Name and publication
Phytophthora alni subsp. alni 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: email@example.com
Note: reclassified as Phytophthora x alni (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
from Brasier et al. (2004)
from Alnus meaning alder
Type: UNITED KINGDOM, Yorkshire, Doncaster, isolated from Alnus bark (alder, Alnus glutinosa), 1994, G. MacAskill. IMI 392314, dried culture on carrot agar (reported as holotypus)
Ex-type: Isolate P772 at the Forestry Commission UK Phytophthora culture collection
Sequences for ex-type in original manuscript: Isolate P772 ITS rDNA AY689133
Ex-type in other collections
Voucher sequences for barcoding genes (ITS rDNA and COI) of the ex-type (see Molecular protocols page)
Sequences for ex-type in other sources
- NCBI: Phytophthora alni subsp. alni CPHST BL1
- NCBI: Phytophthora alni subsp. alni IMI 392314
- NCBI: Phytophthora alni subsp. alni P16203 (some sequences as P. alni subsp alni, others as P. alni)
- Phytophthora DATABASE: Phytophthora alni subsp. alni PD_02130 = P16203
- EPPO-Q-bank: Phytophthora alni subsp. alni PD 20019550
- BOLDSYSTEMS: Phytophthora alni subsp. alni OOMYA2163.10 IMI392314 (barcoding COI & ITS)
Position in ITS phylogenetic tree
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. Minimum growth temperature 3°C, optimum 23–25°C, and maximum 29°C.
Conditions for growth and sporulation
Sporangia nonpapillate; persistent; globose, ovoid, obpyriform (22–65 L x 19–46 W µm), showing nested and extended internal proliferation and borne in long unbranched or simple sympodial sporangiophores. Hyphal swellings absent. Chlamydospores absent.
Homothallic. Oogonia globose (24–62 µm diam) with ornamented walls showing bullate protuberances and tapered bases; antheridia predominantly amphigynous, most single-celled but some two-celled; oospores plerotic (18–52 µm diam).
Most typical characters
Additional specimen(s) evaluated
P. alni subsp. alni CPHST-BL # 1 (Abad) = P16203 [World Phytophthora Collection (WPC) California, USA] duplicate of the ex-type P772
Hosts and distribution
Distribution: Sweden, Latvia, Germany, Austria, Italy, Hungary, probably present in or spreading to other parts of Europe. In some locations, such as southern Germany, overlaps with other P. alni subspecies and varieties.
Substrate: Alnus spp., stem/roots
Disease note: associated with root and collar rot of riparian, nursery, and shelterbelt Alnus glutinosa and other Alnus species, including A. incana and A. cordata
Hosts: Alnus glutinosa and other Alnus species, including A. incana and A. cordata
Retrieved January 19, 2018 from U.S. National Fungus Collections Nomenclature Database.
USA: Phytophthora alni is on the National Cooperative Agricultural Pest Survey (CAPS) Priority Pest Lists for 2017, 2018, and 2019.
Phytophthora alni is listed in the U.S. Regulated Plant Pest Table (last modified Nov. 15, 2017).
P. alni was listed as a species of concern during the 2009 Phytophthora prioritization project conducted by USDA APHIS PPQ CPHST PERAL (Schwartzburg et al.).
Additional references and links
Brasier CM, Cooke DE, and Duncan JM. 1999. Origin of a new Phytophthora pathogen through interspecific hybridization. Proc. Natl. Acad. Sci. 96: 5878–5883.
Metzler B. 2011. Alder rot caused by Phytophthora alni (in German).
Solla A, Pérez-Sierra A, Corcobado T, Haque MM, Diez JJ, and Jung T. 2010. Phytophthora alni on Alnus glutinosa reported for the first time in Spain. Plant Pathology. 59: 798.
- Phytophthora DATABASE: Phytophthora alni sub sp. alni
- EPPO-Q-bank: Phytophthora alni sub. sp. alni
- SMML USDA-ARS: Phytophthora alni subsp. alni
- EPPO Global Database: Phytophthora alni subsp. alni
- Forest Phytophthoras of the world: Phytophthora alni
- Forest Reserach UK: Phytophthora alni
- CABI Invasive Species Compendium: Phytophthora alni
- Encyclopedia of Life (EOL): Phytophthora alni
- Index Fungorum (IF): Phytophthora alni subsp. alni 305732
- Plantwise Knowledge Bank: Phytophthora alni subsp. alni
- Google All Phytophthora alni sub. sp. alni
- Google Images Phytophthora alni sub. sp. alni
- Google Scholar Phytophthora alni sub. sp. alni
Fact sheet author
Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America