@article {4690, title = {Migratory passerine birds in Britain carry Phytophthora ramorum inoculum on their feathers and {\textquotedblleft}feet{\textquotedblright} at low frequency}, journal = {Forest Pathology}, volume = {50}, year = {2020}, month = {Dec-09-2019}, pages = {e12569}, abstract = {

In this study, we investigated whether birds could be vectors facilitating long-distance spread of Phytophthora ramorum in Britain. Migratory bird species associated with the main sporangium-producing host plants and most likely to pick up P.\ ramorum spores were considered. Swabs were taken from the flank and {\textquotedblleft}feet{\textquotedblright} of 1,014 birds over a 12-month period (April 2011{\textendash}March 2012) in the west of Britain and subsequently analyzed for the presence of P.\ ramorum using nested PCR. Ten positive samples from 10 birds were identified: three in Cornwall, one in Devon, three in Gloucestershire, two in north Wales and one in Merseyside. Phytophthora ramorum was detected on samples from four species of thrushes (Redwing Turdus iliacus, Fieldfare T.\ pilaris, Blackbird T.\ merula and Song Thrush T.\ philomelos) and one species of warbler (Chiffchaff Phylloscopus collybita). All birds that tested positive were sampled in late autumn and winter (October{\textendash}February), when long-distance movements (over 100\ km) would have stopped. The low incidence of P.\ ramorum found using PCR suggests that the incidence of inoculum, whether viable or not, on birds was low. The apparently low incidence of inoculum on birds suggests migratory passerine birds can carry P.\ ramorum inoculum on their feathers and {\textquotedblleft}feet,{\textquotedblright} albeit at low frequency. The dates of positive samples indicate that birds would not have been moving long distances at the time but further work is needed to estimate the extent of their contribution to the spread of P.\ ramorum in Britain.

}, doi = {10.1111/efp.v50.110.1111/efp.12569}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/efp.12569}, author = {Dadam, Daria and Siasou, Eleni and Woodward, Stephen and Clark, Jacquie A.} } @article {4250, title = {The occurrence of Phytophthora palmivora (Butl.) Butl. in soil in Ghana}, journal = {Ghana Jnl. Agric. Sci}, volume = {7}, year = {1974}, pages = {37-41}, abstract = {

The occurrence of Phytophthora palmivora (But!.) But!. in soil was studied over 2 consecutive years by baiting the fungus with healthy cocoa pods. The fungus was frequently found in soils of a forest reserve, an abandoned cocoa farm and in farms still under cocoa cultivation; its activity, however, differed under the three soil conditions. Fluctuations in the occurrence of P. palmivora in soil did not depend on atmospheric temperature. At Obomeng, the fungus was isolated more frequently from a cocoa farm than from either an abandoned cocoa farm or a forest area. The isolation of P. palmivora from the uncultivated forest soil indicates that the fungus is indigenous to forest soils.

}, url = {http://gains.org.gh/articles/gjas_v7_1_p37_41.pdf}, author = {Dakwa, JT} } @article {4700, title = {Mitotic Recombination and Rapid Genome Evolution in the Invasive Forest Pathogen Phytophthora ramorum}, journal = {mBio}, volume = {10}, year = {2019}, month = {Mar-12-2019}, abstract = {

Invasive alien species often have reduced genetic diversity and must adapt to new environments. Given the success of many invasions, this is sometimes called the genetic paradox of invasion. Phytophthora ramorum is invasive, limited to asexual reproduction within four lineages, and presumed clonal. It is responsible for sudden oak death in the United States, sudden larch death in Europe, and ramorum blight in North America and Europe. We sequenced the genomes of 107 isolates to determine how this pathogen can overcome the invasion paradox. Mitotic recombination (MR) associated with transposons and low gene density has generated runs of homozygosity (ROH) affecting 2,698 genes, resulting in novel genotypic diversity within the lineages. One ROH enriched in effectors was fixed in the NA1 lineage. An independent ROH affected the same scaffold in the EU1 lineage, suggesting an MR hot spot and a selection target. Differences in host infection between EU1 isolates with and without the ROH suggest that they may differ in aggressiveness. Non-core regions (not shared by all lineages) had signatures of accelerated evolution and were enriched in putative pathogenicity genes and transposons. There was a striking pattern of gene loss, including all effectors, in the non-core EU2 genome. Positive selection was observed in 8.0\% of RxLR and 18.8\% of Crinkler effector genes compared with 0.9\% of the core eukaryotic gene set. We conclude that the P. ramorum lineages are diverging via a rapidly evolving non-core genome and that the invasive asexual lineages are not clonal, but display genotypic diversity caused by MR.

