Abstract Fire blight, cause by the Gram-negative bacterium Erwinia amylovora, is a destructive bacterial disease of pear and apple and other fruit trees and ornamental plants. Molecular detection protocols based on the information of the plasmid pEA29 sequence are impractical when the E. amylovora strains without the plasmid pEA29 exist in nature. This report developed the duplex-PCR method, which combined the primers from chromosomal regions and from the plasmid pEA29 in a PCR reaction, is fast, simple and accurate to identify this plant pathogen.
