JUNE 2009 REPORT (PDF) Monitoring A Forsyth County, GA nursery was found by the GA Department of
Agriculture to have a P. ramorum-positive plant in 12/08. Follow-up surveys conducted from 12/08 to 3/09 detected the pathogen from multiple sample types collected inside the nursery, as well as an off-site positive obtained by filtration of water draining from the nursery. As part of the National P. ramorum Early
Detection Survey of Forests effort in GA, rhododendron leaf baiting was initiated by GA Forestry Commission personnel in 1/09. P. ramorum-positive findings were obtained in 2/09 from a nearby lake. The lake is used to irrigate the positive nursery as well as an adjacent woody ornamental nursery (not known to be P. ramorum-positive) and an adjacent subdivision (not known to be P. ramorum-positive). A stream draining the lake, nurseries, and subdivision was also found
positive just downstream from the nurseries in March, April, and May. Additional positives were obtained in April from one of two streams feeding the lake. Results for some diagnostics are still pending for baits collected in April and May from the steam draining the lake, the lake itself, and its feeder streams. March survey efforts of the vegetation along the stream draining the lake were all negative. A follow-up survey of the streamside vegetation, including that along the lake feeder
streams, is being scheduled for early June. To date, the 2009 National Survey has identified six stream baiting positives in water outside of nurseries in five states: WA (1), MS (1), AL (2), GA (1), and FL (1). All confirmed locations have had more than one positive survey this year. All vegetation samples collected so far in 2009 from an environs survey outside the MS nursery have been negative for the pathogen after multiple positives in 2008. (back to top) Management The Marin County Department of Public Works, Road Maintenance Division is
currently dedicating a substantial amount of resources toward hazard tree removals, particularly in West Marin. Currently the department commits one day a week to SOD tree removals. It is estimated that approximately $90,000 has been spent by the county to remove nearly 100 trees so far this calendar year. While some removals were contracted out, most were conducted by county crews. Target areas for SOD hazard tree removals have been major arterial and corridor
roads; however, with the summer fire season approaching, calls are also being received from neighborhood areas. For more information, contact Pete Maendle at (415) 446-4421 or PMaendle@co.marin.ca.us. (back to top) Nurseries
Three Washington (WA) nurseries were found to have P. ramorum-positive plants in May. On May 1st, a Snohomish County small rhododendron production nursery was found infested with P. ramorum during an annual nursery compliance and certification survey. Identified infected species included: Rhododendron spp. 'Wojrar's Purple,' 'Peppermint Twist,' 'Purple Jack,' 'Tamarindos,' 'Jumping Jeff,' 'Star Trek,' 'Crystal Springs,' 'Chapeau,' 'Dexter's Pink,' and Kalmia sp. 'Sarah.' The
nursery ships rhododendrons interstate and internationally, primarily via mail order sales. Delimitation and trace-back and trace-forward investigations are under way. A second nursery in Pierce County was found to have P. ramorum-positive Rhododendron sp. 'Marie Forte' during a nursery stock cleanliness inspection on May 6th. This retail nursery was also found positive for the pathogen in 2004. It does not
ship interstate. Delimitation and trace-back and trace-forward investigations are under way. The third infested nursery was a production facility in Clark County. The P. ramorum-positive Rhododendron sp. was found during an annual nursery compliance and certification inspection on May 6th. The nursery was also positive for P. ramorum in 2008. The nursery does ship interstate. Delimitation and trace-back and trace-forward investigations have been conducted. A Fulton County, GA retail nursery was confirmed to have
P. ramorum-positive Rhododendron sp. 'Roseum elegans' on May 14th. This is the first time this nursery has been found positive for the pathogen. A Mecklenburg County, NC retail nursery was confirmed to have
P. ramorum-positive Pieris japonica 'Mountain Fire' and Kalmia latifolia 'Pink Charm' on May 22nd. The nursery was found positive in 2008. A Greenville County, SC retail nursery was confirmed to have
P. ramorum-positive Pieris floribunda (Mountain Peris) and Pieris japonica 'Dorothy Wycoff' on May 15th as part of a routine state nursery
inspection. The nursery was found positive in 2008 as part of a trace-forward investigation from the Mecklenburg County, NC 2008 nursery confirmation. As of May 15, 2009, the Oregon Department of Agriculture has surveyed 212 nursery grower sites for Phytophthora ramorum. So far, the pathogen has been detected at four sites, two in Washington County, one in Clackamas County, and one in Lane County. At the first
