MOLECULAR IDENTIFICATION OF PLUM POX VIRUS

Plum pox virus (PPV) (genus Potyvirus of the family Potyviridae) causes devastating stone fruit disease known as sharka and can provoke a serious economic impact. It is known that PPV has four major strain groups – Dideron (D), Marcus (M), El-Amar (EA) and Cherry (C). The severity of crop losses often depends on the strain of the virus, so it is important to identify the most common strain of PPV in our investigation regions. Plum tree leaves with characteristic mottle symptoms were collected from stone-fruit orchards in Lithuania and Ukraine in 2007. In these samples, PPV was detected using ELISA test, immunosorbent electron microscopy and the reverse transcription and polymerase chain reaction (RT-PCR). After confirmation of the virus presence, strain specificity of PPV was determined by amplification of two genomic regions (243 bp sequence flanking the coat protein coding region and 836 bp sequence of the P3-6K1 genomic region) in nested PCR reactions and RFLP analysis of these products with specific restriction endonucleases. In all analyzed samples from Lithuania and Ukraine presence only PPV-D strain of the virus was proved