Name and publication

Phytophthora macilentosa Xiao Yang, Copes & C.X. Hong (2014)

Yang X, Copes WE, and Hong C. 2014. Two novel species representing a new cladeclade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
and cluster of Phytophthora. Fungal Biology 118: 72–82.

Corresponding author: Xiao Yang yxiao9@vt.edu

Nomenclature

from Yang et al. (2014)

Mycobank

MB804934

Etymology

refers to the elongated 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
with great length to width ratio frequently produced by this species

Typification

Type: UNITED STATES OF AMERICA, recovered from the middle of water column in a nursery reservoir, Mississippi, February, 2012; holotype ATCC MYA-4945

Ex-type: 58A7

Sequences for ex-type in original manuscript: 58A7 = ITS rDNA KF192700, cox1 KF192708

Ex-type in other collections

(ET) ATCC MYA-4945 (MCI), WPC P19993, S&T BL 125 (Abad), 58A7 (Hong)

Molecular identification

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

Phytophthora macilentosa isolate CPHST BL 125 (= P19993 WPC) = ITS rDNA MG865527, COI MH136922

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 macilentosa CPHST BL 125
• NCBI: Phytophthora macilentosa 58A7
• EPPO-Q-bank: Phytophthora macilentosa
• BOLDSYSTEMS: Phytophthora macilentosa (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
9a

Morphological identification

adapted from Yang et al. (2014)

Colonies and cardinal temperatures

Minimum temperature for growth is 10°C, optimum 30°C, and maximum 37°C. 

Conditions for growth and sporulation

Phytophthora macilentosa produce abundant 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 V8 cultures flooded with 10% soil solution.

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)
; obpyriformobpyriform:
inversely pear-shaped, i.e. with the widest part at the point of attachment (cf. pyriform)
, ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
, limoniform, 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
, pyriformpyriform:
pear-shaped, with the narrowest part at the base (cf. obpyriform)
, and distorted shapes such as peanut-shaped; showing internal, nested, and extended proliferationextended proliferation:
a type of internal proliferation in which the sporangiophore originates from inside of an empty sporangium, and continues to grow through and out of the old sporangium
. Hyphal swellings catenulatecatenulate:
having a chain-like form
or elongated with irregular shapes are produced in old cultures. 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/heterothallic.

Addtional specimen(s) evaluated

Phytophthora macilentosa CPHST BL 125, duplicate of P19993 (World Phytophthora Collection), which is a duplicate of ATCC MYA-4945

Hosts and distribution

Distribution: North America (USA: CT, MS)
Substrate: isolated from water

Retrieved January 31, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

 

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

 

• Google All Phytophthora macilentosa
• Google Images Phytophthora macilentosa
• Google Scholar Phytophthora macilentosa

Fact sheet author

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