QBOL – Development of a new diagnostic tool using DNA barcoding to identify quarantine organisms in support of plant health

Recently DNA barcoding has arisen as a robust and standardised approach to species identification (Hebert et al., PNAS 270, S96-S99. 2003). QBOL, a new project that has been funded by EU FP7, wants to make DNA barcoding available for plant health diagnostics and to focus on strengthening the link between traditional and molecular taxonomy as a sustainable diagnostic resource. Each group of relevant quarantine organisms (fungi, nematodes, arthropods, bacteria, viruses, and phytoplasmas) are covered in specific workpackages in the project. Phytoplasma ‘barcoding’ has been performed for many years, particularly using the 16S rDNA, but also in other genes such as secY, secA, tuf and ribosomal proteins, however most of these regions span more than 1 kb and/or primers are not generic, which make them impractical for routine barcoding. In this project we will develop robust markers of a size that can easily be sequenced (4-600 bp) and that can be obtained from most if not all phytoplasma ribosomal groups and/or ‘Candidatus Phytoplasma’ species using generic primers. The markers are not intended for phylogenetic analysis but only for diagnostic purposes. First target phytoplasmas will be those associated with diseases enclosed in European quarantine lists of pest and pathogens (EPPO and EU Council directive). In this presentation, preliminary results on the selection of suitable marker regions will be described.