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Mycologist, forest pathologist, geneticist specialising in reform of national and international plant health (biosecurity) protocols; understanding genetic risk from introduced pathogens, including geographic origins and potential for rapid evolution via adaptation and horizontal gene transfer; identifying population units and species boundaries in tree pathogens – continuous variation, fitness, breeding systems and molecular profiles; potential for biological control with fungal viruses and specialising in Phytophthora pathogens and Dutch elm disease.

Providing pedagogic support to Forest Research staff and students.

Currently collaborating with overseas scientists in the USA, Canada, Czech Republic, Hungary, Italy and Japan

Clive Brasier took his first degree in Botany and studied for a PhD on Physiology of Reproduction in Phytophthora at Hull University between 1960 and 1966. From 1966-1969 he was appointed Junior Research Fellow in the Genetics Department at Birmingham University, working on ecological genetics of Basidiomycete populations and teaching genetics of host-pathogen interactions. Clive joined Forest Research in 1969 as Mycologist, specialising in all aspects of Phytophthora and Dutch elm disease pathogens from their pathology and epidemiology to their taxonomy, genetics and evolution. He gained his DSc in Plant Biology and Genetics from the University of Hull in 1984. In 1995 he was awarded Individual Merit Promotion Scientist status, reporting directly to what is now Government Office for Science. In the same year he was made Visiting Professor in Mycology at the Department of Biology, Imperial College London. He became Emeritus Mycologist at Forest Research on his formal retirement from the payroll in 2002.


  • Honorary Fellow, British Mycological Society
  • Honorary Fellow, American Phytopathological Society
  • Honorary Member, British Society for Plant Pathology
  • Fellow, The Linnean Society
  • Member, The Genetical Society
  • Council, International Society for Plant Pathology
  • Visiting Professor, Imperial College 1995-2008
  • Leverhulme Emeritus Fellowship 2009-2012
  • European Chair, Phytophthora Group, International Union of Forest Research Organisations, 1997-2012
  • Science and Education Committee, Royal Horticultural Society, 1999-2011
  • Scientific Advisor Defra/BBSRC NORNEX Ash dieback project 2013-16
Emeritus Mycologist (Research Fellow)

Forest Research

Alice Holt Lodge


Surrey GU10 4LH


Related Publications


[Archive] Dutch elm disease in Great Britain

RIN 252 (1994) Out of print research publications from the 1980s and 1990s. Please note that since publication the products named may have been withdrawn or changed formulation, services may no longer be available, legislation superseded and addresses and contacts changed.


Peer reviewed journal articles

Full list of publications

All publications

Publications since 2010

Enhanced Outcrossing, Directional Selection and Transgressive Segregation Drive Evolution of Novel Phenotypes in Hybrid Swarms of the Dutch Elm Disease Pathogen Ophiostoma novo-ulmi. Brasier C, Franceschini S, Forster J, Kirk S. (2021). Journal of Fungi7(6):452.

The Destructive Tree Pathogen Phytophthora ramorum Originates from the Laurosilva Forests of East Asia. Jung T, Horta Jung M, Webber JF, Kageyama K, Hieno A, Masuya H, Uematsu S, Pérez-Sierra A, Harris AR, Forster J, Rees H, Scanu B, Patra S, Kudláček T, Janoušek J, Corcobado T, Milenković I, Nagy Z, Csorba I, Bakonyi J, Brasier CM. (2021). Journal of Fungi7(3):226.

Complexities underlying the breeding and deployment of Dutch elm disease resistant elms. Martín, J.A., Domínguez, J., Solla, A, Brasier C, Webber JF, Santini A, Bernier L. Gil L. (2021). New Forests:

A survey in natural forest ecosystems of Vietnam reveals high diversity of both new and described Phytophthora taxa including P. ramorum. Jung T, Bruno Scanu B, Brasier C M, Webber J. Milenkovic I, Corcobado T, Tomšovský M, Panek M, Bakonyi J, Maia C, Bačová A, Raco M, Rees H, Pérez-Sierra A, M Horta Jung M. (2020). Forests 11: 93.

Fitness characteristics of the European lineages of Phytophthora ramorum. Harris A, Brasier CM, Scanu B, Webber JF (2019). Plant Pathology 70.

Is there evidence for post-epidemic attenuation in the Dutch elm disease pathogen Ophiostoma novo-ulmi? Brasier CM, Webber JF (2019). Plant Pathology

Ophiostoma ulmi DNA naturally introgressed into an isolate of Ophiostoma novo-ulmi is clustered around pathogenicity and mating type loci. Et-Touil A, Dusabeyagasani M, Bouvet G F, Brasier C M, Bernier L (2019). Phytoprotection 99, 1-11.

Mitotic recombination and rapid genome evolution in the clonal forest pathogen Phytophthora ramorum. Dale A L, Feau N, Everhart S E, Dhillon B, Wong B, Sheppard J, Bilodeau GJ, Brar A, Tabima A F, Shen D, Brasier C M, Tyler B M, Grünwald N J, Hamelin R C (2019). mBio:

A versatile method for assessing pathogenicity of Hymenoscyphus fraxineus to Fraxinus excelsior. Orton E S, Clarke M, Brasier C M, Webber J F, Brown J K M (2018). Forest Pathology DOI 10.1111/efp.12484

High frequency of vegetative incompatibility combined with haploid selfing in the native European ash foliage coloniser Hymenoscyphus albidus. Brasier C, King K, Kirisits T, Orton E, Webber J (2017). Fungal Ecology 28: 11-24.

Ramorum disease of larch. Webber JF, Brasier CM, 2018. In: Hansen EM, Lewis KJ, Chastagner GA, eds. Compendium of Conifer Diseases. 2nd edn. St Paul, MN, USA: APS Press, pp. 13–14.