IMPORTANCE Alien species are often successful invaders in new environments, despite the introduction of a few isolates with a reduced genetic pool. This is called the genetic paradox of invasion. We found two mechanisms by which the invasive forest pathogen causing sudden oak and sudden larch death can evolve. Extensive mitotic recombination producing runs of homozygosity generates genotypic diversity even in the absence of sexual reproduction, and rapid turnover of genes in the non-core, or nonessential portion of genome not shared by all isolates, allows pathogenicity genes to evolve rapidly or be eliminated while retaining essential genes. Mitotic recombination events occur in genomic hot spots, resulting in similar ROH patterns in different isolates or groups; one ROH, independently generated in two different groups, was enriched in pathogenicity genes and may be a target for selection. This provides important insights into the evolution of invasive alien pathogens and their potential for adaptation and future persistence.

}, doi = {10.1128/mBio.02452-18}, url = {https://mbio.asm.org/content/10/2/e02452-18}, author = {Dale, Angela L. and Feau, Nicolas and Everhart, Sydney E. and Dhillon, Braham and Wong, Barbara and Sheppard, Julie and Bilodeau, Guillaume J. and Brar, Avneet and Tabima, Javier F. and Shen, Danyu and Brasier, Clive M. and Tyler, Brett M. and Gr{\"u}nwald, Niklaus J. and Hamelin, Richard C.}, editor = {Taylor, John W.} } @article {davidsonpathways, title = {Pathways of movement for Phytophthora ramorum, the causal agent of Sudden Oak Death}, journal = {The American Phytopathological Society Sudden Oak Death Online Symposium}, year = {2003}, publisher = {American Phytopathological Society}, author = {J. M. Davidson and Shaw, C.G.T.} } @article {doi:10.1094/PHYTO-95-0587, title = {Transmission of Phytophthora ramorum in mixed-evergreen forest in California}, journal = {Phytopathology}, volume = {95}, number = {5}, year = {2005}, pages = {587-596}, doi = {10.1094/PHYTO-95-0587}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-95-0587}, author = {Davidson, Jennifer M. and Wickland, Allison C. and Patterson, Heather A. and Falk, Kristen R. and Rizzo, David M.} } @article {davidson2003sudden, title = {Sudden oak death and associated diseases caused by Phytophthora ramorum.}, journal = {Plant Management Network - Plant Health Progress}, year = {2003}, month = {July 2003}, doi = {10.1094/PHP-2003-0707-01-DG}, url = {http://www.plantmanagementnetwork.org/php/shared/sod/}, author = {J. M. Davidson and Werres, S. and Garbelotto, M. and Hansen, E.M. and D. M. Rizzo} } @article {doi:10.1094/PHYTO-03-10-0064, title = {Forest type influences transmission of Phytophthora ramorum in California oak woodlands}, journal = {Phytopathology}, volume = {101}, number = {4}, year = {2011}, pages = {492-501}, abstract = {

The transmission ecology of Phytophthora ramorum from bay laurel (Umbellularia californica) leaves was compared between mixed-evergreen and redwood forest types throughout winter and summer disease cycles in central, coastal California. In a preliminary multisite study, we found that abscission rates of infected leaves were higher at mixed-evergreen sites. In addition, final infection counts were slightly higher at mixed-evergreen sites or not significantly different than at redwood sites, in part due to competition from other foliar pathogens at redwood sites. In a subsequent, detailed study of paired sites where P. ramorum was the main foliar pathogen, summer survival of P. ramorum in bay laurel leaves was lower in mixed-evergreen forest due to lower recovery from infected attached leaves and higher abscission rates of infected leaves. Onset of inoculum production and new infections of bay laurel leaves occurred later in mixed-evergreen forest. Mean inoculum levels in rainwater and final infection counts on leaves were higher in redwood forest. Based on these two studies, lower summer survival of reservoir inoculum in bay laurel leaves in mixed-evergreen forest may result in delayed onset of both inoculum production and new infections, leading to slower disease progress in the early rainy season compared with redwood forest. Although final infection counts also will depend on other foliar pathogens and disease history, in sites where P. ramorum is the main foliar pathogen, these transmission patterns suggest higher rates of disease spread in redwood forests during rainy seasons of short or average length.