Washington County nursery, the pathogen was initially detected twice on Pieris japonica and, during delimitation, in a third block of P. japonica and in the potting media associated with an infected plant. At the second Washington County nursery, P. ramorum was initially detected on Pieris 'Mountain Fire' and, during delimitation, in the soil. This was the fourth consecutive year P. ramorum was detected at this site. In
response, the State enacted an emergency quarantine that strictly regulates the movement of plants on and off the site and requires specific actions by the nursery to clean up the site. Samples are still being processed from the delimitation surveys at the final two sites. Initially, P. ramorum was detected on P. japonica at the Clackamas County site and twice on Camellia at the Lane County site. So far, additional positives have been detected in Rhododendron at the Lane
County site. To date, cultures have been recovered from every P. ramorum-positive sample found. (back to top) Research Hall, K.M. and Albers, H.J. 2009. Economic Analysis for the Impact of
Phytophthora ramorum on Oregon Forest Industries. The objective of the study is to inform in-state decision makers of some of the economic implications of three different P. ramorum policy scenarios identified by the Oregon Department of Forestry in order to assist with the creation of a P. ramorum control strategy in Curry County. The three policy options being considered are 1) to continue the
current control program, 2) to increase control efforts in an attempt to eradicate P. ramorum from Oregon wildlands, and 3) to eliminate the P. ramorum control program all together. The assessment looks specifically at the impact of the three policy options on the forest products industry in Oregon and includes estimated costs and benefits to forest industries in at-risk counties. This analysis does not attempt to quantify any
ecological losses as a result of the spread of the pathogen nor the ecological costs of the control policies, which should also be considered in control policy analysis. Prospero, S.; Grünwald, N.J.; Winton, L.M.; and Hansen, E.M. 2009.
Migration patterns of the emerging plant pathogen Phytophthora ramorum on the West Coast of the United States of America. Phytopathology 99:739-749. Abstract: Phytophthora ramorum (oomycetes) is the causal agent of
sudden oak death and ramorum blight on trees, shrubs, and woody ornamentals in the forests of coastal California and southwestern Oregon and in nurseries of California, Oregon, and Washington. In this study, we investigated the genetic structure of P. ramorum on the West Coast of the United States, focusing particularly on population differentiation potentially indicative of gene flow. In total, 576 isolates recovered from
2001 to 2005 were genotyped at 10 microsatellite loci. Our analyses of genetic diversity and inferences of reproductive mode confirm previous results for the Oregon and California populations, with the strong majority of the genotypes belonging to the NA1 clonal lineage and showing no evidence for sexual reproduction. The high incidence of genotypes shared among populations and the lack of genetic structure among populations show that important large-scale, interpopulation
genetic exchanges have occurred. This emphasizes the importance of human activity in shaping the current structure of the P. ramorum population on the West Coast of the United States. Riedel, Marko; Calmin, Gautier; Belbahri, Lassaad; Lefort, Francois; Gotz, Monika; Wagner, Stefan; and Werres, Sabine. 2009. Green Fluorescent Protein (GFP) as a Reporter Gene for the Plant Pathogenic Oomycete Phytophthora ramorum. J. Eukaryot. Microbiol., 56(2). pp.
130–135. DOI: 10.1111/j.1550-7408.2008.00376.x. Abstract: Transgenic Phytophthora ramorum strains that produce green fluorescent protein (GFP) constitutively were obtained after stable DNA integration using a polyethylene glycol and CaCl2-based transformation protocol. Green fluorescent protein production was studied in developing colonies and in different propagules of the pathogen to evaluate its use
in molecular and physiological studies. About 12% of the GFP transformants produced GFP to a level detectable by a confocal laser scanning microscope. Green fluorescent protein could be visualized in structures with vital protoplasm, such as hyphal tips and germinating cysts. In infection studies with Rhododendron, one of the GFP expressing strains showed aggressiveness equal to that of the corresponding non-labeled isolate. Thus, GFP could be used as a reporter gene in P.
