TY - BOOK T1 - A range-wide assessment of Port-Orford-Cedar (Chamaecyparis lawsoniana) on federal lands Y1 - 2003 A1 - Betlejewski, F. A1 - Casavan, K. A1 - Dawson, A. A1 - Goheen, D.G. A1 - Mastrofini, K. A1 - Rose, D.L. A1 - White, D.E. PB - U.S. Department of Agriculture, Forest Service, and U.S. Department of the Interior, Bureau of Land Management CY - Portland, OR UR - http://www.fs.fed.us/r6/dorena/publications/in/poc-range-wide-assessment ER - TY - Generic T1 - The role of Phytophthora pathogens in forests and semi-natural communities in Europe and Africa T2 - Proceedings of 1st International Meeting on Phytophthoras in Forest and Wildland Ecosystems Y1 - 1999 A1 - C.M. Brasier ED - Hansen, E.M. ED - Sutton, W. JF - Proceedings of 1st International Meeting on Phytophthoras in Forest and Wildland Ecosystems PB - International Union of Forestry Research Organizations Working Party 7.02.09. CY - Forest Research Laboratory, Oregon State University, Corvallis, OR ER - TY - JOUR T1 - Recent developments in Phytophthora diseases of trees and natural ecosystems in Europe JF - Progress in Research on Phytophthora Diseases of Forest Trees. Proceedings, 3rd Int. IUFRO Working Party Y1 - 2006 A1 - C.M. Brasier A1 - T. Jung VL - 7 ER - TY - THES T1 - Root rots caused by Phycomycetes Y1 - 1927 A1 - Buisman, C.J. PB - University of Utrecht, Meded. Phytopath. Lab. Willie Commelin Scholten Baarn 11: 4,7. ER - TY - JOUR T1 - Re-evaluation of Phytophthora species isolated during 30 years of vegetation health surveys in western Australia using molecular techniques JF - Plant Disease Y1 - 2009 A1 - Burgess, Treena I. A1 - Webster, Janet L. A1 - Ciampini, Juanita A. A1 - White, Diane A1 - Hardy, Giles E. StJ. A1 - Stukely, Michael J. C. AB -

For 30 years, large-scale aerial photography has been used to map the extent of Phytophthora dieback disease in native forests in the southwest of Western Australia, with validation of the observations involving routine testing of soil and root samples for the presence of Phytophthora cinnamomi. In addition to P. cinnamomi, six morpho-species have been identified using this technique: P. citricola, P. megasperma, P. cryptogea, P. drechsleri, P. nicotianae, and P. boehmeriae. In recent years, many new Phytophthora species have been described worldwide, often with similar morphology to existing species; thus, as many of the isolates collected in Western Australia have been difficult to identify based on morphology, molecular identification of the morpho-species is required. Based on amplification of the internal transcribed spacer (ITS) region of the rDNA gene, sequence data of more than 230 isolates were compared with those of existing species and undescribed taxa. P. inundata, P. asparagi, P. taxon PgChlamydo, P. taxon personii, and P. taxon niederhauserii were identified based on sequence data. Phylogenetic analysis revealed that nine potentially new and undescribed taxa can be distinguished. Several of the new taxa are morphologically indistinguishable from species such as P. citricola, P. drechsleri, and P. megasperma. In some cases, the new taxa are closely related to species with similar morphology (e.g., P.sp.4 and P. citricola). However, the DNA sequences of other new taxa such as P.sp.3 and P.sp.9 show that they are not closely related to morphologically similar species P. drechsleri and P. megasperma, respectively. Most of the new taxa have been associated with dying Banksia spp., while P.sp.2 and P.sp.4 have also been isolated from dying Eucalyptus marginata (jarrah). Some taxa (P.sp.3, 6, and 7) appear to have limited distribution, while others like P.sp.4 are widespread.

