How the Netherlands confronted the introduction of crop bacterial diseases: the case of potato

The Netherlands is the biggest exporter of seed potatoes in the world. To guarantee the absence of diseases and pests in seed potatoes, at the Dutch General Inspection Service for Agricultural Seeds and Seed Potatoes, seeds are tested using a system based on field inspections and, for selected pathogens, with advanced laboratory assays. To avoid unnoticed introductions and spread of novel pathogens, surveys are regularly conducted. In last decade, these surveys revealed the presence of blackleg causing bacterial pathogens such as Dickeya solani and Pectobacterium carotovorum subsp. brasiliense, formerly not or hardly present in the Netherlands. For risk assessment and risk reduction, the pathogens were phenotypically and genotypically characterized. Validated detection methods were developed and implemented in testing programs. To study the relative contributions of infection sources in the introduction and spreading of the pathogen, a method for track and trace was developed. The role of diagnostics and seed testing in the management of soft rot Enterobacteriaceae will be discussed