Genetic Fingerprinting of Pseudomonas syringae Pathovars Using ERIC‐, REP‐, and IS50‐PCR

PCR fingerprinting using primers corresponding to repetitive (ERIC and REP) and insertion sequences (IS50) was investigated as a method to distinguish the pathovars of Pseudomonas syringae . After amplification of total DNA with the ERIC‐, REP‐, and IS50‐PCR followed by agarose gel electrophoresis. most of the tested pathovars showed specific patterns of PCR products. The differences between the fingerprints among strains within a pathovar were small, with the exception of pathovars syringae, aptata , and atrofaciens . The fingerprints of the related pathovars savastanoi, phaseolicola, glycinea, morsprunorum, tabaci, lachrymans , and mori generated with the ERIC‐ and REP‐primers were found to be very similar, showing the potential of this technique for taxonomical studies. In contrast, the IS50‐PCR fingerprints of these pathovars were clearly distinguishable. The fingerprint patterns of a strain were highly reproducible with all three tested primer sets, also when whole cells were added to the reaction mixture. Thus, the PCR technique with the ERIC‐, REP‐, and IS50‐primers is a rapid, simple, reproducible, and low cost method to identify and classify strains of the Pseudomonas syringae pathovars.