@article {4678, title = {CPHST Pest Datasheet for Phytophthora kernoviae}, year = {2015}, publisher = {USDA-APHIS-PPQ-CPHST}, url = {http://download.ceris.purdue.edu/file/2780}, author = {Mackesy, D. and Sullivan, M.} } @article {3999, title = {Analyses of the population structure in a global collection of Phytophthora nicotianae isolates inferred from mitochondrial and nuclear DNA sequences}, journal = {Phytopathology}, volume = {Early release}, year = {2013}, month = {02/2013}, abstract = {

Genetic variation within the heterothallic cosmopolitan plant pathogen Phytophthora nicotianae was determined in 96 isolates from a wide range of hosts and geographic locations by characterizing four mitochondrial (10\% of the genome) and three nuclear loci. Fifty-two SNPs (average of 1 every 58 bp) and 313 sites with gaps representing 5450 bases, enabled the identification of 50 different multilocus mitochondrial haplotypes. Similarly, 24 SNPs (average of 1 every 69 bp), with heterozygosity observed at each locus, were observed in three nuclear regions (hyp, scp, β-tub) differentiating 40 multilocus nuclear genotypes. Both mitochondrial and nuclear markers revealed a high level of dispersal of isolates and an inconsistent geographic structuring of populations. However, a specific association was observed for host of origin and genetic grouping with both nuclear and mitochondrial sequences. In particular, the majority of citrus isolates from Italy, California, Florida, Syria, Albania and Philippines clustered in the same mitochondrial group and shared at least one nuclear allele. A similar association was also observed for isolates recovered from Nicotiana spp. and Solanum spp. The present study suggests an important role of nursery populations in increasing genetic recombination within the species and the existence of extensive phenomena of migration of isolates that have been likely spread worldwide with infected plant material.

}, issn = {0031-949X}, doi = {10.1094/PHYTO-10-12-0263-R}, author = {Mammella, Marco A. and Martin, Frank N. and Cacciola, Santa O. and Coffey, Michael and Faedda, Roberto and Schena, Leonardo} } @article {4481, title = {Limited morphological, physiological and genetic diversity of Phytophthora palmivora from cocoa in Papua New Guinea}, journal = {Plant Pathology}, volume = {66}, year = {2017}, month = {Jan-05-2016}, pages = {124{\textendash}130}, abstract = {

In Papua New Guinea (PNG) cocoa (Theobroma cacao) is one of the most important cash crops grown in the tropical lowland and island regions. As in most cocoa-growing areas, phytophthora black pod and canker cause significant yield losses. Cocoa breeding activities in PNG are focused in East New Britain province where disease control recommendations are also developed. This study tested the hypothesis that there was no diversity in the Phytophthora palmivora population causing black pod on cocoa by characterizing the variation in pathogen populations within and between the five major cocoa-growing areas. Diseased pods were sampled hierarchically from the five locations and additional isolates were collected from soil, stem and leaf lesions, or retrieved from culture collections. Morphological characters showed continuous variation within the range described for P.\ palmivora. Genetic analysis revealed that the isolates belonged to one dominant clonal lineage, with restricted distributions of several other subpopulations. Lowest diversities were found in the geographically isolated Karkar Island and East Sepik province. Soil isolates showed greater genetic diversity than isolates from cocoa lesions. Intra-farm variation was as much as inter-farm or inter-province variation. Both mating types were detected, although no strong evidence of sexual recombination was observed. The analysis revealed limited geographic, temporal or host specialization, suggesting continuous selection for pathogenicity from a genetic pool of P.\ palmivora. These findings have significant implications on the deployment of cocoa genotypes, enforcement of inter-province quarantine and sustainable disease management strategies.

}, doi = {10.1111/ppa.12557}, url = {http://doi.wiley.com/10.1111/ppa.12557}, author = {Maora, J. S. and Liew, E. C. Y. and Guest, D. I.} } @article {269, title = {Modelling the influence of winter frosts on the development of the stem canker of red oak, caused by Phytophthora cinnamomi.}, journal = {Annales des Sciences Forestiere}, volume = {53}, year = {1996}, pages = {369-382}, doi = {DOI: 10.1051/forest:19960219}, url = {http://dx.doi.org/10.1051/forest:19960219}, author = {Mar{\c c}ais, B. and Dupuis, F. and Desprez-Loustau, M.L.} } @article {martin_phylogenetic_2003, title = {Phylogenetic relationships of Phytophthora ramorum, P. nemorosa, and P. pseudosyringae, three species recovered from areas in California with sudden oak death.}, journal = {Mycological research}, volume = {107}, year = {2003}, pages = {1379{\textendash}1391}, keywords = {California, cytochrome-c oxidase, forest trees, fungal anatomy, internal transcribed spacers, mitochondrial DNA, molecular systematics, phylogeny, Phytophthora, Phytophthora ramorum, plant pathogenic fungi, Quercus, ribosomal DNA, sequence analysis}, issn = {09537562}, doi = {http://dx.doi.org/10.1017/S0953756203008785}, author = {F.N. Martin and P.W. Tooley} } @article {1297, title = {Molecular detection of Phytophthora ramorum, the causal agent of sudden oak death in California, and two additional species commonly recovered from diseased plant material}, journal = {Phytopathology}, volume = {94}, year = {2004}, pages = {621-631}, abstract = {

