ELISA Detection of <em>Odontoglossum</em> Ringspot Virus in Mature Plants and Protocorms of <em>Cymbidium</em> Orchids: Potential Solutions to Problems of Sample Preparation Time and Low Virus Concentration.

The ability to detect Odontoglossum ringspot virus (ORSV) released from the cut surfaces of leaf discs by ELISA was examined. Results indicate that ORSV from leaf discs can be detected but that multiple discs are necessary to obtain reliable detection of low virus concentrations. ELISA of Cymbidium protocorms, known from immunosorbent electron microscopy to be infected with ORSV, frequently produced A405 values which would be considered either negative or marginally positive on the basis of commonly accepted statistical limits (i.e. 2 x mean, or mean + 3 x standard deviation}. The comparison of paired samples, one of which had been pretreated with ORSV antiserum, improved the sensitivity of the test from 10 ng ml of virus to 2 ng ml. [ABSTRACT FROM AUTHOR]