Bacterial canker is one of the most important diseases of stone fruit trees in various locations of Kurdistan province, Iran. Genetic diversity and evolu- tionary relationships among 20 fluorescent pseudomo- nads isolated from stone fruit trees with symptoms similar to bacterial canker were investigated using a polyphasic approach by means of phenotypic character- izations, repetitive PCR using the REP and ERIC primers and multilocus sequence typing (MLST) of four housekeeping genes (gapA, rpoD, gyrB and gltA). The pathogenicity of strains was carried out under green- house conditions. Twelve strains produced an expected amplified DNA fragment of about 752-bp which indi- cated the presence of the syrB gene. Based on MLST, these strains belonged to P. syringae species complex and included in the genomospecies 1, phylogroup 2b and 2d. Phylogenetic analysis of the other eight fluores- cent pseudomonad strains by using gyrB and rpoD sequences allowed the identification of strains into P. fluorescens, P. putida and P. lutea groups. Unweighted pair group method analysis (UPGMA) of genomic fingerprints obtained by rep-PCR revealed 17 different patterns which grouped P. syringae strains into three clusters clearly separated from other fluorescent pseudomonads.MLST confirmed the genetic variability among strains obtained by rep-PCR. Grouping identified of P. syringae strains by both rep-PCR and MLST was related to geographic locations of strains.