VL - 93 IS - 3 JO - Plant Disease ER - TY - JOUR T1 - Report of the imperial mycologist, 1918–1919 JF - Science Report Institute Pusa Y1 - 0 A1 - Butler, EJ ER - TY - JOUR T1 - Root disease of Castanea species and some coniferous and broadleaf nursery stocks, caused by Phytophthora cinnamomi JF - Phytopathology Y1 - 1945 A1 - Crandall, B.S. A1 - G.F. Gravatt A1 - M.M. Ryan AB -

The fungus, Phytophthora cinnamomi Rands, is responsible for a destructive root rot of Chestnut and Chinkapin trees (Castanea spp.) in the United States. The author gives an outline of the work leading to the identification of the fungus, and reports on inoculation and field tests that have proved its pathogenicity on Chestnut and other hosts. The fungus causes a similar root disease in forest-tree nursery stock. Infection has been observed in the nursery on twenty broadleaf and coniferous species. Field and greenhouse inoculation tests have demonstrated the susceptibility to the disease of European Chestnut (Castanea sativa). The Asiatic species, C. crenata, C. mollissima, C. henryi, and C. seguinii, however, show a high degree of resistance. It seems probable that root rot of this type has been responsible for the recession of the American Chestnut in some areas of the United States. No satisfactory control measures have been evolved. Hybrid varieties resistant to both blight and root rot are being developed by crossing American Chestnut and Chinkapins with Asiatic species.

VL - 35 ER - TY - JOUR T1 - Root-rot of sweet chestnut and beech caused by species of Phytophthora. JF - Forestry Y1 - 1938 A1 - Day, W.R. VL - 12 ER - TY - JOUR T1 - Root infections may challenge management of invasive Phytophthora spp. in U.K. woodlands JF - Plant Disease Y1 - 2011 A1 - Fichtner, E. J. A1 - D. M. Rizzo A1 - Kirk, S.A. A1 - Webber, JF AB -

Because sporulation of Phytophthora ramorum and P. kernoviae on Rhododendron ponticum, an invasive plant, serves as primary inoculum for trunk infections on trees, R. ponticum clearance from pathogen-infested woodlands is pivotal to inoculum management. The efficacy of clearance for long-term disease management is unknown, in part due to lack of knowledge of pathogen persistence in roots and emerging seedlings. The main objectives of this work were to (i) investigate whether both pathogens infect R. ponticum roots, (ii) determine the potential for residual inoculum of P. kernoviae to infect R. ponticum seedlings in cleared woodlands, and (iii) assess potential for R. ponticum roots to support survival and transmission of P. kernoviae. Roots of R. ponticum were collected from both unmanaged and cleared woodlands and assessed for pathogen recovery. Both P. ramorum and P. kernoviae were recovered from asymptomatic roots of R. ponticum in unmanaged woodlands, and P. kernoviae was recovered from asymptomatic roots from seedlings in cleared woodland. Oospore production of P. kernoviae was observed in naturally infected R. ponticum foliage and in inoculated roots. Roots also supported P. kernoviae sporangia production. The results of this study suggest that post-clearance management of R. ponticum regrowth is necessary for long-term inoculum management in invaded woodlands.

VL - 95 UR - http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-03-10-0236 ER - TY - JOUR T1 - Real-time PCR assay to distinguish Phytophthora ramorum lineages using the cellulose binding elicitor lectin (CBEL) locus JF - Canadian Journal of Plant Pathology Y1 - 2014 A1 - Gagnon, Marie-Claude A1 - Bergeron, Marie-Josée A1 - Hamelin, Richard C. A1 - Grünwald, Niklaus J. A1 - Bilodeau, Guillaume J. AB -

Phytophthora ramorum is a pathogenic oomycete that causes sudden oak death in the Western USA and sudden larch death in the UK. Until recently, three genetically divergent clonal lineages of P. ramorum were known (EU1, NA1 and NA2), named according to the continent on which they were first detected. In 2009, a fourth lineage named EU2 was discovered in the UK. Sequencing and microsatellite genotyping revealed that the EU2 lineage is genetically distinct from all other lineages. Allele-specific oligonucleotide-PCR (ASO-PCR) assays using real-time PCR were developed in this study, allowing for the identification of the EU2 lineage. Also, a combination of ASO-PCR assays targeting the cellulose binding elicitor lectin (CBEL) locus was validated to rapidly identify all four lineages. Sequencing of the CBEL locus revealed eight single nucleotide polymorphisms (SNPs) that distinguished EU2 from the other three lineages. Two ASO-PCR assays were developed from these SNPs, providing the ability to rapidly identify EU2 individuals relative to EU1, NA1 and NA2 individuals. These new assays were combined with two existing assays targeting the same locus to allow rapid and simple identification of all four lineages. Blind tests performed on a panel of representative samples revealed diagnostic profiles unique to each lineage. These markers can be used with diseased field samples, making them well suited for routine procedures in diagnostic laboratories to identify P. ramorum.

