Phylogenetic Distribution Of An Endogenous Strain Of Dahlia Mosaic Virus In Members Of Asteraceae

A newly discovered strain of Dahlia mosaic virus (DMV) called DMV-D10 was first observed in Dahlia variabilis in 2008. DMV-D10 does not induce visible symptoms of infection in the host plant, and is classified as an endogenous virus. Endogenous viruses like DMV-D10 have the ability to integrate their viral sequences into the host plant genome, which can be transmitted to offspring. No studies have examined the host range of DMV-D10 outside of the Dahlia genus. Because DMV-D10 has only been observed in Dahlia, the objective for this study was to determine if presence of DMVD10 follows an evolutionary relationship among species closely related to Dahlia. It was hypothesized species in the same tribe (Coreopsideae) as Dahlia were more likely to be infected with DMV-D10 compared to species in other Asteraceae tribes. Ten tribes consisting of thirty-five species were collected and DNA was extracted to determine DMV-D10 infection. Polymerase chain reaction (PCR) results for a movement protein gene indicate DMV-D10 is widely spread across Asteraceae. Fragments of the DMV-D10 genome were present in thirteen species across seven tribes. Thirty-seven percent of species in this study contained DMV-D10 viral sequences. Additionally, six species across five tribes contained Dahlia common mosaic virus sequences, and three species across two tribes contained Dahlia mosaic virus sequences. Phylogenetic relationship of host plants does not necessarily determine DMV-D10 infection. This leads to questions of how this virus can move to species in other Asteraceae tribes. Some potential hypotheses include pollen transmission or possible plant-virus coevolution.