Name and publication

Phytophthora psychrophila T. Jung & E.M. Hansen (2002)

Jung T, Hansen EM, Winton L, Osswald W, and Delatour C. 2002. Three new species of Phytophthora from European oak forests. Mycological Research 106: 397–411.

Corresponding author: jung@bot.forst.tu-muenchen.de

Nomenclature

from Jung et al. (2002)

Mycobank

MB484598

Etymology

refers to the low temperature growth attributes of the species

Typification

Type: GERMANY, isolated from the rhizosphere on decaying oak (Quercus robur) by Thomas Jung, LMU, in Rosenheim (Bavaria - Schechen, Südbayern), during May 1995 (IFB-Mühl1/2) Institute of Forest Botany / Forest Pathology, Technische Universität München, Germany

Ex-type: CBS 803.95 and IFB-PSY 1 (living cultures)

Sequences for ex-type in original manuscript: CBS 805.95: ITS rDNA AF449494

Note: Table 1 in Jung et al. (2002) indicates PSY 1 sequence, however NCBI AF449494 refers to isolate PSY 2 which is from Nime, France, 1996. 

Ex-type in other collections

(ET) CBS 803.95, IFB-PSY 1, WPC P10433, S&T BL 52 (Abad), 29J5 (Hong)

Molecular identification

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

Phytophthora psychrophila isolate CPHST BL 52 (= P10433 WPC) = ITS rDNA MG865576, COI MH136968

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 psychrophila CPHST BL 52 
• NCBI: Phytophthora psychrophila P10433
• NCBI: Phytophthora psychrophila CBS 80395
• EPPO-Q-bank: Phytophthora psychrophila CBS 80395 = IFB-PSY 1 = P10433 ITSrDNA, TUB, COI, TEF
• BOLDSYSTEMS: Phytophthora psychrophila (barcoding COI & ITS)

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
3

Morphological identification

adapted from Jung et al. (2002)

Colonies and cardinal temperatures

Colony colony:
assemblage of hyphae which usually develops form a single source and grows in a coordinated way
morphology on PDA and MEA with non-distinctive pattern. No growth on V-8 agar. Minimum growth temperature 3°C, optimum 15°C, and maximum 21°C.

Conditions for growth and sporulation

Chlamydospores produced in water cultures.

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
semipapillatesemipapillate:
pertaining to the production of shallow having papilla that are not well developed, shallow and less nipple-like than fully papillate structures
with some bipapillated; persistentpersistent:
pertaining to sporangia that remain attached to the sporangiophore and do not separate or detach easily (cf. caducous)
and sometimes caducouscaducous:
pertaining to sporangia that become dislodged readily (i.e. deciduous) and separate from the sporangiophore (cf. persistent)
with short and medium pedicels; ellipsoidellipsoid:
refers to a solid body that forms an ellipse in the longitudinal plane and a circle in cross section; many fungal spores are ellipsoidal or elliptic
, ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
, obpyriformobpyriform:
inversely pear-shaped, i.e. with the widest part at the point of attachment (cf. pyriform)
(22–51 L x 18–34 W µm) originated in unbranched and simple sympodial sporangiophores. Hyphal swellings absent. 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
globoseglobose:
having a rounded form resembling that of a sphere
, terminal and intercalaryintercalary:
positioned within a hypha (cf. terminal)
.

Sexual phase

Homothallichomothallic:
pertaining to sexual reproduction that can take place within a single thallus (i.e. self-fertile, non-outcrossing) (cf. heterothallic).
. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
smooth-walled; spherical to slightly globoseglobose:
having a rounded form resembling that of a sphere
(32–47µm diam); antheridiaantheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
amphigynousamphigynous:
pertaining to the sexual stage in which the antheridium completely surrounds the stalk of the oogonium (cf. paragynous)
, ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
, elongate, short cylindrical, sometimes with digitate projections; oosporesoospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
pleroticplerotic:
pertaining to an oospore that fills the oogonium (cf. aplerotic)
, apleroticaplerotic:
pertaining to a mature oospore that does not fill the oogonium; i.e. there is room left between the oospore wall and oogonium wall (cf. plerotic)
, and slightly apleroticaplerotic:
pertaining to a mature oospore that does not fill the oogonium; i.e. there is room left between the oospore wall and oogonium wall (cf. plerotic)
(24–33 µm diam). OosporesOospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
showing thick walls are frequently observed.

Most typical characters

Phytophthora psychrophila is characterized by the presence of 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
semipapillatesemipapillate:
pertaining to the production of shallow having papilla that are not well developed, shallow and less nipple-like than fully papillate structures
which are persistentpersistent:
pertaining to sporangia that remain attached to the sporangiophore and do not separate or detach easily (cf. caducous)
and sometimes caducouscaducous:
pertaining to sporangia that become dislodged readily (i.e. deciduous) and separate from the sporangiophore (cf. persistent)
with short and medium pedicels, and presence of 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
.

Additional specimen(s) evaluated

Phytophthora psychrophila ex-type CPHST BL 52, duplicate of P10433 (World Phytophthora Collection)

Hosts and distribution

Distribution: Europe (France, Germany, UK)
Substrate: soil (rhizosphere)
Disease note: only weakly pathogenic in soil infestation tests, but capable of producing necrotic bark lesions on suberized tap roots of Quercus robur seedlings (Jung et al. 2002)
Host: infects Ilex aquifolium and Quercus spp. in inoculation tests

Retrieved February 01, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

 

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

 

• Google All Phytophthora psychrophila
• Google Images Phytophthora psychrophila
• Google Scholar Phytophthora psychrophila

Fact sheet author

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