VL - 36 UR - http://www.tandfonline.com/doi/abs/10.1080/07060661.2014.924999 IS - 3 JO - Canadian Journal of Plant Pathology ER - TY - JOUR T1 - Root disease of alder in Britain Y1 - 1995 A1 - Gibbs, J. N. UR - http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2338.1995.tb01118.x/abstract ER - TY - JOUR T1 - Role of salicylic acid in phosphite-induced protection against Oomycetes; a Phytophthora cinnamomi - Lupinus augustifolius model system JF - European Journal of Plant Pathology Y1 - 2015 A1 - Groves, Emma A1 - Howard, Kay A1 - Hardy, Giles A1 - Burgess, Treena AB -

Phosphite is used to control Oomycetes in a wide range of horticultural and native plant species worldwide. However, phosphite can be phytotoxic, and some pathogens have exhibited a reduction in the effectiveness of phosphite due to prolonged use. In this study, salicylic acid (SA) was investigated as an alter- native, or supplementary, treatment to be used to protect plant species. With the use of aeroponics chambers, foliar application of phosphite, SA, and phosphite/SA to Lupinus augustifolius was assessed in relation to root tip damage, in planta phosphite and SA concentration and lesion development. Both phosphite and SA were measurable at the root tip within 24 h of application, and all treatments significantly (P0.05) reduced the lesion length at 7 days. However, while phosphite and SA application increased the in planta SA concentration, phosphite caused significantly more damage to the root tip by reducing root cap layers and length than the SA, or phosphite/SA application. This study supports the notion that phosphite-induced sensitivity may be SA- dependent, as both phosphite and SA were found to control P. cinnamomi and stimulate SA accumulation. A combination of phosphite and SA may be more beneficial to plants if it can reduce phytotoxic effects and reduce the chance of pathogen sensitivity to phosphite.

VL - 141 UR - http://link.springer.com/article/10.1007%2Fs10658-014-0562-y IS - 3 JO - Eur J Plant Pathol ER - TY - JOUR T1 - Redesignation of Phytophthora taxon Pgchlamydo as Phytophthora chlamydospora sp. nov. JF - North American Fungi Y1 - 2015 A1 - Everett Hansen A1 - Paul Reeser A1 - Wendy Sutton A1 - Clive Brasier KW - chlamydospora KW - new species KW - Pg chlamydo KW - Phytophthora KW - soil KW - streams AB -

A new species, Phytophthora chlamydospora, is described. P. chlamydospora, previously known informally as P. taxon Pgchlamydo, is found in streams and wet soil worldwide and is a pathogen of some riparian tree species. It is self-sterile, and produces persistent non-papillate sporangia, usually on unbranched sporangiophores. Clamydospores are formed most regularly at warmer temperatures. Phytophthora chlamydospora is classified in ITS Clade 6.

VL - 10 UR - https://www.pnwfungi.org/index.php/pnwfungi/article/view/1414 ER - TY - JOUR T1 - Relationships between health of Quercus robur, occurrence of Phytophthora species and site conditions in southern Sweden JF - Plant Pathology Y1 - 2005 A1 - Jonsson, U. A1 - T. Jung A1 - Sonesson, K. A1 - Rosengren, U. AB -

The effect of Phytophthora species, soil chemistry, precipitation and temperature on the vitality of oak was evaluated in 32 oak stands in southern Sweden. In addition, the relationship between the occurrence of Phytophthora species and soil conditions was determined. The results showed that there was a weak association between the presence of P. quercina, the most frequently recovered Phytophthora species in southern Sweden, and the vitality of the oak stands (determined from estimates of crown defoliation of individual trees). The pathogens occurred more frequently in clayey and loamy soils that were less acidic and which had higher base saturation. However, they were found in all but the most acidic soils (pH < 3·5). In stands where Phytophthora species were not present, positive correlations between the average crown defoliation and proportion of damaged trees with average summer precipitation and average annual precipitation were found. There were no significant differences in soil chemistry between healthy and declining stands included in this study, and no significant correlations were found between any soil parameter and crown vitality. Based on the results from these 32 oak stands, it is likely that the decline of oaks in southern Sweden can be attributed to several different site-specific factors, such as infection by P. quercina or unusual weather events, which interact with a number of biotic and abiotic factors, leading to oak decline.