Sudden oak death is a disease currently devastating forest ecosystems in several coastal areas of California. The pathogen causing this is Phy-tophthora ramorum, although species such as P. nemorosa and P. pseudo-syringae often are recovered from symptomatic plants as well. A molecular marker system was developed based on mitochondrial sequences of the cox I and II genes for detection of Phytophthora spp. in general, and P. ramorum, P. nemorosa, and P. pseudosyringae in particular. The first-round multiplex amplification contained two primer pairs, one for amplification of plant sequences to serve as an internal control to ensure that extracted DNA was of sufficient quality to allow for polymerase chain reaction (PCR) amplification and the other specific for amplification of sequences from Phytophthora spp. The plant primers amplified the desired amplicon size in the 29 plant species tested and did not interfere with amplification by the Phytophthora genus-specific primer pair. Using DNA from purified cultures, the Phytophthora genus-specific primer pair amplified a fragment diagnostic for the genus from all 45 Phytophthora spp. evaluated, although the efficiency of amplification was lower for P. lateralis and P. sojae than for the other species. The genus-specific primer pair did not amplify sequences from the 30 Pythium spp. tested or from 29 plant species, although occasional faint bands were observed for several additional plant species. With the exception of one plant species, the resulting amplicons were smaller than the Phytophthora genus-specific amplicon. The products of the first-round amplification were diluted and amplified with primer pairs nested within the genus-specific amplicon that were specific for either P. ramorum, P. nemorosa, or P. pseudo-syringae. These species-specific primers amplified the target sequence from all isolates of the pathogens under evaluation; for P. ramorum, this included 24 isolates from California, Germany, and the Netherlands. Using purified pathogen DNA, the limit of detection for P. ramorum using this marker system was ≈2.0 fg of total DNA. However, when this DNA was spiked with DNA from healthy plant tissue extracted with a commercial miniprep procedure, the sensitivity of detection was reduced by 100- to 1,000-fold, depending on the plant species. This marker system was validated with DNA extracted from naturally infected plant samples collected from the field by comparing the sequence of the Phytophthora genus-specific amplicon, morphological identification of cultures recovered from the same lesions and, for P. ramorum, amplification with a previously published rDNA internal transcribed spacer species-specific primer pair. Results were compared and validated with three different brands of thermal cyclers in two different laboratories to provide information about how the described PCR assay performs under different laboratory conditions. The specificity of the Phytophthora genus-specific primers suggests that they will have utility for pathogen detection in other Phytophthora pathosystems.

}, url = {http://dx.doi.org/10.1094/PHYTO.2004.94.6.621}, author = {Martin, Frank N. and Tooley, Paul W. and Cheryl Blomquist} } @article {1273, title = {Identification and detection of Phytophthora: reviewing our progress, identifying our needs}, journal = {Plant Disease}, volume = {96}, year = {2012}, pages = {1080-1103}, abstract = {

With the increased attention given to the genus Phytophthora in the last decade in response to the ecological and economic impact of several invasive species (such as P. ramorum, P. kernoviae, and P. alni), there has been a significant increase in the number of described species. In part, this is due to the extensive surveys in historically underexplored ecosystems (e.g., forest and stream ecosystems) undertaken to determine the spread of invasive species and the involvement of Phytophthora species in forest decline worldwide (e.g., oak decline). The past decade has seen an approximate doubling in the number of described species within the genus Phytophthora, and the number will likely continue to increase as more surveys are completed and greater attention is devoted to clarifying phylogenetic relationships and delineating boundaries in species complexes. The development of molecular resources, the availability of credible sequence databases to simplify identification of new species, and the sequencing of several genomes have provided a solid framework to gain a better understanding of the biology, diversity, and taxonomic relationships within the genus. This information is much needed considering the impact invasive or exotic Phytophthora species have had on natural ecosystems and the regulatory issues associated with their management. While this work is improving our ability to identify species based on phylogenetic grouping, it has also revealed that the genus has a much greater diversity than previously appreciated.

}, url = {http://dx.doi.org/10.1094/PDIS-12-11-1036-FE}, author = {Martin, Frank N. and Z. Gloria Abad and Yilmaz Balci and Ivors, Kelly} } @mastersthesis {martin_developing_2008, title = {Developing techniques for evaluating the susceptibility of root-disease resistant Port-Orford-Cedar to foliar and stem canker diseases.}, year = {2008}, type = {mastersphd}, author = {Danielle Martin} } @article {4374, title = {First Report of Phytophthora tentaculata Causing Root and Stem Rot of Oregano in Italy}, journal = {Plant Disease}, volume = {93}, year = {2009}, month = {Jan-08-2009}, pages = {843 - 843}, abstract = {

Oregano (Origanum vulgare L.; Lamiaceae) is cultivated for culinary and medicinal purposes and as an ornamental. In October of 2007, 1- to 2-year-old potted plants of oregano showed symptoms of decline associated with root and basal stem rot in a nursery in Liguria (northern Italy) that produces 1 million to 1.5 million potted aromatic plants per year. Aboveground symptoms included leaf russeting and chlorosis, wilt, defoliation and dieback of twigs, browning of the basal stem, and subsequent collapse of the entire plant. Approximately 80\% of the plants died within 30 days after the appearance of the first symptoms on the canopy. Approximately 20\% of a stock of 30,000 oregano plants was affected. Stocks of other aromatic species, such as mint, lavender, rosemary, and sage, appeared healthy. A Phytophthora species was consistently isolated from symptomatic stems and roots of oregano plants on BNPRAH selective medium (2). Ten pure cultures were obtained by single-hypha transfers, and the species was identified as Phytophthora tentaculata Kr{\"o}ber \& Marwitz by morphological criteria and sequencing of the internal transcribed spacer (ITS) region of rDNA using the ITS 4 and ITS 6 universal primers for DNA amplification. Isolates from oregano formed stoloniferous colonies with arachnoid mycelium on potato dextrose agar and had a growth rate of 2 to 3 mm per day at 24{\textdegree}C with optimum, minimum, and maximum temperatures of 24, 8, and 34{\textdegree}C, respectively. Sporangia formed in soil extract solution and were papillate and spherical or ovoid to obpyriform with a length/breadth ratio of 1.3:1. Few sporangia were caducous and all had a short pedicel (\<5 μm). Hyphal swellings and chlamydospores were produced in sterile distilled water and corn meal agar, respectively. All isolates were homothallic and produced globose terminal oogonia (mean diameter of 34 μm) with one or occasionally two paragynous, monoclinous, or diclinous antheridia. Amphigynous antheridia were also observed. The sequence of the ITS region of the rDNA (GenBank No. FJ872545) of an isolate from oregano (IMI 395782) showed 99\% similarity with sequences of two reference isolates of P. tentaculata (Accession Nos. AF266775 and AY881001). To test for pathogenicity, the exposed root crowns of 10 6-month-old potted plants of oregano were drench inoculated with 10 ml of a suspension of 2 {\texttimes} 104 zoospores/ml of isolate IMI 395782. Sterile water was pipetted onto the roots of 10 control plants. All plants were maintained in 100\% humidity at 22 to 24{\textdegree}C in a greenhouse under natural light and watered once a week. Within 3 weeks after inoculation, all inoculated plants developed symptoms identical to those observed in the nursery and died within 30 to 40 days after the appearance of the first symptoms. Control plants remained healthy. P. tentaculata was reisolated solely from symptomatic plants. P. tentaculata has been reported previously on several herbaceous ornamental plants (1,3). However, to our knowledge, this is the first report of this species on O. vulgare. Root and basal stem rot caused by P. tentaculata is the most serious soilborne disease of oregano reported in Italy so far.