}, doi = {10.1094/PHYTO-03-10-0064}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-03-10-0064}, author = {Davidson, Jennifer M. and Patterson, Heather A. and Wickland, Allison C. and Elizabeth J. Fichtner and Rizzo, David M.} } @article {doi:10.1094/PHYTO-98-8-0860, title = {Sources of inoculum for Phytophthora ramorum in a redwood forest}, journal = {Phytopathology}, volume = {98}, number = {8}, year = {2008}, pages = {860-866}, doi = {10.1094/PHYTO-98-8-0860}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-98-8-0860}, author = {J. M. Davidson and Patterson, H. A. and D. M. Rizzo} } @article {430, title = {Root-rot of sweet chestnut and beech caused by species of Phytophthora.}, journal = {Forestry}, volume = {12}, year = {1938}, pages = {101{\textendash}116}, author = {Day, W.R.} } @article {PPA:PPA2212, title = {Effect of host factors on the susceptibility of Rhododendron to Phytophthora ramorum}, journal = {Plant Pathology}, volume = {59}, number = {2}, year = {2010}, pages = {301{\textendash}312}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora ramorum causes sudden oak death (SOD) in western coastal forests of the USA. In Europe, the pathogen is mainly present in the nursery industry, particularly on Rhododendron. Because of the primary role of Rhododendron as a host and potentially as a vector, the effect of Rhododendron host factors on P. ramorum susceptibility and sporulation was investigated. Inoculation methods using either wounded or non-wounded detached leaves were applied to 59 Rhododendron cultivars and 22 botanical species, replicated in three separate years. All Rhododendron species and cultivars were susceptible when using wounded leaves, but not when using non-wounded leaves, suggesting a resistance mechanism operating at the level of leaf penetration. Using a regression tree analysis, the cultivars and species were split into four susceptibility classes. Young leaves were more susceptible than mature leaves when wounded, but less susceptible when non-wounded. This effect was not correlated with leaf hydrophobicity or the number of leaf hairs. The presence or the type of rootstock did not affect the cultivar susceptibility level. Sporangia and chlamydospore production in the leaf lesions varied widely among Rhododendron cultivars and was not correlated with the susceptibility level. The susceptibility to P. ramorum correlated well with the susceptibility to P. citricola and P. hedraiandra\ {\texttimes}\ cactorum, suggesting that the resistance mechanisms against these species are non-specific. Susceptibility to P. kernoviae was low for most cultivars. These findings have implications for detection, spread and disease control, and are therefore important in pest risk assessment.

}, keywords = {host resistance, leaf age, leaf hairs, Phytophthora kernoviae, rootstock, sporulation}, issn = {1365-3059}, doi = {10.1111/j.1365-3059.2009.02212.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2009.02212.x}, author = {De Dobbelaere, I. and Vercauteren, A. and Speybroeck, N. and Berkvens, D. and Van Bockstaele, E. and Maes, M. and Heungens, K.} } @article {denitto1991first, title = {First report of Phytophthora lateralis on Pacific yew}, journal = {Plant Disease}, volume = {75}, number = {9}, year = {1991}, pages = {968}, doi = {10.1094/PD-75-0968C.}, url = {http://www.apsnet.org/publications/PlantDisease/BackIssues/Documents/1991Abstracts/PD_75_968C.htm}, author = {DeNitto, GA and J.T. Kliejunas} } @article {EPP:EPP2243, title = {Phytophthora ramorum and Phytophthora kernoviae on naturally infected asymptomatic foliage}, journal = {EPPO Bulletin}, volume = {39}, number = {1}, year = {2009}, pages = {105{\textendash}111}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora ramorum and Phytophthora kernoviae are recently discovered invasive Phytophthoras causing leaf necrosis and shoot tip dieback mostly on ornamental and forest understorey species, but also cause bleeding cankers on stems of a wide range of tree species. Sporulation occurs only on infected shoots or fruits and foliage so foliar hosts are central to the disease epidemiology. In field trials to assess infection in trap plants exposed to natural inoculum of P. ramorum and P. kernoviae on rhododendron in south west England, it was discovered that leaves of the trap plants (Rhododendron {\textquoteleft}Cunninghams White{\textquoteright}) and holm oak (Quercus ilex) were asymptomatically infected and supported sporulation of both pathogens. More than half the rhododendron trap plants exposed to inoculum of P. kernoviae became infected compared with approximately a third of those exposed to P. ramorum in a natural situation. Approximately one third of the infections were detected from asymptomatic foliage for both pathogens. The significance of these findings for plant health regulation based on visual inspection as a measure to prevent introduction and dissemination of both these pathogens is explored and research gaps identified.

