@article {2753228920071201, title = {Phytophthora cambivora in Oregon and its pathogenicity to Chrysolepis chrysophylla.}, journal = {Forest Pathology}, volume = {37}, number = {6}, year = {2007}, pages = {409 - 419}, abstract = {

A new canker disease causing mortality of golden chinquapin trees [Chrysolepis chrysophylla (Dougl.) Hjelmqvist], in Oregon was recently observed. Most of the symptomatic or dead trees were located near roads. The cankers on the lower boles of trees are similar to those caused by species of Phytophthora on other trees in western North America. The cankers in the inner bark were reddish-orange in colour and extended upward from necrotic roots. Phytophthora (Petri) Buisman was isolated from the cankers; identity was confirmed by morphological comparison with known isolates and internal transcribed spacer sequence analysis. Pathogenicity was confirmed by inoculation of chinquapin seedlings and mature trees. Seven of nine isolates from chinquapin were A2 mating type; 27 of 28 isolates from other hosts in Oregon and Washington were A1 mating type.

}, keywords = {Biodiversity, Canker (Plant disease), diseases, Forests. forestry, Oregon, Pathogenic microorganisms, pests, PLANT diseases}, issn = {14374781}, doi = {10.1111/j.1439-0329.2007.00515.x}, url = {http://onlinelibrary.wiley.com.proxy.library.oregonstate.edu/doi/10.1111/j.1439-0329.2007.00515.x/abstract}, author = {Saavedra, A. and Hansen, E.M. and Goheen, D. J.} } @article {EFP:EFP261, title = {Phytophthora disease of Quercus ilex in south-western Spain}, journal = {Forest Pathology}, volume = {32}, number = {1}, year = {2002}, pages = {5{\textendash}18}, publisher = {Blackwell Science Ltd.}, abstract = {

Oak decline that was affecting three holm oak sites in the province of Huelva (south-western Spain) was studied during 1998{\textendash}1999. The syndromes of dieback and sudden death have been observed and, in both cases, foliar symptoms were associated with root rot. Characterization of the fungal isolates from necrotic roots led us to identify Phytophthora cinnamomi A2 as consistently associated with the disease. The optimum growth temperatures of these isolates were very high (30{\textdegree}C). Inoculation tests under controlled conditions demonstrated the pathogenicity of the isolates on holm and cork oak seedlings. None of the other biotic factors of Mediterranean oak decline that have been previously described were found in the present study and so, in this case, the forest decline model does not seem to be necessary in order to explain the disease observed. The defoliation and mortality of the oaks was primarily caused by P. cinnamomi, although some abiotic factors such as alternating periods of drought and wet weather in the region may play an important role.

}, issn = {1439-0329}, doi = {10.1046/j.1439-0329.2002.00261.x}, url = {http://dx.doi.org/10.1046/j.1439-0329.2002.00261.x}, author = {Sanchez, M. E. and Caetano, P. and Ferraz, J. and Trapero, A.} } @article {4471, title = {Phytophthora kernoviae isolated from fallen leaves of Drymis winteri in native forest of southern Chile}, journal = {Australasian Plant Disease Notes}, volume = {11}, year = {2016}, month = {Jan-06-2016}, abstract = {

Phytophthora kernoviae is an invasive species first described from Britain and later New Zealand. We conducted surveys for Phytophthora species in forests in southern Chile. Symptomatic fallen leaves of Drimys winteri were encountered in a native forest. P. kernoviae was isolated. This is the first report of P. kernoviae outside of UK and New Zealand.

}, doi = {10.1007/s13314-016-0205-6}, url = {http://link.springer.com/10.1007/s13314-016-0205-6}, author = {Sanfuentes, E. and Fajardo, S. and Sabag, M. and Hansen, E. and Gonz{\'a}lez, M.} } @article {599, title = {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.}, volume = {Deliverable Report 28}, year = {2009}, pages = {311 p.}, address = {Sand Hutton, York, UK}, url = {http://rapra.csl.gov.uk/RAPRA-PRA_26feb09.pdf}, author = {Sansford, C.E. and Inman, A..J. and Baker, R. and Brasier, C. and Frankel, S. and de Gruyter, J. and Husson, C. and Kehlenbeck, H. and Kessel, G. and Moralejo, E. and Steeghs, M. and Webber, J. and Werres, S.}, editor = {Forest Research, Central Science Laboratory and EU Sixth Framework Project, RAPRA} } @article {doi:10.1094/PDIS.2001.85.5.560A, title = {A new Phytophthora root disease of alder in Italy}, journal = {Plant Disease}, volume = {85}, number = {5}, year = {2001}, pages = {560-560}, doi = {10.1094/PDIS.2001.85.5.560A}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.2001.85.5.560A}, author = {Santini, A. and Barzanti, G. P. and Capretti, P.} } @article {388, title = {Pathogenicity of four Phytophthora species on wild cherry and Italian alder seedlings}, journal = {Journal of Phytopathology}, volume = {154}, year = {2006}, month = {03/2006}, pages = {163{\textendash}167}, abstract = {

Abstract Inoculation tests were carried out in the greenhouse on wild cherry (Prunus avium) and Italian alder (Alnus cordata) seedlings, to determine their susceptibility to certain Phytophthora species (P. citrophthora, P. alni, P. megasperma and P. cinnamomi) that are commonly present in the soil. Host susceptibility was evaluated in accordance with a disease index, with the lesion length after stem inoculation, and with a root system disease index. Wild cherry was found to be highly susceptible to P. citrophthora, and was also found to be susceptible to P. alni, although to a lesser extent. Italian alder was very susceptible to P. alni, but had only low susceptibility to P. citrophthora. The other Phytophthora species caused only modest symptoms. The danger to alder and wild cherry is all the greater because these trees not only share the same pathogens, but also commonly planted together in mixed stands. The results will now have to be confirmed by using a more natural inoculation method.

}, keywords = {Alnus cordata, inoculation test, pathogenicity, Phytophthora, Prunus avium}, doi = {10.1111/j.1439-0434.2006.01077.x}, url = {http://dx.doi.org/10.1111/j.1439-0434.2006.01077.x}, author = {Santini, A. and Biancalani, F. and Barzanti, G. P. and Capretti, P.} } @article {387, title = {Susceptibility of some mesophilic hardwoods to alder Phytophthora}, journal = {Journal of Phytopathology}, volume = {151}, year = {2003}, month = {08/2003}, pages = {406{\textendash}410}, abstract = {

Abstract Inoculation tests were carried out in the greenhouse on seedlings of five hardwoods (Alnus cordata, A. glutinosa, Castanea sativa, Juglans regia and Quercus robur) to determine their susceptibility to an isolate of alder Phytophthora obtained in Italy from A. cordata. A Phytophthora cinnamomi strain was used for comparison. Host susceptibility to infection was determined as the lesion length after stem inoculation and the percentage of necrotized rootlets after soil infestation with inoculated millet seeds. The aggressiveness of the alder Phytophthora isolate was significantly higher in the two Alnus species than in the other hosts. Our results were confirmed with both methods of inoculation. Alnus cordata was consistently the most susceptible host species when compared with the other hardwoods. Damage by P. cinnamomi was severe, particularly after soil infestation tests. The most susceptible species were alders, chestnut and walnut. The test also suggests that alder Phytophthora is able to spread through infected seedlings of different hardwood species.

}, keywords = {Alnus cordata, Alnus glutinosa, Castanea sativa, Hardwoods, inoculation test, Juglans regia, Phytophthora cinnamomi, Phytophthora spp., Quercus robur}, doi = {10.1046/j.1439-0434.2003.00739.x}, url = {http://dx.doi.org/10.1046/j.1439-0434.2003.00739.x}, author = {Santini, Alberto and Barzanti, Gian Paolo and Capretti, Paolo} } @article {4519, title = {Gomose da ac{\'a}cia-negra: etiologia, an{\'a}lise temporal, perdas e controle gen{\'e}tico.}, journal = {Boletim de Pesquisa e Desenvolvimento, Embrapa Florestas, Minist{\'e}rio da Agricultura}, volume = {31}, year = {2007}, pages = {28 p.}, abstract = {

Gummosis is one of the most serious phytosanitary problems of black wattle (Acacia mearnsii) in the State of Rio Grande do Sul, Brazil. The objectives of this work were: 1) to identify the species of Phytophthora associated with gummosis; 2) to analyze the temporal distribution of the gummosis; 3) to quantify losses caused by this disease; and 4) to rank black wattle lines based on resistance to gummosis. The major results were: Phytophthora nicotianae and P. boehmeriae are the causal agent of gummosis on black-wattle in Brazil. This disease was found in all the surveyed black-wattle plantations and the species P. nicotianae was the major species found in the samples, suggesting that this is the main species causing this disease in Brazil. It was found two kinds of symptoms: 1) gummosis at the base of the trunks, associated to P. nicotianae; e 2) gummosis spread on the trunk, associated to P. boehmeriae. Plants killed by gummosis or other causes showed exponential growth, and started to die after 34 months. Plants showing gummosis had losses ranging from 3,5 to 0,5\% for bark and timber production, respectively. Both, natural and artificial inoculations assays showed variation on the resistance of plants to gummosis.

A gomose {\'e} um dos mais s{\'e}rios problemas fitossanit{\'a}rios da ac{\'a}cia-negra (Acacia mearnsii) no Rio Grande do Sul. Este trabalho teve como objetivos: 1) identificar a(s) esp{\'e}cie(s) de Phytophthora associada(s) {\`a} gomose; 2) analisar a distribui{\c c}{\~a}o temporal da gomose; 3) quantificar as perdas causadas pela doen{\c c}a; e 4) agrupar os materiais gen{\'e}ticos de ac{\'a}cia-negra de acordo com o n{\'\i}vel de resist{\^e}ncia {\`a} gomose. Os principais resultados foram: Phytophthora nicotianae e P.boehmeriae s{\~a}o os agentes causais da gomose da ac{\'a}cia-negra no Brasil. A gomose de Phytophthora foi encontrada em todos os plantios de ac{\'a}cia-negra e, no levantamento, evidenciou-se a predomin{\^a}ncia de P. nicotianae, mostrando que este pat{\'o}geno {\'e} o principal agente da gomose da ac{\'a}cia-negra no Brasil. As avalia{\c c}{\~o}es em plantios comerciais em idade de corte apresentaram at{\'e} 48 \% de indiv{\'\i}duos atacados. Tanto plantas mortas por outras causas quanto plantas mortas por gomose cresceram exponencialmente, e as mortes come{\c c}aram a partir do 34{\textordmasculine} m{\^e}s. Os dados mostraram perdas de produ{\c c}{\~a}o de at{\'e} 3,5 \% para casca e at{\'e} 0,5 \% para madeira nas {\'a}rvores com gomose. Tanto por infec{\c c}{\~a}o natural quanto por inocula{\c c}{\~a}o artificial, ocorreram varia{\c c}{\~o}es entre as proced{\^e}ncias quanto a resist{\^e}ncia {\`a} gomose.

}, issn = { 1980-041X}, url = {http://www.infoteca.cnptia.embrapa.br/infoteca/bitstream/doc/312305/1/BPD31CD.pdf}, author = {Santos, A. F. dos and Luz, E.D.M.N. and Maffia, L.A. and Souza, J.T.} } @article {JPH:JPH1741, title = {Root and crown rot of Brazilian pine (Araucaria angustifolia) caused by Phytophthora cinnamomi}, journal = {Journal of Phytopathology}, volume = {159}, number = {3}, year = {2011}, pages = {194{\textendash}196}, publisher = {Blackwell Publishing Ltd}, abstract = {

In an area reforested with Brazilian pine (Araucaria angustifolia) located in Paran√{\textdegree} 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.

