Name and publication

Phytophthora subarctica T. Jung, T. Corcobado, J. Oliva & I. Milenković (2022)

Jung T, Milenković I, Corcobado T. et al. 2022. Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Cladeclade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
10 and its evolutionary implications. Persoonia-Molecular Phylogeny and Evolution of Fungi 49: 1–57.

Corresponding authors: thomas.jung@mendelu.cz and dr.t.jung@gmail.com

Nomenclature

Mycobank

MB 843134

Etymology

Name refers to the origin of all known isolates from the subarctic zone in northern Sweden.

Typification

Type: Sweden, Kiruna area, isolated from riverbank soil, Sept. 2017, I. Milenković & T. Corcobado, holotype HNHM-MYC- 020632, dried culture on V8A, Herbarium of the Hungarian Natural History Museum, Budapest, Hungary

Ex-type: CBS 148850 = NRRL 64339 = SW176

Sequences for ex-type in original manuscript:  LSU ON000696, ITS ON000790, β-tubulin OM975969, hsp90 OM976486, tigA OM974663, rpl10 OM97523, tef-1a OM984949, enolase OM976580, cox1 ON013856, ypt1 ON025006, nadh1 OM976965, rps10 OM976724

Ex-type in other collections

(ET) CBS 148850, NRRL 64339, SW176 

Molecular identification

Voucher sequences for barcoding genes (ITS rDNA and COI) of the ex-type (see Molecular protocols page)

Phytophthora subtractica ITS rDNA, COI

Voucher sequences for Molecular Toolbox with seven genes (ITS, β-tub, COI, EF1α, HSP90, L10, and YPT1

(see Molecular protocols page) (In Progress)

Voucher sequences for Metabarcoding High-throughput Sequencing (HTS) Technologies [Molecular Operational Taxonomic Unit (MOTU)]

(see Molecular protocols page) (In Progress)

Sequences with multiple genes for ex-type in other sources

• NCBI: Phytophthora subtractica
• EPPO-Q-bank: Phytophthora subtractica
• BOLDSYSTEMS: Phytophthora subtractica

Position in multigenic phylogeny with 7 genes (ITS, β-tub, COI, EF1α, HSP90, L10, and YPT1)

Clade clade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
10c

Morphological identification

Colonies and cardinal temperatures

Colony colony:
assemblage of hyphae which usually develops form a single source and grows in a coordinated way
morphology submerged and radiate on V8A and CA, and stoloniferous and dense felty with very slow growth on PDA. Optimum growth temperature 20°C and maximum 30°C.

Conditions for growth and sporulation

SporangiaSporangia:
sac within which zoospores form, especially when water is cooled to about 10°C below ambient temperature; in solid substrates, sporangia usually germinate by germ tubes
produced in non-sterile soil extract after 1–2d. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
were not produced in paired cultures using several known tester strains.

Asexual phase

SporangiaSporangia:
sac within which zoospores form, especially when water is cooled to about 10°C below ambient temperature; in solid substrates, sporangia usually germinate by germ tubes
were nonpapillatenonpapillate:
pertaining to the production of a non-distinct, or inconspicuous, papilla at the distal end of the sporangium (cf. papillate and semipapillate)
, persistentpersistent:
pertaining to sporangia that remain attached to the sporangiophore and do not separate or detach easily (cf. caducous)
, and predominantly ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
to elongated ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
in shape. SporangiaSporangia:
sac within which zoospores form, especially when water is cooled to about 10°C below ambient temperature; in solid substrates, sporangia usually germinate by germ tubes
averaged 53.8 x 31.6 µm (overall range 32.7–127.6 x 16.3–39.5 µm), proliferationproliferation:
formation of a sporangium within an empty sporangium that has previously emitted zoospores (internal or nested) or after the sporangiophore has emerged from the empty sporangium (external)
internal, nested, and extended; Sporangiophores unbranched or rarely on lax sympodiasympodia:
a type of sporangiophore which appears simple, but where each successive sporangium develops on a branch behind and to one side of the previous apex, where growth has already ceased
. Hyphal swellings rare. ChlamydosporesChlamydospores:
an asexual spore with a thickened inner wall that is delimited from the mycelium by a septum; may be terminal or intercalary, and survives for long periods in soil
absent.

Sexual phase

Sterile in culture.

Most typical characters

Resides in phylogenetic cladeclade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
10b and is closely related to P. gallica. While both sterile in culture, chlamydosporeschlamydospores:
an asexual spore with a thickened inner wall that is delimited from the mycelium by a septum; may be terminal or intercalary, and survives for long periods in soil
are formed in P. gallica.

Additional specimen(s) evaluated

Sweden, Kiruna area, isolated from forest stream, Sept. 2017, I. Milenković & T. Corcobado, SW639, SW640, SW641

Hosts and distribution

Distribution: Sweden
Substrate: forest stream
Disease note: no known disease
Host: no known host

Additional references and links

• SMML USDA-ARS: Phytophthora subarctica
• EPPO Global Database: Phytophthora subarctica
• Forest Phytophthoras of the world: Phytophthora subarctica
• CABI Digital Library: Phytophthora subarctica
• Encyclopedia of Life (EOL): Phytophthora subarctica
• Index Fungorum (IF): Phytophthora subarctica

Fact sheet author

Treena Burgess, Ph.D., Phytophthora Science and Management, Harry Butler Institute, Murdoch University, Australia

Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Plant Pathogen Confirmatory Diagnostics Laboratory (PPCDL), United States of America.