Download (PDF 10 KB): https://research.fs.usda.gov/download/treesearch/52955.pdf
Abstract
The proceeding worldwide spread and the expanding host spectrum of
P. ramorum has become a serious threat to natural plant communities. To encounter this threat detailed knowledge about infection pathways and tissue colonization is essential. To analyze these issues, histological studies of infected tissue with epifluorescence microscopy have been started. For first infection tests
Rhododendron has been taken as a model host. Root infection of potted
Rhododendron cuttings with the
P. ramorum isolate BBA 9/95 (ex-type strain) were started. Inoculation of the non injured plants was done by application of a zoospore suspension onto the surface of the pot soil. The plants were then incubated with 16 hour light at 20°C in a quarantine chamber. Samples of healthy looking plants and plants with typical symptoms were taken and fixed. Unstained hand-cuttings were analyzed with fluorescence microcopy. The development of zoosporangia on the leafsurface was analyzed using the vital stain FUN®1 (Molecular Probes). Natural autofluorescence of
P. ramorum and plant tissue is enhanced using the fixing fluid FAA (formaline-aceto-alcohol). Epifluorescence images showing
P. ramorum structures in different tissues and in different stages of disease development are presented. An overview of the development of
P.ramorum in
Rhododendron root, twig and leaf tissue is offered for discussion.
Parent Publication
Citation
Riedel, M.; Wagner, S.; Gotz, M.; Belbahri, L.; Lefort, F.; Werres, S. 2009.
Phytophthora ramorum tissue colonization studied with fluorescense microscopy. [poster] In: Goheen, E.M.; Frankel, S.J., tech. coords. Proceedings of the fourth meeting of the International Union of Forest Research Organizations (IUFRO) Working Party S07.02.09: Phytophthoras in forests and natural ecosystems. Gen. Tech. Rep. PSW-GTR-221. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 315.