}, keywords = {chromistan fungi, forest pathology, fungal plant pathogen}, issn = {1439-0434}, doi = {10.1111/j.1439-0434.2010.01741.x}, url = {http://dx.doi.org/10.1111/j.1439-0434.2010.01741.x}, author = {Santos, A. F. dos and Tessmann, Dauri J. and Alves, Tatiane C. A. and Vida, Jo{\~a}o B. and Harakava, Ricardo} } @article {4514, title = {Phytophthora nicotianae: agente etiol{\'o}gico da gomose da ac{\'a}cia negra no Brasil}, journal = {Fitopatologia Brasileira}, volume = {30}, year = {2005}, pages = {81{\textendash}4}, abstract = {

A gomose, causada por Phytophthora sp., {\'e} a mais importante enfermidade da ac{\'a}cia-negra (Acacia mearnsii) no Rio Grande do Sul, Brasil. A identifica{\c c}{\~a}o espec{\'\i}fica permanecia indeterminada. Procurou-se, ent{\~a}o, identificar a esp{\'e}cie de Phytophthora causadora desta doen{\c c}a no Rio Grande do Sul, usando caracter{\'\i}sticas fisiomorfol{\'o}gicas e estudos moleculares baseados no seq{\"u}enciamento das regi{\~o}es de Internal Transcribed Spacer (ITS). A patogenicidade dos isolados estudados para a ac{\'a}cia-negra foi confirmada. Os estudos confirmaram Phytophthora nicotianae como a correta identidade dos isolados fitopatog{\^e}nicos. Este {\'e} o primeiro relato de P. nicotianae em ac{\'a}cia-negra no Brasil.

Gummosis caused by Phytophthora sp. is the most important disease of black wattle (Acacia mearnsii) in Rio Grande do Sul, Brazil. Isolates of Phytophthora sp. associated with diseased plants were obtained from Rio Grande do Sul and their pathogenicity was confirmed. In order to elucidate the correct identity of the fungus at the species level physiomorphological characteristics were determined and molecular studies were conducted based on sequences of Internal Transcribed Spacer (ITS) region. The fungus was identified as Phytophthora nicotianae. This is the first report of P. nicotianae on black wattle in Brazil.

}, issn = {1982-5676 }, doi = {10.1590/s0100-41582005000100015 }, url = {https://doi.org/10.1590/s0100-41582005000100015 }, author = {Santos, A. F. dos and Luz, EDMN and Souza, J. T.} } @article {4528, title = {Comportamento diferenciado da gomose de Phytophthora em diferentes alturas ao longo de troncos de ac{\'a}cia-negra (Acacia mearnsii) em Piratini, RS}, journal = {Boletim de Pesquisa Florestal }, volume = {43}, year = {2001}, pages = {145-149}, abstract = {

The symptoms of gummosis of Phytophthora of black wattle (Acacia mearnsii) occur\  predominantly\  in\  the\  basal\  region of\  the\  trunk.\  The\  highest\  severity\  is usually observed in the basal section (up to 0,50 m from ground level, along the trunk). Black wattle gummosis was observed in trees growing at Piratini, RS, in 1998. In this case, a different kind of symptoms was observed: necrotic lesions occurring severily in heights above the basal section of the trunks. Phytophthora was isolated from diseased bark from differents heights of the trunk up to 10 m. All isolates of Phytophthora showed\  pathogenicity to black wattle.

Os sintomas da gomose de Phytophthora da ac{\'a}cia-negra (Acacia mearnsii) ocorrem predominantemente na regi{\~a}o basal do tronco das {\'a}rvores, com maior severidade na por{\c c}{\~a}o que vai do colo at{\'e} 0,50 m de altura. No ano de 1998, na regi{\~a}o de Piratini-RS, ocorreu um surto de gomose em {\'a}rvores adultas, caracterizando-se pela predomin{\^a}ncia de les{\~o}es necr{\'o}ticas, n{\~a}o exsudativas, atingindo severamente alturas superiores {\`a}quelas normalmente encontradas nos troncos. Procedeu-se a uma coleta sistematizada de amostras de casca de troncos de {\'a}rvores com sintomas, na regi{\~a}o do colo, aos 2 m, aos 4 m, aos 6 m, aos 8 m e aos 10 m de altura. Nos isolamentos e testes de patogencidade feitos, confirmouse a associa{\c c}{\~a}o de Phytophthora {\`a}s les{\~o}es.

}, url = {http://ainfo.cnptia.embrapa.br/digital/bitstream/CNPF-2009-09/30242/1/santos.pdf}, author = {Santos, A. F. dos} } @article {4504, title = {A gomose da ac{\'a}cia-negra no Brasil: a review}, journal = {Summa Phytopathologica}, volume = {33}, year = {2007}, month = {Jan-01-2007}, pages = {113 - 118}, abstract = {

A ac{\'a}cia-negra (Acacia mearnsii) {\'e} cultivada no Brasil, especialmente no Estado do Rio Grande do Sul, visando tanto {\`a} produ{\c c}{\~a}o de tanino, a partir da casca, quanto o uso da madeira para papel, celulose, carv{\~a}o, lenha e chapas de aglomerados. A gomose causada por Phytophthora nicotianae e P. boehmeriae, {\'e} o seu principal problema fitossanit{\'a}rio. Discute-se nesta revis{\~a}o a exist{\^e}ncia de dois padr{\~o}es distintos de sintomatologia da gomose de Phytophthora que t{\^e}m sido observados nas planta{\c c}{\~o}es brasileiras: gomose basal, associada a P. nicotianae, e gomose generalizada, mais associada a P. boehmeriae. S{\~a}o discutidos aspectos relacionados {\`a} etiologia, {\`a} epidemiologia e {\`a}s estrat{\'e}gias de controle.

The black wattle (Acacia mearnsii ) is cultivated in Brazil for bark tannin, paper, cellulose, plywood, charcoal and firewood production. Gummosis of Phytophthora, caused by P. nicotianae and P. boehmeriae is the main disease problem on black wattle. The existence of two distinct symptom patterns observed on plants in the commercial fields are: butt gummosis which is associated with P. nicotianae and general gummosis more related to P. boehmeriae. Etiological, epidemiological and control aspects of this disease are presented and discussed on this review.

}, issn = {0100-5405}, doi = {10.1590/S0100-54052007000200002}, url = {https://doi.org/10.1590/s0100-54052007000200002 }, author = {Santos, A. F. dos and Luz, E. D. M. N.} } @article {SANTOS2004, title = {Primeiro relato da podrida da estipe da pupunheira, causada por Phytophthora palmivora, no estado do Parana{\textquoteleft}}, journal = {Fitopatologia Brasileira}, volume = {29}, year = {2004}, month = {12}, pages = {680 - 682}, publisher = {scielo}, abstract = {

Phytophthora palmivora was isolated from infected peach palm (Bactris gasipaes) plants with stem rot symptoms in Paran{\'a} State, in 2002. Pathogenicity tests and subsequent reisolations of P. palmivora confirmed the hypothesis that this fungus was the causal agent of the disease. This is the first report of P. palmivora causing stem rot on peach palm (Bactris gasipaes) in the southern State of Paran{\'a}. RESUMO Phytophthora palmivora foi isolado de plantas de pupunheira (Bactris gasipaes) com sintomas de podrid{\~a}o da estipe, no Paran{\'a}, em 2002. Testes de patogenicidade e o subseq{\"u}ente reisolamento do fungo confirmaram a hip{\'o}tese de que P. palmivora {\'e} o agente causal da podrid{\~a}o do estipe. Este {\'e} o primeiro relato de P. palmivora causando podrid{\~a}o do estipe na pupunheira no estado do Paran{\'a}.

}, issn = {0100-4158}, url = {http://www.scielo.br/scielo.php?script=sci_arttext\&pid=S0100-41582004000600016\&nrm=iso}, author = {Santos, A. F. dos and Luz, Edna Dora. M. N. and Finato, Priscila D. and Tessmann, Dauri J. and Vida, J. B.} } @conference {4526, title = {Phytophthora spp: distribui{\c c}{\~a}o e associa{\c c}{\~a}o com esp{\'e}cies florestais}, booktitle = {Congresso Brasileiro de Fitopatologia, 47}, year = {2014}, publisher = {Sociedade Brasileira de Fitopatologia}, organization = {Sociedade Brasileira de Fitopatologia}, address = {Londrina, Brazil}, url = {http://www.alice.cnptia.embrapa.br/handle/doc/993792}, author = {Santos, A. F. dos and Luz, EDMN and Reis, A.} } @article {4503, title = {First report of Phytophthora boehmeriae on black wattle in Brazil}, journal = {Plant Pathology}, volume = {55}, year = {2006}, month = {Jan-12-2006}, pages = {813 - 813}, abstract = {

Black wattle (Acacia mearnsii) is an Australian tree species cultivated in several countries. In Brazil, particularly in Rio Grande do Sul State (RS), approximately 140\ 000 ha are cultivated for tannin extraction (Dos Santos et\ al., 2005).

The gummosis complex, which has Phytophthora nicotianae as one of the causal agents, is the main disease of black wattle in Brazil and is characterised by lesions at the trunk base with gum exudation (Dos Santos et\ al., 2005). Different symptoms were observed in plantations at the municipality of Piratini, RS (southern Brazil) and were characterised by dark lesions without gum exudation on trunks of 3- to 4-year-old wattle trees up to 10 m height. Isolates of Phytophthora spp. were obtained from the lesions and deposited in the Brazilian collection of Phytophthora species, under accession numbers CBP 307, 308 and 309. Sporangia of all isolates were ovoid to spherical, papillate and caducous, measuring 35 {\textmu}m {\textpm} 1{\textperiodcentered}42 {\texttimes} 30 {\textmu}m {\textpm} 1{\textperiodcentered}37, with a length/width ratio of 1{\textperiodcentered}16:1, mean depth of papillae of 4{\textperiodcentered}83 {\textmu}m {\textpm} 0{\textperiodcentered}04, and pore exit of 4{\textperiodcentered}69 {\textmu}m {\textpm} 0{\textperiodcentered}04. The isolates were homothallic, forming plerotic oospores with smooth walls and amphigynous antheridia. The ITS sequences obtained for isolates CBP 307 (AY428533), CBP 308 (AY428534), and CBP 309 (AY428535) were identical and most closely matched those of two isolates of P. boehmeriae KACC40173 (AY228076) from Korea and SCRP23 (DQ297406) from China. This and the morphological similarity (Erwin \& Ribeiro, 1996) suggest that these isolates are P. boehmeriae. However, seven clear single base pair differences were noted between the Brazilian and other P. boehmeriae isolates. This, combined with isozyme variation (Oudemans \& Coffey, 1991) suggests that further studies are needed to confirm the taxonomic status of P. boehmeriae.

Pathogenicity tests were done by inoculating five 1-year-old wattle plants with 7 mm mycelial discs of 5-day old cultures of the three isolates used in this study. The mycelial discs were placed in 7 mm diameter holes made in the bark with a cork borer, at 5 cm above the soil. Plants were maintained at approximately 25{\textdegree}C and were assessed 45 days after inoculation. All three isolates were pathogenic to black wattle and were re-isolated from the lesions.

Phytophthora boehmeriae was reported as one of the causal agents of the gummosis complex on black wattle in South Africa (TPCP, 2004) and is of quarantine importance for the citrus industry in Brazil. This is the first report of the involvement of P. boehmeriae in the aetiology of the gummosis complex of black wattle in Brazil.

}, issn = {0032-0862}, doi = {10.1111/j.1365-3059.2006.01462.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3059.2006.01462.x/full}, author = {Santos, A. F. dos and Luz, E. D. M. N. and Souza, J. T.} } @article {4524, title = {O complexo gomose da ac{\'a}cia-negra}, journal = {Colombo-PR: Embrapa Florestas}, volume = {Circular T{\'e}cnica, 44}, year = {2001}, pages = {8 pp.}, abstract = {

A ac{\'a}cia-negra {\'e} uma esp{\'e}cie florestal que foi introduzida no Brasil, no Estado do Rio Grande do Sul, na d{\'e}cada de 30. Atualmente, com uma {\'a}rea plantada de aproximadamente 100.000 ha, envolve cerca de 10 mil pequenos produtores rurais (Higa \& Dedecek, 1999), compondo um dos maci{\c c}os florestais daquele Estado, onde desempenha importante papel s{\'o}cio-econ{\^o}mico para as pequenas propriedades rurais (Fleig, 1993).