}, issn = {0191-2917}, doi = {10.1094/PDIS-93-8-0843B}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-93-8-0843B}, author = {Martini, P. and Pane, A. and Raudino, F. and Chimento, A. and Scibetta, S. and Cacciola, S. O.} } @article {MEC:MEC3773, title = {Reconstruction of the sudden oak death epidemic in California through microsatellite analysis of the pathogen Phytophthora ramorum}, journal = {Molecular Ecology}, volume = {17}, number = {11}, year = {2008}, pages = {2755{\textendash}2768}, publisher = {Blackwell Publishing Ltd}, abstract = {

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{\textquoteright}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{\textendash}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{\textquoteright} 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{\textquoteright} 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.

}, keywords = {genetic structure, microsatellite, network analysis, Phytophthora ramorum, spatial autocorrelation, Sudden oak death}, issn = {1365-294X}, doi = {10.1111/j.1365-294X.2008.03773.x}, url = {http://dx.doi.org/10.1111/j.1365-294X.2008.03773.x}, author = {Mascheretti, S. and Croucher, P. J. P. and Vettraino, A. Vettraino and Prospero, S and Garbelotto, M.} } @article {4079, title = {Two new Phytophthora species from South African Eucalyptus plantations}, journal = {Mycological Research}, volume = {111}, year = {2007}, month = {11/2007}, pages = {1321 - 1338}, abstract = {

A recent study to determine the cause of collar and root rot disease outbreaks of cold tolerant Eucalyptus species in South Africa resulted in the isolation of two putative new Phytophthora species. Based on phylogenetic comparisons using the ITS and β-tubulin gene regions, these species were shown to be distinct from known species. These differences were also supported by robust morphological characteristics. The names, Phytophthora frigida sp. nov. and Phytophthora alticola sp. nov. are thus provided for these taxa, which are phylogenetically closely related to species within the ITS clade 2 (P. citricola, P. tropicali and P.multivesiculata) and 4 (P. arecae and P. megakarya), respectively. Phytophthora frigida is heterothallic, and produces stellate to rosaceous growth patterns on growth medium, corraloid hyphae, sporangia with a variety of distorted shapes and has the ability to grow at low temperatures. Phytophthora alticola is homothallic and has a slower growth rate in culture. Both P. frigida and P. alticola are pathogenic to Eucalyptus dunnii. In pathogenicity tests, they were, however, less pathogenic than P. cinnamomi, which is a well-known pathogen of Eucalyptus in South Africa.

}, issn = {09537562}, doi = {10.1016/j.mycres.2007.08.011}, url = {http://www.sciencedirect.com/science/article/pii/S0953756207001955}, author = {Maseko, Bongani and Burgess, Treena I. and Coutinho, Teresa A. and Michael J. Wingfield} } @mastersthesis {612, title = {An undescribed Phytophthora sp. recovered from beneath stands of Pinus radiata.}, volume = {MS}, year = {1970}, pages = {63}, school = {Auckland University}, type = {mastersMS}, address = {New Zealand}, author = {McAlonan, M.J.} } @article {4198, title = {Phytophthora cinnamomi as a Contributor to White Oak Decline in Mid-Atlantic United States Forests}, journal = {Plant Disease}, volume = {98}, year = {2014}, month = {Jan-03-2014}, pages = {319 - 327}, abstract = {

To evaluate Phytophthora cinnamomi as a cause of white oak (Quercus alba) decline in mid-Atlantic forests, sampling was conducted at 102 sites from 2011 to 2012. Soil and roots from healthy and declining white oak trees were collected. Phytophthora spp. were isolated using baiting and CFU of P. cinnamomi quantified using wet-sieving. Fine roots were scanned and measured. Phytophthora spp. were isolated from 43\% of the sites. P. cinnamomi was common; six other species were isolated infrequently. Little difference in lesion size existed on white oak seedlings inoculated with 32 isolates of P. cinnamomi; only 13 isolates caused significant mortality. Soils from white oak versus nine other hosts did not have significantly different CFU. P. cinnamomi was restricted to United States Department of Agriculture hardiness zones six and seven and never found in zone five. The presence of Phytophthora spp. in soil can be associated with white oak fine root health. When Phytophthora spp. were present, white oak trees in zones five and six had less fine roots. In mid-Atlantic oak forests, however, environmental conditions appear to play a key role in determining the impact of P. cinnamomi on the root system. P. cinnamomi alone does not appear to be a causal factor of white oak decline.

}, issn = {0191-2917}, doi = {10.1094/PDIS-06-13-0649-RE}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-06-13-0649-RE}, author = {McConnell, M. E. and Balci, Y.} } @article {4046, title = {Isozyme diversity in Phytophthora palmivora: evidence for a southeast Asian centre of origin}, journal = {Mycological Research}, volume = {98}, year = {1994}, month = {9/1994}, pages = {1035 - 1043}, abstract = {

Isozyme and morphological data were obtained for 93 isolates of P. palmivora and six described as P. arecae. Sporangial shape for both species ranged from spherical to ellipsoid with a high percentage of sporangia predominantly ellipsoid with a broad base and a short occluded pedicel less than 5 m in length. Fourteen enzymes stained in starch gels yielding 17 putative loci, 11 of which were monomorphic, the remainder being polymorphic (GPI, HEX2, IDH1, MDH1, PEP and SOD). Phosphoglucose isomerase (GPI) and isocitric dehydrogenase (IDH1) were the most variable loci. Isozyme analysis of the 99 isolates revealed 18 electrophoretic types (ETs). Isolates of P. arecae clustered with P. palmivora in ET7 and ET8, the most common ETs found in P. palmivora. Considerable genetic diversity was found amongst P. palmivora isolates from coconut (Cocos nucifera) with 8 ETs, durian (Durio zibethinus) with 5 ETs and other non-cacao hosts from Indonesia, Malaysia, Philippines and Thailand. Since coconut and durian are indigenous to the region, a southeast Asian origin for P. palmivora seems probable. Finally, since no significant differences were found in either morphology or isozymes between isolates of P. palmivora and P. arecae, this study provides definitive evidence that the two species are conspecific.

