<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Reeser, Paul W.</style></author><author><style face="normal" font="default" size="100%">Sutton, W.</style></author><author><style face="normal" font="default" size="100%">Hansen, E.M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Phytophthora species causing tanoak stem cankers in southwestern Oregon</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Disease</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">08/2008</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1094/PDIS-92-8-1252B</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">92</style></volume><pages><style face="normal" font="default" size="100%">1252</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Tanoak&lt;/span&gt; (&lt;em&gt;Lithocarpus densiflorus&lt;/em&gt;) is a principal host of &lt;em&gt;&lt;span class=&quot;searchTerm0 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Phytophthora&lt;/span&gt; ramorum&lt;/em&gt;, &lt;span class=&quot;searchTerm2 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cause&lt;/span&gt; of sudden oak death (SOD), in the western United States (1). In the course of SOD surveys in &lt;span class=&quot;searchTerm7 searchToken&quot; onclick=&quot;highlight()&quot;&gt;southwestern&lt;/span&gt; &lt;span class=&quot;searchTerm8 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Oregon&lt;/span&gt;, other &lt;em&gt;&lt;span class=&quot;searchTerm0 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Phytophthora&lt;/span&gt;&lt;/em&gt; &lt;span class=&quot;searchTerm1 searchToken&quot; onclick=&quot;highlight()&quot;&gt;species&lt;/span&gt; were encountered to be &lt;span class=&quot;searchTerm2 searchToken&quot; onclick=&quot;highlight()&quot;&gt;causing&lt;/span&gt; &lt;span class=&quot;searchTerm4 searchToken&quot; onclick=&quot;highlight()&quot;&gt;stem&lt;/span&gt; &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt; on &lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;tanoak&lt;/span&gt; that were indistinguishable from those &lt;span class=&quot;searchTerm2 searchToken&quot; onclick=&quot;highlight()&quot;&gt;caused&lt;/span&gt; by &lt;em&gt;P. ramorum&lt;/em&gt;. In &lt;span class=&quot;searchTerm8 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Oregon&lt;/span&gt;, SOD is subject to quarantine and eradication. Aerial surveys are flown two or more times a year to locate symptomatic &lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;tanoaks&lt;/span&gt;, which are then examined from the ground to determine the &lt;span class=&quot;searchTerm2 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cause&lt;/span&gt; of death. Isolations on selective media were attempted from all trees with &lt;span class=&quot;searchTerm4 searchToken&quot; onclick=&quot;highlight()&quot;&gt;stem&lt;/span&gt; &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt; typical of &lt;em&gt;&lt;span class=&quot;searchTerm0 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Phytophthora&lt;/span&gt;&lt;/em&gt;. &lt;em&gt;&lt;span class=&quot;searchTerm0 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Phytophthora&lt;/span&gt;&lt;/em&gt; &lt;span class=&quot;searchTerm1 searchToken&quot; onclick=&quot;highlight()&quot;&gt;species&lt;/span&gt; were identified by morphological features and DNA sequencing of either internal transcribed spacer (ITS) or the mitochondrial COX spacer region. ITS sequences were compared with validated GenBank records, and COX spacer sequences were compared with known reference isolates in the OSU collection. From 2001 through 2006, &lt;em&gt;&lt;span class=&quot;searchTerm0 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Phytophthora&lt;/span&gt;&lt;/em&gt; spp. were isolated from 482 of 1,057 &lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;tanoak&lt;/span&gt; &lt;span class=&quot;searchTerm4 searchToken&quot; onclick=&quot;highlight()&quot;&gt;stem&lt;/span&gt; &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt; sampled. &lt;em&gt;P. ramorum&lt;/em&gt; was isolated from 359 &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt;, &lt;em&gt;P. nemorosa&lt;/em&gt; was isolated from 102 &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt;, &lt;em&gt;P. gonapodyides&lt;/em&gt; was isolated from six &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt;, &lt;em&gt;P. cambivora&lt;/em&gt; was isolated from four &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt; (all A1 mating type), &lt;em&gt;P. siskiyouensis&lt;/em&gt; was isolated from four &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt;, &lt;em&gt;P. pseudosyringae&lt;/em&gt; was isolated from two &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt;, &lt;em&gt;P. cinnamomi&lt;/em&gt; was isolated from one &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;canker&lt;/span&gt; (mating type A2), and &lt;em&gt;P&lt;/em&gt;. taxon “Pgchlamydo” was isolated from one &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;canker&lt;/span&gt;. Three &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt; yielded isolates that were not identified but were closely related to &lt;em&gt;P. pseudosyringae&lt;/em&gt; based on ITS sequence. No &lt;em&gt;&lt;span class=&quot;searchTerm0 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Phytophthora&lt;/span&gt;&lt;/em&gt; spp. were cultured from the remaining &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt;. One isolate from each &lt;span class=&quot;searchTerm1 searchToken&quot; onclick=&quot;highlight()&quot;&gt;species&lt;/span&gt; identified (except &lt;em&gt;P. ramorum&lt;/em&gt; and &lt;em&gt;P. pseudosyringae&lt;/em&gt;) was tested for pathogenicity on &lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;tanoak&lt;/span&gt; &lt;span class=&quot;searchTerm4 searchToken&quot; onclick=&quot;highlight()&quot;&gt;stems&lt;/span&gt; (11.4 to 16.0 cm DBH) in the field. A 5-mm-diameter plug from the margin of a V8 agar culture was placed in a hole in the bark, covered with wet cheesecloth, and sealed with aluminum foil and duct tape. Each isolate was inoculated into five different &lt;span class=&quot;searchTerm4 searchToken&quot; onclick=&quot;highlight()&quot;&gt;stems&lt;/span&gt;. Each &lt;span class=&quot;searchTerm4 searchToken&quot; onclick=&quot;highlight()&quot;&gt;stem&lt;/span&gt; received three different isolates and an agar control. After 4 weeks, bark was removed to reveal lesion development. Lesions were measured (length by width), and pieces from four points on the lesion margin were plated in selective media to reisolate. &lt;em&gt;P. cambivora, P. cinnamomi, P. gonapodyides, P. nemorosa, P. siskiyouensis&lt;/em&gt; and &lt;em&gt;P&lt;/em&gt;. taxon “Pgchlamydo” all &lt;span class=&quot;searchTerm2 searchToken&quot; onclick=&quot;highlight()&quot;&gt;caused&lt;/span&gt; substantial lesions in inoculated &lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;tanoak&lt;/span&gt; trees (average area 11.5 to 18.6 cm&lt;sup&gt;2&lt;/sup&gt;). In all cases, the &lt;span class=&quot;searchTerm1 searchToken&quot; onclick=&quot;highlight()&quot;&gt;species&lt;/span&gt; used for inoculation was recovered on reisolation from lesion margins. Control inoculations &lt;span class=&quot;searchTerm2 searchToken&quot; onclick=&quot;highlight()&quot;&gt;caused&lt;/span&gt; necrotic areas averaging 0.2 cm&lt;sup&gt;2&lt;/sup&gt;. Isolations from these areas were clean. Prior to the recent SOD epidemic, no &lt;span class=&quot;searchTerm1 searchToken&quot; onclick=&quot;highlight()&quot;&gt;species&lt;/span&gt; of &lt;em&gt;&lt;span class=&quot;searchTerm0 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Phytophthora&lt;/span&gt;&lt;/em&gt; were known as pathogens of &lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;tanoak&lt;/span&gt;. The discovery of &lt;em&gt;P. ramorum&lt;/em&gt; as a pathogen of &lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;tanoak&lt;/span&gt; in California was quickly followed by the discovery that &lt;em&gt;P. nemorosa&lt;/em&gt; and &lt;em&gt;P. pseudosyringae&lt;/em&gt; were also associated with &lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;tanoak&lt;/span&gt; &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt; (2). Six years of diagnostic support for survey and detection of &lt;em&gt;P. ramorum&lt;/em&gt; in &lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;tanoak&lt;/span&gt; forests of southwest &lt;span class=&quot;searchTerm8 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Oregon&lt;/span&gt; has revealed the occurrence, at very low frequency, of at least five additional &lt;span class=&quot;searchTerm1 searchToken&quot; onclick=&quot;highlight()&quot;&gt;species&lt;/span&gt; of &lt;em&gt;&lt;span class=&quot;searchTerm0 searchToken&quot; onclick=&quot;highlight()&quot;&gt;Phytophthora&lt;/span&gt;&lt;/em&gt; &lt;span class=&quot;searchTerm2 searchToken&quot; onclick=&quot;highlight()&quot;&gt;causing&lt;/span&gt; &lt;span class=&quot;searchTerm4 searchToken&quot; onclick=&quot;highlight()&quot;&gt;stem&lt;/span&gt; &lt;span class=&quot;searchTerm5 searchToken&quot; onclick=&quot;highlight()&quot;&gt;cankers&lt;/span&gt; in &lt;span class=&quot;searchTerm3 searchToken&quot; onclick=&quot;highlight()&quot;&gt;tanoak&lt;/span&gt;.&lt;/p&gt;</style></abstract></record></records></xml>