FURTHER OBSERVATIONS ON THE EFFECTS OF CYMBIDIUM MOSAIC-VIRUS AND ODONTOGLOSSUM RINGSPOT VIRUS ON THE GROWTH OF CYMBIDIUM ORCHIDS

Two cultivars of Cymbidium orchid were mechanically inoculated with Odontoglossum ring-spot virus (ORSV) and Cymbidium mosaic virus (CyMV), individually and in combination, one year after transfer from in vitro culture to the glasshouse. Plant growth and disease symptoms were monitored over the following 4 years. Plants infected with CyMV showed severe mosaic symptoms with necrotic streaks and the virus was easily detectable by ELISA throughout the experiment. Plants infected with ORSV alone showed no obvious symptoms, and by the end of the experiment the virus could not be detected in the new growth using ELISA. Both viruses reduced plant growth, the effect of CyMV being more severe than that of ORSV.