Onderzoek ter opheldering van kennislacunes met betrekking tot de quarantaineorganismen Diaporthe vaccinii, Ditylenchus destructor, Eotetranychus lewisi en Candidatus Phytoplasma ulmi (FOD-GAPHANNEX)

At the request of the FPS for Health, Food Chain Safety and Environment, ILVO coordinates research into four different organisms that are harmful to plants and are currently still on the European quarantine list. The ultimate goal is to provide advice on the reassessment of this quarantine status at European level. Should they become a regulated non-Q organism? Or are they eligible for deregulation? The answer to this can only come after filling the knowledge gaps in relation to detection methodology, harmfulness, endangered host plants, presence or dissemination etc. This concerns specifically 1) the fungus Diaporthe vaccinii (in blueberries and in wild host plants), 2) the nematode Ditylenchus destructor (threatening the potato cultivation and other crops), 3) the mite Eotetranychus lewisi (which threatens fruit and ornamental plants), 4) the phytoplasma Candidatus Phytoplasma ulmi (which can attack elms).

Each of the four Q-organisms gets a tailored approach: In cases 1), 3) and 4), we determine the presence or absence in the listed host plants or sectors with an extensive survey. For the molecular diagnostics of D. vaccinii we develop specific qPCR primers and probes. We then investigate the potential spread of D. vaccinii between wild host plants and cultured Vaccinium species as well as the susceptibility of blueberry varieties important to Belgium. For this fungus we determine the efficiency of crop protection agents in the cultivation of blueberry. For D. destructor we find out about a number of important crops for Belgium whether or not they are a host plant. This happens, among other things, through pot trials and induced contamination. The survival of D. destructor in the absence of a host plant and the remediation of soil to prevent spreading are also examined. If the mite E. lewisi appears to be present in Belgium during the survey, then the collection of biological data on the life cycle and its potential natural enemies is planned.

The relevance of this project is both national and European: The developed method for molecular identification of D. vaccinii means an additional diagnostic option and therefore services in the diagnostic laboratories such as ILVO's Diagnostic Center for Plants. At European level, experts in plant health will be able to carry out an expert re-evaluation of the quarantine status of the target organisms mentioned.