}, issn = {09537562}, doi = {10.1016/S0953-7562(09)80430-9}, url = {http://www.sciencedirect.com/science/article/pii/S0953756209804309}, author = {Mchau, Godwin R.A. and Michael D. Coffey} } @mastersthesis {mcwilliams_port-orford-cedar_2000, title = {Port-Orford-cedar and Phytophthora lateralis: grafting and heritability of resistance in the host, and variation in the pathogen}, volume = {PhD}, year = {2000}, school = {Oregon State University}, type = {masters}, address = {Corvallis}, abstract = {

Port-Orford-cedar (Chamaecyparis lawsoniana) is a forest tree native to a small area of Oregon and California. A root disease caused by Phytophthora lateralis causes widespread mortality of Port-Orford-cedar. This dissertation examines three important elements of the Port-Orford-cedar P. lateralis pathosystem related to breeding for disease resistance: use of resistant rootstocks to maintain genotypes of Port-Orford-cedar for breeding; the heritability and genetic basis of disease resistance; and variability in virulence and DNA fingerprint among a sample of P. lateralis isolates. Port-Orford-cedar was reciprocally grafted to western redcedar (Thuja plicata), incense cedar (Calocedrus decurrens), and Alaska yellow-cedar (Chamaecyparis nootkatensis). Port-Orford-cedar scion graft success was moderate with western red cedar and incense cedar, but extreme overgrowth of the rootstock by the scion indicated incompatibility. Xylem union was good, but phloem union was incomplete or lacking. Nearly all Port-Orford-cedar rootstocks and seedlings exposed to P. lateralis died of root disease. Four percent of the Alaska yellow-cedar exposed also died, confirming this tree as a host for P. lateralis. Resistance of Port-Orford-cedar to P. lateralis is rare. A small number of trees have been identified exhibiting resistance. A number of families were tested to determine the genetic basis for resistance. Estimates of narrow-sense and family mean heritability of resistance, as exhibited by restriction of lesion length after inoculation, were determined. Both narrow-sense and family mean heritabilities were between 0.61 and 0.98 in most tests. Between 21\% and 32\% of the variance was due to differences among families. Thirteen isolates of P. lateralis were collected from three hosts throughout the geographic range of the fungus. Variation in growth rate on artificial media at three temperatures, virulence when used to inoculate Port-Orford-cedar, and DNA fingerprint were compared. There were significant differences in growth rate among isolates at 24C, but fewer differences at lower temperatures and on a rich medium. One isolate produced significantly shorter lesions in three different inoculation tests. Isolates differed at only two of 189 bands produced by Inter Simple Sequence Repeat (ISSR) DNA primers, indicating very little genetic variation among isolates.

}, url = {http://oasis.oregonstate.edu/record=b2155969}, author = {Michael G McWilliams} } @article {doi:10.1094/PDIS-07-10-0505, title = {Effects of fuel reduction treatments on incidence of Phytophthora species in soil of a southern Appalachian Mountain forest}, journal = {Plant Disease}, volume = {95}, number = {7}, year = {2011}, pages = {811-820}, abstract = {

The National Fire and Fire Surrogate Study was initiated to study the effects of fuel reduction treatments on forest ecosystems. Four fuel reduction treatments were applied to three sites in a southern Appalachian Mountain forest in western North Carolina: prescribed burning, mechanical fuel reduction, mechanical fuel reduction followed by prescribed burning, and a nontreated control. To determine the effects of fuel reduction treatments on Phytophthora spp. in soil, incidences were assessed once before and twice after fuel reduction treatments were applied. Also, the efficiency of the baiting bioassay used to detect species of Phytophthora was evaluated, and the potential virulence of isolates of Phytophthora spp. collected from forest soils was determined. Phytophthora cinnamomi and P. heveae were the only two species recovered from the study site. Incidences of these species were not significantly affected by fuel reduction treatments, but incidence of P. cinnamomi increased over time. In the baiting bioassay, camellia leaf disks were better than hemlock needles as baits. P. cinnamomi was detected best in fresh soil, whereas P. heveae was detected best when soil was air-dried and remoistened prior to baiting. Isolates of P. heveae were weakly virulent and, therefore, potentially pathogenic{\textemdash}causing lesions only on wounded mountain laurel and rhododendron leaves; however, isolates of P. cinnamomi were virulent and caused root rot and mortality on mountain laurel and white pine plants.

}, doi = {10.1094/PDIS-07-10-0505}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-07-10-0505}, author = {Meadows, I. M. and Zwart, D. C. and Jeffers, S. N. and Waldrop, T. A. and Bridges, W. C.} } @article {doi:10.1890/ES10-00192.1, title = {Epidemiological modeling of invasion in heterogeneous landscapes: spread of sudden oak death in California (1990{\textendash}2030)}, journal = {Ecosphere}, volume = {2}, number = {2}, year = {2011}, pages = {art17}, doi = {10.1890/ES10-00192.1}, url = {http://www.esajournals.org/doi/abs/10.1890/ES10-00192.1}, author = {Meentemeyer, Ross K. and Cunniffe, Nik J. and Cook, Alex R. and Filipe, Joao A. N. and Hunter, Richard D. and Rizzo, David M. and Gilligan, Christopher A.} } @article {4375, title = {First Report of Stalk Rot Caused by Phytophthora tentaculata on Aucklandia lappa in China}, journal = {Plant Disease}, volume = {92}, year = {2008}, month = {Jan-09-2008}, pages = {1365 - 1365}, abstract = {