O r{\'a}pido crescimento da ac{\'a}cia-negra, associado ao aproveitamento integral da madeira, torna essa esp{\'e}cie ideal para reflorestamento e para utiliza{\c c}{\~a}o industrial. Sua contribui{\c c}{\~a}o aos mais variados segmentos econ{\^o}micos e industriais {\'e} ampla, tanto pelo aproveitamento da casca para extra{\c c}{\~a}o do tanino (a casca possui cerca de 28\% de tanino), quanto pelo uso da madeira para diversos fins, tais como a fabrica{\c c}{\~a}o de papel e celulose, chapas de aglomerados, carv{\~a}o e lenha. No Brasil, {\'e} plantada principalmente para produ{\c c}{\~a}o de tanino.

A ac{\'a}cia-negra {\'e} uma planta que exsuda goma na casca do tronco. A goma {\'e} aparentemente produzida pelas {\'a}rvores em resposta a alguma condi{\c c}{\~a}o anormal, como pat{\'o}genos ou inj{\'u}rias provocadas por insetos, danos mec{\^a}nicos ou fatores externos que afetam o seu crescimento (Zeijlemaker, 1968). Quimicamente, a goma da ac{\'a}cia-negra {\'e} uma combina{\c c}{\~a}o de arabinose, galactose, ramnose e {\'a}cido glucur{\^o}nico (Stephen 1951). A quantidade de goma produzida por uma {\'a}rvore depende da caracter{\'\i}stica gen{\'e}tica do material e da influ{\^e}ncia de fatores ambientais, tais como a temperatura e a disponibilidade de umidade.

Como resultado, tem-se pouca goma no per{\'\i}odo seco, enquanto muita goma pode ser exsudada no per{\'\i}odo {\'u}mido (Zeijlemaker, 1968). Um dos principais problemas da ac{\'a}cia-negra {\'e} a doen{\c c}a conhecida como gomose de Phytophthora sp. (Santos et al., 1998). Os sintomas ocorrem no tronco e se caracterizam por les{\~o}es necr{\'o}ticas na casca, chegando a atingir o lenho. A abundante exsuda{\c c}{\~a}o gomosa {\'e} o sintoma mais caracter{\'\i}stico dessa doen{\c c}a, que {\'e} facilmente confundido com outros problemas, uma vez que o tronco da ac{\'a}cia-negra exsuda goma quando lesionado por a{\c c}{\~a}o tanto bi{\'o}tica quanto abi{\'o}tica. Assim sendo, embora a les{\~a}o exsudativa seja o tipo de sintoma mais caracter{\'\i}stico da gomose de Phytophthora, essa n{\~a}o {\'e} uma caracter{\'\i}stica exclusiva como indicadora da associa{\c c}{\~a}o Phytophthora -ac{\'a}cia. Portanto, este trabalho tem o objetivo de discutir aspectos relacionados {\`a} gomose de Phytophthora e aos de outros tipos de problemas associados {\`a} ac{\'a}cia-negra e que tenham a exsuda{\c c}{\~a}o de goma como parte de seu quadro sintomatol{\'o}gico, de maneira que se possam elucid{\'a}-los, para facilitar a sua identifica{\c c}{\~a}o no camp.

}, issn = {1517-5278}, url = {https://core.ac.uk/download/pdf/15427678.pdf}, author = {Santos, A. F. dos and Grigoletti, A. Jr. and Auer, CG} } @article {4033, title = {A taxonomic re-evaluation reveals that Phytophthora cinnamomi and P.~cinnamomi var. parvispora are separate species}, journal = {Forest Pathology}, year = {2013}, month = {07/2013}, pages = {n/a - n/a}, abstract = {

Between 2008 and 2011, severe dieback associated with root and collar rot was reported on Arbutus unedo in several sites in Sardinia, Italy. Isolations from infected tissues and rhizosphere soil samples consistently yielded a Phytophthora species. It was initially identified as Phytophthora cinnamomi var. parvispora Kr{\"o}ber and Marwitz by comparing morphological features with the original description and the internal transcribed spacer (ITS) sequences with those present in GenBank. A multigene phylogeny based on DNA sequence data from two nuclear (ITS and β-tubulin) and two mitochondrial (cox1 and cox2) gene regions combined with extensive morphological and physiological properties of these isolates, including the ex-type culture of P.\ cinnamomi var. parvispora, demonstrates that this taxon is unique and it is redesignated here as Phytophthora parvispora sp. nov. Although morphologically similar to P.\ cinnamomi, P.\ parvispora differs by its smaller-sized sporangia, chlamydospores, oogonia and oospores, higher oospore wall index, single-celled antheridia, higher minimum and maximum temperatures for growth and faster growth at optimum temperature. In the phylogeny, P.\ parvispora falls within Phytophthora ITS clade 7a, grouped in a well-supported clade sister to P.\ cinnamomi. In pathogenicity tests, P.\ parvispora and P.\ cinnamomi were equally aggressive towards A.\ unedo seedlings. The possible geographic origin of P.\ parvispora is also discussed.

}, doi = {10.1111/efp.12064}, url = {http://onlinelibrary.wiley.com/doi/10.1111/efp.12064/abstract}, author = {Scanu, B. and Hunter, G. C. and Linaldeddu, B. T. and Franceschini, A. and Maddau, L. and T. Jung and Denman, S.}, editor = {Andrea, V.} } @article {4007, title = {Occurrence of Phytophthora cinnamomi in cork oak forests in Italy}, journal = {Forest Pathology}, volume = {43}, year = {2013}, month = {08/2013}, pages = {340{\textendash}343}, abstract = {

An increasing decline and mortality of cork oak trees have been recently observed in central Italy and Sardinia Island. Following surveys conducted in three declining cork oak forests, a Phytophthora species was consistently isolated from soil samples collected from trees displaying different level of decline. Based on morphological features, growth rates at different temperatures and analysis of DNA sequences of the ITS region, all isolates were identified as Phytophthora cinnamomi Rands. This pathogen caused large brownish lesions on inoculated freshly cut branches of cork oak. It was re-isolated from all infected tissues. These findings represent the first report of P.\ cinnamomi on cork oak trees in Italy.

}, doi = {10.1111/efp.12039}, url = {http://onlinelibrary.wiley.com/doi/10.1111/efp.12039/abstract}, author = {Scanu, B. and Linaldeddu, B. T. and Franceschini, A. and Anselmi, N. and A. Vannini and A.M. Vettraino}, editor = {Belbahri, L.} } @article {4448, title = {Dieback and mortality of Nothofagus in Britain: ecology, pathogenicity and sporulation potential of the causal agent Phytophthora pseudosyringae}, journal = {Plant Pathology}, volume = {65}, year = {2016}, month = {Jan-01-2016}, pages = {26 - 36}, abstract = {

Since 2009 extensive dieback and mortality of Nothofagus obliqua, associated with bleeding cankers on stems and branches, has been observed in the UK. The causal agent was identified as Phytophthora pseudosyringae, based on morphological and analysis of the internal transcribed spacer (ITS) sequences. Between 2011 and 2013, a survey assessed the frequency and nature of these P. pseudosyringae infections. Mature trees of Nothofagus with stem lesions caused by P. pseudosyringae were found across England, Scotland and Wales. Additional symptoms such as twig blight and leaf necrosis indicated that aerial infection was occurring. Besides N. obliqua, other hosts regularly encountered included Nothofagus alpina, Fagus sylvatica and Vaccinium myrtillus. In pathogenicity tests involving inoculation of logs, P. pseudosyringae was shown to be an aggressive bark pathogen of N. obliqua and F. sylvatica, but significantly less aggressive on N. alpina. Foliage susceptibility and sporulation tests showed marked differences between the six host species tested. Leaves of N. obliqua and V. myrtillus were highly susceptible. Leaves of N. alpina were moderately susceptible, those of Rhododendron ponticum slightly susceptible and those of F. sylvatica not susceptible at all. High levels of sporulation were observed only on inoculated N. obliqua and V. myrtillus leaves. This suggests that P. pseudosyringae may sporulate heavily on N. obliqua foliage in the field and that this inoculum initiates the aerial lesions observed on the shoots, branches and stems. The results also suggest that P. pseudosyringae has the potential to pose a serious threat to N. obliqua and other Nothofagus species in their Southern Hemisphere native ranges.

}, doi = {10.1111/ppa.12399}, url = {http://doi.wiley.com/10.1111/ppa.12399http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2Fppa.12399}, author = {Scanu, B. and Webber, J. F.} } @article {EFP:EFP784, title = {Detecting asymptomatic ink-diseased chestnut trees by the composition of the ectomycorrhizal community}, journal = {Forest Pathology}, year = {2012}, pages = {n/a{\textendash}n/a}, abstract = {The research was performed in a new and isolated ink disease outbreak. Nine sweet chestnuts of comparable age, growing under same environmental and site conditions, and belonging to three phytosanitary classes (healthy, infected but asymptomatic and symptomatic) were randomly selected. Their ectomycorrhizal community was monitored during two periods, with regard to species abundance, to verify whether the community composition can be useful as an ink disease bioindicator. From the 216 samples, 29 ectomycorrhizal species were recorded, with abundances that changed with the health status of the tree. The results demonstrated that the mycorrhizal community composition was highly related to the ink disease level, allowing the consideration of the use of this parameter as a tool for the quick detection and control of the early stages of the disease.}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2012.00784.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2012.00784.x}, author = {Scattolin, L. and Dal Maso, E. and Mutto Accordi, S. and Sella, L. and Montecchio, L.} } @article {4624, title = {First Report of Phytophthora ramorum Causing Japanese Larch Dieback in France}, journal = {Plant Disease}, year = {2018}, month = {Aug-08-2018}, pages = {PDIS-02-18-0288}, abstract = {

Phytophthora ramorum Werres, De Cock \& Man in{\textquoteright}t Veld, an oomycete known in the United States as the causal agent of sudden oak death, has spread across Europe since the early 2000s. It is responsible for damage and death to a wide range of plant species, including mature trees. In 2009 it was identified on Japanese larch (Larix kaempferi) in southwest England (Webber et al. 2010), and since then it has caused severe damage and losses to Larix spp. in the United Kingdom and the Republic of Ireland. There are two lineages of the oomycete, EU1 and EU2, found in Europe (King et al. 2015), EU2 being the more aggressive. The symptoms on larch include necrosis and loss of needles, wilting of shoots, dieback of branches, and death, often with abundant resin bleeding on trunks and branches. As sporulating hosts, Larix spp. may disperse P. ramorum over long distances. In May 2017, wilting, yellowing/reddening needles, and branch mortality were observed on mature Larix kaempferi (about 50 years old) in the forest of Saint-Cadou, Finist{\`e}re, in the far northwestern part of France (3{\textdegree}59'49.2" W; 48{\textdegree}22'22.4" N). Approximately, 27\% of the trees were affected in May, and 42\% later in September 2017. The presence of P. ramorum was suspected and was first confirmed by testing samples collected from trunks and branches with necrosis and resin bleeds, using the specific conventional polymerase chain reaction (PCR) method developed by Ioos et al. (2006). The oomycete was also isolated in pure culture, using a Phytophthora selective medium (PARB[H]). The features observed, such as a coralloid mycelium, the presence of numerous thin-walled chlamydospores (up to 75 {\textmu}m large), and deciduous, semipapillate sporangia arranged in clusters, matched those reported for P. ramorum. In June 2017, the presence of P. ramorum was confirmed in another larch stand in Hanvec, Finist{\`e}re (4{\textdegree}12'45.0" W; 48{\textdegree}20'10.8" N), using the same identification techniques. In this stand, the prevalence was not precisely estimated but was deemed much lower than in Saint-Cadou. Based on the analysis of Cox1 partial sequence and the PCR restriction fragment length polymorphism pattern described by Van Poucke et al. (2012) on Cox1, the P. ramorum isolates collected in these two forests could be assigned to the EU1 lineage. This is the first report of P. ramorum affecting Japanese larch in France and in mainland Europe. Until now it had only been detected on shrubs in nurseries, green spaces, and in rare circumstances in the natural environment on understory vegetation (rhododendron) in Normandy and Brittany, but not in the vicinity of the infected larch stands. The presence of this pathogen in the natural environment represents a major threat for larch trees, but also for the other potential forest host trees in this region, such as sweet chestnut, and might have a severe impact on both forest and ornamental tree species. Research is in progress to learn more about this outbreak, the possible origin of the inoculum, the extension of the disease, and its progression.

