TY - JOUR T1 - Phytophthora alni sp. nov. and its variants: designation of emerging heteroploid hybrid pathogens spreading on Alnus trees JF - Mycological Research Y1 - 2004 A1 - Clive M. Brasier A1 - Kirk, S.A. A1 - Jose Delcan A1 - David E.L. Cooke A1 - Thomas Jung A1 - Man In’t Veld, W.A. AB -

In 1993 a destructive new Phytophthora pathogen of riparian Alnus trees was discovered in the UK and subsequently shown to be present in other parts of Europe. The new Phytophthora comprised a group of emergent heteroploid hybrids, probably between P. cambivora and a species related to P. fragariae. These included a common, near tetraploid standard hybrid, the presumptive allopolyploid; and four scarcer major variant types with chromosome numbers intermediate between diploid and tetraploid, named the Swedish, Dutch, German and UK variants. The standard hybrid type is formally designated here as Phytophthora alni subsp. alni. The Swedish variant is designated as P. alni subsp. uniformis; and the Dutch, German and UK variants collectively as P. alni subsp. multiformis. The properties of the Dutch, German and UK variants within subsp. multiformis are informally described. The problems of designating emergent species hybrids under the International Code of Botanical Nomenclature and the reasons for the taxonomic choices made are discussed.

VL - 108 UR - http://dx.doi.org/10.1017/S0953756204001005 ER - TY - JOUR T1 - Four phenotypically and phylogenetically distinct lineages in Phytophthora lateralis JF - Fungal Biology Y1 - 2012 A1 - Clive M. Brasier A1 - Selma Franceschini A1 - Vettraino, Anna Maria A1 - Hansen, Everett M. A1 - Sarah Green A1 - Cecile Robin A1 - Joan F. Webber A1 - Andrea Vannini KW - Colony pattern KW - evolution KW - Growth rate KW - Multigene phylogeny KW - Multivariate analysis KW - Sporangial morphology AB -

Until recently Phytophthora lateralis was known only as the cause of dieback and mortality of Chamaecyparis lawsoniana in its native range in the Pacific Northwest. Since the 1990s however disease outbreaks have occurred increasingly on ornamental C. lawsoniana in Europe; and in 2007 the pathogen was discovered in soil around old growth C. obtusa in Taiwan, where it may be endemic. When the phenotypes of over 150 isolates of P. lateralis from Taiwan, across the Pacific Northwest (British Columbia to California) and from France, the Netherlands and the UK were compared three growth rate groups were resolved: one slow growing from Taiwan, one fast growing from the Pacific Northwest and Europe and one of intermediate growth from a small area of the UK. Within these growth groups distinct subtypes were identified based on colony patterns and spore metrics and further discriminated in a multivariate analysis. The assumption that the three main growth groups represented phylogenetic units was tested by comparative sequencing of two mitochondrial and three nuclear genes. This assumption was confirmed. In addition two phenotype clusters within the Taiwan growth group were also shown to be phylogenetically distinct. These four phenotypically and genotypically unique populations are informally designated as the Pacific Northwest lineage, the UK lineage, the Taiwan J lineage and the Taiwan K lineage. Their characteristics and distribution are described and their evolution, taxonomic and plant health significance is discussed.

UR - http://www.sciencedirect.com/science/article/pii/S1878614612001717?v=s5 ER - TY - JOUR T1 - Phytophthora kernoviae sp. nov., an invasive pathogen causing bleeding stem lesions on forest trees and foliar necrosis of ornamentals in the UK JF - Mycological Research Y1 - 2005 A1 - Clive M. Brasier A1 - Paul A. Beales A1 - KIRK,Susan A. A1 - Denman,Sandra A1 - Joan Rose AB -

A new Phytophthora pathogen of trees and shrubs, previously informally designated Phytophthora taxon C, is formally named here as P. kernoviae. P. kernoviae was discovered in late 2003 during surveys of woodlands in Cornwall, south-west England, for the presence of another invasive pathogen, P. ramorum. P. kernoviae is self-fertile (homothallic), having plerotic oogonia, often with distinctly tapered stalks and amphigynous antheridia. It produces papillate sporangia, sometimes markedly asymmetric with medium length pedicels. Its optimum temperature for growth is ca 18 $ınfty$C and upper limit ca 26$ınfty$. Currently, P. kernoviae is especially noted for causing bleeding stem lesions on mature Fagus sylvatica and foliar and stem necrosis of Rhododendron ponticum. P. kernoviae is the latest of several invasive tree Phytophthoras recently identified in the UK. Its geographical origins and the possible plant health risk it poses are discussed.

VL - 109 UR - http://www.sciencedirect.com/science/article/B7XMR-4RS503Y-5/2/2264e8910ee36f4e72255d6160ebf9e4 ER - TY - JOUR T1 - Multiple new phenotypic taxa from trees and riparian ecosystems in Phytophthora gonapodyides-P. megasperma ITS Clade 6, which tend to be high-temperature tolerant and either inbreeding or sterile JF - Mycological Research Y1 - 2003 A1 - Clive M. Brasier A1 - David E.L. Cooke A1 - James M. Duncan A1 - Hansen, Everett M. VL - 107 UR - http://www.sciencedirect.com/science/article/B7XMR-4RT04VN-6/2/68f2582c518f07f52e7a0db891ca14dd ER -