Odontoglossum Ringspot Virus

Odontoglossum ringspot virus (ORSV) was first described by Jensen and Gold (1951) as a pathogen of Odontoglossum grande. This pathogen, sometimes referred to as the orchid strain of tobacco mosaic virus (Kado et al., 1968), infects numerous commercially important orchid genera and may be found wherever orchids are cultivated, including Taiwan (Ko, 1982; Inouye and Leu, 1983), Hawaii (Ishii and Martinez, 1973), and Florida (Zettler et al., 1978). Diseases reportedly caused by ORSV include Cymbidium diamond mottle (Jensen, 1953), Cattleya infectious blossom necrosis (Izadpanah et al., 1968), Cattleya mild flower break (Jensen, 1955), and Cattleya color break (Murakishi, 1958). ORSV and the potexvirus, Cymbidium mosaic virus, are considered to be the most prevalent and troublesome of the 22 orchid viruses listed by Lawson and Horst (1984).