DISINFECTION OF ODONTOGLOSSUM RINGSPOT VIRUS AND CYMBIDIUM MOSAIC VIRUS FROM TOOLS USED DURING ORCHID CULTIVATION

Abstract

A novel sanitation approach by using liquid culture filtrate (CF) of a Streptomyces isolate (CA5) that can readily disinfect coat proteins (CP) of Odohtoglossum ringspot virus (ORSV) and Cymbidium mosaic virus (CymMV) and eliminate their infectivities is demonstrated. By treating for only 30 s with a preparation of CA5 CF on the materials or tools commonly used in orchid nurseries including razor blades, plastic clips, labels and gloves coated previously with ORSV and CymMV infected plant sap, it is shown that no ELISA signals and infectivity could be recovered on the treated materials. Similarly, virus contaminated human nails and surfaces of Phalaenopsis orchid leaf tissue can also be treated without detecting any leftover ELISA signal and virus infectivity. We also showed that CA5 CF has the potential to eliminate virus contamination on the surface of orchid seeds leading to the production of clean orchid seedlings. The virus degradation activity of CA5 culture filtrate is heat labile to temperature treatments higher than 60°C, indicating that the activity is possibly due to a proteinaceous substance. Further experiments of dialyzing CA5 culture filtrate using different molecular cut-off membranes showed that the molecular mass of the substance should be larger than 100 kDa.