VL - 54 IS - 4 JO - Plant Pathology ER - TY - JOUR T1 - Re-evaluation of Phytophthora citricola isolates from multiple woody hosts in Europe and North America reveals a new species, Phytophthora plurivora sp. nov. JF - Persoonia - Molecular Phylogeny and Evolution of Fungi Y1 - 2009 A1 - T. Jung A1 - Burgess, T. I. KW - Beech KW - citricola KW - Decline KW - dieback KW - forest KW - multivora KW - nursery KW - oak KW - phylogeny AB -

During large-scale surveys for soilborne Phytophthora species in forests and semi-natural stands and nurseries in Europe during the last decade, homothallic Phytophthora isolates with paragynous antheridia, semipapillate persistent sporangia and a growth optimum around 25 °C which did not form catenulate hyphal swellings, were recovered from 39 host species in 16 families. Based on their morphological and physiological characters and the similarity of their ITS DNA sequences with P. citricola as designated on GenBank, these isolates were routinely identified as P. citricola. In this study DNA sequence data from the internal transcribed spacer regions (ITS1 and ITS2) and 5.8S gene of the rRNA operon, the mitochondrial cox1 and β-tubulin genes were used in combination with morphological and physiological characteristics to characterise these isolates and compare them to the ex-type and the authentic type isolates of P. citricola, and two other taxa of the P. citricola complex, P. citricola I and the recently described P. multivora. Due to their unique combination of morphological, physiological and molecular characters these semipapillate homothallic isolates are described here as a new species, P. plurivora sp. nov.

VL - 22 IS - 1 JO - Pers - Int Mycol J ER - TY - JOUR T1 - A risk assessment of climate change and the impact of forest diseases on forest ecosystems in the Western United States and Canada. Y1 - 2011 A1 - John T. Kliejunas KW - Armillaria KW - canker diseases KW - Climate change KW - dwarf mistletoe KW - environmental risk assessment KW - foliar diseases KW - forest pathogens KW - Phytophthora KW - root diseases KW - stem rusts KW - yellow-cedar decline PB - U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station, Albany, CA UR - http://www.fs.fed.us/psw/publications/documents/psw_gtr236/ ER - TY - JOUR T1 - Response of selected South Australian native plant species to Phytophthora cinnamomi JF - Plant Pathology Y1 - 2012 A1 - Kueh, K. H. A1 - McKay, S. F. A1 - Facelli, E. A1 - Facelli, J. M. A1 - Velzeboer, R. M. A. A1 - Able, A. J. A1 - Scott, E. S. KW - native vegetation KW - phytophthora dieback KW - survival KW - susceptibility KW - threatened species AB -

Thirty-seven South Australian native plant species from 11 families, including 15 threatened species in the state (of which six are listed as threatened under the federal Environment Protection and Biodiversity Conservation Act 1999) were assessed for response to infection by Phytophthora cinnamomi. Seedlings, 3-6 months old and grown in a greenhouse, were inoculated by placing infested pine wood plugs in the potting mix, maintained in moist conditions and assessed for mortality and disease symptoms for between 3 and 10 months. Thirty species were found to be susceptible, of which nine were highly susceptible, 15 moderately susceptible and six slightly susceptible. Three species were found to be resistant and results for four species were inconclusive. Six of the 15 threatened, rare or locally endangered species tested (Eucalyptus viminalis var. viminalis, Correa aemula, C. calycina, Olearia pannosa ssp. pannosa, Pomaderris halmaturina ssp. halmaturina and Prostanthera eurybioides) were moderately susceptible, while two (Allocasuarina robusta and Pultenaea graveolens) were highly susceptible.Significant populations of at least five of the threatened species susceptible to the disease are located close to confirmed or suspected Phytophthora-infested areas or growing in areas conducive for P.cinnamomi. An effective management strategy is therefore required to avoid extinction of such species due to infection by the phytophthora dieback pathogen.