Phytophthora tentaculata causes root and stalk rot of Chrysanthemum spp., Delphinium ajacis, and Verbena spp. in nurseries in the Netherlands and Germany (2). In later years, P. tentaculata was isolated from Verbena hybrids (3) and lavender cotton (Santolina chamaecyparissus) in Spain (1). In August 2007, stalk rot symptoms were observed on Aucklandia lappa (Asteraceae), an economically important Chinese medicinal plant, in some fields in Yunnan Province of China. Small groups of infected plants were randomly distributed throughout the fields. Plants showing stalk rot and wilting died rapidly. Diseased tissues were cut into 10-mm pieces and plated onto Phytophthora selective medium, P5ARP (2), to obtain the pure cultures. Seven isolates were obtained, and five isolates were grown on solidified LBA (60 g of lima bean powder and 15 g of agar per 10,000 ml of distilled water) and 10\% V8 juice liquid medium for examination of morphological and physiological characteristics (4). The colony surface texture was uniform and formed sparse, loosely branched mycelium on LBA medium. Radial growth rate was 2 to 3 mm per day at 24{\textdegree}C on LBA. In water, relatively small swellings were formed at hyphal branches. Sporangia were spherical or ovoid to obpyriform and some were distorted and papillate with a narrow exit pore. Approximately 10\% of the sporangia were caducous with a short pedicel. Sporangial dimensions were 28 to 47 (35) {\texttimes} 21 to 36 (29) μm, length/breadth ratio 1.2. Chlamydospores formed on LBA after 1 week and were terminal, spherical, thin walled, and 21 to 31 (27) μm in diameter. The isolates were homothallic. Oogonia abundantly formed on LBA and were 25 to 36 (31) μm in diameter. One or two paragynous antheridia (15 {\texttimes} 10 μm) were attached to the oogonia. Oospores were spherical, hyaline, aplerotic, and 20 to 32 (25) μm in diameter. The minimum temperature for mycelium growth was 8{\textdegree}C and maximum temperature was 34{\textdegree}C. The internal transcribed spacer (ITS) region was amplified and sequenced and agreed 100\% with sequences of four P. tentaculata isolates deposited in GenBank (Accession Nos. AJ854302, AY881001, DQ335634, and AF266775). Pathogenicity was assessed by flooding three potted A. lappa plants with a 104 ml{\textendash}1 zoospore suspension and incubating at 20 to 22{\textdegree}C. As controls, two potted A. lappa plants were flooded with deionized water. All three inoculated A. lappa plants exhibited stalk rot after 15 days, from which the pathogen was reisolated using selective medium, P5ARP. Controls remained healthy 15 days after inoculation, To our knowledge, this is the first report of P. tetaculata H. Kroeber \& R. Marwitz infection of A. lappa in China. We speculate that the pathogen might have been introduced from other countries on seeds.

}, issn = {0191-2917}, doi = {10.1094/PDIS-92-9-1365B}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-92-9-1365B}, author = {Meng, J. and Wang, Y. C.} } @article {Mfegue01092012, title = {Microsatellite markers for population studies of Phytophthora megakarya (Pythiaceae), a cacao pathogen in Africa}, journal = {American Journal of Botany}, volume = {99}, year = {2012}, pages = {e353-e356}, abstract = {

{\quotesinglbase}{\"A}{\textcent} Premise of the study: Phytophthora megakarya is the agent of black pod disease of cacao and is the main pathogen of this crop in Africa. Population genetic studies are required to investigate how this pathogen emerged. To this end, we developed 12 novel polymorphic microsatellite markers for P. megakarya.{\quotesinglbase}{\"A}{\textcent} Methods and Results: Microsatellite sequences were obtained by pyrosequencing of multiplex-enriched libraries. Candidate loci with di- or trinucleotide motifs were selected, and primer pairs were tested with nine P. megakarya isolates. The 12 most polymorphic and unambiguous loci were selected to develop three multiplex PCR pools. The total number of alleles varied from two to nine, depending on loci, and higher than expected heterozygosity was observed.{\quotesinglbase}{\"A}{\textcent} Conclusions: These markers were used for population genetic studies of P. megakarya in Cameroon and for comparison with reference strains from West Africa. This is the first time that microsatellite markers have been developed for P. megakarya.

}, doi = {10.3732/ajb.1200053}, url = {http://www.amjbot.org/content/early/2012/08/29/ajb.1200053.abstract}, author = {Mfegue, C. V. and Herail, C. and Adreit, H. and Mbenoun, M. and Techou, Z. and Ten Hoopen, M. and Tharreau, D. and Ducamp, M.} } @article {253, title = {The occurrence of Phytophthora and Pythium species on roots of native plants in northern California and southern Oregon.}, journal = {Phytopathology}, volume = {45}, year = {1955}, pages = {694 (abstract)}, author = {Middleton, J.T. and Baxter, D.V.} } @article {Mills199131, title = {Taxonomic structure of Phytophthora cryptogea and P. drechsleri based on isozyme and mitochondrial DNA analyses}, journal = {Mycological Research}, volume = {95}, number = {1}, year = {1991}, pages = {31 - 48}, abstract = {

Intra- and interspecific isozyme variation was evaluated for 123 isolates assigned to either Phytophthora cryptogea or P. drechsleri, and compared with that of 15 isolates of P. erythroseptica and 11 isolates of P. lateralis. Isolates of P. cryptogea and P. drechsleri were from worldwide sources and displayed a high degree of variability. The majority of these isolates were subsequently divided into ten distinct groups based on numerical analysis of 24 putative enzyme loci. None of the enzyme loci were monomorphic for all ten groups. Analysis of mitochondrial (mt) DNA restriction fragment length polymorphisms of selected isolates from each isozyme group supported the isozyme data. Differences in morphological features of the ten isozyme groups of P. cryptogea and P. drechsleri were not sufficiently distinct to readily distinguish between them. Isozyme analysis of P. erythroseptica revealed that it is a uniform and distinct taxon. The isolates of P. lateralis also formed a homogeneous and discrete group. An interspecific comparison revealed that the variation among the ten isozyme groups of P. cryptogea and P. drechsleri was as great as that observed among P. cinnamomi, P. cambivora, P. lateralis, P. erythroseptica and P. richardiae. The combined results of isozyme and mtDNA analysis indicate that there are at least seven distinct molecular species represented by the 123 isolates of P. cryptogea and P. drechsleri evaluated in this study.

}, issn = {0953-7562}, doi = {DOI: 10.1016/S0953-7562(09)81359-2}, url = {http://www.sciencedirect.com/science/article/B7XMR-4VN66D4-6/2/554a78ec5ee059d8f8ca3d1ba95638fd}, author = {Scott D. Mills and Helga F{\"o}rster and Michael D. Coffey} } @article {4658, title = {Taxonomic structure of Phytophthora cryptogea and P. drechsleri based on isozyme and mitochondrial DNA analyses}, journal = {Mycological Research}, volume = {95}, year = {1991}, month = {Jan-01-1991}, pages = {31 - 48}, abstract = {

Intra- and interspecific isozyme variation was evaluated for 123 isolates assigned to either Phytophthora cryptogea or P. drechsleri, and compared with that of 15 isolates of P. erythroseptica and 11 isolates of P. lateralis. Isolates of P. cryptogea and P. drechsleri were from worldwide sources and displayed a high degree of variability. The majority of these isolates were subsequently divided into ten distinct groups based on numerical analysis of 24 putative enzyme loci. None of the enzyme loci were monomorphic for all ten groups. Analysis of mitochondrial (mt) DNA restriction fragment length polymorphisms of selected isolates from each isozyme group supported the isozyme data. Differences in morphological features of the ten isozyme groups of P. cryptogea and P. drechsleri were not sufficiently distinct to readily distinguish between them. Isozyme analysis of P. erythroseptica revealed that it is a uniform and distinct taxon. The isolates of P. lateralis also formed a homogeneous and discrete group. An interspecific comparison revealed that the variation among the ten isozyme groups of P. cryptogea and P. drechsleri was as great as that observed among P. cinnamomi, P. cambivora, P. lateralis, P. erythroseptica and P. richardiae. The combined results of isozyme and mtDNA analysis indicate that there are at least seven distinct molecular species represented by the 123 isolates of P. cryptogea and P. drechsleri evaluated in this study.

