Genetic diversity of Pseudomonas syringae pv. lachrymans strains isolated from cucumber leaves collected in Poland

Several strains of Pseudomonas syringae pathovar (pv.) lachrymans and related bacterial pathogens were isolated from cucumber (Cucumis sativus) leaves collected in central and southern Poland in 2001 and 2002. Twenty five original strains, together with five reference strains of P. syringae pv. lachrymans, pv. syringae and pv. tomato, were genetically characterized by PCR‐RFLP (polymerase chain reaction − restriction fragment length polymorphism), ADSRRS (amplification of DNA fragments surrounding rare restriction sites), and PCR‐MP (PCR − melting profiles) fingerprinting techniques. Genetic similarity analyses of the PCR‐RFLP and ADSRRS fingerprints showed that strains of P. syringae pv. lachrymans form distinct clusters. The results also indicated that the ADSRRS and the PCR‐MP fingerprinting techniques may serve as more efficient tools for evaluating genetic similarity among pathovars and strains of P. syringae than PCR‐RFLP. The 25 strains showed diverse pathogenicity to cucumber seedlings and biochemical tests were varied. The syrB gene was identified in four cucumber strains, characterized as P. syringae pv. syringae.