Isolation and characterisation of wheat dwarf virus found for the first time in Hungary

Winter wheat plants showing symptoms of dwarfing, leaf mottling and yellowing were collected at Martonvasar (Central Hungary). Adults and nymphs of the leafhopper Psammotettix alienus Dahlb. transmitted the pathogen from diseased plants to young wheat seedlings with high frequency. A combined method with extraction in liquid nitrogen by using ascorbic acid and 2-mercapto-ethanol in the extraction buffer at pH 4.0 led to the best results. Electron microscopy of the purified preparation showed typical geminivirus particles, about 20x30 nm in size. Agarose gel electrophoresis of nucleic acid demonstrated the presence of a single stranded DNA (ssDNS). Results indicate that the causal agent of the disease is the wheat dwarf virus. This is the first report on the occurrence of this virus in Hungary.