Name and publication
Phytophthora alni subsp. uniformis Brasier & Kirk (2004)
Brasier CM, Kirk SA, Delcan J, Cooke DEL, and Jung T. 2004. Phytophthora alni sp. nov. and its variants: designation of emerging heteroploid hybrid pathogens spreading on Alnus trees. Mycol. Res. 108: 1172–1184.
Corresponding author: clive.brasier@forestry.gsi.gov.uk
Notes: reclassified as Phytophthora uniformis (Brasier & S.A. Kirk) Husson, Ioos & P. Frey (2015) (SMML). Reclassification under nomenclature evaluation.
Husson C, Aguayo J, Revellin C, Frey P, Ioos R, and Marcais B. 2015. Evidence for homoploid speciation in Phytophthora alni supports taxonomic reclassification in this species complex. Fungal Genet. Biol. 77: 12–21.
Phytophthora alni species complex (alder Phytophthora) Invasive Species Compendium
The alder Phytophthora species complex of oomycetes encompasses the hybrid P. × alni and its two parental species, P. uniformis and P. × multiformis.
Nomenclature
from Brasier et al. (2004)
Mycobank
Etymology
from uni and formis meaning of a more uniform phenotype
Typification
Type: SWEDEN, Gothenberg, isolated from Alnus bark, 1996, C. Olsson CH161 IMI 392315 (dried culture on carrot agar)
Ex-type: Isolate P875 at the Forestry Commission UK in Phytophthora culture collection
Sequences for ex-type in original manuscript: not provided
Ex-type in other collections
P875 = P875 (Brasier - DEFRA), PD 20019549, 2001 9549 (PPS Wageningen), P16206 (WPC), CPHST BL 3 (Abad)
Molecular identification
Voucher sequences for barcoding genes (ITS rDNA and COI) of the ex-type (see Molecular protocols page)
Phytophthora alni subsp uniformis isolate CPHST BL 3 ( = P16206) ITS rDNA MK496514, COI MH136992
Sequences for ex-type in other sources
- NCBI: Phytophthora alni subsp. uniformis CPHST BL 3
- NCBI: Phytophthora alni sub. sp. uniformis P16206
- Phytophthora DATABASE: Phytophthora alni subsp. uniformis PD_02131 = P16206
- EPPO-Q-bank: Phytophthora alni subsp. uniformis P875, PD 20019549
- BOLDSYSTEMS: Phytophthora alni subsp. alni
Position in ITS phylogenetic tree
Clade 7a
Morphological identification
adapted from Brasier et al. (2004)
Colonies and cardinal temperatures
Colonies in V8 agar, potato dextrose agar, and malt extract agar with no distinctive pattern and slow growth. Minimum growth temperature 3°C, maximum 30°C, and optimum 24–27°C.
Conditions for growth and sporulation
Sporangia produced sparsely in pea broth or when plugs from margins of actively growing cultures on V8-A or PDA are partially submerged in unsterile pond water or unsterile soil leachate.
Asexual phase
Sporangia nonpapillate, persistent, ellipsoid, ovoid, obovoid, obpyriform (28–69 µm length,17–42 µm width) showing internal proliferation and borne single in long sporangiophores. Hyphal swellings absent. Chlamydospores absent.
Sexual phase
Homothallic. Oogonia mostly smooth-walled, but some slightly wavy-edged (verrucose). Occasionally, oogonia have large, distorted beak-like protuberances (37.5–55 µm wide). Antheridia amphigynous and consistently two-celled. The antheridial cross-wall is often close to the base of the antheridium and can be overlooked. Oospore plerotic (overall range ca 30–47.5 µm).
Most typical characters
P. alni subsp. uniformis produces oogonia with a smooth surface and some with slightly wavy edge (verrucose).
Additional specimen(s) evaluated
P. alni subsp. uniformis CPHST-BL # 3 (Abad) = P16206 [World Phytophthora Collection (WPC) California, USA] duplicate of the ex-type P875 Brasier
P. alni subsp. uniformis Abad S511 from Alaska
Hosts and distribution
Distribution: France, Spain, Belgium, Slovenia, USA (Alaska and Oregon)
Substrate: stem/roots
Disease note: root and collar rot
Hosts: Alnus spp. (alder, black alder)
Retrieved January 19, 2018 from U.S. National Fungus Collections Nomenclature Database.
Additional references and links
Adams GC, Catal M, Trummer L, Hansen EM, Reeser P, and Worrall JJ. 2008. Phytophthora alni subsp. uniformis found in Alaska beneath thinleaf alders. Online. Plant Health Progress doi:10.1094/PHP-2008-1212-02-BR. http://www.forestpathology.org/pdfs/adams2008Palni.pdf
Aguayo J, Adams GC, Halkett F, Catal M, Husson C, Nagy ZA, Hansen EM, Marçais B, and Frey P. 2013. Strong genetic differentiation between North American and European populations of Phytophthora alni subsp. uniformis. Phytopathology 103: 190–199.
Bakonyi J, Nagi ZA, and Ersek T. 2006. PCR-based DNA markers for identifying hybrids within Phytophthora alni. Journal of Phytopathology 154: 168–177. http://dx.doi.org/10.1111/j.1439-0434.2006.01079.x
Ioos, R., Andrieux, A., Marcais, B., & Frey, P. 2006. Genetic characterization of the natural hybrid species Phytophthora alni as inferred from nuclear and mitochondrial DNA analyses. Fungal Genetics and Biology 43:511–529.
Ioos R, Andrieux A, Marcais B, and Frey P. 2007. New hypothesis on the origin of the interspecific hybrid Oomycete Phytophthora alni. Pages 61–62. in: Fourth Meeting of the IUFRO Working Party S07.02.09 EM Goheen and SJ Frankel, eds. USDA-FS PSW-GTR-221, Monterey, CA, August, 26, 2007.
Pintos Varela C, Rial Martínez C, Aguín Casal O, Mansilla Vázquez JP, and Ares Yebra A. 2012. First report of Phytophthora alni subsp. uniformis on black alder in Spain. Plant Disease 96: 589 http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-10-11-0891-PDN
Sims L, Navarro S, and Hansen EM. 2012. Phytophthora species isolated from Alnus rubra in western Oregon riparian ecosystems. Proceedings of the 6th Meeting of the International Union of Forest Research Organizations (IUFRO) Working Party S07-02-09 September 9–14, 2012, Còrdoba, Spain. Pg. 46
Winton L. 2012. Phytophthora alni subsp. uniformis) in Alaska
- Phytophthora DATABASE: Phytophthora alni subsp. uniformis
- Q-bank: Phytophthora alni subsp. uniformis
- SMML USDA-ARS: Phytophthora alni subsp. uniformis
- EPPO Global Database: Phytophthora alni subsp. uniformis
- Forest Phytophthoras of the world: Phytophthora alni subsp. multiformis (the 3 subspp. are cited together as P. alni)
- Forest Research UK: Phytophthora alni
- CABI Invasive Species Compendium: Phytophthora alni subsp. uniformis
- Encyclopedia of Life (EOL): Phytophthora alni
- Index Fungorum (IF): Phytophthora alni subsp. uniformis 488624
- Plantwise Knowledge Bank: Phytophthora alni subsp. uniformis
- Google All Phytophthora alni subsp. uniformis
- Google Images Phytophthora alni subsp. uniformis
- Google Scholar Phytophthora alni subsp. uniformis
Fact sheet author
Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America