Phylogenetic analysis of cymbidium mosaic and odontoglossum ringspot viruses isolated from Phalaenopsis sp.

Cymbidium mosaic virus and Odontoglossum ringspot virus are the most common and widespread viruses in ornamental orchids. Infections caused by these viruses can lead to a decrease in the phenotypic diversity of orchid collections, and as a result – to their complete depletion. The aim of the study is to determine the origin of Ukrainian isolates of orchid viruses in the collection of protected soil from O.V. Fomin Botanical Garden of Taras Shevchenko National University of Kyiv. The properties of nucleotide and amino acid sequences of the coat proteins (CP) of Cymbidium mosaic virus (CymMV) and of Odontoglossum ringspot virus (ORSV) were investigated. RNAs of CymMV and ORSV were isolated from leaves of Phalaenopsis sp. collected from A.V. Fomin Botanical Garden of Taras Shevchenko National University of Kyiv, amplified through RT-PCR and sequenced. Obtained sequences were compared at nucleotide and amino acid levels with CymMV and ORSV isolates available in the GenBank. ORSV isolated in Ukraine shared 96-99 % and 93,4-98 % CP similarity to other known ORSV isolates at nucleotide and amino acid levels, respectively. CymMV isolated in Ukraine revealed approximately 77-97 % similarity for nucleotide sequences and 84-100 % for amino acid sequences to isolates from the GenBank. Phylogenetic analysis showed that studied ORSV and CymMV isolates may have common origin with some South Korean isolates.