Diagnosis of Plant Pathogens and Implications for Plant Quarantine: A Risk Assessment Perspective

The Scientific Panel on Plant Health (PLH) of the European Food Safety Authority was established in 2006 as the reference EU body for risk assessment in the plant health area in the frame of phytosanitary measures to prevent the introduction and further spread of organisms harmful (pests) to plants or plants products. Proper diagnosis and detection are critical for the categorization and assessment of pests that are or may qualify as quarantine pests, and for appropriate application of phytosanitary measures. In carrying out its responsibilities, the PLH Panel is frequently faced by the changes in taxonomy and nomenclature: these may often lead to a re-evaluation of previous pest records, concerns with published literature, and in some cases with the increased use of molecular taxonomic and identification tools. Pathogens that were previously considered strains/varieties of a single species, in some cases have now been elevated to specific status. In other cases pathogens previously recognised as species complexes have now been partitioned into named species, using molecular criteria rather than traditional methods. The problems that can arise are illustrated in this Chapter by examples representative of the main pathogen taxa.