Comparison of bi‐directional electrophoresis and molecular hybridization methods to detect potato spindle tuber viroid and chrysanthemum stunt viroid¹

Abstract

A comparison was made of methods for viroid detection. Molecular hybridization using cDNA is a very sensitive method that can handle large quantities of samples at the same time but it has the disadvantage that only small amounts of the sample can be applied to the nitrocellulose filter. The method therefore can only detect viroid in plants when its concentration is 1&20 ng g-' of leaves, using 32P as a marker system. Bi-directional electrophoresis can detect viroid in plants when its concentration is 10 ng g-' of leaves, because it uses larger samples. It does not need hazardous chemicals like 32P and formamide, and the reading of the results of the test is less liable to failures because it is based on two criteria (position and intensity of RNA band). The Dutch Plant Protection Service and the Dutch General Inspection Service for Ornamentals therefore use a modified bi-directional electrophoresis method to detect potato spindle tuber viroid and chrysanthemum stunt viroid, respectively.

Natural infections of tomato by Citrus exocortis viroid, Columnea latent viroid, Potato spindle tuber viroid and Tomato chlorotic dwarf viroid

“…The presence of the viroids in these symptomatic tomatoes was established by return-polyacrylamide gel electrophoresis (r-PAGE, Huttinga et al, 1987;Roenhorst et al, 2000). However, their identity could not be established by electrophoresis alone.…”

Detection of Chrysanthemum stunt viroid and Potato spindle tuber viroid by return‐polyacrylamide gel electrophoresis*

“…Results are discussed in relation to those obtained by the previous procedure (Huttinga et al, 1987).…”

Diagnosis of viruses in ornamental plants with special reference to serological methods: new developments

“…Slab gel electrophoretic assay can be used for detection of chrysanthemum chlorotic mottle viroid (CChMVd) (Macquaire et al, 1981) and cDNA probes have been also developed for chrysanthemum stunt viroid (CSVd), capable of specifically detecting the viroid (Palukaitis & Symons, 1979). Bi-directional electrophoresis combined with silver staining has proved to be useful for detecting CSVd directly in chrysanthemum leaves (Huttinga et al, 1987).…”