}, issn = {1365-2338}, doi = {10.1111/j.1365-2338.2009.02243.x}, url = {http://dx.doi.org/10.1111/j.1365-2338.2009.02243.x}, author = {Denman, S. and Kirk, S.A. and Moralejo, E. and Webber, JF} } @article {PPA:PPA1243, title = {In vitro leaf inoculation studies as an indication of tree foliage susceptibility to Phytophthora ramorum in the UK}, journal = {Plant Pathology}, volume = {54}, number = {4}, year = {2005}, pages = {512{\textendash}521}, publisher = {Blackwell Science Ltd}, abstract = {

Leaves of 11 coniferous and 23 broad-leaved tree species important to UK forestry were tested for their susceptibility to the quarantine pathogen Phytophthora ramorum using a detached leaf assay. Two European and two USA isolates were used. Wounded and unwounded leaves were dipped in zoospore suspensions during summer; conifers were also tested in winter. Successful infection of tissue and amount of necrosis were assessed. Highly susceptible broad-leaved hosts included Aesculus hippocastanum, Fraxinus excelsior, Quercus ilex, Ulmus procera and, to a lesser extent, Castanea sativa, Q. cerris and Q. petraea, together with Umbellularia californica and rhododendrons. Acer pseudoplatanus, Alnus glutinosa, Carpinus betulus, Corylus avellana, Fagus sylvatica, Prunus avium, Q. robur, Q. rubra and Q. suber showed consistently low susceptibility. Conifer species including Abies procera, Picea abies, P. sitchensis, Pseudotsuga menziesii, Sequoia sempervirens and Tsuga heterophylla were also susceptible. Pseudotsuga menziesii and A. procera were severely affected. Pinus contorta, P. nigra var. maritima and P. sylvestris were virtually resistant, while Taxus baccata was only slightly affected. Increased necrosis was apparent on leaves that were wounded prior to inoculation. These results extend the known range of trees that P. ramorum is able to attack and confirm its relative host-nonspecificity.

}, keywords = {broad-leaved species, conifers, detached leaf dip assay, foliage, forest species, Sudden oak death}, issn = {1365-3059}, doi = {10.1111/j.1365-3059.2005.01243.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2005.01243.x}, author = {Denman, S. and Kirk, S.A. and C.M. Brasier and Webber, JF} } @article {1106, title = {Victoria{\textquoteright}s Public Land Phytophthora cinnamomi Management Strategy}, year = {2008}, pages = {37 pp}, publisher = {Department of Sustainability and Environment, PO Box 500, East Melbourne, Victoria, Australia}, isbn = {978-1-74152-795-7}, url = {http://lakeshub.com/wp-content/uploads/2013/04/Phytophthora_cinnamomi_Strategy-1.pdf}, author = {Department of Sustainability and Environment} } @article {4631, title = {First Report of Phytophthora chlamydospora Causing Root Rot on Walnut (Juglans regia ) Trees in Turkey}, journal = {Plant Disease}, volume = {100}, year = {2016}, month = {Jan-11-2016}, pages = {2336}, abstract = {

