Pseudomonas marginalis as a potential pathogen of greenhouse grown plants and crops with sprinkler irrigation

During 2010-2017, samples of different plants grown in greenhouses and crops with sprinkler irrigation systems, in Chaharmahal va Bakhtiary province, showing symptoms of necrotic spots, marginal leaf blight, fruit rot, and wilting were collected and tested for the presence of bacteria associated with those symptoms. The isolated bacteria were identified based on standard methods for the identification of plant pathogenic bacteria. Pathogenicity of strains was tested on appropriate hosts under greenhouse conditions. Although various genera of bacteria were isolated, isolation frequency of fluorescent pseudomonads was more than other genera of bacteria. Fifty-three and a half percent of pseudomonads was identified as Pseudomonas marginalis and 18.2% as P. syringae pv syringae. The isolates of P. marginalis from cucumber, potato, tomato, pepper, wheat, beet, and dieffenbachia and strains of P. syringae pv syringae from cucumber, sugar beet, wheat, and tomato were pathogenic on their respective hosts. Polymerase chain reaction with universal primers 16Sf / 16Sr and R1378 / PO27F, designed for detection of γ-Proteobacteria, confirmed the identity of the isolated bacteria based on biochemical and physiological tests by the alignment of nucleotide sequences in the GeneBank. Phylogenetic analysis based on 16SrDNA gene sequences of 10 isolates of  P. marginalis were differentiated from each other. This investigation showed that strains of P. marginalis can  bepotential pathogens for greenhouse plants and field crops  with sprinkler irrigation.