Untangling the taxonomy of dahlia mosaic virus

In this brief note, we review the taxonomic history of dahlia mosaic virus (DMV) and related viruses. DMV is the only officially recognized caulimovirus known to infect dahlia (Dahlia variabilis) plants, although this virus appears to be relatively rare as a pathogen compared to a more recently described but unclassified caulimovirus called dahlia common mosaic virus (DCMV). We have undertaken a new set of analyses to test the hypothesis that DCMV represents a new caulimovirus species whose members infect dahlia, but we ultimately reject this hypothesis. A probable sequencing error was identified in the reference genome sequence of DMV, and consequently, we recommend that an alternative virus isolate be nominated as the exemplar for this species. In accordance with the new binomial nomenclatural system, it is proposed that the virus species be called “Caulimovirus dahliae”.