Common or English (Persian) walnut (Juglans regia L.) is an important nut crop in Turkey, which is the fourth largest producer of walnut in the world. In August 2015, we observed sudden wilt and subsequent death associated with root rot. Approximately 15\% of 2,000 5- to 7-year-old J. regia cv. Chandler trees grafted on wild walnut (J. regia) in waterlogged areas of a commercial walnut orchard in Bing{\"o}l province of eastern Turkey were affected. Most fine roots were completely rotted and the inner bark of infected lateral and taproots showed a reddish brown discoloration. Tissue samples taken from the margins of root lesions of 10 symptomatic trees were placed on grated carrot corn meal agar (GCCMA) (T{\"u}rk{\"o}lmez et al. 2015) amended with 5 mg of pimaricin, 250 mg of ampicillin, 10 mg of rifampicin, 100 mg of pentachloronitrobenzene, and 50 mg of hymexazol per liter (P5ARPH). Plates were incubated for 5 days at 28{\textdegree}C in the dark. A Phytophthora species was consistently isolated from the tissues. On GCCMA, colonies had a distinct petaloid growth pattern and produced abundant spherical, thin-walled, intercalary and terminal chlamydospores (30 to 46 μm diameter) and hyphal chains of globose to subglobose swellings. After incubation of mycelial disks in nonsterile soil extracts at 25{\textdegree}C, all isolates produced hyaline, nonpapillate, noncaducous sporangia of ovoid to obpyriform shape, with internal proliferation, measuring 34.5 to 56.5 μm in length, 27.0 to 39.5 μm wide, with a length/breadth ratio of 1.4 to 1.7, formed on unbranched or sympodial sporangiophores. Growth rate on carrot agar (CA) at 25{\textdegree}C was 3.3 to 3.5 mm d-1; the optimum and maximum temperatures for mycelium growth on CA were 29 and 37{\textdegree}C, respectively. All these characteristics were similar to those described for Phytophthora chlamydospora Brasier and Hansen (Hansen et al. 2015), previously known as P. taxon Pgchlamydo. Genomic DNA was extracted from three representative isolates. The internal transcribed spacer (ITS) region of rDNA and cox2 gene regions were amplified using the ITS6/ITS4 and FMPhy10b/FMPhy8b primer pairs, respectively, and sequenced (GenBank accession nos. KU725882, KU725883, KU707216, KX446861, KX446862). BLAST searches of ITS region showed 100\% identity to many P. chlamydospora isolates, including the ex-type culture P236 (AF541900) (Brasier et al. 2003), deposited in GenBank and of cox2 gene regions of two isolates had 100\% identity with PD_01777_cox2 and PD_00174_cox2 accessions deposited at Phytophthora-ID databases, which confirmed the morphological identification. Pathogenicity of P. chlamydospora was evaluated using the soil infestation method on 10 1-year-old potted J. regia cv. Chandler seedlings by growing P. chlamydospora on sterilized millet seeds for 4 weeks at 29{\textdegree}C and adding infested millet seeds to potting soil at a rate of 3\% (w/v). In 10 noninoculated control plants, sterilized millet seeds were added to the potting soil. Both inoculated and control plants were flooded for 24 h at 2 week intervals. All inoculated plants showed severe wilting within a month and necrosis on lateral and taproots and rot on fineroots after 2 months of incubation in a greenhouse where air temperatures ranged from 24 to 30{\textdegree}C, while control plants remained asymptomatic. Koch{\textquoteright}s postulates were satisfied after reisolating P. chlamydospora, which was identified morphologically, from symptomatic roots of inoculated plants. P. chlamydospora has been previously recovered from several ornamental and woody species (Blomquist et al. 2012; Brasier et al. 2003; Ginetti et al. 2014), and to our knowledge, this is the first report of P. chlamydospora infection of walnut, which represents a new host for this pathogen.