}, issn = {0191-2917}, doi = {10.1094/PDIS-02-18-0288-PDN}, url = {https://apsjournals.apsnet.org/doi/10.1094/PDIS-02-18-0288-PDN}, author = {Schenck, N. and Saurat, C. and Guinet, C. and Fourrier-Jeandel, C. and Roche, L. and Bouvet, A. and Husson, C. and Saintonge, F.-X. and Contal, C. and Ioos, R.} } @article {EPP:EPP2431, title = {A duplex PCR method for the simultaneous identification of Phytophthora ramorum and Phytophthora kernoviae}, journal = {EPPO Bulletin}, volume = {41}, number = {1}, year = {2011}, pages = {27{\textendash}29}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora ramorum and Phytophthora kernoviae are two fungus-like organisms affecting a wide range of hardy ornamental plants and trees. Emergency measures are implemented in the European Union for P.\ ramorum and aim to eradicate, or at least prevent the further spread of this harmful pathogen. Phytophthora kernoviae has so far been found only in New Zealand, the UK and Ireland, and is regulated on a UK level using the same measures as for P.\ ramorum. Both Phytophthora species have a similar host range and can be diagnosed using similar methods. Therefore a duplex PCR detection, based on the internal transcribed spacer (ITS) regions of the ribosomal DNA, was developed to enable simultaneous testing to reduce diagnostic times. The method was tested for its specificity and sensitivity, and on plant samples, and was shown to be reliable for identification of the two organisms.

}, issn = {1365-2338}, doi = {10.1111/j.1365-2338.2010.02431.x}, url = {http://dx.doi.org/10.1111/j.1365-2338.2010.02431.x}, author = {Schlenzig, A.} } @article {761, title = {Involvement of Phytophthora species in the decline of beech Fagus sylvatica in Wallonia (Belgium)}, journal = {Commun Agric Appl Biol Sci.}, volume = {72}, year = {2007}, pages = {879-85.}, abstract = {

During the last decade, typical symptoms of Phytophthora diseases were observed in beech stands of several European countries. The main symptoms were the presence of bleeding cankers on the stem, a low crown density as well as the yellowing of foliage and the small size of leaves. Several species of Phytophthora, such as Phytophthora citricola, P. cambivora and P. cactorum, were reported as the causal agents. In order to evaluate the implication of the different Phytophthora species in beech decline in the southern part of Belgium (Wallonia), a monitoring was undertaken with the help of managers of public and private forests. Phytophthora strains isolated from beech of different stands as well as from soil were characterized through morphological and molecular analyses (PCR-RFLP of ITS). All the isolated strains were identified as P. cambivora, except for one strain whose identification is ongoing. Molecular analysis was also directly applied to necrosed tissues of bleeding beeches and enabled the detection of additional cases. All positive cases exhibited a profile characteristic of the species P. cambivora, except for one of the sampled trees showing a different Phytophthora profile also corresponding to the unidentified isolated strain. Identification of the Phytophthora species linked to this different RFLP profile is also ongoing. Both complementation types (A1 and A2) of P. cambivora were identified, sometimes in the same sampling site. Ornamented oogonia characteristic of this species were produced by pairing A1 and A2 strains isolated from the same site.

}, author = {Schmitz, S. and Zini, J and Chandelier, A.} } @article {3975, title = {Detection and quantification of Phytophthora species which are associated with root-rot diseases in European deciduous forests by species-specific polymerase chain reaction}, journal = {Forest Pathology}, volume = {29}, year = {1999}, month = {06/1999}, pages = {169 - 188}, abstract = {

Oligonucleotide primers were developed for the polymerase chain reaction (PCR)-based detection of selected Phytophthora species which are known to cause root-rot diseases in European forest trees. The primer pair CITR1/CITR2, complementing both internal transcribed spacer regions of the ribosomal RNA genes, gave a 711 bp amplicon with Phytophthora citricola. The Phytophthora cambivora specific primer pair CAMB3/CAMB4, producing a 1105bp amplicon, as well as the Phytophthora quercina specific primer pair QUERC1/QUERC2, producing a 842 bp amplicon, were derived from randomly amplified polymorphic DNA (RAPD)-fragments presented in this paper. All three primer pairs revealed no undesirable cross-reaction with a diverse test collection of isolates including other Phytophthora species, Pythium, Xerocomus, Hebeloma, Russula, and Armillaria. Under the PCR conditions described the detection of a well discernable amplicon was possible down to 100 pg (P. cambivora), 4pg (P. quercina), and 2pg (P. citricola) target DNA. This diagnostic PCR system was able to detect P. citricola, P. quercina, and P. cambivora in seedlings of pendunculate oak (Quercus robur) and European beech (Fagus sylvatica) which were artificially infected under controlled conditions.

}, issn = {1437-4781}, doi = {10.1046/j.1439-0329.1999.00141.x}, author = {Schubert, R. and Bahnweg, G. and Nechwatal, J. and T. Jung and Cooke, D. E. L. and Duncan, J. M. and Muller-Starck, G. and Langebartels, C. and Sandermann, H. Jr2 and W. Osswald} } @article {4086, title = {Phytophthora species associated with diseased woody ornamentals in Minnesota nurseries}, journal = {Plant Disease}, volume = {91}, year = {2007}, month = {01/2007}, pages = {97 - 102}, abstract = {

Phytophthora species are responsible for causing extensive losses of ornamental plants worldwide. Recent international and national surveys for the detection of P. ramorum have led to the finding of previously undescribed Phytophthora species. Since no previous Phytophthora surveys have been carried out in Minnesota, surveys of ornamental nurseries were performed over 4 years to isolate and identify the Phytophthora species causing diseases of woody plants in Minnesota. Species were identified by direct sequencing of internal transcribed spacer (ITS) rDNA, β-tub, and mitochondrial coxI genes. Species associated with diseased ornamental plants include P. cactorum, P. cambivora, P. citricola, P. citrophthora, P. hedraiandra, P. megasperma, P. nicotianae, and the previously identified but undescribed taxon P. Pgchlamydo. The most common species encountered were P. cactorum, P. citricola, and P. citrophthora. Two additional isolates obtained did not match known species. One was similar to P. alni subsp. alni, and the other appeared to be a new species and is referred to as P. sp. MN1. In addition, species are reported for the first time from several hosts. Results indicated that several Phytophthora species were more widespread in the nursery industry than previously thought, and undescribed species were causing disease in Minnesota ornamental nurseries.

}, issn = {0191-2917}, doi = {10.1094/PD-91-0097}, url = {http://dx.doi.org/10.1094/PD-91-0097 }, author = {Schwingle, B. W. and Smith, J. A. and Blanchette, R. A.} } @article {4236, title = {Phytophthora diseases in New Zealand forests}, journal = {New Zealand Journal of Forestry}, volume = {59}, year = {2014}, pages = {14-21}, abstract = {

This article provides a brief overview of the status of Phytophthora diseases in New Zealand forests. Recent outbreaks of Phytophthora diseases internationally and within these forests, including Red Needle Cast of Pinus radiata caused by Phytophthora pluvialis and Agathis australis (kauri) dieback caused by Phytophthora taxon Agathis (PTA), have highlighted the biosecurity threat these species pose to New Zealand. In isolated cases, Red Needle Cast has impacted P. radiata plantations through the premature defoliation of mature needles. Kauri dieback, caused by Phytophthora taxon Agathis, has resulted in devastating disease within some sites. Preliminary research indicates that both these diseases will respond to treatment with phosphite, consistent with current international Phytophthora management. Ongoing research into Red Needle Cast, Phytophthora taxon Agathis induced kauri dieback and other Phytophthora diseases within P. radiata and kauri is focusing on understanding the epidemiology of the diseases, the chemical and genetic mechanisms of resistance, and also screening for durable resistance to multiple Phytophthora species. Many other Phytophthora pathogens have been identified within New Zealand. These have not been found to cause serious disease in native or exotic forest systems, despite some being known to cause diseases of great consequence internationally. Significant examples include P. cinnamomi, P. multivora and P. kernoviae. As a result of increased global movement of plant material, New Zealand{\textquoteright}s and other international forests are vulnerable to new Phytophthora diseases. However, through the world{\textquoteright}s best practice adaptive management the threat and impacts of these diseases can be reduced.

}, url = {http://www.nzjf.org/abstract.php?volume_issue=j59_2\&first_page=14}, author = {Peter Scott and Nari Williams} } @article {Scott:30 June 2009:0031-5850:1, title = {Phytophthora multivora sp. nov., a new species recovered from declining Eucalyptus, Banksia, Agonis and other plant species in Western Australia}, journal = {Persoonia - Molecular Phylogeny and Evolution of Fungi}, volume = {22}, year = {2009}, pages = {1-13(13)}, abstract = {

A new Phytophthora species, isolated from rhizosphere soil of declining or dead trees of Eucalyptus gomphocephala, E. marginata, Agonis flexuosa, and another 13 plant species, and from fine roots of E. marginata and collar lesions of Banksia attenuata in Western Australia, is described as Phytophthora multivora sp. nov. It is homothallic and produces semipapillate sporangia, smooth-walled oogonia containing thick-walled oospores, and paragynous antheridia. Although morphologically similar to P. citricola, phylogenetic analyses of the ITS and cox1 gene regions demonstrate that P. multivora is unique. Phytophthora multivora is pathogenic to bark and cambium of E. gomphocephala and E. marginata and is believed to be involved in the decline syndrome of both eucalypt species within the tuart woodland in south-west Western Australia.

}, doi = {10.3767/003158509X415450}, url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2789538/}, author = {P.M. Scott and Burgess, T. I. and P.A. Barber and Shearer, B. L. and Stukely, M. J. C. and G.E.St.J. Hardy and T. Jung} } @article {EFP:EFP753, title = {Pathogenicity of Phytophthora multivora to Eucalyptus gomphocephala and Eucalyptus marginata}, journal = {Forest Pathology}, volume = {42}, year = {2011}, pages = {289{\textendash}298}, publisher = {Blackwell Publishing Ltd}, abstract = {

Phytophthora multivora is associated with the rhizosphere of declining Eucalyptus gomphocephala, Eucalyptus marginata and Agonis flexuosa. Two pathogenicity experiments were conducted. The first experiment examined the pathogenicity of five P. multivora isolates and one Phytophthora cinnamomi isolate on the root systems of E. gomphocephala and one P. multivora isolate on the root system of E. marginata. In the second experiment, the pathogenicity of P. multivora to E. gomphocephala and E. marginata saplings was measured using under-bark stem inoculation. In Experiment 1, the P. cinnamomi isolate was more aggressive than all P. multivora isolates causing significant loss of fine roots and plant death. Two P. multivora isolates and the P. cinnamomi isolate caused significant losses of E. gomphocephala fine roots 0-2 mm in diameter and significantly reduced the surface area of roots 0-1 mm in diameter. One P. multivora and the P. cinnamomi isolate significantly reduced the surface area of roots 1-2 mm in diameter. Two of the P. multivora isolates significantly reduced the number of E. gomphocephala root tips. In E. marginata, the length and surface area of roots 0-1 mm in diameter and number of root tips were significantly reduced by P. multivora infestation. Rhizosphere infestation with the P. multivora isolates and P. cinnamomi isolate on E. gomphocephala, and one P. multivora isolate on E. marginata, did not significantly influence the foliar nutrient concentrations. In Experiment 2, under-bark inoculation with P. multivora caused significant lesion extension in E. gomphocephala and E. marginata saplings, compared to the control. We propose that P. multivora is inciting E. gomphocephala and E. marginata decline by causing fine root loss and subsequently interfering with nutrient cycling throughout the plant. The impact of fine root loss on the physiology of plants in sites infested with P. multivora requires further research.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00753.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00753.x}, author = {P.M. Scott and T. Jung and Shearer, B. L. and P.A. Barber and Calver, M. and Hardy, G. E. St. J.} } @article {4047, title = {Coconut bud rot in Florida}, volume = {Technical Bulletin 199}, year = {1928}, pages = {87 pp.}, publisher = {University of Florida, Agricultural Experiment Station, Gainsville, FL}, url = {http://ufdc.ufl.edu/UF00027165/00001}, author = {JL Seal} } @article {4074, title = {Dieback and Mortality of Pinus radiata Trees in Italy Associated with Phytophthora cryptogea}, journal = {Plant Disease}, volume = {98}, year = {2014}, month = {01/2014}, pages = {159 - 159}, abstract = {

