Differentiation of phytopathogenic Pseudomonas and Xanthomonas pathovars and strains by PCR analysis for DNA topoisomerase genes

Differentiation of pathovars of Pseudomonas syringae and Xanthomonas campestris was conducted by analysis with polymerase chain reaction (PCR) of topoismerase genes. Differences among the pathovars were observed on the migration patterns of the PCR products on agarose gel. Banding patterns of respective strains were pathovar specific with some exceptions. The technique is rapid, simple and reproductive to identify and classify phytopathogenic Pseudomonas syringae and Xanthomonas campestris at pathovar level, and it may be a useful diagnostic tool for these important plant pathogens.