}, issn = {09537562}, doi = {10.1016/S0953-7562(09)81359-2}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0953756209813592}, author = {Mills, Scott D. and F{\"o}rster, Helga and Coffey, Michael D.} } @mastersthesis {4516, title = {Produtividade e sustentabilidade de planta{\c c}{\~o}es de ac{\'a}cia-negra (Acacia mearnsii De Wild.) no Rio Grande do Sul. Curitiba}, volume = {Doctoral}, year = {2007}, month = {03/2007}, pages = {266}, school = {Universidade Federal do Paran{\'a}}, address = {Curitiba, Brazil}, abstract = {

This work aimed to evaluate the factors related to the productivity, sustainability and environmental impacts of the black wattle plantation in Rio Grande do Sul, Brazil. The studies made about those plantations analyzed the utilization of the genetically improved seeds, the soil attributes influence, the P and K fertilization profit, the uptake, cycling and exportation of nutrients, the biomass production and partition, the black wattle invasion in the grassland area and riparian forest, the forest succession and the understorey herbaceous vegetation of the black wattle plantation. The timber production at the age of five years increased in 9.1 m3/ha through the seed improvement adoption that represented a net profit of R$ 180.00 per ha; however those increments depended on the utilization of suitable silvicultural practices. The gummosis (Phytophthora sp.) was observed in 33.9\% of the dead trees during the period from three to five years and reduced in 9.0\% the growth of attacked plants. The optimal economic rotation defined by the net present worth, considering an infinite horizon, was at the age of four years for the land owner and at the age of six years for the renters. The P, K and organic matter on the soil had positive effects on the black wattle growth. Similarly, it was found the response to the P and K fertilization, with a medium increase of 36.2\% in the timber volume, and the P also promoted the greatest increments and the response to the K were great on the optimal dose of the P. The greatest foliage efficiency for the biomass production and the maximum timber productivity occurred at the age of five years. At the age of seven years the trunk represented around 80\% of the aboveground biomass and stored a greater quantity of P,K, Ca and Mg. The N and S accumulation was greater in the crown trees compartments. The nutrients cycling rate via litter during de rotation of seven years varied from 25.3 to 59.6\% and after the age of four years they represented more then 60\% of the nutrients absorbed by the plants. The Ca and K were the nutrients exported in a greater quantity by the forest harvest. The best efficiency of the nutrients to the trunk biomass production and the least nutrients exportation per biomass unit harvested occurred when the plantations were six and seven years old. The black wattle was able to invade only disturbed grassland area with total exposure of the soil, for this reason it must be considered as a causal invasive plant. The native vegetation recomposition of those areas provoked mortality of a greater number of invasive plants. In the other hand, the black wattle does not become an invasive plant in the riparian forest and when planted in those areas proportioned an abundant and diversified succession in its understorey. The black wattle plantation in grassland area reduced part of the floristic diversity of the herbaceous vegetation and propitiated the typical species settlement in the understorey forests, however they did not affected the site environmental resilience.

}, url = {http://www.floresta.ufpr.br/pos-graduacao/defesas/pdf_dr/2007/t218_0266-D.pdf}, author = {Mochiutti, S.} } @article {EFP:EFP674, title = {Diplanetism and microcyclic sporulation in Phytophthora ramorum}, journal = {Forest Pathology}, volume = {41}, number = {5}, year = {2011}, pages = {349{\textendash}354}, publisher = {Blackwell Publishing Ltd}, abstract = {

The zoosporic phase of the pathogen Phytophthora ramorum plays a crucial role in the process of plant infection, yet little is known about the fate of zoospores failing to target their hosts. Here, we describe new stages in the life cycle of P. ramorum concerning the in vitro development of monomorphic diplanetism and microcyclic sporulation in free water. Papillate cysts were formed after zoospore suspensions of isolates of the EU1 and NA1 clonal lineages were vortexed. Cysts usually germinated directly forming an emerging tube, or indirectly by releasing a secondary zoospore, which leaves behind an empty cyst with a short evacuation tube. Germinate cysts frequently developed either an appressorium or a microsporangium both terminally. We also observed microcyclic sporulation, i.e. sporangia indirectly germinated by forming a microsporangium, as in microcyclic conidiation of true fungi. Temporal progress of encysted zoospores in solution showed that percentage of germination varied significantly among and within isolates as well as between experiments, suggesting that germination is partly ruled by internal mechanisms. Diplanetism and microcyclic sporulation in P. ramorum may provide a second opportunity for host infection and may increase the chance of long dispersal in moving water.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2010.00674.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2010.00674.x}, author = {Moralejo, E. and Descals, E.} } @article {4635, title = {Multiple alien Phytophthora taxa discovered on diseased ornamental plants in Spain}, journal = {Plant Pathology}, volume = {58}, year = {2009}, month = {Jan-02-2009}, pages = {100 - 110}, abstract = {

The plant trade is unwittingly accelerating the worldwide spread of well-known and new or undescribed Phytophthora species and creating novel niches for emerging pathogens. The results of a survey carried out from 2001 to 2006 in garden centres and nurseries of the Balearic Islands and eastern Spain combined with the analysis of samples received from ornamental nurseries from northern Spain reflected the extent of this global issue at the local scale. A total of 125 Phytophthora isolates were obtained from 37 different host species and 17 putative species identified on morphological features and direct sequencing of the internal transcribed spacer and four mitochondrial and nuclear genes. Five species, P. ramorum, P. hedraiandra, P. {\textquoteleft}niederhauserii{\textquoteright}, P. {\textquoteleft}kelmania{\textquoteright} and P. {\textquoteleft}taxon Pgchlamydo{\textquoteright} were formally unknown to science prior to 2001. In addition, 37 new host/pathogen combinations were first records for Spain, highlighting the risk of non-coevolved organisms from different biogeographic origins coming into contact under managed environments. The problem generated by new or rare taxa of Phytophthora found in nurseries for which no prior information on natural habitat and ecology is available for pest risk analysis is discussed.

