Isolation of copper and streptomycin resistant phytopathogenic Pseudomonas syringae from lakes and rivers in the central north island of New Zealand

Abstract

Plant pathogenic strains of Pseudomonas syringae were isolated from lakes and rivers in the central North Island of New Zealand. These strains were identified by their ability to produce a fluorescent pigment on a modified King's B medium, by their ability to cause a hypersensitive reaction when infiltrated into tobacco plant and by the absence of a cytochrome c oxidase. Different aspects of the protocol used to isolate these strains have been assessed. Some of the strains isolated, and in some cases the majority of them, were resistant to copper and/or streptomycin. Significantly, these plant pathogenic bacteria were isolated from waterways in areas where no agriculture or horticulture is present and waterways used for crop irrigation. These results suggest that natural waterways could be a source of inoculum of plant pathogenic bacteria, and a source of genes that confer streptomycin resistance and/or copper resistance to these bacteria.