GENETIC DIVERSITY OF PSEUDOMONAS SYRINGAE pv SYRINGAE STRAINS CAUSING BACTERIAL STEM BLIGHT DISEASE OF ALFALFA IN THE KURDISTAN PROVINCE OF IRAN
E. Hamedan, B. Harighi
In 2008 and 2009, 66 isolates of Pseudomonas syringae pv. syringae were obtained from infected alfalfa leaf tissues collected from various locations of the Kurdistan province of Iran. These strains, together with the Pseudomonas syringae pv. syringae reference strain were tested for the presence of the syrP gene and were also phenotypically characterized. According to phenotypic properties, 87% and 13% of the strains belonged to LOPAT group 1a and 1b, respectively. Genetic diversity of all strains was assessed by repetitive sequence- based polymerase chain reaction (rep-PCR) using REP (repetitive extragenic palindromic), ERIC (enterobacterial repetitive intergenic consensus) and BOX primer sets. Cluster analysis of rep-PCR revealed three groups at a similarity level of 50%. Group 1 of rep-PCR including all strains belongs to LOPAT group 1a, whereas group 2 and 3 comprise strains of LOPAT group 1a and 1b. A specific band corresponding to syrP gene was produced by 84% of the strains belonging to LOPAT group Ia. Strains belonging to LOPAT group Ib produced only non-specific bands.