Isolation, Purification, and Some Properties of Two Viruses from Cultivated Cymbidium Orchids

Abstract

Two distinct viruses have been isolated from cultivated Oymbidium plants in Australia. Each virus isolate has been transmitted to herbaceous plants, has been purified, and high-titre antiserum has been produced. One isolate has been identified as a serotype of tobacco mosaic virus; the other is suspected of being Oymbidium mosaic virus and has flexuous rods about 13 by 475 mIL. Electron micrographs of particles of the latter show that they have hollow central canals and consist of helical structures with a pitch of approximately 2� 8 mIL' Results indicate that inoculation to herbaceous plants and electron-microscopic examination and serological testing of leaf extracts can be used as methods for the routine indexing of Oymbidium plants.