Genetic and pathogenic diversity of Pseudomonas syringae strains isolated from cucurbits

This work was done to determine the diversity of pathogenic Pseudomonas syringae pv. lachrymans and pv. syringae strains, isolated from cucurbit plants. Pathogenicity tests performed in this work on cucumber indicated that the 22 tested strains differed dramatically in virulence level. Genetic characterization using MLST loci, as well as ITS1, ERIC and REP fingerprinting, allowed the grouping of strains into four phylogenetic groups. After amplicon sequencing and BLAST alignment the collected strains comply with P. syringae pathovars: lachrymans and syringae and with saprophytic P. fluorescens. The strains of Pseudomonas syringae pv. lachrymans may be categorized into at least two types differing in both disease symptoms and molecular characteristics. We confirmed that MLST-loci-based grouping of strains corresponds well to grouping based on pathogenicity tests.