Southern hybridization and PCR for detection of Clavibacter michiganensis subsp. michiganensis
A specific detection method for Clavibacter michiganensis subsp. michiganensis (EPPO A2 quarantine pest) has been developed in Germany, based on Southern hybridization with DNA-probes derived from plasmid-borne genes (celA encoding an endonuclease and pat-1 involved in pathogenicity). The celA probe allowed differentiation between the subspecies of Clavibacter michiganensis and the pat-1 probe distinguished between the virulent and avirulent strains of Clavibacter michiganensis subsp. michiganensis. A PCR test using primers derived from the pat-1 region has been developed and gave specific detection of the virulent strains of the bacterium. The latter were detectable in homogenates prepared from infected tomato plants, naturally contaminated seeds, and healthy plant homogenates containing as few as 2. 102 bacteria per ml.
Sources
Dreier, J.; Bermpohl, A.; Eichenlaub, R. (1995) Southern hybridization and PCR for specific detection of phytopathogenic Clavibacter michiganensis subsp. michiganensis.
Phytopathology, 85(4), 462-468.