Simultaneous and selective detection of two major soft rot pathogens of potato: Pectobacterium atrosepticum ( Erwinia carotovora subsp. atrosepticum ) and Dickeya spp. ( Erwinia chrysanthemi )

Dickeya spp. and Pectobacterium atrosepticum are major pathogens of potato. Current methods to detect these soft-rotting bacteria require separate identification steps. Here we describe a simple method allowing simultaneous detection of both pathogens based on multiplex PCR. The sensitivity of the primer sets was first examined on purified genomic DNA of the type strains Dickeya chrysanthemi 2048 T and P. atrosepticum 1526 T . The specificity and detection limits of the primer sets were successfully tested on 61 strains belonging to various Dickeya and Pectobacterium species, on artificially inoculated and on naturally contaminated potato plants. This new method provides a gain in time and materials, the main advantages for large-scale processes such as pathogen-free seed certification.