Comparative genomic analysis of Chinese <i>Erwinia amylovora</i> strains reveals genetic variations, plasmid diversity, and potential common ancestor

The bacterial pathogen <i>Erwinia amylovora</i> is the causative agent of fire blight, a devastating disease affecting rosaceous plants globally. Pathogenicity tests in immature pears demonstrated <i>E. amylovora</i> discovered in China exhibit different virulences. Through full-genome sequencing and genetic variations assay, Each strain exhibited a chromosome size of approximately 3.8 Mb, with distinct distribution patterns in plasmids. The genomes of all sequenced strains were compared to the model strain CFBP1430. Single-nucleotide polymorphisms (SNPs) and short deletions, insertions, and other polymorphisms (DIPs) were identified and shared SNPs and DIPs among strains suggest genomic homogeneity, with a higher level of specificity in DIPs. Phylogenetic analysis inferred that the primary pathway of fire blight spread to China followed a trajectory from the Middle East to Central Asia, ultimately reaching Xinjiang.