CHARACTERIZATION OF RUSSIAN PLUM POX VIRUS ISOLATES PROVIDES FURTHER EVIDENCE OF A LOW MOLECULAR HETEROGENEITY WITHIN THE PPVC STRAIN
M. Glasa, Y. Shneyder, L. Predajna, T. Zhivaeva, Y. Prikhodko
Plum pox virus (PPV)-positive samples from one sweet (Prunus avium) and four sour cherry (P. cerasus) trees from three geographically distinct regions of Russia (Moscow, Samara and Volgograd) were analysed. The average genetic distance among the five Russian PPV-C isolates in the region spanning the 3 ́terminal part of the nuclear inclusion b gene (NIb) and the hypervariable 5 ́terminal part of the coat protein gene reached 1.6%. To widen the information on PPV-C diversity, the full-length genome sequence of an isolate (Volk143) was determined directly from the original host tissues. The analysis of the complete genome sequences showed a high identity of Volk143 and the previously characterised PPV-C isolates with only 1.4-1.8% divergence. Co-infection with the recently identified PPV-CR strain was not observed, even though the PPV-CR isolate is known to occur in the regions of origin of the isolates studied here. The present results unambiguously confirm the natural infection of sweet and sour cherry trees by PPV-C in different Russian regions and further contribute to our understanding of the poorly known PPV-C diversity.