Odontoglossum ringspot virus (ORSV) is a plant pathogenic virus that belongs to the family Virgaviridae. It is one of the most common viruses affecting cultivated orchids, perhaps second only to the Cymbidium mosaic virus.[1] It causes spots on leaves and colored streaks on flowers.[1] If a plant is also infected with the Cymbidium mosaic virus, it can lead to a condition called blossom brown necrotic streak.[1]
Phylogenetics
Its genome has been sequenced and contains approximately 6600 nucleotides organized into four open reading frames.[2][3] Its similarity to other tobamoviruses can be seen from the genetic data and the (limited) ability of a Tobacco mosaic virus modified to contain ORSV movement protein to infect tobacco.[4] However, only about 60% of the nucleotides in ORSV are identical with Tobacco mosaic virus.[3]