PB - Blackwell Publishing Ltd VL - 61 UR - http://dx.doi.org/10.1111/j.1365-3059.2012.02593.x ER - TY - JOUR T1 - Reconstruction of the sudden oak death epidemic in California through microsatellite analysis of the pathogen Phytophthora ramorum JF - Molecular Ecology Y1 - 2008 A1 - Mascheretti, S. A1 - Croucher, P. J. P. A1 - Vettraino, A. Vettraino A1 - Prospero, S A1 - Garbelotto, M. KW - genetic structure KW - microsatellite KW - network analysis KW - Phytophthora ramorum KW - spatial autocorrelation KW - Sudden oak death AB -

The genetic structure of the clonally reproducing Sudden Oak Death (SOD) pathogen in California was investigated using seven variable microsatellites. A total of 35 multilocus genotypes were identified among 292 samples representative of populations from 14 forest sites and of the nursery trade. amova indicated significant genetic variability both within (44.34%) and among populations (55.66%). Spatial autocorrelation analyses indicated that Moran’s index of similarity reached a minimum of 0.1 at 350 m, increased to 0.4 at 1500 m and then decreased to zero at 10 km. These results suggest a bimodal pattern of spread, with medium range dispersal (1500–10 000 m) putatively attributed to the presence of strong winds. Lack of genetic structure was identified for three groups of populations. One group notably included the nurseries’ population and two forest populations, both linked to early reports of the pathogen. A neighbour-joining analysis based on pairwise ΦST values indicated that the clade inclusive of the nurseries’ populations is basal to all California populations. A network analysis identified three common genotypes as the likely founders of the California infestation and proposes a stepwise model for local evolution of novel genotypes. This was supported by the identification in the same locations of novel genotypes and of their 1- or 2-step parents. We hypothesize that the few undifferentiated population groups indicate historical human spread of the pathogen, while the general presence of genetically structured populations indicates that new infestations are currently generated by rare medium or long-range natural movement of the pathogen, followed by local generation of new genotypes.

PB - Blackwell Publishing Ltd VL - 17 UR - http://dx.doi.org/10.1111/j.1365-294X.2008.03773.x ER - TY - JOUR T1 - Relationship between field resistance to Phytophthora ramorum and constitutive phenolic chemistry of coast live oak JF - Forest Pathology Y1 - 2011 A1 - Nagle, A. M. A1 - Mcpherson, B. A. A1 - Wood, D. L. A1 - Garbelotto, M. A1 - Bonello, P. AB -

Sudden oak death, caused by Phytophthora ramorum, has resulted in high levels of coast live oak (CLO) mortality. However, some CLO survive in areas with high disease pressure and may thus be resistant. We tested the hypothesis that such field-resistant trees contain constitutively higher levels of phenolics than susceptible trees. Phloem was sampled from the trunks of two groups of trees (one previously inoculated, one naturally infected with P. ramorum) categorized over the course of several years as putatively resistant (PR, no symptoms), in remission (IR, showed symptoms but then recovered) and symptomatic (S). Individual and total soluble phenolics from these trees were quantified. There were no significant differences in individual or total soluble phenolics between groups of naturally infected trees. However, inoculated PR and IR trees were characterized by higher constitutive levels of ellagic acid, a tyrosol derivative, and an unidentified phenolic than S trees. Ellagic acid and tyrosol-like compounds in CLO phloem are promising resistance biomarker candidates.

PB - Blackwell Publishing Ltd VL - 41 UR - http://dx.doi.org/10.1111/j.1439-0329.2010.00703.x ER - TY - JOUR T1 - Rapid diagnosis of pathogenic Phytophthora species in soil by real-time PCR JF - Forest Pathology Y1 - 2016 A1 - Nowakowska, J. A. A1 - Malewski, T. A1 - Tereba, A. A1 - Oszako, T. ED - Belbahri, L. AB -

Real-time PCR assays based on the TaqMan system and using ITS sequences were developed for the identification of Phytophthora species, including P. cactorum, P. megasperma, P. plurivora, P. pseudosyringae and P. quercina, all of which are currently causing significant damage to roots of forest trees in both managed stands and natural ecosystems. Total genomic DNA was extracted from mycelia of aforementioned Phytophthora isolates. Species-specific primers for P. cactorum, P. megasperma, P. plurivora, P. pseudosyringae and P. quercina were designed based on ITS sequences of rDNA. The amplification efficiency of target DNA varied from 93.1% (P. pseudosyringae) to 106.8% (P. quercina). The limit of the detection was calculated as 100 – 1,000 fg DNA, depending on the Phytophthora species. In mixed soil samples, all Phytophthora species were detected for Ct values shifted by 0.7 – 2.1 cycles. Based on these real-time PCR assays we were able to identify the five Phytophthora species. These techniques will be of value in the identification of these pathogens, which may cause up to 80 – 90% fine root loss in oak stands.

