Viral diseases of flower plants 16. Identification of viruses affecting orchids (Cymbidium Sw.)

Abstract

Two viruses, Cymbidium mosaic potexvirus (CymMV) and Odontoglossum ringspot tobamovirus (ORSV), were isolated and identified from Cymbidium Sw. plants in Lithuania. Viruses were identified by the methods of test-plants and electron microscopy. The optimum techniques for purification of the viruses were selected and the purified preparations (antigens) were obtained. The yield of purified preparations was 7.5 mg from 100 g of infected plant tissue for CymMV and 12.4 mg for ORSV. The titres of the produced specific diagnostic antisera in DAS-ELISA test were 1: 2560 to CymMV and 1: 40960 to ORSV. The IgGs from antisera were precipitated and purified. Specific enzyme-labeled ORSV antibodies (conjugates) with horseradish peroxidase and inorganic pyrophosphatase of Escherichia coli were prepared and estimated. The possibly optimal conditions for the DAS-ELISA test were developed. Our experiments showed the possibility and advantages of using inorganic pyrophosphatase of Escherichia coli in the DAS-ELISA system. Keywords: Cymbidium Sw., Cymbidium mosaic potexvirus, Odontoglossum ringspot tobamovirus, identification, DAS-ELISA