Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Isabelle De Dobbelaere; Kurt Heungens; Martine Maes
    Date: 2008
    Source: In: Frankel, Susan J.; Kliejunas, John T.; Palmieri, Katharine M., tech. coords. 2008. Proceedings of the sudden oak death third science symposium. Gen. Tech. Rep. PSW-GTR-214. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. pp. 95-97
    Publication Series: General Technical Report (GTR)
    Station: Pacific Southwest Research Station
    PDF: View PDF  (162 KB)

    Description

    Although Rhododendron is the most important host of Phytophthora ramorum. in Europe, there is little scientific information about the susceptibility levels of different Rhododendron species and cultivars. Increasing this knowledge would help nurseries in the management of the disease and could be used by plant protection services to target their inspections. In this study a total of 80 Rhododendron species and hybrids were screened for their susceptibility to P. ramorum using two detached leaf inoculation assays. Due to the variability in susceptibility for a given cultivar within and between years, multi-year data was deemed necessary to establish a reliable susceptibility ranking. The zoospore inoculation method involving nonwounded leaves was most informative. Using this method, a wide range in susceptibility to P. ramorum was demonstrated. A second objective of this study was to get a better handle on some of the internal and external factors (time of year, temperature, leaf age) that seem to effect the susceptibility level. Susceptibility was significantly lower during late fall and winter, and seems correlated with the physiological status of the plant. Leaf age mainly seems to affect susceptibility during the early stages of leaf maturity. In general, new leaves were more susceptible to pathogen development. However, young leaves of some cultivars seem covered by leaf hairs, which prevent the zoospores to reach the leaf surface. Environmental factors that affect stomatal regulation, such as temperature, also seemed to have an effect on the degree of symptom development.

    Publication Notes

    • You may send email to psw_communications@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Dobbelaere,Isabelle De,; Heungens, Kurt,; Maes, Martine. 2008. Effect of environmental and seasonal factors on the susceptibility of different rhododendron species and hybrids to Phytophthora ramorum. In: Frankel, Susan J.; Kliejunas, John T.; Palmieri, Katharine M., tech. coords. 2008. Proceedings of the sudden oak death third science symposium. Gen. Tech. Rep. PSW-GTR-214. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. pp. 95-97

    Keywords

    Phytophthora ramorum, Rhododendron, susceptibility, host resistance, cultivars

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/29832