Pinus radiata D. Don is a forest tree species native to the Monterey Baja in California. Due to its rapid growth and desirable lumber and pulp qualities, between 1960 and 1980, about 12,000 ha of P. radiata were planted in Sardinia, Italy. The only disease reported on this conifer species has been Diplodia pinea, which causes tip and branch dieback (3). In January 2012, dieback and mortality of 25-year-old radiata pine trees were observed in a reforestation area of about 20 ha located in northern Sardinia (40{\textdegree}43'N, 9{\textdegree}22'E, 600 m a.s.l.). Symptoms included chlorosis, reddish-brown discoloration of the whole crown or dieback starting in the upper crown and progressing downward through the crown, and necrotic bark tissues at root collar. Approximately 25\% of the trees were affected. In a first attempt, a Phytophthora species was consistently isolated from the rhizosphere of 23 symptomatic trees, which included necrotic fine roots using oak leaves as bait (4). Afterwards, it was also isolated from phloem samples taken from the margins of fresh lesions at the stem base and upper roots of affected trees using synthetic mucor agar medium (1). Isolation from soil samples of six healthy pine trees randomly selected in the site did not yield any Phytophthora isolate. On carrot agar (CA), Phytophthora colonies were stellate to slightly radiate with limited aerial mycelium. Sporangia were obpiryform, non-papillate, and non-caducous, measuring 46.9 to 51.2 {\texttimes} 29.1 to 32.6 μm (l:b ratio 1.9). Hyphal swellings were formed in chains or clusters; chlamydospores were not observed. These isolates had cardinal temperatures of \<5{\textdegree}C, 25{\textdegree}C, and 35{\textdegree}C, respectively. Their morphological and cultural features were typical of Phytophthora cryptogea Pethybridge \& Lafferty. They were heterothallic and produced oogonia with amphyginous antheridia when paired with an A2 mating type tester strain of P. cryptogea. This identity was corroborated by sequence analysis of the internal transcribed spacer (ITS) region of the rDNA. BLAST searches showed 99\% homology with sequences of P. cryptogea available in GenBank (DQ479410 and HQ697245). The ITS sequence of a representative isolate (PH101) was submitted to GenBank (Accession Nos. KC603895). The strain PH101 was stored in the culture collection of the Department of Agriculture at the University of Sassari. Pathogenicity of isolate PH101 was verified by inoculating five freshly cut logs of radiata pine (1 m long and 15 cm diam.) with a 5-mm agar plug taken from the margin of 4-day-old culture grown on CA (4). The plug was inserted in a 5-mm hole made through the bark with a cork borer. Five control logs were inoculated with sterile CA. All logs were incubated in a growth chamber at 20{\textdegree}C. Phloem lesion sizes were assessed after 1 month and measured 9.7 {\textpm} 5.5 cm2 (average {\textpm} standard deviation). Control logs had no lesions. The pathogen was re-isolated from the lesions, thus fulfilling Koch{\textquoteright}s postulates. P. cryptogea has been previously reported in Australia, causing decline of radiata pine trees in wet and flooded soils (2). To our knowledge, this is the first report of P. cryptogea on P. radiata trees in Europe.

}, issn = {0191-2917}, doi = {10.1094/PDIS-05-13-0572-PDN}, url = {http://dx.doi.org/10.1094/PDIS-05-13-0572-PDN}, author = {Sechi, C. and Seddaiu, S. and Linaldeddu, B. T. and Franceschini, A. and Scanu, B.} } @article {4697, title = {First Report of Phytophthora acerina, P. plurivora, and P. pseudocryptogea Associated with Declining Common Alder Trees in Italy}, journal = {Plant Disease}, volume = {104}, year = {2020}, month = {Apr-17-2020}, pages = {1874}, abstract = {

Since the early 1990s, common alder (Alnus glutinosa) trees showing a variety of symptoms such as a partial or complete canopy dieback, reddening of foliage, and bleeding cankers at the collar and lower stem were observed in several torrential mountain streams in Sardinia (Italy). In order to clarify the etiology of the symptoms observed, three riparian alder stands along three streams in northern Sardinia were surveyed in the spring of 2017. In each stand a 100-m-long transect was established, and 10 symptomatic alder trees per transect were sampled for Phytophthora species. Phytophthora isolations from 30 rhizosphere samples (300 g of soil and roots) collected around the selected alder trees and 30 inner bark samples taken from the margin of active lesions at the collar region of the same trees were performed as described by Linaldeddu et al. (2020). Disease incidence among transects ranged from 81 to 97\%. Based on colony growth patterns on carrot agar (CA), morphological features of sporangia and sequence analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) of rDNA, the 40 Phytophthora isolates obtained were identified as Phytophthora acerina (seven isolates with ovoid sporangia measuring 48.9 {\texttimes} 33.1 μm), P. plurivora (24 isolates with ovoid sporangia measuring 50.1 {\texttimes} 32.9 μm), and P. pseudocryptogea (nine isolates with ellipsoid sporangia measuring 44.8 {\texttimes} 26.9 μm). For all Phytophthora species, BLAST searches in GenBank showed 100\% identity with reference sequences of representative isolates including those of ex-type cultures (JX951285, FJ665225, and KP288376). The ITS sequence of a representative isolate of each species was deposited in GenBank (P. acerina MN589653, P. plurivora MN589655, and P. pseudocryptogea MN589656). The representative isolates were stored at 10{\textdegree}C under water at the Culture Collection of the University of Padova. The pathogenicity of the representative isolate of each Phytophthora species was evaluated by inoculating five 3-year-old common alder seedlings per isolate. For each seedling a plastic beaker was positioned and sealed at the base of the stem, filled with 130 ml of pond water, and inoculated with 10 agar-mycelium plugs (10 mm) cut from the margin of a 5-day-old CA colony. The water of five control plants was inoculated with sterile CA plugs. Plants were kept in a laboratory at 25{\textdegree}C and watered regularly for 4 weeks. At the end of the experiment, all inoculated plants were symptomatic and displayed reddened to browned leaves and dark brown lesions on the inner bark. The three Phytophthora species were successfully reisolated from symptomatic inner bark tissues of the stem of all plants, fulfilling Koch{\textquoteright}s postulates. No disease symptoms were detected on control seedlings, and no Phytophthora species were isolated. The pathogenicity test was conducted twice. P. plurivora was the dominant species and the only species obtained from stem cankers and rhizosphere samples in all sites. This species is regarded as native to Europe and known as an aggressive pathogen of A. glutinosa (Aday Kaya et al. 2018; Haque et al. 2014). P. acerina and P. pseudocryptogea were obtained from both bleeding cankers and rhizosphere samples in two sites. All three Phytophthora species are reported for the first time to be associated with declining common alder trees in Italy, and for the first time the pathogenicity of P. acerina and P. pseudocryptogea has been demonstrated on A. glutinosa. The widespread occurrence and virulence of these Phytophthora species represents a serious threat to riparian alder ecosystems in Sardinia.

}, issn = {0191-2917}, doi = {10.1094/PDIS-01-20-0186-PDN}, url = {https://apsjournals.apsnet.org/doi/10.1094/PDIS-01-20-0186-PDN}, author = {Seddaiu, S. and Linaldeddu, B. T.} } @article {EFP:EFP758, title = {Susceptibility to Phytophthora cinnamomi of the commonest morphotypes of Holm oak in southern Spain}, journal = {Forest Pathology}, volume = {42}, year = {2012}, pages = {345{\textendash}347}, publisher = {Blackwell Publishing Ltd}, abstract = {

The four main morphotypes of Holm oak (Quercus ilex subsp. ballota) present in Andalusia (expansa, macrocarpa, microcarpa and rotundifolia) were infected with Phytophthora cinnamomi to determine their susceptibility to the root pathogen. No large differences were found among the four morphotypes in the infection of roots, which always showed a high degree of necrosis. However, the different responses of the foliage to infection separated the four morphotypes of Holm oak into three groups: very susceptible (microcarpa), susceptible (expansa) and moderately susceptible (rotundifolia and macrocarpa). The natural hybrid Q.ilex ballota-Q.faginea exhibited a low level of root and foliar symptoms when infected with P.cinnamomi. Quercus faginea could be considered as a source of resistance to P.cinnamomi in future breeding programmes.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00758.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00758.x}, author = {Serrano, M. S. and De Vita, P. and Carbonero, M. D. and Fern{\'a}ndez, F. and Fern{\'a}ndez-Rebollo, P. and S{\'a}nchez, M. E.} } @article {4662, title = {A microsatellite analysis identifies global pathways of movement of Phytophthora cinnamomi and the likely sources of wildland infestations in California and Mexico}, journal = {Phytopathology}, year = {2019}, month = {Jun-05-2019}, abstract = {

The genetic structure of a sample of isolates of the oomycete plant pathogen Phytophthora cinnamomi from natural and agricultural outbreaks, and the long-distance movement of individual genotypes, were studied using four microsatellite markers genotyped for 159 isolates of Californian, Mexican, and worldwide origin. Allelic profiles identified 75 multilocus genotypes; STRUCTURE analysis placed them in three groups characterized by different geographic and host ranges, different genic and genotypic diversity, and different reproductive modes. When relationships among genotypes were visualized on a minimum spanning network (MSN), genotypes belonging to the same STRUCTURE group were contiguous with rare exceptions. A putatively ancestral Group 1 has high genic diversity, includes all A1 mating type isolates and all Papuan isolates in the sample, was rarely isolated from natural settings in California and Mexico, and was positioned at the center of the MSN. Putatively younger Groups 2 and 3 had lower genic diversity, were both neighbors to Group 1 but formed two distinct peripherical sectors of the MSN, and were equally present in agricultural commodities and natural settings in Mexico and California. A few genotypes, especially in Group 2 and 3, were isolated multiple times in different locations and settings. The presence of identical genotypes from the same hosts in different continents indicates that long-distance human-mediated movement of P. cinnamomi has occurred. The presence of identical genotypes at high frequency in neighboring wildlands and agricultural settings suggests that specific commodities may have been the source of recent wild infestations caused by novel invasive genotypes.

}, issn = {0031-949X}, doi = {10.1094/PHYTO-03-19-0102-R}, url = {https://apsjournals.apsnet.org/doi/10.1094/PHYTO-03-19-0102-R}, author = {Serrano, Maria S and Osmundson, Todd and Almaraz-Sanchez, Alejandra and Croucher, Peter JP and Swiecki, Ted and Alvarado, Dionisio and Garbelotto, Matteo} } @article {4621, title = {An Overview of Canadian Research Activities on Diseases Caused by Phytophthora ramorum: Results, Progress, and Challenges}, journal = {Plant Disease}, volume = {102}, year = {2018}, month = {Jan-07-2018}, pages = {1218 - 1233}, abstract = {

International trade and travel are the driving forces behind the spread of invasive plant pathogens around the world, and human-mediated movement of plants and plant products is now generally accepted as the primary mode of their introduction, resulting in huge disturbance to ecosystems and severe socio-economic impact. These problems are exacerbated under the present conditions of rapid climatic change. We report an overview of the Canadian research activities on Phytophthora ramorum. Since the first discovery and subsequent eradication of P. ramorum on infected ornamentals in nurseries in Vancouver, British Columbia, in 2003, a research team of Canadian government scientists representing the Canadian Forest Service, Canadian Food Inspection Agency, and Agriculture and Agri-Food Canada worked together over a 10-year period and have significantly contributed to many aspects of research and risk assessment on this pathogen. The overall objectives of the Canadian research efforts were to gain a better understanding of the molecular diagnostics of P. ramorum, its biology, host-pathogen interactions, and management options. With this information, it was possible to develop pest risk assessments and evaluate the environmental and economic impact and future research needs and challenges relevant to P. ramorum and other emerging forest Phytophthora spp.

