| Taxonomic status and genotypes of kiwifruit canker bacteria in western Hunan was clarified and preliminarily explored the molecular mechanism of the pathogenesis. Bacteria pathogens of kiwifruit were isolated by culture-dependent methods, and identified based on sequence analysis of the internal transcribed spacer of 16S-23S rRNA gene. Genome sequencing and bio-information analysis were used to explore the molecular mechanism of the pathogenic bacterium. The results showed that five strains of bacterial pathogens, named after strain L211, L212, L321, L322, L323, were isolated from the infected branches of the kiwifruit " Miliang No.1" and "Hong Yang" in western Hunan, and these were identified as Pseudomonas syringae pv. actinidae (Psa). In vitro branching inoculation experiments using the L211 strain as a representative showed that it could cause typical kiwifruit canker disease. Following whole genome sequencing of strain L211 and bioinformation analysis, 5 741 genes with a total length of 5 412 072 bp were obtained, L211 strain was found to harbor 121 virulence factors, 71 plant-interactions factors and 77 drug-resistance genes. Single nucleotide polymorphism analysis indicated that the L211 strain belonged to the Psa biovar Ⅲ. To conclude, Psa biovar Ⅲ is the leading cause of kiwifruit canker disease in western Hunan, which is the same pathogenic bacterium bringing about global pandemic kiwifruit canker as reported home and abroad. The pathogenesis of kiwifruit canker disease may be the result of the synergistic action of multiple virulence and reciprocal genes of the pathogen. |