UR - http://dx.doi.org/10.1111/efp.12303 JO - For. Path. ER - TY - THES T1 - Resistance mechanisms of Port-Orford-cedar to Phytophthora lateralis Y1 - 2004 A1 - Oh, Eunsung PB - Oregon State University CY - Corvallis ER - TY - JOUR T1 - A revised systematics of twelve papillate Phytophthora species based on isozyme analysis JF - Mycological Research Y1 - 1991 A1 - Oudemans, Peter A1 - Coffey, Michael D. AB -

Isoenzyme analysis was used to examine intraspecific diversity and interspecific relatedness of P. cactorum (group I) and 12 papillate species of Phytophthora within group II of Waterhouse's (1963) taxonomic scheme. Isolates of 6 species, specifically P. botryosa, P. heveae, P. katsurae, P. meadii, P. palmivora and P. parasitica (P. nicotianae var. parasitica), contained low levels of genetic diversity and were judged to be valid species. Based upon isoenzyme analysis, all isolates of P. arecae were found to be identical with some isolates of P. palmivora. Thus, it is proposed that these 2 species are synonymous. For P. nicotianae var. parasitica, differences in oospore size or host plant were contrasted with the isoenzyme data using single locus coefficients and no evidence was found to support the existence of distinct varieties. In contrast, several other species, particularly P. capsici, P. citrophthora and P. megakarya, demonstrated much higher levels of variation in isoenzyme pattern and subgroups were readily identified. Isolates of P. capsici, including those previously identified as P. palmivora 'MF4' separated into 3 subgroups CAP1, CAP2 and CAP3. Those in CAP1 were from widely distributed geographical locations on a range of hosts including Capsicum sp., tomato, cucurbits, as well as cocoa and black pepper and it contained the greatest amount of intraspecific diversity. A single representative of P. mexicana also clustered with this subgroup and as such is considered conspecific to P. capsici. CAP2 isolates were found primarily on black pepper and from Hawaii on Macadamia integrifolia as well as other hosts. In some instances, specifically with isolates from India and Indonesia on black pepper both CAP1 and CAP2 were found. However, the evidence from isoenzymes suggests that the 2 groups are genetically isolated from one another. All representatives of CAP3 were derived from diseased cocoa in Brazil and this subgroup was monomorphic for all loci examined. P. citrophthora was divided into 2 subgroups. Isolates of CTR1 were derived from a large range of hosts including citrus and kiwi fruit. CTR2 was composed of only Brazilian isolates from cocoa. P. megakarya, which has only been reported on cocoa from West Africa, was also divided into 2 subgroups which were separated geographically. Isolates of MGK1 originated from either Nigeria or Guinea and isolates of MGK2 were from Cameroon. P. boehmeriae was the most genetically diverse species examined with 4 isoenzymatically diverse ETs representing only 11 isolates. Interspecific comparisons revealed relationships which would not have been predicted based on morphological comparisons alone. For example, P. meadii and P. botryosa clustered together indicating a very close genetic relatedness. P. katsurae and P. heveae also formed a single cluster. However, comparison of oospores of these 2 species showed that the oogonial stalk length of P. katsurae was consistently much longer. Unexpectedly, P. capsici and P. citrophthora also formed a cluster indicating that they were genetically related. Finally, the results of this isoenzyme analysis suggest that the papillate species of Group II of Waterhouse's (1963) scheme may form at least 6 distinct evolutionary lines.