}, issn = {00320862}, doi = {10.1111/j.1365-3059.2008.01930.x}, url = {http://doi.wiley.com/10.1111/j.1365-3059.2008.01930.x}, author = {Moralejo, E. and P{\'e}rez-Sierra, A. M. and {\'A}lvarez, L. A. and Belbahri, L. and Lefort, F. and Descals, E.} } @article {4378, title = {First report of Phytophthora tentaculata on Verbena sp. in Spain}, journal = {Plant Pathology}, volume = {53}, year = {2004}, month = {Jan-12-2004}, pages = {806 - 806}, abstract = {

The oomycete Phytophthora tentaculata causes root and stalk rot of Chrysanthemum spp., Delphinium ajacis and Verbena spp. in nurseries in the Netherlands and Germany (Kr{\"o}ber \& Marwitz, 1993). In June 2001, P. tentaculata was isolated from a young potted Verbena hybrid, showing a collar and stalk rot, in a nursery in Majorca (Balearic Islands, Spain). It was initially recovered by plating \~{}10\ mm pieces of necrotic tissue from the leading lesion on to a phytophthora selective medium, P5ARP (Erwin \& Ribeiro, 1996). A pure culture (isolate CBS 115458) was obtained by transferring aseptically a hyphal tip onto corn meal agar (CMA) and was first identified from morphological characters.

The colony surface texture was uniform and formed sparse, loosely branched mycelium on carrot piece agar (CPA: 50\ g carrot pieces and 20\ g agar per 1000\ mL distilled water) and CMA. The radial growth rate was 2{\textendash}3\ mm\ day-1 at 20{\textdegree}C on CMA. Sporangia did not appear on either agar media but formed readily in soil extract (50\ g soil from a holm oak forest suspended in 1\ L ionized water for 24 h at 20{\textdegree}C and then filtered and autoclaved). The sporangia were ovoid to globose, 27{\textendash}52 (36{\textperiodcentered}9)\ {\texttimes}\ 17{\textendash}31 (24{\textperiodcentered}6) {\textmu}m, length:breadth ratio 1{\textperiodcentered}4, papillate with a narrow exit pore, and some were caducous with a short pedicel (\<\ 5\ {\textmu}m). Hyphal swellings were present in water. Chlamydospores were only seen on CMA after 2 weeks. Oogonia, readily produced on CPA in pure culture, were globose, mostly terminal or a few lateral, and ranged from 17 to 41 (34{\textperiodcentered}0) {\textmu}m in diameter. Single paragynous, monoclinous or diclinous, usually long-stalked antheridia were club-shaped or spherical, 9{\textendash}16 (12{\textperiodcentered}7) {\textmu}m in diameter and many had appendages. Occasionally two paragynous antheridia per oogonium, as well as some amphigynous antheridia, were observed. Oospores were aplerotic 16{\textendash}33 (28{\textperiodcentered}4)\ {\textmu}m in diameter and thin-walled.

To further confirm its identity, isozyme analysis based on malate dehydrogenase (EC 1.1.1.37) and malic enzymes (EC 1.1.1.40) was performed. Isozyme profiles fitted exactly those of three P. tentaculata strains: two strains ex-Chrysanthemum (including CBS 552.96 paratype) and one strain ex-Verbena; and differing from those of all other papillate species (Oudemans \& Coffey, 1991a,b). Pathogenicity was assessed by flooding three potted Verbena plants with a 104 mL-1 zoospore suspension for 48 h at 20{\textendash}22{\textdegree}C. As controls, two potted Verbena plants were flooded with ionized water. Controls remained healthy 15\ days after inoculation. All three inoculated Verbena plants exhibited collar rot after 15\ days, from which the pathogen was reisolated using PARP medium, thus confirming Koch{\textquoteright}s postulates. This is the first report of P. tentaculata in Spain.

}, issn = {0032-0862}, doi = { http://dx.doi.org/10.1111/j.1365-3059.2004.01089.x }, url = {http://www.blackwell-synergy.com/toc/ppa/53/6http://doi.wiley.com/10.1111/j.1365-3059.2004.01089.xhttp://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2Fj.1365-3059.2004.01089.x}, author = {Moralejo, E. and Puig, M. and Man in{\textquoteright}t Veld, W. A.} } @article {Moralejo20061323, title = {Stromata, sporangiomata and chlamydosori of Phytophthora ramorum on inoculated Mediterranean woody plants}, journal = {Mycological Research}, volume = {110}, number = {11}, year = {2006}, pages = {1323 - 1332}, abstract = {

Three types of multihyphal structures, stromata, sporangiomata and chlamydosori, are described for the plant pathogen Phytophthora ramorum. Their morphology, morphogenesis and position on the host organ were observed by dissecting, compound and scanning electron microscopy. Stromata were consistently formed one to two weeks after zoospore inoculation of detached leaves and fruits of an assortment of Mediterranean sclerophyll shrubs. Stroma initials appeared subcuticularly or subepidermally and developed as small hyphal aggregates by repeated branching, budding, swelling and interweaving, eventually forming a prosenchyma. They always emerged through the adaxial side of the leaf by rupture of the overlying host tissue. Occasionally sporangia and chlamydosori (packed clusters of chlamydospores) were formed on the stromata. Sporangiomata bore short sporangiophores and clusters of 20-100 sporangia and resembled sporodochia of the mitosporic fungi. The biological significance of these multihyphal structures is discussed. Some epidemiological aspects were also studied: several understorey species of the holm oak (Quercus ilex) woodland were susceptible to in vitro infection with three isolates of P. ramorum originally collected from different ornamental hosts. The risk of spread to this ecosystem is evaluated.

