A Subgroup 1 Tobamovirus Isolated from Brugmansia sp. and its Detection by RT-PCR

A new virus, isolated from a mixed infected Brugmansia sp., was characterized. The viral genome was about 6380 nucleotides (nts) long and showed an organization typically for tobamoviruses with overlapping open reading frames (ORF) of the RNA-dependent RNA polymerase (RdRP) and the movement protein (MP). The coat protein (CP) was in the same size as known for other tobamoviruses. Phylogenetic analyses of the complete genome indicated that the new isolate belongs to the tobamovirus subgroup 1, despite strong serological reactions with Ribgrass mosaic virus (RMV) specific antiserum in a plate trapped antigen ELISA. Sequence comparisons with species of the genus Tobamovirus revealed >10% overall sequence divergence, which indicates according to the rules of the International Committee on Taxonomy of Viruses (ICTV) that this virus is a new species and we suggest the name Brugmansia mild mottle virus (BMMV) for that isolate. Furthermore, we present a diagnostic reverse transcriptase-polymerase chain reaction (RT-PCR) protocol for the detection of this isolate which uses a drastically reduced cycling time