Detection of virus in tissue culture plantlets of Solanum tuberosum L.

Abstract

Healthy, virus tested potato plants of the cultivars Rua, Desiree and Maris Court were inoculated with potato virus X (PVX), potato virus Y, (PVY) and potato virus S (PVS). Tissue cultured plantlets were established from these plants and used to determine the effectiveness of various methods for detecting virus in in vitro cultured potato plants.

The Enzyme-linked immunosorbent assay (ELISA) established the presence of virus in the cultured plantlets. ELISA was also successfully used to monitor the presence of virus levels in long term in vitro cultures (500 to 758 days).

The precipitin methods of microprecipitin, gel diffusion and latex agglutination, were not as sensitive as ELISA or as definitive. PVX was detected in Desiree in the microprecipitin and double diffusion assays, while PVY was detected in Maris Court in the latex agglutination test.

The electron microscope techniques of Immunosorbent Electron Microscopy and Serologically Specific Electron Microscopy (SSEM) detected PVY in all three cultivars. PVX was found in both Desiree and Rua. PVS was present in Maris Court and Desiree.

Electrophoretic gels were used to compare the proteins of purified PVX with a PVX infected plant let sap sample of Desiree. The virus protein was not detected in Desiree with this method.

Local lesion test plants, Gomphrena globosa, Chenopodium quinoa and Chenopodium amaranticolor were inoculated with sap samples from the tissue culture plantlets. PVX was detected in both Desiree and Rua with G.globosa. PVS was detected with C.amaranticolor in Maris Court.