ramorum. Limitations of the technology are discussed. The following abstracts on P. ramorum and related topics are being presented at the 2009 APS Annual Meeting in Portland, OR August 1 – 5, 2009. Botts, M.; Hansen, E.; and Kitin, P. 2009. Interactions between tanoak and Phytophthora ramorum studied on a microscopic and molecular scale. Phytopathology 99:S15. Britt, J. and Hansen, E. 2009. Phenotypic plasticity, fitness and multilocus genotypes of Phytophthora ramorum populations in southern Oregon tanoak forests. Phytopathology 99:S16.
Britt, J. and Hansen, E. 2009. Trees, soils, streams and rain traps: Intensive sampling leads to recovery of multiple genotypes from hosts of Phytophthora ramorum in Oregon forests. Phytopathology 99:S16. Chastagner, G.A.; DeBauw, A.; Riley, K.; and Dart, N.L. 2009. Residual
effectiveness of fungicides in protecting rhododendron leaves from Phytophthora ramorum. Phytopathology 99:S180. Dart, N.L.; Chastagner, G.A.; and Coats, K. 2009. Initial assessment of genotypic diversity of Phytophthora ramorum associated with Washington state ornamental nurseries. Phytopathology 99:S181. Elliott, M.
; Holmes, T.; Sumampong, G.; Shamoun, S.F.; De Boer, S.H.; Li, S.; Varga, A.; Masri, S.; and James, D. 2009. Bacterial soft rot in Daphne laureola (Thymelaceae): A histopathological investigation. Phytopathology 99:S32. Elliott, C.R.; McDonald, V.; and Grunwald, N.J. 2009. Phytophthora ramorum - pathogenic fitness of the three clonal lineages.
Phytopathology 99:S32. Elliott, C.R.; McDonald, V.; Henslee, K.A.; and Grunwald, N.J. 2009. Comparative epidemiology of Phytophthora ramorum and other Phytophthora species. Phytopathology 99:S32. Goss, E.M.
; Larsen, M.; Chastagner, G.A.; Givens, D.R.; and Grunwald, N.J. 2009. Variation within the NA1 clonal lineage of Phytophthora ramorum from US nurseries reveals migration pathways. Phytopathology 99:S45. Jinek, A.; Simard, M.; Brière, S.; Watson, A.; Tweddell, R.J.; and Rioux, D. 2009. In vitro inoculations with Phytophthora ramorum: Foliage
susceptibility of six eastern Canadian forest species. Phytopathology 99:S193. Kanaskie, A.; Goheen, E.M.; Hansen, E.M.; Sutton, W.; Reeser, P.; and Osterbauer, N. 2009. Monitoring the effectiveness of Phytophthora ramorum eradication treatments in southwest Oregon tanoak forests. Phytopathology 99:S61. Kanaskie, A.
; Goheen, E.; Hansen, E.; Osterbauer, N.; McWilliams, M.; Schultz, R.; Savona, S.; Sutton, W.; and Reeser, P. 2009. Early detection and eradication of Phytophthora ramorum (sudden oak death) in Oregon forests. Phytopathology 99:S61. Manter, D.K. 2009. Pathogenicity of Phytophthora ramorum. Phytopathology 99:S163.
Meentemeyer, R. 2009. Landscape epidemiology of Phytopthora ramorum: Measuring, mapping, and modeling spread. Phytopathology 99:S163. Nagle, A.M.; McPherson, B.A.; Wood, D.L.; Bonello, P.; and Garbelotto, M. 2009. Does phloem phenolic chemistry contribute to coast live oak resistance to Phytophthora ramorum? Phytopathology 99:S92. Parke, J.L.; Pscheidt, J.; Regan, R.; Hedberg, J.; and Grunwald, N.
2009. Online outreach: Phytophthora training for nursery growers. Phytopathology 99:S175. Rizzo, D.M. 2009. Phytophthora in forests: Feedbacks between pathogen and plant communities in forests. Phytopathology 99:S163. Santamaria, L.; MMBAGA, M.T.; Sauve, R.J.; and Mrema, F.A. 2009. Plant pathogenic Phytophthora species found in Tennessee commercial nurseries.