VL - 95 UR - http://linkinghub.elsevier.com/retrieve/pii/S0953756209805431 IS - 9 JO - Mycological Research ER - TY - JOUR T1 - Root Rot of Juniperus and Microbiota by Phytophthora lateralis in Oregon Horticultural Nurseries JF - Plant Disease Y1 - 2020 A1 - Peterson, Ebba K. A1 - Rupp, Franziska A1 - Eberhart, Joyce A1 - Parke, Jennifer L. AB -

Widespread symptoms of root rot and mortality on Juniperus communis and Microbiota decussata were observed in two horticultural nurseries in Oregon, leading to the isolation of a Phytophthora sp. from diseased roots. Based on morphology and sequencing the internal transcribed spacer ITS1-5.8S-ITS2 region, isolates were identified as the invasive pathogen Phytophthora lateralis, causal agent of Port-Orford-cedar (POC; Chamaecyparis lawsoniana) root disease. Additional sequencing of the cytochrome c oxidase subunit 1 and 2 genes identified all isolates as belonging to the PNW lineage. Utilizing recovered isolates plus a POC-wildlands isolate and susceptible POC as controls, we completed Koch's postulates on potted Juniperus and Microbiota plants. Nursery isolates were more aggressive than the forest isolate, which was used in the POC resistance breeding program. Increased aggressiveness was confirmed using a branch stem dip assay with four POC clones that differed in resistance, although no isolate completely overcame major-gene resistance. Isolates were sensitive to mefenoxam, a fungicide commonly used to suppress Phytophthora spp. growth in commercial nurseries. Although POC resistance is durable against these more aggressive nursery isolates, the expanded host range of P. lateralis challenges POC conservation through the continued movement of P. lateralis by the nursery industry.

VL - 104 UR - https://apsjournals.apsnet.org/doi/10.1094/PDIS-04-19-0808-RE IS - 5 JO - Plant Disease ER - TY - JOUR T1 - Root and aerial infections of Chamaecyparis lawsoniana by Phytophthora lateralis: a new threat for European countries JF - Forest Pathology Y1 - 2010 A1 - Robin, C. A1 - Piou, D. A1 - Feau, N. A1 - Douzon, G. A1 - Schenck, N. A1 - Hansen, E.M. VL - 41 UR - http://dx.doi.org/10.1111/j.1439-0329.2010.00688.x ER - TY - JOUR T1 - Report on the risk of entry, establishment, spread and socio-economic loss and environmental impact and the appropriate level of management for Phytophthora ramorum for the EU. Y1 - 2009 A1 - Sansford, C.E. A1 - Inman, A..J. A1 - Baker, R. A1 - Brasier, C. A1 - Frankel, S. A1 - de Gruyter, J. A1 - Husson, C. A1 - Kehlenbeck, H. A1 - Kessel, G. A1 - Moralejo, E. A1 - Steeghs, M. A1 - Webber, J. A1 - Werres, S. ED - Forest Research, Central Science Laboratory ED - EU Sixth Framework Project, RAPRA CY - Sand Hutton, York, UK VL - Deliverable Report 28 UR - http://rapra.csl.gov.uk/RAPRA-PRA_26feb09.pdf ER - TY - JOUR T1 - Root and crown rot of Brazilian pine (Araucaria angustifolia) caused by Phytophthora cinnamomi JF - Journal of Phytopathology Y1 - 2011 A1 - Santos, A. F. dos A1 - Tessmann, Dauri J. A1 - Alves, Tatiane C. A. A1 - Vida, João B. A1 - Harakava, Ricardo KW - chromistan fungi KW - forest pathology KW - fungal plant pathogen AB -

In an area reforested with Brazilian pine (Araucaria angustifolia) located in Paran√° State, southern Brazil, 20- to 40-year-old trees representing 0.2% of the surveyed area had symptoms of root and crown rot, yellowing and browning of leaves from the uppermost branches and death. Three Phytophthora isolates obtained from diseased plant tissue were tested against 1-year-old Brazilian pine seedlings and found to display positive pathogenicity. Based on their morphological and physiological characteristics, the isolates were identified as Phytophthora cinnamomi. A GenBank BLAST search of partial sequences from the β-tubulin and elongation factor-1α genes, as well as the ITS regions and 5.8S gene of rDNA, confirmed the species identification. This is the first report of the involvement of this pathogen on the aetiology of Brazilian pine root and crown rot.

