –Serological: Immunodiffusion ELISA –Transmission electron microscopy: negative staining, Immunosorbent EM, immunogold labelling, ultrathin sectioning. –Polymerase chain reaction

3. Viruses detected: In 83 genus of the ornamental plants investigated, 48 viruses were detected, –most often detected were: ToRSV, TRV, ToSWV, CMV, TNV, TMV In cereal plants were identified: BYDV, Cocksfoot streak V, Ryegrass MV. In horticultural plants were detected: PPV, TNV, RBDV In vegetable plants identified: CMV, ToMV, TMV, TNV, OYDV, LYSV.

4. Viruses causing some problems Cereals Barley: Barley yellow dwarf luteovirus Grasses Cocksfoot: Cocksfoot streak potyvirus Festuca: Festuca necrosis closterovirus Ryegrass: Ryegrass mosaic rymovirus Potatoes: Carlaviruses, Potyviruses, Potato X virus Other Sugar beet: Beet necrotic yellow vein virus (just detected) Beet yellows viruses Viruses of Horticultural crops Field Vegetables Carrot: Carrot red leaf luteovirus, Carrot mottle virus Cucumber: Cucumber mosaic virus Tomato: Tomato mosaic virus Protected Vegetables Tomatoes: Tomato mosaic virus Cucumber: Tobacco necrosis virus, Cucumber green mottle virus Ornamentals: Tomato spotted wilt virus, Tobacco rattle virus Protected Ornamentals: Tomato ringspot nepovirus, Tobacco necrosis necrovirus Top Fruit Plums: Plum pox virus (controlled, under irradication) Others - not investigated Soft Fruit Raspberies: Raspberry bushy dwarf virus, Tobacco necrosis virus Strawberries: Tobacco necrosis virus