A rapid and sensitive detection of Clavibacter michiganensis subsp. michiganensis in tomato seeds by polymerase chain reaction

Abstract

A polymerase chain reaction-based method was applied for the detection and identification of Clavibacter michiganensis subsp. michiganensis in tomato seed. Two primers, CM 3 and CM 4 , were used to amplify a specific 645bp DNA fragment when the target bacterium was present in the amplification step. This fragment was produced with DNA from all C. m. subsp. michiganensis strains and contaminated seed extracts tested from as less as 40 cells ml -1 , but not from DNA of other plant-pathogenic bacteria or tomato saprophytes. The results were confirmed by isolation, IF, pathogenicity tests and RFLP analysis of the amplified fragments by the endonuclease SalI.