DOI 10.1007/s00705-005-0586-x Mint virus X: a novel potexvirus associated with symptoms in ‘Variegata ’ mint

Abstract

Summary. Mentha×gracilis ‘Variegata’, an ornamental mint clone first de-scribed about 200 years ago, exhibits virus-like vein banding symptoms. Double-stranded RNA and virion isolations revealed the presence of three viruses in a ‘Variegata ’ plant. Cloning and sequencing disclosed that one of the viruses was a previously unidentified species with similarities to members of the Flexiviridae family, designated as Mint virus X (MVX). The complete nucleotide sequence of the virus was determined. Phylogenetic analysis divulged the close relationship of the virus with lily virus X and strawberry mild yellow edge virus, members of the Potexvirus genus. A reverse transcription-polymerase chain reaction protocol was developed and used for detection of MVX in other ‘Variegata ’ plants. All clones tested, obtained from nurseries around the United States were infected with MVX, making the virus a possible causal agent of the variegated symptoms