Treesearch

Investigating the population genetics of Phytophthora ramorum, the causal agent of sudden oak death (SOD), is critical to understanding the biology and epidemiology of this important phytopathogen. Raw sequence data (445,000 reads) of P. ramorum was provided by the Joint Genome Institute. Our objective was to develop and utilize Simple Sequence Repeat (SSR) techniques for fingerprinting large numbers of P. ramorum isolates originating from different host species within Europe and the United States. Using a computer program developed at Plant Research International, 1334 potential microsatel...

A draft genome sequence has been determined for Phytophthora ramorum, together with a draft sequence of the soybean pathogen Phytophthora sojae. The P. ramorum genome was sequenced to a depth of 7-fold coverage, while the P. sojae genome was sequenced to a depth of 9-fold coverage. The genome size of P. ramorum was estimated to be significantly smaller than that of P. sojae, 65 Mb compared to 95 Mb, with the difference lying primarily in the amount of repetitive sequences in the P. sojae genome. Computer predictions estimate the number of genes in P. ramorum to be 15,743, while 19,027 are...

It is my great pleasure to be with you today at this impressive gathering of women and men of science. As a member of the House Science Committee, I am privileged to regularly hear from people from many disciplines in the scientific community. I so enjoy those hearings with not only brilliant, rigorous thinkers, but also people with a passion for the truth and compassion for all living things. I am certain that would describe the people in this room. How could it not be when your mission is, in the simplest terms, to save this state’s, this country’s, and perhaps a great part of the...

We are studying how P. ramorum survives and spreads in Oregon tanoak forests. The Oregon outbreak is similar to the epidemic in redwood-tanoak forests of California, with several important differences, however. The disease is confined to scattered stands within a 12 m2 area, and it is subject to an ongoing eradication effort. While eradication has not yet eliminated the disease, inoculum levels are low. As a consequence, myrtlewood is seldom infected and is not important in the epidemic.

The ultimate goal of Phytophthora ramorum research is to develop disease management strategies. To date, studies have been focused at three management levels: the individual tree, the landscape (or forest stand), and the regional to international scale (Garbelotto and others 2003, Rizzo and Garbelotto 2003, Rizzo and others 2005). I will focus my brief remarks on the forest landscape, possibly the most difficult level to implement disease control strategies (for a more comprehensive discussion see Rizzo and others 2005).

The California Oak Mortality Task Force was formed in August 2000 as a consensus group to address the impacts caused by Phytophthora ramorum. It is over 1000 strong with over 80 agencies, universities, public, and private groups currently involved. The Task Force has been a tremendous success and may serve as model for other similar efforts.

Good morning. I want to thank the planning committee for allowing me to share some of my thoughts at this Symposium as we try to better understand sudden oak death (SOD) and Phytophthora ramorum. I bring you regards from Dr. Ann Bartuska, the Deputy Chief for Forest Service Research and Development. Ann is a big supporter of the work that has already been done and encourages you to continue your valiant efforts on SOD.

Molecular techniques have been developed for detection and identification of P. ramorum and other Phytophthora species that are based on the mitochondrially encoded sequences. One technique uses a Phytophthora genus specific primer to determine if a Phytophthora species is present, followed by a nested amplification with species-specific primers to determine if the pathogen is P. ramorum or one of several other species (such as P. nemorosa or P. pseudosyringe). This procedure also uses a plant primer pair to serve as a positive control ensuring the ability of the template DNA to amplify....

Phytophthora ramorum has the potential to infect many forest types found throughout the United States. Efforts to model the potential habitat for P. ramorum and sudden oak death (SOD) are important for disease regulation and management. Yet, spatial models using identical data can have differing results. In this paper we examine the results from five types of models generated from common input parameters, and investigate model agreement for distribution of risk for P. ramorum. We examine five models: (1) Rule-based, (2) Logistic regression, (3) Classification and Regression Trees, (4)...

The existence of native and exotic species of Phytophthora in soils of eastern and central oak ecosystems is largely unknown. This informational void and the potential threat of P. ramorum to eastern oak species provided the impetus for a multiple state survey of soils associated with oak cover types. The initial survey was conducted from April to June 2004 in oak forests in Illinois, Indiana, Maryland, Michigan, Minnesota, Ohio, Pennsylvania, Wisconsin and West Virgina. Sampling sites were chosen to avoid areas impacted by oak wilt, recent storm damage or major defoliation. Although most...