THE RAPID AND SENSITIVE DETECTION OF PLANT-PATHOGENS BY MOLECULAR METHODS

A range of molecular methods is available for detecting specific compo nents of pathogens in plant material. Of these, the detection of antig enic proteins by immunological methods is rapid and inexpensive. The d etection of genome components by nucleic acid based technologies, alth ough more complex, is approaching the simplicity of immunological meth ods with the advantage of greater sensitivity and specificity. The lat ter techniques are suitable for most pathogens, but are particularly r elevant for non-immunogenic pathogens, such as viroids, and for applic ations where sensitivity of detection must be at least as high as Ibr current biological diagnoses, such as in quarantine situations. Nuclei c acid component analysis can also be used for investigations of disea ses of unknown etiology. In an overview, available techniques relevant to plant pathology are briefly described and compared.