The first subantarctic plant virus report: Stilbocarpa mosaic bacilliform badnavirus (SMBV) from Macquarie Island

Abstract

We report here the finding of a new plant virus, Stilbocarpa mosaic bacilliform badnavirus (SMBV) in Stilbocarpa polaris (Homb. et Jacq.) Gray on subantarctic Macquarie Island. This is the first vascular plant virus reported from any of the remote subantarctic islands, and represents the southernmost plant virus found anywhere. The virus causes mild to severe yellow mosaic symptoms in the perennial megaherb S. polaris. Virus distribution appears most widespread in the northern third of Macquarie Island, although S. polaris occurs around the whole island. DNA sequencing of a conserved part of the virus genome showed it is most closely related to badnaviruses of temperate and tropical plants, which are mainly transmitted by mealybugs (Hemiptera: Coccoidea). No mealybugs have been found on Macquarie Island, where the vector may be an aphid (Hemiptera: Aphidoidea) or thrip (Thysanoptera). We discuss possible origins, dispersal and evolution of this plant virus on isolated Macquarie Island. Show more