}, issn = {0191-2917}, doi = {10.1094/PDIS-11-17-1730-FE}, url = {https://apsjournals.apsnet.org/doi/10.1094/PDIS-11-17-1730-FE}, author = {Shamoun, Simon Francis and Rioux, Danny and Callan, Brenda and James, Delano and Hamelin, Richard C. and Bilodeau, Guillaume J. and Elliott, Marianne and L{\'e}vesque, Andr{\'e} and Becker, Elisa and McKenney, Dan and Pedlar, John and Bailey, Karen and Bri{\`e}re, S. C. and Niquidet, Kurt and Allen, Eric} } @proceedings {3954, title = {Sudden oak death, a science symposium: the state of our knowledge (abstracts)}, year = {2002}, month = {2002}, pages = {98 pp}, publisher = {U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station, University of California, Integrated Hardwood and Range Management Program, Center for Forestry, Division of Agriculture and Natural Resources, Berkeley, California}, address = {Monterey, California}, abstract = {

Conference Purpose A Symposium designed to bring together a broad array of the scientific community from throughout the world working on Phytophthora ramorum and the phenomena known as {\textquotedblleft}Sudden Oak Death{\textquotedblright}

}, url = {http://www.suddenoakdeath.org/?bibliography=a-survey-of-sudden-oak-death-in-native-california-forest-and-woodland-communities-relating-incidence-and-intensity-of-phytophthora-ramorum-to-plant-community-and-site-variables}, author = {Dr. Patrick J. Shea and Dr. Richard B. Standiford and Dr. Patrick J. Shea and Dr. Richard B. Standiford} } @article {899, title = {Quantification of the susceptibility of the native flora of the South-West Botanical Province, Western Australia, to Phytophthora cinnamomi}, journal = {Australian Journal of Botany}, volume = {52 (4)}, year = {2004}, pages = {435 - 443}, abstract = {

This study compares, for the first time, variation in estimates of susceptibility of native flora to Phytophthora cinnamomi Rands among four databases and proposes an estimate of the proportion of the flora of the South-West Botanical Province of Western Australia that is susceptible to the pathogen. Estimates of the susceptibility of south-western native flora to P. cinnamomi infection were obtained from databases for Banksia woodland of the Swan Coastal Plain, jarrah (Eucalyptus marginata Donn. ex Smith) forest, the Stirling Range National Park and Rare and Threatened Flora of Western Australia. For the woodland, forest and national park databases, hosts were naturally infected in uncontrolled diverse natural environments. In contrast, threatened flora were artificially inoculated in a shadehouse environment. Considerable variation occurred within taxonomic units, making occurrence within family and genus poor predictors of species susceptibility. Identification of intra-specific resistance suggests that P. cinnamomi could be having a strong selection pressure on some threatened flora at infested sites and the populations could shift to more resistant types. Similar estimates of the proportion of species susceptible to P. cinnamomi among the databases from the wide range of environments suggests that a realistic estimate of species susceptibility to P. cinnamomi infection in the south-western region has been obtained. The mean of 40\% susceptible and 14\% highly susceptible equates to 2284 and 800 species of the 5710 described plant species in the South-West Botanical Province susceptible and highly susceptible to P. cinnamomi, respectively. Such estimates are important for determining the cost of disease to conservation values and for prioritising disease importance and research priorities. P. cinnamomi in south-western Australia is an unparalleled example of an introduced pathogen with a wide host range causing immense irreversible damage to unique, diverse but mainly susceptible plant communities.

}, doi = {http://dx.doi.org/10.1071/BT03131}, url = {http://www.publish.csiro.au.proxy.library.oregonstate.edu/?paper=BT03131}, author = {Shearer, B. L. and C. E. Crane and A. Cochrane} } @article {4615, title = {Effects of temperature on germination of sporangia, infection and protein secretion by Phytophthora kernoviae}, journal = {Plant Pathology}, volume = {67}, year = {2018}, month = {Jan-04-2018}, pages = {719 - 728}, abstract = {

Phytophthora kernoviae is a pathogen on a wide range of plants, but little is known of optimal infection conditions. Rhododendron ponticum leaves were inoculated with six different isolates of P.\ kernoviae sporangia and incubated at different temperatures from 10 to 28\ {\textdegree}C. After 1\ week, lesion development and pathogen recovery were only observed from all isolates at 15 and 20\ {\textdegree}C and a few isolates at 10\ {\textdegree}C. In an experiment with temperatures ranging from 20 to 25\ {\textdegree}C, lesion development and pathogen recovery on R.\ ponticum, Magnolia stellata and Viburnum tinus occurred consistently at 20 and 21\ {\textdegree}C, was limited at 22\ {\textdegree}C, and did not occur at 23\ {\textdegree}C and above. There was no difference in sporangia and zoospore germination at 20{\textendash}25\ {\textdegree}C. In a temperature fluctuation experiment, the necrotic area of inoculated R.\ ponticum leaves increased with longer incubation at 20\ {\textdegree}C and decreased with longer incubation at 24\ {\textdegree}C. Crude extracts of secreted proteins from P.\ kernoviae cultures grown at 20 and 24\ {\textdegree}C were compared to determine any effects of temperature on pathogenicity. When spot tested on R.\ ponticum leaves, crude protein suspensions from cultures grown at 20\ {\textdegree}C induced necrosis, while proteins from cultures grown at 24\ {\textdegree}C did not. Proteomic analysis confirmed that a 10\ kDa protein secreted at both 20 and 24\ {\textdegree}C shared sequence homology to the conserved domains of known elicitins of other Phytophthora spp. The protein secreted at 20\ {\textdegree}C that was responsible for necrosis has not been identified.

}, doi = {https://doi.org/10.1111/ppa.12782}, url = {https://doi.org/10.1111/ppa.12782}, author = {Shelley, B. A. and Luster, D. G. and Garrett, W. M. and McMahon, M. B. and Widmer, T. L.} } @article {1132, title = {A test system to quantify inoculum in runoff from Phytophthora ramorum-infected plant roots}, journal = {Phytopathology}, volume = {101}, year = {2011}, pages = {1457-1464}, abstract = {

Foliar hosts of Phytophthora ramorum are often susceptible to root infection but the epidemiological significance of such infections is unknown. A standardized test system was developed to quantify inoculum in runoff from root-infected Viburnum tinus {\textquoteleft}Spring Bouquet{\textquoteright} or Rhododendron {\textquoteleft}Cunningham{\textquoteright}s White{\textquoteright} cuttings. Cuttings of both species gave off a maximum amount of inoculum 1 to 3 weeks after inoculation. The greatest amount of inoculum was recovered from Viburnum roots that were 48 to 70 days old at the time of inoculation, or roots incubated at 15 to 20{\textdegree}C rather than 25{\textdegree}C. Inoculum in runoff from inoculated Viburnum roots was similar for four different isolates of P. ramorum representing both the NA1 and EU1 lineages. When Rhododendron cuttings were inoculated with P. ramorum, P. citricola, or P. cactorum, inoculum of all three pathogens was recovered from runoff, with the highest amount recovered from plants inoculated with P. citricola, followed by the other two. Compared with the other two pathogens, P. ramorum colonized root tissue to a smaller extent. The epidemiology of root infection by P. ramorum is important in itself but the assay might lend itself for use in risk analysis for root infection of other plant species and evaluation of control measures, and also shed light on other root-infecting Phytophthora spp.

}, doi = {10.1094/PHYTO-09-10-0260}, url = {http://dx.doi.org/10.1094/PHYTO-09-10-0260}, author = {Shishkoff, Nina} } @article {4318, title = {Action of fosetyl-al and metalaxyl against Phytophthora austrocedri}, journal = {Forest Pathology}, volume = {46}, year = {2015}, month = {Jan 2016}, pages = {54{\textendash}66}, abstract = {

Fosetyl-Al and metalaxyl, the most commonly used systemic fungicides against Phytophthora, were evaluated for their efficacy to control Phytophthora austrocedri, the pathogen that causes a serious disease at the Austrocedrus chilensis forests in Patagonia. The effect of the chemicals on pathogen development in\ vitro and in planta was analysed. Both chemicals were shown to protect plants from the pathogen. In vitro assays showed that asexual reproduction was sensitive to both chemicals. However, mycelial growth and sexual reproduction, which were clearly sensitive to metalaxyl, were sensitive only to high concentrations of fosetyl-Al. Fosetyl-Al and metalaxyl had almost the same efficacy when applied preventively by soil drench to seedlings. This difference between in\ vitro and in planta results can be attributed to the dual action of fosetyl-Al, not only inhibiting the pathogen but also stimulating host defence. In adult trees, preventive and curative treatments were tested, but only the fosetyl-Al preventive treatment was effective in the assayed conditions. Interestingly, seedlings pretreated with both fungicides were less susceptible to the effectors secreted by the pathogen. Our results indicate that fosetyl-Al and metalaxyl provide some resistance to the plant besides the fungistatic direct action on the pathogen. Further studies to elucidate a possible resistance-inducing activity of these chemicals and the mechanisms involved are underway.

}, doi = {10.1111/efp.12216}, url = {http://doi.wiley.com/10.1111/efp.12216}, author = {Silva, P. V. and V{\'e}lez, M. L. and Ota{\~n}o, D. H. and Nu{\~n}ez, C. and Greslebin, A. G.}, editor = {Osswald, W.} } @article {4614, title = {Phytophthora Contamination in a Nursery and Its Potential Dispersal into the Natural Environment}, journal = {Plant Disease}, volume = {102}, year = {2018}, month = {Jan-01-2018}, pages = {132 - 139}, abstract = {

A detailed site investigation of a eucalypt nursery suffering disease losses revealed the causal agent to be Phytophthora boodjera. The pathogen was detected in vegetation surrounding the nursery production area, including the lawn, under the production benches during the growing season, and, most importantly, from plant debris in used trays. However, it was not found in the container substrate, water supplies, or production equipment or on the workers themselves. The sterilization methods used by the nursery were shown to be ineffective, indicating that a more rigorous method was required. Boiling trays for 15 min or steaming at 65{\textdegree}C for 60 min eradicated P. boodjera. This pathogen was more pathogenic to the eucalypts tested in their early seedling stage than P. cinnamomi. Tracing of out-planting to revegetation sites showed that P. boodjera was able to spread into the environment. Dispersal via out-planting to native vegetation may affect seedling recruitment and drive long-term shifts in native plant species. Inadequate nursery hygiene increases the risk of an outbreak and can limit the success of biosecurity efforts as well as damage conservation efforts.