Development and validation of polymorphic microsatellite loci for the NA2 lineage of Phytophthora ramorum from whole genome sequence data. Gagnon MC, Feau N, Dale A, Dhillon B, Hamelin RC, Brasier CM, Grunwald NJ. Brière SC, Bilodeau GJ (2017). Plant Disease 101: 666-673.

Local population structure of the ash dieback pathogen, Hymenoscyphus fraxineus, in relation to its mode of arrival in the UK. Orton ES, Brasier CM, Bilham L, Bansal A, Webber JF, Brown JKM (2017).  Plant pathology 67: 255-264.

Contrasting microsatellite diversity in the evolutionary lineages of Phytophthora lateralis. Anna Maria Vettraino, Clive Brasier, Joan Webber, Everett Hansen, Sarah Green, Cecile Robin, Alessia Tomassini; Natalia Bruni, Andrea Vannini (2017). Fungal Biology 12: 112-126.

Host-induced aneuploidy and phenotypic diversification in the Sudden Oak Death pathogen Phytophthora ramorum. Kasuga T, Bui M, Bernhardt E, Swiecki T, Aram K, Cano LM, Webber JF, Brasier CM, Press C, Grünwald NJ, Rizzo DM, Garbelotto M (2016). BMC Genomics 17: 385. Doi 10: 1186/s12864-016-2717-z

Redesignation of Phytophthora taxon Pgchlamydo as P. chlamydospora sp. nov. Hansen  EM, Reeser  P Sutton  W, Brasier  CM (2015). North American Fungi

Increasing forest loss worldwide from invasive pests requires new trade regulations. Roy B A, Alexander HM, Davidson J, Campbell FT, Burdon JJ, Sniezko R, Brasier CM (2014). Frontiers in Ecology and the Environment 12: 457-465.

Phytophthora siskiyouensis causing stem lesions and cankers on Alnus incana. Perez Sierra A, Kalantarzadeh M, Sancisi-Frey s, Brasier CM (2015). New disease Reports 31: Doi  10.5197/j.2044-0588.2015.031.017

Pathogenicity of Phytophthora lateralis lineages on resistant and susceptible selections of Chamaecyparis lawsonianaRobin CBrasier CM,  Reeser PW,  Sutton W,  Vannini AVettraino AM,  Hansen E. (2015).  Plant Disease 99: 1133-1139.

Gene x environment tests discriminate the new EU2 evolutionary lineage of Phytophthora ramorum and indicate that it is adaptively different. Franceschini S, Webber JF, Sancisi-Frey S, Brasier CM (2014). Forest Pathology 44: 219-232.

The morphology, behaviour and molecular phylogeny of Phytophthora taxon Salixsoil and its redesignation as Phytophthora lacustris sp. nov. Nechwatal J. Bakonyi S, Cacciola O,  Cooke DE L, Jung T, Nagy, A, Vannini  A,  Vettraino  AM, Brasier  CM (2013). Plant Pathology 62: 355-369.

Vegetative incompatibility in the ash dieback pathogen Hymenoscyphus pseudoalbidus and its ecological implications Brasier CM, Webber JF (2013). Fungal Ecology 6: 501-512.

Four phenotypically and phylogenetically distinct lineages in Phytophthora lateralis. Brasier CM, Franceschini S, Vettraino AM, Hansen EM, Green S, Robin C, Webber JF, Vannini A (2013.) Fungal Biology 116: 1232-1249.

Discovery of a fourth evolutionary lineage of Phytophthora ramorum: EU2. Van Poucke K, Franceschini S, Webber JF, Vercauteren A, Turner J, McCracken AR, Heungens K, Brasier CM (2012). Fungal Biology 116: 1178-1191.

The destructive invasive pathogen Phytophthora lateralis found on Chamaecyparis lawsoniana across the UK. Green S, Brasier CM, Schlenzig A, McCracken A, MacAskill GA, Wilson M, Webber JF (2012). Forest Pathology 43: 19-28.

Rapid evolution of tree pathogens via episodic selection and horizontal gene transfer. Brasier CM (2012). In Proceedings of the 4th International Workshop on Genetics of Host-Parasite Interactions in Forestry. USDA PSW-GTR General Technical Report 240: 133-142.

Isolation of Phytophthora lateralis from Chamaecyparis foliage in Taiwan. Webber JF, Vettraino AM, Chang TT, Bellgard SE, Brasier CM, Vannini A. (2012). Forest Pathology 42: 136-143.

Phytophthora chrysanthemi sp. nov., a new species causing root rot of chrysanthemum in Japan. Naher M, Motohash K, Watanabe H, Chikuo Y, Senda M, Suga H, Brasier C, Kageyama K (2011). Mycological Progress 10: 21–31

Phytophthora himalsilva sp. nov. an unusually phenotypically variable species from a remote forest in Nepal. Vettraino AM, Brasier CM, Brown AV, Vannin A (2011).  Fungal Biology115: 275-287.

Dieback and mortality of plantation Japanese larch (Larix kaempferi) associated with infection by Phytophthora ramorum. Webber JF, Mullett M, Brasier CM (2010). Plant Pathology New Disease Reports 22, 19.

Sudden larch death. Brasier CM, Webber JF (2010). Nature 466, 824-825.

Phytophthora lateralis discovered in a Taiwan old growth Chamaecyparis forestBrasier CM, Vettraino AM, Chang TT, Vannini A. (2010).  Plant Pathology 59, 595-603.

Rapid emergence of hybrids between the two subspecies of Ophiostoma novo-ulmi with a high level of pathogenic fitness Brasier CM, Kirk S A (2010). Plant Pathology 59,186-99.