PB - Blackwell Publishing Ltd VL - 159 UR - http://dx.doi.org/10.1111/j.1439-0434.2010.01741.x ER - TY - JOUR T1 - Revised tabular key to the species of Phytophthora JF - Mycological papers, CAB International, Wallingford Oxon Y1 - 1990 A1 - Stamps, D. J. A1 - Waterhouse, G. M. A1 - Newhook, F. J. A1 - Hall, G. S. VL - 162 UR - http://www.cabdirect.org/abstracts/19902300161.html;jsessionid=1D85C493563BECA35F0E55609ABAF21C ER - TY - JOUR T1 - A review of New Zealand kauri (Agathis australis (D.Don) Lindl.): its ecology, history, growth and potential for management for timber JF - New Zealand Journal of Forestry Science Y1 - 2010 A1 - Steward, G. A. A1 - Beveridge, A. E. AB -

Kauri (Agathis australis (D.Don) Lindl.) is endemic to New Zealand, where it is the only indigenous member of the Araucariaceae. It has the most southerly distribution of any species in the genus and is currently confined to the warm temperate areas of the North Island. At the time of European settlement, forests containing kauri covered 1 000 000 ha or more in New Zealand. Following uncontrolled logging, land clearance for alternative land use and destruction by fire, only 7500 ha of virgin or primary forest remain, mainly in conservation reserves. An additional 60 000 ha of scrub/shrubland and secondary forest contain varying amounts of regenerating kauri. Kauri is reputed to produce greater volumes of wood from single stems than any other timber tree in the world. Its timber is regarded as one of the finest due to qualities of decay resistance and dimensional stability under moist conditions. A wide range of products was developed by Maori and European settlers. Kauri timber and gum made a substantial contribution to the physical and economic development of New Zealand between 1830 and 1900. Agathis australis shares a number of biological characteristics with lowland Agathis species found in the tropics and subtropics. These include a juvenile form with narrow tapering crown; mature emergent trees with massive, spreading, dome-shaped crowns and upwardly-arched branches; self-pruning in sapling and pole-stage trees; flaking bark; winddispersed, small-winged seeds formed in cones that disintegrate at time of seed maturity while still on the tree; and only a few months of seed viability after shedding. Juvenile trees with taproots and mature trees with wide-spreading lateral roots and descending peg roots are windfirm, assisting longevity. Although surviving trees of massive dimensions (3-5 m diameter) are usually hollow, their life span may be 1500 years or more. Large kauri have a podsolising effect on some acidic soils, making them less fertile. Efficiency in the use of water and nutrients has enabled the species to become dominant on infertile and drought-prone ridge tops. Observations of growth in natural stands indicate mean annual increment of 2.5-6.0 mm in diameter and 0.3 m in height. Interplanting of kauri in scrub and shrubland developed on former kauri forest sites has produced poor results. Mean annual increments of 6.9 mm in diameter and 0.44 m in height have been recorded in young untended plantations. Greater success has been achieved through attention to site selection, improved establishment techniques and silvicultural tending. The most suitable sites for planting are those with fertile, well-drained, light-textured soils, a warm, humid climate, and a history of previous occupation by broadleaved (angiosperm) plant species. Current research suggests that rotation length can be reduced by best-practice management, and that planted stands could be a continuing source of kauri timber in the future.

VL - 40 UR - http://www.scionresearch.com/__data/assets/pdf_file/0019/17164/NZJFS40201033-59_STEWARD.pdf ER - TY - JOUR T1 - Risk factors for the Phytophthora-induced decline of alder in northeastern France JF - Phytopathology Y1 - 2007 A1 - Thoirain, B. A1 - Husson, C. A1 - Marçais, B. VL - 97 UR - http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-97-0099 ER - TY - JOUR T1 - Root rot of Chamaecyparis caused by a species of Phytophthora JF - Mycologia Y1 - 1942 A1 - Tucker, C. M. A1 - Milbrath, J.A. KW - Phytophthora lateralis VL - 34 UR - http://www.jstor.org/stable/3754945 ER - TY - JOUR T1 - Record of decision and land and resource management plan amendment for management of Port-Orford-cedar in southwest Oregon, Siskiyou National Forest Y1 - 2004 A1 - USDA-FS A1 - USDI-BLM KW - Chamaecyparis lawsoniana KW - disease detection KW - Phytophthora lateralis PB - U.S. Department of Agriculture Forest Service, Rogue River-Siskiyou National Forest CY - Medford, OR UR - http://www.fs.fed.us/r6/rogue-siskiyou/projects/foresthealth/poc/poc-rod-fs.pdf ER -