}, issn = {0191-2917}, doi = {10.1094/PDIS-03-16-0306-PDN}, url = {http://apsjournals.apsnet.org/doi/10.1094/PDIS-03-16-0306-PDN}, author = {Dervi{\c s}, S. and T{\"u}rk{\"o}lmez, {\c S}. and {\c C}ift{\c c}i, O. and Ser{\c c}e, {\c C}. U.} } @inbook {4136, title = {Phytophthora diseases of Theobroma cacao}, booktitle = {Improvement of cocoa tree resistance to Phytophthora diseases}, year = {2004}, pages = {15{\textendash}44}, publisher = {CIRAD}, organization = {CIRAD}, address = {Montpellier, France}, author = {Despreaux, Denis}, editor = {Cilas, C. and Despreaux, Denis} } @article {4230, title = {Pathogenicity of Phytophthora pluvialis to Pinus radiata and its relation with red needle cast disease in New Zealand}, journal = {New Zealand Journal of Forestry Science}, volume = {44}, year = {2014}, month = {Jan-01-2014}, pages = {6}, abstract = {

Background

Red needle cast, a new foliage disease of Pinus radiata in New Zealand is described. The disease has been variable in incidence and severity both regionally and in different years. The early symptoms of discrete olive coloured lesions, often with a narrow dark resinous mark or band, were first recognised in winter of 2008 in plantation forests on the eastern coast of the North Island. These lesions develop further to result in rapid needle senescence and premature defoliation. The disease has been termed red needle cast in New Zealand as affected trees have a reddish appearance prior to the casting of the needles. The subsequent four years of monitoring have confirmed that, depending on location, symptoms are first observed in late autumn through late winter. Newly developing spring and summer foliage is seldom affected. Isolation from needles using a Phytophthora-selective medium frequently yielded an unknown species of Phytophthora which was subsequently found to be identical to Phytophthora pluvialis, a species described from Oregon, USA in 2013 where it is not associated with disease. Infection appears to be limited to the needles with no recoveries of Phytophthora pluvialis having been made from the roots, stems or branches. Occasionally a second species of Phytophthora, P. kernoviae, was also recovered from needles with the same symptoms.

Methods

Needle symptoms were described in the field from 2008-2012 with isolation onto Phytophthora selective media. Koch{\textquoteright}s postulates was completed on potted plants and detached needles.

Results

Symptoms were reproduced on both detached needles and potted plants of Pinus radiata when inoculated with zoospore suspensions of Phytophthora pluvialis.

Conclusions

This paper presents evidence that Phytophthora pluvialis is the primary cause of red needle cast in New Zealand.

}, issn = {1179-5395}, doi = {10.1186/s40490-014-0006-7}, url = {http://www.nzjforestryscience.com/content/44/1/6}, author = {Dick, Margaret and Williams, Nari and Bader, Martin and Gardner, Judy and Bulman, Lindsay} } @article {NPH:NPH2450, title = {Evidence for the role of synchronicity between host phenology and pathogen activity in the distribution of sudden oak death canker disease}, journal = {New Phytologist}, volume = {179}, number = {2}, year = {2008}, pages = {505{\textendash}514}, publisher = {Blackwell Publishing Ltd}, abstract = {

Variations in synchronicity between colonization rate by the pathogen and host phenology may account for unexplained spatial distribution of canker disease. The hypothesis that synchronous pathogenicity and host development are necessary for incidence of sudden oak death disease was tested by correlating seasonal variations in host cambial phenology and response to inoculation with Phytophthora ramorum.

}, keywords = {exotic pathogen, inoculation, Phytophthora ramorum, Quercus agrifolia, resistance, spatial distribution, synchronicity}, issn = {1469-8137}, doi = {10.1111/j.1469-8137.2008.02450.x}, url = {http://dx.doi.org/10.1111/j.1469-8137.2008.02450.x}, author = {Richard S. Dodd and H{\"u}berli, , Daniel and Mayer, Wasima and Harnik, Tamar Y. and Afzal-Rafii, Zara and Garbelotto, Matteo} } @article {655, title = {A crown rot of hollyhock caused by Phytophthora megasperma n. sp.}, journal = {J Wash Acad Sci}, volume = {21}, year = {1931}, pages = {513-526}, author = {Drechsler, C.} } @article {4335, title = {First evidence of genetic-based tolerance to red needle cast caused by Phytophthora pluvialis in radiata pine}, journal = {New Zealand Journal of Forestry Science}, volume = {44}, year = {2014}, pages = {31}, abstract = {

