Xanthomonas fragariae in strawberry production in Flanders

  • Maes, Martine (Former Project Manager)

    Project Details


    Main research question/goal
    Angular leaf spot occurs in strawberry plants in Belgium. This disease is caused by the quarantine bacterium Xanthomonas fragariae (Xf). How can one correctly identify and detect Xf in planting material and in plants during growth? Which conditions (weather, culture techniques, etc.) influence disease expression and severity? What are effective control measures?  Growers are sometimes confused about the symptoms caused by Xf, and little is known about infection pathways of Xf and spread inside the plants. Quarantine measures focus on trade of pest-free plants for planting, but new Xf introductions frequently occur due to plants that harbor Xf without showing symptoms.

    Research approach
    Angular leaf spot symptoms and other atypical symptoms are sampled during the whole period of the project and subjected to diagnostic research  using various methods. Parameters of weather and culture techniques are registered. We develop a Xf-specific Q-PCR detection technique and a fluorescent Xf strain. We study the spread of Xf in planting material and during production. We sequence the whole genome of Xf.

    Our research on Xf and strawberry provides new information on the bacterium and its strategy to either hide inside the plant or to behave as a pathogen. Certain characteristics in the genome support in planta observations done in ILVO and in the literature. We describe those symptoms that are caused by Xf and differentiate them from mistaken Xf symptoms. On the basis of the matrix Xf incidence/weather and culture, we can make conclusions on the factors that promote or suppress disease. Also the results on detection and incidence of the pathogen are of concern for the growers. Policymakers want to know if a zero tolerance policy can be implemented, supported by sanitary control of imported planting material. ILVO also incorporates the research results and conclusions in a Pest Risk Analysis produced for the EU region.

    External partner(s)
    PCFruit - Proefcentrum Fruitteelt
    PCH - Proefcentrum Hoogstraten
    UGent - Fac. Wetenschappen
    Effective start/end date1/09/0830/09/12