Name and publication

Phytophthora crassamura Scanu, A. Deidda & T. Jung (2015)

Scanu B, Linaldeddu BT, Deidda A, and Jung T. 2015. Diversity of Phytophthora species from declining Mediterranean maquis vegetation, including two new species, Phytophthora crassamura and Phytophthora ornamentata sp. nov. PLoS ONE 10 (12): 1–24 (pg. 24).

Corresponding author: bscanu@uniss.it

Nomenclature

from Scanu et al. (2015)

Mycobank

MB814006

Etymology

refers to the thick-walled oosporesoospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
(‘crassa’ = ‘thick’ and ‘mura’ = ‘wall’)

Typification

Type: ITALY, Sardinia. Isolated from rhizosphere soil of a dying Juniperus phoenicea tree. Collected: B. Scanu, 2012; CBS H-22392 (holotype, dried culture on CA, Herbarium CBS-KNAW Fungal Biodiversity Centre)

Ex-type: CBS 140357 = PH138 (ex-type culture)

Sequences for ex-type: Phytophthora crassamura isolate PH138: ITS rDNA KP863493, cox1 KP863485

Ex-type in other collections

(ET) CBS 140357, WPC P20138, PH138 (Scanu), S&T BL 150A Abad, 66D1 (Hong)

Molecular identification

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

Phytophthora crassamura isolate CPHST BL 150A (= P20138) ITS rDNA MG865481, COI MK493474

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 crassamura Ph138
• NCBI: Phytophthora crassamura isolate CPHST BL 150A
• EPPO-Q-bank: Phytophthora crassamura
• BOLDSYSTEMS: Phytophthora crassamura

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
6b

Morphological identification

adapted from Scanu et al. (2015)

Colonies and cardinal temperatures

Colony colony:
assemblage of hyphae which usually develops form a single source and grows in a coordinated way
morphology after 7 days on PDA and CMA with no distinct pattern, and on MEA faintly petaloid. Minimum growth temperature 5°C, optimum 25°C, and maximum 33°C.

Conditions for growth and sporulation

Phytophthora crassamura produces 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
in both solid media (CA) and more abundantly in liquid culture (soil extract water) after 24 hours of incubation at 20°C.

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
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)
; ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
and obpyriformobpyriform:
inversely pear-shaped, i.e. with the widest part at the point of attachment (cf. pyriform)
, sometimes with a distorted and pointed apex (48–73 x 23–52 µm); with external and internal in extended and nested proliferationnested proliferation:
a type of internal proliferation where a new sporangium develops successively inside the old sporangium after it has emptied
, and originated terminally on simple, mostly unbranched sporangiophores. Hyphal swellings globoseglobose:
having a rounded form resembling that of a sphere
, elongated, and catenulated. 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

Homothallic. Oogonia smooth-walled (35–52 µm diam); antheridiaantheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
predominantly paragynousparagynous:
pertaining to the sexual stage in which the antheridium is attached to the side of the oogonium (cf. amphigynous)
(8–16 x 8–14 µm); oospores aplerotic aplerotic:
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)
(28–45 µm diam).

Additional specimen(s) evaluated

Phytophthora crassamura ex-type CPHST BL 150, duplicate of P20138 World Phytophthora Collection – California, USA, duplicate of ex-type CBS 140357

Hosts and distribution

Distribution: Europe (Italy, Turkey)
Substrate: collar; rhizosphere soil
Disease note: collar rot, decline
Host: Juniperus phoenicea (Cupressaceae), Picea abies (Pinaceae), Castanea sativa (Fagaceae)

Retrieved January 29, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

 

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

 

• Google All Phytophthora crassamura
• Google Images Phytophthora crassamura
• Google Scholar Phytophthora crassamura

Fact sheet author

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