BACKGROUND:Red needle cast (RNC) is a new needle disease of Pinus radiata D. Don (radiata pine) in New Zealand that is causing significant, but as-yet un-quantified, loss of growth and productivity. This foliar disease has recently been attributed to the infection of the needles by Phytophthora pluvialis Reeser, Sutton \& E Hansen. Genetic improvement is seen as a possible solution to mitigate the effects of this needle disease on forest productivity.FINDINGS:To quantify the ability of genetics to provide a solution, RNC was assessed on a single clones-within-families genetics trial using two methods: the percentage needle cast that was attributable to red needle cast symptoms; and the percentage needle cast where the causal agent was not clearly identifiable. Both needle cast assessment methods were found to be heritable (h2 0.21-0.31).CONCLUSIONS:Selecting for tolerance to RNC is likely to deliver healthier trees. More assessments across a number of sites and seasons are required to confirm this result.

}, issn = {1179-5395}, doi = {10.1186/s40490-014-0028-1}, url = {http://www.nzjforestryscience.com/content/44/1/31}, author = {Dungey, Heidi and Williams, Nari and Low, Charlie and Stovold, Graham} } @article {murdoch2427, title = {Control of Phytophthora cinnamomi with phosphite: some recent developments in application methods}, journal = {Australasian Plant Conservation}, volume = {34}, number = {4}, year = {2005}, pages = {10{\textendash}11}, publisher = {Australian Network for Plant Conservation Inc.}, abstract = {

Phytophthora cinnamomi has a world-wide distribution, causes disease in a very wide range of plants and is responsible for the destruction of certain plant communities in Europe and Australia. P. cinnamomi was probably introduced into Australia in the nineteenth century and is now established in south-western Australia and Tasmania, and throughout eastern Australia, from South Australia to the wet tropics. P. cinnamomi is listed as a Key Threatening Process under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999.

}, url = {http://researchrepository.murdoch.edu.au/2427/}, author = {Dunstan, W.A. and G.E.St.J. Hardy} } @article {4459, title = {An overview of Australia{\textquoteright}s Phytophthora species assemblage in natural ecosystems recovered from a survey in Victoria}, journal = {IMA Fungus}, volume = {7}, year = {2016}, month = {Jan-01-2016}, pages = {47-58}, abstract = {

Although Phytophthora species cause serious diseases worldwide, until recently the main focus on disease in natural ecosystems in southern Australia has been on the distribution and impact of P. cinnamomi. However, new Phytophthora pathogens have emerged from natural ecosystems, and there is a need to better understand the diversity and distribution of these species in our natural forests, woodlands and heathlands. From a survey along a 70 km pipeline easement in Victoria, Phytophthora species were isolated from 249 rhizosphere samples and 25 bait bags deployed in 21 stream, river, or wetland locations. Of the 186 Phytophthora isolates recovered, 130 were identified to species based on ITS sequence data. Ninety-five isolates corresponded to 13 described Phytophthora species while additionally 35 isolates were identified as Clade 6 hybrids. Phytophthora cinnamomi was the most common species isolated (31 \%), followed by P. elongata (6 \%), both species were only recovered from soil. Samples from sites with the highest soil moisture at the time of sampling had the highest yield of isolates. Consistent with other studies throughout the world, Clade 6 species and their hybrids dominated water samples, although many of these species were also recovered less frequently from soil samples. Many of the species recovered in this study have not previously been reported from eastern Australia, reinforcing that Phytophthora species are widespread, abundant and diverse in natural ecosystems. We have probably been underestimating Phytophthora diversity in Australia.

}, doi = {10.5598/imafungus.2016.07.01.04}, url = {http://www.ingentaconnect.com/content/ima/imafung/pre-prints/content-k4_Vol7_no1_Article4}, author = {William A. Dunstan and Kay Howard and Giles E. StJ. Hardy and Treena I. Burgess} } @article {Dur{\textperiodcentered}n2010746, title = {AFLP analysis reveals a clonal population of Phytophthora pinifolia in Chile}, journal = {Fungal Biology}, volume = {114}, number = {9}, year = {2010}, pages = {746 - 752}, keywords = {Pinus radiata}, issn = {1878-6146}, doi = {DOI: 10.1016/j.funbio.2010.06.008}, url = {http://www.sciencedirect.com/science/article/B9879-50GMMRW-1/2/c0c76996906d7b589f9430c65d0b2880}, author = {Dur{\'a}n, Alvaro and Marieka Gryzenhout and Andr{\`E} Drenth and Bernard Slippers and Rodrigo Ahumada and Brenda D. Wingfield and Michael J. Wingfield} } @article {483, title = {DNA-based method for rapid identification of the pine pathogen, Phytophthora pinifolia}, journal = {FEMS Microbiology Letters}, volume = {298}, year = {2009}, pages = {99-104}, abstract = {

