Complete sequencing and phylogenetic analysis of tomato isolates of Pepino mosaic virus from Canada and other geographic regions

• Published in: Phytopathology Vol. 95; no. 6
• Main Authors: French, C, Bunckle, A, Ferguson, G, Bernardy, M
• Format: Journal Article
• Language: English
• Published: 01.06.2005
• Subjects: Lycopersicon esculentum; Pepino mosaic virus; Potexvirus; Solanum
• ISSN: 0031-949X

Pepino mosaic potexvirus (PepMV) infecting greenhouse tomato (Lycopersicon esculentum L.) was first reported in Ontario, Canada in 2000. PepMV has subsequently been reported from Alberta and British Columbia in Canada. Original symptoms observed were a bright yellow mosaic but more typical symptoms are a mild leaf mosaic and necrotic leaf spots. Initial diagnosis was by ELISA confirmed by RT-PCR using primers designed against a tomato isolate of PepMV from the United Kingdom. Complete molecular sequencing of tomato isolates was conducted using three isolates from Ontario, Canada, an isolate from British Columbia, Canada, an isolate from Southern Europe and an isolate from Arizona, USA. For comparison, the original isolate of PepMV from Peru was also completely sequenced. Sequences were compared to each other and to data in Genebank. All tomato isolates were very similar to each other (99% overall nucleotide homology). The Peruvian isolate from pepino (Solanum muricatum Ait.) was distinct from the tomato isolates (96% overall nucleotide identity). The coat protein gene was the most conserved region and the triple gene block gene 3 was the most variable. Phylogenetic analysis showed that the three Ontario isolates formed a separate subclade that might indicate introduction of PepMV into the region with subsequent molecular evolution.