}, keywords = {Sporangial dispersal}, issn = {0953-7562}, doi = {10.1016/j.mycres.2006.09.004}, url = {http://www.sciencedirect.com/science/article/pii/S0953756206002656}, author = {Moralejo, Eduardo and Miquel Puig and Jose A. Garcia and Enrique Descals} } @article {4453, title = {Efficacy of Biofumigation with Brassica carinata Commercial Pellets (BioFence) to Control Vegetative and Reproductive Structures of Phytophthora cinnamomi}, journal = {Plant Disease}, volume = {100}, year = {2016}, month = {Jan-02-2016}, pages = {324 - 330}, abstract = {

The efficacy of biofumigation with Brassica carinata pellets (BioFence) to control vegetative and reproductive structures of Phytophthora cinnamomi was investigated in vitro at different doses and temperatures. Biofumigation was effective in inhibiting mycelial growth (culture diameter) and chlamydospore and zoospore germination, and was lethal at 24 mg of pellet per plate (approximately 0.4 mg/liter). The 50\% effective concentration values showed that efficacy of B. carinata pellets in inhibiting or killing the vegetative and reproductive structures of P. cinnamomi was maximum at 15{\textdegree}C and decreased as temperature rose to 25{\textdegree}C. However, the fungicide effect was independent of the temperature. In vivo biofumigation of Quercus cerris seedlings with BioFence confirmed efficacy by reducing the inoculum density (CFU/g) of P. cinnamomi, thus protecting the host from root infection. The use of BioFence provides an alternative to synthetic pesticides to control P. cinnamomi within disease management programs in agroforestry systems.

}, issn = {0191-2917}, doi = {10.1094/PDIS-03-15-0245-RE}, url = {http://apsjournals.apsnet.org/doi/10.1094/PDIS-03-15-0245-RE}, author = {Morales-Rodr{\'\i}guez, C. and Vettraino, A. M. and Vannini, {\'A}.} } @article {EFP:EFP397, title = {Influence of site factors on the impact of Phytophthora cinnamomi in cork oak stands in Portugal}, journal = {Forest Pathology}, volume = {35}, number = {3}, year = {2005}, pages = {145{\textendash}162}, publisher = {Blackwell Verlag GmbH}, abstract = {

Although decline of cork (Quercus suber) and holm oak trees (Quercus rotundifolia) has been described in Portugal in the late years of the 19th century, its development has become a motive of high concern during the last two decades. The presence of Phytophthora cinnamomi in cork and holm oak stands was surveyed in four different regions of the country (Tr{\'a}s-os-Montes, Alentejo, Ribatejo and Algarve) during 1995{\textendash}98. Tree decline severity, sudden death and site characteristics were assessed in 56 sites representing varied conditions. The pathogen was isolated from oak roots and rhizosphere samples in 27 of those places. Other plant species from natural vegetation were sampled in three active disease centres. This survey showed that 56\% of the surveyed species of shrub flora were infected with P. cinnamomi, which was detected mainly on species belonging to the families Ericaceae, Cistaceae and Leguminosae. Recovery of P. cinnamomi was more frequent in shallow soils (Leptosols and complex Leptosols and Luvisols). These soils are more common in the south (Algarve), where decline has a high impact. Soils with low fertility and low mineral nutrient levels, particularly phosphorus, seemed to favour infection. Site aspect and topographic tree situation were also evaluated. Sites facing south showed higher occurrence of P. cinnamomi, which was also more frequent in slopes and valleys than on hilltops. In Algarve, a relationship could be established between the crown status and the presence of P. cinnamomi in roots and rhizosphere. Different morphotypes of P. cinnamomi could be distinguished in vitro, and their occurrence in the field was correlated with particular site characteristics. Further research needs and management strategies to limit the extension of the disease are discussed.

}, author = {Moreira, A. C. and Martins, J. M. S.} } @article {4489, title = {Endemic and Emerging Pathogens Threatening Cork Oak Trees: Management Options for Conserving a Unique Forest Ecosystem}, journal = {Plant Disease}, volume = {100}, year = {2016}, month = {Jan-11-2016}, pages = {2184 - 2193}, abstract = {

Cork oak (Quercus suber) forests are economically and culturally intertwined with the inhabitants of the Mediterranean basin and characterize its rural landscape. These forests cover over two million hectares in the western Mediterranean basin and sustain a rich biodiversity of endemisms as well as representing an important source of income derived from cork production. Currently cork oak forests are threatened by several factors including human-mediated disturbances such as poor or inappropriate management practices, adverse environmental conditions (irregular water regime with prolonged drought periods), and attacks of pathogens and pests. All these adverse factors can interact, causing a complex disease commonly known as {\textquotedblleft}oak decline.{\textquotedblright} Despite the numerous investigations carried out so far, decline continues to be the main pathological problem of cork oak forests because of its complex etiology and the resulting difficulties in defining suitable control strategies. An overview of the literature indicates that several pathogenic fungi and oomycota can play a primary role in the etiology of this syndrome. Therefore, the aim of this review is to analyze the recent advances achieved regarding the bio-ecology of the endemic and emerging pathogens that threaten cork oak trees with particular emphasis on the species more directly involved in oak decline. Moreover, the effect of climate change on the host-pathogen interactions, a task fundamental for making useful decisions and managing cork oak forests properly, is considered.

}, issn = {0191-2917}, doi = {10.1094/PDIS-03-16-0408-FE}, url = {http://apsjournals.apsnet.org/doi/10.1094/PDIS-03-16-0408-FE}, author = {Moricca, Salvatore and Linaldeddu, Benedetto T. and Ginetti, Beatrice and Scanu, Bruno and Franceschini, Antonio and Ragazzi, Alessandro} } @article {4020, title = {Development of a quantitative real-time PCR assay for the detection of Phytophthora austrocedrae, an emerging pathogen in Britain}, journal = {Forest Pathology}, year = {2013}, month = {05/2013}, pages = {Early view}, abstract = {

A TaqMan real-time PCR assay was developed for Phytophthora austrocedrae, an emerging pathogen causing severe damage to juniper in Britain. The primers amplified DNA of the target pathogen down to 1\ pg of extracted DNA, in both the presence and absence of host DNA, but did not amplify any of the non-target Phytophthora and fungal species tested. The assay provides a useful tool for screening juniper populations for the disease.

}, doi = {10.1111/efp.12058}, url = {http://onlinelibrary.wiley.com/doi/10.1111/efp.12058/abstract}, author = {Mulholland, V. and Schlenzig, A. and MacAskill, G. A. and Green, S.} } @article {doi:10.1094/PDIS.1997.81.12.1400, title = {Susceptibility of Pacific Yew to Phytophthora lateralis}, journal = {Plant Disease}, volume = {81}, number = {12}, year = {1997}, pages = {1400-1404}, doi = {10.1094/PDIS.1997.81.12.1400}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.1997.81.12.1400}, author = {Murray, Marion S. and Hansen, Everett M.} }