}, issn = {0191-2917}, doi = {10.1094/PDIS-05-17-0689-RE}, url = {https://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-05-17-0689-RE}, author = {Simamora, Agnes V. and Paap, Trudy and Howard, Kay and Stukely, Michael J. C. and Hardy, Giles E. St. J. and Burgess, Treena I.} } @mastersthesis {4649, title = {Phytophthora species and riparian alder tree damage in western Oregon}, volume = {Ph.D.}, year = {2013}, month = {02/2014}, abstract = {

The genus Phytophthora contains some of the most destructive pathogens of forest trees, including the most destructive pathogen of alder in recent times, Phytophthora alni. Alder trees were reported to be suffering from canopy dieback in riparian ecosystems in western Oregon, which prompted a survey of alder health and monitoring for P. alni. In 2010 surveys in western Oregon riparian ecosystems were initiated to gather baseline data on damage and on the Phytophthora species associated with alder. Damage was recorded and analyzed from transects containing alder trees with canopy dieback symptoms according to damage type: (1) pathogen, (2) insect, or (3) wound. Phytophthora species from western Oregon riparian ecosystems were systematically sampled, isolated, identified, stored and compared. Koch{\textquoteright}s Postulates were evaluated for three key Phytophthora species recovered: P. alni, P. siskiyouensis and P. taxon Oaksoil, and alder disease in the western United States was described. Then, the ecological role of the most abundant Phytophthora species from streams was evaluated. The data indicated that many of the same agents reported causing damage to alder trees in the western United States were also damaging alder trees in western Oregon including the alder flea beetle, sawflies, flood debris, Septoria alnifolia, and Mycopappus alni. The most important damage correlated with canopy dieback was incidence of Phytophthora cankers, and isolation of Phytophthora siskiyouensis. In the initial systematic survey of Phytophthora species, 1190 individual Phytophthora isolates were recovered but were of many different species. In the survey of alder roots, P. alni subsp. uniformis was one of the species recovered from necrotic red alder roots, but overall incidence was low; it was isolated four times. From the evaluation of Koch{\textquoteright}s postulates, Phytophthora canker of alder in the western United States was described, and is a bole canker caused by Phytophthora. Phytophthora canker of alder was only found caused by P. siskiyouensis in nature, and it was isolated 74 times. Isolation was mainly from bole cankers and diseased roots on red and white alder, and from water and alder leaf debris floating in the stream. The most abundant Phytophthora species associated with red alder is an informally described species P. taxon Oaksoil, which appears to be a relatively benign aquatic saprotroph of alder leaf debris. Canopy dieback was more prevalent in riparian alder trees from transects with P. siskiyouensis than from transects with P. taxon Oaksoil but without P. siskiyouensis (70\% and 35\%, respectively). The informally described P. taxon Oaksoil from western Oregon is formally described here as P. obrutafolium sp. nov., closely related to P. bilorbang from western Australia, and P. taxon Oaksoil ss from an oak forest in France. In summary, other agents besides Phytophthora can damage alder trees in western Oregon. Many Phytophthora species associate with alder in western Oregon but not all of them are important damaging agents of alder. However, Phytophthora canker of alder is widespread in western Oregon. In the United States, Phytophthora canker of alder has only been found to be caused by P. siskiyouensis.

}, url = {http://hdl.handle.net/1957/46441 }, author = {Sims, Laura} } @article {4342, title = {The Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA}, journal = {Mycologia}, volume = {107}, year = {2015}, month = {October 2015}, pages = {889 - 902}, abstract = {

Phytophthora species were systematically sampled, isolated, identified and compared for presence in streams, soil and roots of alder (Alnus species) dominated riparian ecosystems in western Oregon. We describe the species assemblage and evaluate Phytophthora diversity associated with alder. We recovered 1250 isolates of 20 Phytophthora species. Only three species were recovered from all substrates (streams, soil, alder roots): P. gonapodyides, the informally described {\textquotedblleft}P. taxon Pgchlamydo{\textquotedblright}, and P. siskiyouensis. P. alni ssp. uniformis along with five other species not previously recovered in Oregon forests are included in the assemblage: P.citricola s.l., P. gregata, P. gallica, P. nicotianae and P. parsiana. Phytophthora species diversity was greatest in down- stream riparian locations. There was no significant difference in species diversity comparing soil and unwashed roots (the rhizosphere) to stream water. There was a difference between the predominating species from the rhizosphere compared to stream water. The most numerous species was the informally described {\textquotedblleft}P. taxon Oaksoil{\textquotedblright}, which was mainly recovered from, and most predominant in, stream water. The most common species from riparian forest soils and alder root systems was P. gonapodyides.

}, issn = {0027-5514}, doi = {10.3852/14-255}, url = {http://www.mycologia.org/cgi/doi/10.3852/14-255}, author = {Sims, L. L. and Sutton, W. and Reeser, P. and Hansen, E. M.} } @article {4619, title = {Susceptibility to the rare Phytophthora tentaculata and to the widespread Phytophthora cactorum is consistent with host ecology and history}, journal = {Forest Pathology}, year = {2018}, month = {Apr-05-2020}, pages = {e12446}, abstract = {

We evaluated the susceptibility of three California endemic plant species Heteromeles arbutifolia, Platanus racemosa and Quercus agrifolia to the two congeneric soilborne pathogen species: Phytophthora tentaculata and Phytophthora cactorum. These pathogens were recently introduced in ecosystems east of the San Francisco Bay, where the three plant species above are dominant. Phytophthora cactorum has a worldwide distribution inclusive of California, and a broad host range. Phytophthora tentaculata, in contrast, is suspected to be a {\textquotedblleft}new{\textquotedblright} exotic to California and has been described on relatively few hosts. By separately challenging the roots and the stems of the three plant species above, we show that: (a) Both were equally pathogenic, but the type of disease differed based on host; (b) disease was consistent with host ecology and with previous disease reports, even if caused by different Phytophthora spp. and; (c) there were intraspecific differences in virulence. This study provides the following significant information regarding the management and early modelling of polyphagous soilborne Phytophthoras: (a) Endemic species can be as problematic as recently introduced exotics. (b) Multiple introductions should be avoided due to varying virulence levels among genotypes. (c) Riparian species like P.\ racemosa may develop disease tolerance in their root systems, but remain susceptible in their aerial portions, and thus, diseases could be facilitated by flooding or splash of infectious structures of soilborne pathogens onto aerial plant portions.

}, doi = {https://doi.org/10.1111/efp.12446}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/efp.12446?campaign=wolearlyview}, author = {Sims, Laura L. and Garbelotto, Matteo} } @article {4405, title = {Alder Canopy Dieback and Damage in Western Oregon Riparian Ecosystems}, journal = {Northwest Science}, volume = {89}, year = {2015}, month = {Jan-01-2015}, pages = {34 - 46}, abstract = {

We gathered baseline data to assess alder tree damage in western Oregon riparian ecosystems. We sought to determine if Phytophthora-type cankers found in Europe or the pathogen Phytophthora alni subsp. alni, which represent a major threat to alder forests in the Pacific Northwest, were present in the study area. Damage was evaluated in 88 transects; information was recorded on damage type (pathogen, insect or wound) and damage location. We evaluated 1445 red alder (Alnus rubra), 682 white alder (Alnus rhombifolia) and 181 thinleaf alder (Alnus incana spp. tenuifolia) trees. We tested the correlation between canopy dieback and canker symptoms because canopy dieback is an important symptom of Phytophthora disease of alder in Europe. We calculated the odds that alder canopy dieback was associated with Phytophthora-type cankers or other biotic cankers. P. alni subsp. alni (the causal agent of alder disease in Europe) was not identified in western Oregon; however, Phytophthora siskiyouensis was isolated from Phytophthora-type cankers which were present on 2\% of red alder trees and 3\% of white alder trees. The odds of canopy dieback were 5.4 and 4.8 times greater for red and white alder (respectively) with Phytophthora-type canker symptoms than in trees without such cankers. The percentage of trees with canopy dieback was 51\%, 32\%, and 10\% for red, white, and thinleaf alder respectively. Other common damage included wounding, foliar pathogens and insects on red alder. This is the first report of Phytophthora canker of alder in United States forests and first report of P. siskiyouensis isolation from alder in forests anywhere.

}, issn = {0029-344X}, doi = {10.3955/046.089.0103}, url = {http://www.bioone.org/doi/10.3955/046.089.0103}, author = {Sims, Laura and Goheen, Ellen and Kanaskie, Alan and Hansen, Everett} } @proceedings {214, title = {Another new? species of Phytophthora on alder {\textquoteleft}down under{\textquoteright} (Australia).}, volume = {7}, year = {2006}, pages = {Poster 30}, address = {Freising Germany}, author = {Smith, I. W., and J. Cunnington and I Pascoe}, editor = {Brasier, C. and T. Jung and W. Osswald} } @article {3963, title = {Phytophthora alni on Alnus glutinosa reported for the first time in Spain}, journal = {Plant Pathology}, volume = {59}, year = {2010}, month = {08/2010}, pages = {798 - 798}, doi = {10.1111/ppa.2010.59.issue-410.1111/j.1365-3059.2009.02254.x}, author = {Solla, A. and P{\'e}rez-Sierra, A. and Corcobado, T. and Haque, M. M. and Diez, J. J. and T. Jung} } @article {859, title = {Phytophthora katsurae. [Descriptions of Fungi and Bacteria].
}, journal = {IMI Descriptions of Fungi and Bacteria}, volume = {84}, year = {1985}, pages = {Sheet 837}, abstract = {

A description is provided for Phytophthora katsurae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Chestnut, coconut. DISEASE: Trunk rot of chestnut. GEOGRAPHICAL DISTRIBUTION: Asia (Japan, Taiwan), Oceania (Hawaii), Africa (Ivory Coast), Australasia (Australia (Queensland), Papua New Guinea). TRANSMISSION: Soil-borne, isolated from forest soils in Taiwan (59, 2349), Queensland and Papua New Guinea and from chestnut orchard soils in Japan (58, 2951).

}, author = {Stamps, D. J.} } @article {197, title = {Revised tabular key to the species of Phytophthora}, journal = {Mycological papers, CAB International, Wallingford Oxon}, volume = {162}, year = {1990}, pages = {1-28}, issn = {0027-5522 }, url = {http://www.cabdirect.org/abstracts/19902300161.html;jsessionid=1D85C493563BECA35F0E55609ABAF21C}, author = {Stamps, D. J. and Waterhouse, G. M. and Newhook, F. J. and Hall, G. S.} } @article {4363, title = {A review of New Zealand kauri (Agathis australis (D.Don) Lindl.): its ecology, history, growth and potential for management for timber}, journal = {New Zealand Journal of Forestry Science}, volume = {40}, year = {2010}, pages = {33-59}, abstract = {

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.

}, issn = {1179-5395}, url = {http://www.scionresearch.com/__data/assets/pdf_file/0019/17164/NZJFS40201033-59_STEWARD.pdf}, author = {Steward, G. A. and Beveridge, A. E.} } @article {4362, title = {Growth and productivity of New Zealand kauri (Agathis australis (D.Don) Lindl.) in planted forests}, journal = {New Zealand Journal of Forestry Science}, volume = {44}, year = {2014}, month = {Jan-12-2014}, pages = {13 pp}, abstract = {

Background

The establishment of even-aged planted stands of New Zealand kauri (Agathis australis (D.Don) Lindl.) for timber has been constrained by a lack of quantitative information on productivity and rotation length on which forest management and investment decisions could be made.

Methods

Stand-level models of height and basal area against time were developed (as well as a stand-volume function to calculate volume from height and basal area) based on planted stands that were up to 83-years old and represented planting sites both within and outside the current natural range of the species.

Results

Planted kauri was shown to be slow to establish with little height growth for the first five years after planting. Similar trends were observed for basal area and whole-tree volume development. A Schumacher equation with local slope parameter and asymptote bounded at 45\ m gave the best fit for height, while a von Bertalanffy-Richards equation in difference form with local slope parameter gave the best fit for basal area. For plantations with an average site index (20.4), height was predicted to be 22.3\ m in height at age 60, with a basal area of 78.1\ m2\ ha?1. Whole-tree volume was predicted to be 702\ m3\ ha?1. Predicted volume mean annual increment was 11.7\ m3\ ha?1\ yr?1for all stands at age 60. From age 20-60 years, stands with a higher site index had a volume mean annual increment of 18.6\ m3\ ha?1\ yr?1. The best stand exceeded 20\ m3\ ha?1\ yr?1.

Conclusions

This study indicates an opportunity to grow kauri in plantations on selected good-quality sites over rotations of 60-80 years or less.

}, doi = {10.1186/s40490-014-0027-2}, url = {http://www.nzjforestryscience.com/content/44/1/27http://link.springer.com/content/pdf/10.1186/s40490-014-0027-2}, author = {Steward, Gregory A and Kimberley, Mark O and Mason, Euan G and Dungey, Heidi S} } @article {4447, title = {Variation in Alnus glutinosa susceptibility to Phytophthora~{\texttimes}alni infection and its geographic pattern in the Czech Republic}, journal = {Forest Pathology}, volume = {46}, year = {2016}, month = {Jan-02-2016}, pages = {3 - 10}, abstract = {

Variation in natural susceptibility of the black alder population to Phytophthora\ {\texttimes}alni (PA), the oomycete pathogen causing a devastating disease of alder, and its possible relationship to geographic origin, was studied in\ vitro using branch inoculation tests. Ninety black alder genotypes from different regions of the Czech Republic and two isolates of PA were employed. Host susceptibility varied significantly. After 1\ week of infection, the lesion surface areas ranged from 254 to 2051\ mm2 and from 19 to 970\ mm2 for the two isolates, respectively. The differences were also dependent on the geographical origin and altitude of the sites from which particular host genotypes were taken. These findings have important implications for restoration plantings and for PA resistance breeding programmes, as there is potential to make selections from natural populations.

