Characterization and genetic diversity of Pseudomonas syringae isolates from stone fruits in north‐western Iran

From 33 Iranian fluorescent Pseudomonas isolates originating from symptomatic tissues of peach ( Prunus persica ), plum ( Prunus domestica ), sweet ( Prunus avium ) and sour cherry ( Prunus cerasus ), 27 were identified as Pseudomonas syringae using LOPAT tests. Further characterization of those isolates by GATT a and L‐lactate utilization tests and the detection of syringomycin and coronatine and yersiniabactin coding genes showed that five of them belonged to race 1 and four to race 2 of P. syringae pv. morsprunorum ( Psm ) and eighteen other isolates were identified as P. syringae pv. syringae ( Pss ). Based on the analysis of the fingerprint patterns generated by REP , ERIC and BOX ‐ PCR , the strains were differentiated into three main groups at the 67% similarity level. Strains of the groups 1, 2 and 3 belong to Psm race 1, Psm race 2 and Pss , respectively. Rep‐ PCR analysis showed high intra‐pathovar variation within the Pss isolates, which grouped into four distinct clusters. Using the REP primers, the percentage of polymorphic loci was 74.61%, whereas with BOX and ERIC primers, it was 60.5 and 55.21%, respectively. Finally, this study is the first report of the isolation of P. syringae pv. morsprunorum race 1 and 2 strains from stone fruit trees in Iran.