Status of orchid viruses in India and management strategies for them

Orchids are gaining economic importance for their use as cut flowers. However, viruses are becoming a limiting factor in their production because of the effect on flower quality and shelf life. Worldwide, more than 50 viruses are reported in orchids. However, only few of them are important. The important viruses which are of concern in orchids are Cymbidium mosaic virus, Odontoglossum ringspot virus, Calanthe mild mosaic virus, orchid fleck virus, Cymbidium ringspot virus, and groundnut bud necrosis virus. Because detection of the virus is the first step toward management, a number of diagnostic assays, particularly protein- and nucleic-acid–based methods have been developed. In this chapter, we review the current state of diagnostics and how they can be used to restrict orchid viruses. These diagnostics will have great application in the elimination of viruses through tissue cultures. Because most of the orchid viruses are transmitted by mechanical means, strict sanitary measures play an important role in restricting the inadvertent spread of orchid viruses. Attempts are being made to develop transgenic resistance against CymMV and ORSV using coat protein– and replicase-mediated resistance in number of orchid genera. However, their application in virus management in orchids is yet to be seen.