}, doi = {10.1111/efp.2016.46.issue-110.1111/efp.12205}, url = {http://doi.wiley.com/10.1111/efp.2016.46.issue-1http://doi.wiley.com/10.1111/efp.12205http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2Fefp.12205}, author = {{\v S}tochlov{\'a}, P. and Novotn{\'a}, K. and Cerny, K.} } @article {EFP:EFP282, title = {Phytophthora disease of alder (Alnus glutinosa) in France: investigations between 1995 and 1999}, journal = {Forest Pathology}, volume = {32}, number = {3}, year = {2002}, pages = {179{\textendash}191}, publisher = {Blackwell Verlag GmbH}, abstract = {

A severe decline of alder associated with an undescribed Phytophthora species was identified for the first time in England in 1993. No generalized decline of alder was reported in France before 1990. The first diebacks and mortalities of common alder were observed at the beginning of the 1990s, but the so-called alder Phytophthora was not isolated in France until 1996. First, a synthesis about alder declines that were known in France before 1995 is presented. Then, a survey was established in north-eastern France; 108 sites were visited and the alder Phytophthora was isolated from 57 of them. All the main rivers were found to be affected and damage levels are significant along some of them. The frequency of the alder Phytophthora and other fungi isolated from declining alders is discussed. Finally, information on other alder declines in France is presented region by region, and a map summarizes the known distribution of the disease. The alder Phytophthora is quite common and widespread in France, with western and north-eastern France being especially affected; however, the number of diseased or dead trees varies greatly from one site to another. All records are from Alnus glutinosa; other Alnus species were seldom seen in the surveys.

}, issn = {1439-0329}, doi = {10.1046/j.1439-0329.2002.00282.x}, url = {http://dx.doi.org/10.1046/j.1439-0329.2002.00282.x}, author = {Streito, J-C. and Legrand, PH. and Tabary, F. and De Villartay, G. Jarnouen} } @article {4672, title = {Genome sequencing of oomycete isolates from Chile supports the New Zealand origin of Phytophthora kernoviae and makes available the first Nothophytophthora sp. genome}, journal = {Molecular Plant Pathology}, volume = {20}, year = {2019}, month = {Jan-03-2019}, pages = {423 - 431}, abstract = {

Genome sequences were generated for six oomycete isolates collected from forests in Valdivia, Chile. Three of the isolates were identified morphologically as Phytophthora kernoviae, whereas two were similar to other clade 10 Phytophthora species. One isolate was tentatively identified as Nothophytophthora valdiviana based on nucleotide sequence similarity in the cytochrome oxidase 1 gene. This is the first genome sequence for this recently described genus. The genome assembly was more fragmented and contained many duplicated genes when compared with the other Phytophthora sequences. Comparative analyses were performed with genomic sequences of the P.\ kernoviae isolates from the UK and New Zealand. Although the potential New Zealand origin of P.\ kernoviae has been suggested, new isolations from Chile had cast doubt on this hypothesis. We present evidence supporting P.\ kernoviae as having originated in New Zealand. However, investigation of the diversity of oomycete species in Chile has been limited and warrants further exploration. We demonstrate the expediency of genomic analyses in determining phylogenetic relationships between isolates within new and often scantly represented taxonomic groups, such as Phytophthora clade 10 and Nothophytophthora. Data are available on GenBank via BioProject accession number PRJNA352331.

}, doi = {10.1111/mpp.2019.20.issue-310.1111/mpp.12765}, url = {https://bsppjournals.onlinelibrary.wiley.com/doi/full/10.1111/mpp.12765}, author = {Studholme, David J. and Panda, Preeti and Sanfuentes von Stowasser, Eugenio and Gonz{\'a}lez, Mariela and Hill, Rowena and Sambles, Christine and Grant, Murray and Williams, Nari M. and McDougal, Rebecca L.} } @article {4340, title = {Genome sequences of six Phytophthora species associated with forests in New Zealand}, journal = {Genomics Data}, volume = {7}, year = {2016}, month = {Jan-03-2016}, pages = {54 - 56}, abstract = {
In New Zealand there has been a long association of Phytophthora diseases in forests, nurseries, remnant plantings and horticultural crops. However, new Phytophthora diseases of trees have recently emerged. Genome sequencing has been performed for 12 Phytophthora isolates, from six species: Phytophthora pluvialis, P. kernoviae, P. cinnamomi, P. agathidicida, P. multivora and P. taxon Totara. These sequences will enable comparative analyses to identify potential virulence strategies and ultimately facilitate better control strategies. This Whole Genome Shotgun data have been deposited in DDBJ/ENA/GenBank under the accession numbers LGTT00000000, LGTU00000000, JPWV00000000, JPWU00000000, LGSK00000000, LGSJ00000000, LGTR00000000, LGTS00000000, LGSM00000000, LGSL00000000, LGSO00000000, and LGSN00000000.
}, issn = {22135960}, doi = {10.1016/j.gdata.2015.11.015}, url = {http://www.sciencedirect.com/science/article/pii/S2213596015300854}, author = {Studholme, D.J. and McDougal, R.L. and Sambles, C. and Hansen, E. and Hardy, G. and Grant, M. and Ganley, R.J. and Williams, N.M.} } @article {1315, title = {Stream monitoring for detection of Phytophthora ramorum in Oregon tanoak forests}, journal = {Plant Disease}, volume = {93}, year = {2009}, pages = {1182{\textendash}1186}, abstract = {

Stream monitoring using leaf baits for early detection of Phytophthora ramorum has been an important part of the Oregon Sudden Oak Death (SOD) program since 2002. Sixty-four streams in and near the Oregon quarantine area in the southwest corner of the state were monitored in 2008. Leaves of rhododendron (Rhododendron macrophyllum) and tanoak (Lithocarpus densiflorus) were placed in mesh bags, and bags were floated in streams. Leaf baits were exchanged every 2 weeks throughout the year. Leaves were assayed by isolation on selective medium and by multiplex rDNA internal transcribed spacer polymerase chain reaction (ITS PCR). The two methods gave comparable results, but multiplex PCR was more sensitive. P. ramorum was regularly recovered at all seasons of the year from streams draining infested sites 5 years after eradication treatment. In streams with lower inoculum densities, recovery was much higher in summer than in winter. P. ramorum was isolated from streams in 23 watersheds. When P. ramorum was detected, intensive ground surveys located infected tanoaks or other host plants an average of 306 m upstream from the bait station. P. ramorum was isolated from stream baits up to 1,091 m from the probable inoculum source.

}, url = {http://dx.doi.org/10.1094/PDIS-93-11-1182}, author = {Sutton, W. and Hansen, E.M. and Reeser, Paul W. and Kanaskie, Alan} } @article {4467, title = {Phytophthora ramorum can survive introduction into finished compost}, journal = {California Agriculture}, volume = {69}, year = {2015}, month = {Jan-10-2015}, pages = {237 - 241}, abstract = {

Composted municipal green waste is a potential vehicle for the transmission of Phytophtora ramorum, the pathogen responsible for the disease known as sudden oak death. To assess the survival rate of the pathogen in compost, we introduced zoospores {\textemdash} a type of infectious propagule {\textemdash} into six composts of varying provenance and maturity. The compost samples represented three production facilities, two production techniques (turned windrow and forced air static pile) and two levels of maturity (fresh, defined as aged for less than 1 week; and mature, aged for more than 4 weeks). Positive re-isolations {\textemdash} indicating survival of the pathogen {\textemdash} were obtained from all composts. The re-isolation rate from the compost from one of the three production facilities was greater than that obtained from an inert substrate (filter paper) inoculated with the pathogen (P \< 0.01), while re-isolation rates from the other two sources were statistically indistinguishable from those obtained from the inert substrate (P \< 0.01). There was no significant difference in re-isolation rate between composts produced by the turned windrow method and composts produced by the forced air static pile technique. Re-isolation rates were greater from mature composts than from fresh composts (P \< 0.01). The results show that P. ramorum may be present and infectious if introduced into finished compost, and that variations in compost characteristics appear to influence survival rates.

}, issn = {0008-0845}, doi = {10.3733/ca.v069n04p237}, url = {http://californiaagriculture.ucanr.edu/landingpage.cfm?articleid=ca.v069n04p237}, author = {Swain, Steven and Garbelotto, Matteo} } @article {doi:10.1094/PDIS.2003.87.11.1395B, title = {First report of root and crown rot caused by Phytophthora cinnamomi affecting native stands of Arctostaphylos myrtifolia and A. viscida in California}, journal = {Plant Disease}, volume = {87}, number = {11}, year = {2003}, pages = {1395-1395}, doi = {10.1094/PDIS.2003.87.11.1395B}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.2003.87.11.1395B}, author = {Swiecki, T. J. and Bernhardt, E. A. and Garbelotto, M.} } @proceedings {959, title = {Increasing distance from California bay reduces the risk and severity of Phytophthora ramorum canker in coast live oak}, volume = {Gen. Tech. Rep. PSW-GTR-214}, year = {2008}, pages = {181-194}, publisher = {U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station}, address = {Santa Rosa, California}, url = {http://www.fs.fed.us/psw/publications/documents/psw_gtr214/}, author = {Swiecki, T. J. and E. Bernhardt}, editor = {Frankel, S.J. and J.T. Kliejunas and K. M. Palmieri} } @article {doi:10.1094/PDIS.2000.84.11.1251A, title = {First report of Phytophthora root and collar rot of alder in Hungary}, journal = {Plant Disease}, volume = {84}, number = {11}, year = {2000}, pages = {1251-1251}, doi = {10.1094/PDIS.2000.84.11.1251A}, url = {http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.2000.84.11.1251A}, author = {Szab{\'o}, Ilona and Nagy, Z. and Bakonyi, J. and {\'E}rsek, T.} } @article {4668, title = {Variation in Susceptibility of Tanoak to the NA1 and EU1 Lineages of Phytophthora ramorum, the Cause of Sudden Oak Death}, journal = {Plant Disease}, year = {2019}, month = {Feb-09-2021}, pages = {PDIS-04-19-0831}, abstract = {

Phytophthora ramorum, the cause of sudden oak death (SOD), kills tanoak (Notholithocarpus densiflorus) trees in southwestern Oregon and California. Two lineages of P. ramorum are now found in wildland forests of Oregon (NA1 and EU1). In addition to the management of SOD in forest ecosystems, disease resistance could be used as a way to mitigate the impact of P. ramorum. The objectives of this study were to (i) characterize the variability in resistance of N. densiflorus among families using lesion length; (ii) determine whether lineage, isolate, family, or their interactions significantly affect variation in lesion length; and (iii) determine whether there are differences among isolates and among families in terms of lesion length. The parameters isolate nested within lineage (isolate[lineage]) and family {\texttimes} isolate(lineage) interaction explained the majority of the variation in lesion length. There was no significant difference between the NA1 and EU1 lineages in terms of mean lesion length; however, there were differences among the six isolates. Lesions on seedlings collected from surviving trees at infested sites were smaller, on average, than lesions of seedlings collected from trees at noninfested sites (P = 0.0064). The results indicate that there is potential to establish a breeding program for tanoak resistance to SOD and that several isolates of P. ramorum should be used in an artificial inoculation assay.

}, issn = {0191-2917 e-ISSN:1943-7692}, doi = {10.1094/PDIS-04-19-0831-RE}, url = {https://apsjournals.apsnet.org/doi/10.1094/PDIS-04-19-0831-RE}, author = {S{\o}ndreli, Kelsey L. and Kanaskie, Alan and Keri{\"o}, Susanna and LeBoldus, Jared M.} }