Phytopathology 99:S114. Sechler, K.E.; Carras, M.M.; Shishkoff, N.; and Tooley, P.W. 2009. Detection limit of Phytophthora ramorum-infected Rhododendron leaves using the Cepheid SmartCycler. Phytopathology 99:S205. Tooley, P.W. and Browning, M. 2009. Sporulation capacity of Phytophthora ramorum on northern red oak and chestnut oak.
Phytopathology 99:S205. Widmer, T.L. and Dodge, S.C. 2009. Susceptibility of sprouted oak acorns to Phytophthora ramorum zoospores. Phytopathology 99:S205. (back to top) Related Research Ghimire, S.R.; Richardson, P.A.; Moorman, G.W.; Lea-Cox, J.D.;
Ross, D.S.; and Hong, C.X. 2009. An in-situ baiting bioassay for detecting Phytophthora species in irrigation runoff containment basins. Plant Pathology 58:577–583. DOI: 10.1111/j.1365-3059.2008.02016.x. McCarren, K.L.; McComb, J.A.; Shearer, B.L.; and St. J. Hardy, G.E.
2009. Phosphite impact on the in vitro production and viability of selfed oospores by Phytophthora cinnamomi. Forest Pathology 39:124–132. DOI: 10.1111/j.1439-0329.2008.00571.x. Williams, N.; St. J. Hardy, G.E.; and O'Brien, P.A. 2009. Analysis of the distribution of Phytophthora cinnamomi in soil at a disease site in Western Australia using nested PCR. Forest Pathology 39:95–109. DOI: 10.1111/j.1439-0329.2008.00567.x. (back to top) Sod Symposium 4 Workshops Two new meetings have been added to the Fourth Sudden Oak Death Science Symposium: USDA APHIS PPQ and CPHST are holding a P. ramorum Program Technical Review on Monday, June 15 from 8:00 a.m. to 12:00 p.m. The
objective of the meeting is to initiate discussions about the scientific integrity of current nursery regulations based on the best available science. Areas which will be emphasized include identifying or improving mitigation measures that impact industry confidence of the current system; identifying possible knowledge gaps; determining levels of protection and programmatic success; and the practicality of implementing mitigation measures. It is anticipated that finalized
considerations and/or conclusions may be not be achieved during this meeting, and that additional work may be required following the meeting to fully evaluate the identified areas for review. The meeting is open to anyone interested in participating. USDA APHIS National Quality Assurance and Program and Planning will hold a P. ramorum Quality Assurance Program Review: Industry
Focus Discussion on Wednesday, June 17 from 5:15 – 6:45 p.m. The objective of the meeting is to provide a brief overview of the federal P. ramorum program quality assurance review. Discussions will also explore how the regulatory program works for the various impacted industries and user groups, how it affects those parties, and how some processes might be improved. (back to top) Regulations Israel has included P. ramorum in its 2009 "Plant Import
Regulations." To access the regulations, go to the Ministry of Agriculture and Rural Development Plant Protection and Inspection Services website at http://www.ppis.moag.gov.il/NR/rdonlyres/BFAAC1EB-EBBC-430D
-BD31-D92401EA691B/0/PlantImportRegulations2009UnofficialTranslation.pdf or click here. (back to top) Calendar of Events 6/15 – 6/18 – Fourth Sudden Oak Death Science Symposium;
Hilton, Scotts Valley (near Santa Cruz). For Symposium registration information, go to http://nature.berkeley.edu/comtf/sodsymposium4/ or contact Janice Alexander at JAlexander@ucdavis.edu. For conference logistics and facilities information, contact Katie Palmieri at Palmieri@nature.berkeley.edu. For hotel room reservations, go to http://www.hilton.com/en/hi/groups/personalized/SJCSVHF-SODS-20090612/index.jhtml. 3/7/10 – 3/12/10 - 5th IUFRO Phytophthora in Forest Trees and Natural Ecosystems Conference; Rotorua, New Zealand; For more information, contact Pam Taylor at pam.taylor@scionresearch.com. (back to top) | 
