Detection through RT-PCR technique of CymMV and ORSV viruses in orchid culture

Cymbidium mosaic potexvirus (CymMV) and Odontoglossum ringspot tobamovirus (ORSV) are the most prevalent pathogens affecting worldwide the cultivation of orchids, causing incalculable losses in revenue. They reduce growth vigor and quality, and what is most problematic they are not curable once infected. A diagnostic method, based on the chain reaction reverse transcription polymerase (RT-PCR), was developed to detect both viruses. The method consists of the extraction of nucleic acids of infected plants and applying the RT-PCT method, similar to the ELISA (enzyme linked immuno-sorbent assay) virus indexing technique. Leave, flower and bulb samples of different species of in vitro reproduced healthy and affected Cattleya orchids were analyzed in the molecular biotechnology laboratory of Concept Blue Corporation in Guayaquil, Ecuador. The comparative analysis revealed that RT-PCR is more effective in the detection of CymMV and ORSV viruses than the ELISA technique. Furthermore the study revealed that CymMV was preferentially detected in leaves, flowers and small bulbs, while the ORSV virus was only detected in leaves and bulbs. The latter permitted to describe the symptoms associated to each type of infection and the propagation of virus-free plants applying the meristem-tip culture.