Phytophthora psychrophila

Name and publication

Phytophthora psychrophila Jung & 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

CBS 803.95 = P10433 (WOC/WPC), CPHST BL 52 (Abad), 29J5 (Yang)

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

Sequences for ex-type in other sources
Position in ITS phylogenetic tree

Clade 3a

Morphological identification

adapted from Jung et al. (2002)

Colonies and cardinal temperatures

Colony 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

Sporangia semipapillate with some bipapillated; persistent and sometimes caducous with short and medium pedicels; ellipsoid, ovoid, obpyriform (22–51 L x 18–34 W µm) originated in unbranched and simple sympodial sporangiophores. Hyphal swellings absent. Chlamydospores globose, terminal and intercalary.

Sexual phase

HomothallicOogonia smooth-walled; spherical to slightly globose (32–47µm diam); antheridia amphigynous, ovoid, elongate, short cylindrical, sometimes with digitate projections; oospores plerotic, aplerotic, and slightly aplerotic (24–33 µm diam). Oospores showing thick walls are frequently observed.

Most typical characters

Phytophthora psychrophila is characterized by the presence of sporangia semipapillate which are persistent and sometimes caducous with short and medium pedicels, and presence of chlamydospores.

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

Fact sheet author

Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America