Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: July 30, 2004
Publication Date: August 5, 2005
Citation: Shishkoff, N. 2005. Susceptibility of Camellia to Phytophthora ramorum, the sudden oak death pathogen [abstract]. Phytopathology. 95:S157. Technical Abstract: Six species of Camellia were tested for susceptibility to Phytophthora ramorum, including two cultivars of C. sasanqua and three cultivars of C. japonica. Plants were inoculated with sporangial suspensions (2000-6800 sporangia/mL) from a P. ramorum isolate originally from camellia. Inoculated plants were placed in a dew chamber at 20 C for 4-5 days, then incubated in the greenhouse for up to a week at 20 C. Camellias differed in susceptibility to the pathogen, with C. sasanqua 'Midnight Lover' and C. oleifera the most susceptible, exhibiting defoliation up to 41.4% and lesions covering up to 9.8% of area of inoculated foliage; C. japonicum and C. sinensis were intermediate, while C. brevistyla and C. crapnelliana showed no symptoms. Defoliation of camellias occurred even when leaves showed no visible lesions, although the pathogen could often be recovered from the petiole of the fallen leaf. Rhododendrons inoculated at the same time showed little defoliation but significant lesion development, up to 72% of inoculated leaf area.