Molecular biological properties of new isolates of plum pox virus strain Winona

Abstract

Plum pox virus (PPV, genus Potyvirus, family Potyviridae) is the most important virus pathogen of stone fruit cultures of the genus Prunus from an economical standpoint. Winona strain (PPV-W) is the most variable of nine known virus strains and one of the most widespread in the European part of Russia. Six new PPV-W isolates were first discovered in green plantations of Moscow (Kp2U, Avang, Pulk, Pulk-1), in Taldomsky district of Moscow region (Karm), and in Kovrovsky district of Vladimir region (Vlad-4) on wild trees of plum Prunus domestica. 3’-Terminal segment of genome of new isolates was notable for high variability level. The study on the relationship with other isolates of this strain by means of phylogenetic analysis of gene sequence of the coat protein showed the lack of clusterization of Russian PPV-W isolates according to geographical principle. Inoculation of Nicotiana benthamiana plants by hop plant louse Phorodon humili from plum trees infected with Avang and Pulk isolates and by thistle aphid Brachycaudus cardui from the tree infected with Kp2U isolate led to the systemic viral infection in indicator plants, suggesting the possibility of PPV-W spread by both aphid species in nature. Transmission of PPV-W through seeds was not observed.