Phytophthora pinifolia causes a needle and shoot disease in Pinus radiata, referred to as {\textquoteleft}Da{\~n}o Foliar del Pino{\textquoteright}. This newly discovered disease requires intensive research efforts that necessitate the processing of large numbers of samples for which accurate identification, often by people not experienced in Phytophthora taxonomy, is required. The aim of this study was, therefore, to develop species-specific primers for P. pinifolia that amplify the internal transcribed spacer region of the ribosomal operon and the nuclear Ypt1 gene, respectively. The primers were tested over several Phytophthora spp., as well as fungi isolated from P. radiata. In all cases, only P. pinifolia was amplified. In addition to the species-specific primers, a PCR-restriction fragment length polymorphism protocol using available Phytophthora genus-specific primers was also used to generate a species-specific profile for P. pinifolia. This provided a characteristic profile that allows the identification of P. pinifolia, and it could also discriminate between 27 different species of Phytophthora. Both techniques reported in this study make it possible to identify large numbers of P. pinifolia cultures accurately and efficiently, which will be important for both quarantine work and biological research on this important new pathogen.

}, keywords = {Monterey pine, oomycetes, Pinus radiata, tree defoliation}, doi = {DOI: 10.1111/j.1574-6968.2009.01700.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1574-6968.2009.01700.x/abstract}, author = {Dur{\'a}n, Alvaro and Bernard Slippers and Marieka Gryzenhout and Rodrigo Ahumada and Drenth, Andre and Brenda D. Wingfield and Michael J. Wingfield} } @article {481, title = {Phytophthora pinifolia sp. nov. associated with a serious needle disease of Pinus radiata in Chile}, journal = {Plant Pathology}, volume = {57}, year = {2008}, pages = {715{\textendash}727}, abstract = {

During the course of the past three years, a new disease of ,em\>Pinus radiata, referred to as {\textquoteleft}Da{\~n}o Foliar del Pino{\textquoteright} (DFP) has appeared in the Arauco province of Chile and subsequently spread to other areas. The disease is typified by needle infections, exudation of resin at the bases of the needle brachyblasts and, in younger trees, necrotic lesions in the cambium, which eventually girdle the branches. The disease causes the death of young seedlings and mature trees can also succumb after a few years of successive infection, probably hastened by opportunistic fungi such as ,em\>Diplodia pinea. Isolations on selective medium for Phytophthora spp. led to the consistent isolation of a Phytophthora sp. from needle tissue. DNA sequence comparisons for the ITS rDNA and cox II gene regions, and morphological observation showed that this oomycete represents a previously undescribed species for which the name Phytophthora pinifolia sp. nov. is provided. This new species is characterized by unbranched sporangiophores, and non-papillate, sub-globose to ovoid sporangia that are occasionally free from the sporangiophore with medium length pedicels. Despite using a number of oospore inducing techniques, oogonia/antheridia were not observed in isolates of P. pinifolia. Pathogenicity trials with P. pinifolia showed that it is pathogenic to P. radiata and causes rapid death of the succulent apical parts of young plants. Phytophthora pinifolia is the first Phytophthora known to be associated with needles and shoots of a Pinus sp. and its aerial habit is well matched with the occurrence and symptoms of DFP in Chile.

}, keywords = {Monterey pine, oomycete phylogeny, plantation forestry}, doi = {10.1111/j.1365-3059.2008.01893.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2008.01893.x}, author = {Dur{\'a}n, A. and Gryzenhout, M. and Slippers, B. and Ahumada, R. and Rotella, A. and Flores, F. and Wingfield, B. D. and Wingfield, M. J.} }