Genomic and phenotypic characterization of the bacterium causing blight of kiwifruit in New Zealand

Abstract

Strains of the pathogen causing bacterial blight of kiwifruit in New Zealand, previously identified as Pseudomonas viridiflava, were examined using phenotypic and genotypic methods. Percentage DNA-DNA reassociation values for strains of the pathogen, with the type strains representing P. viridiflava and P. savastanoi, and representative strains within P. syringae, were obtained using the S1 endonuclease method. Strains of the pathogen were most similar to the type strain of P. savastanoi. This similarity was supported by examination of the AT to between representative strains. It is concluded that the pathogen can be considered as a member of the P. savastanoi genomic species. The pathogen from kiwifruit in New Zealand was also differentiated in genomic terms from P. syringae pv. actinidiae. Strains of the kiwifruit pathogen compared using the Biomerieux API Biotype 100 system exhibited consistent determinative tests which distinguished the pathogen from P. viridiflava and P. syringae pv. actinidiae. The origins of the pathogen in New Zealand are discussed.