Name and publication

Phytophthora sansomeana E.M. Hansen & Reeser (2009)

Hansen EM, Wilcox WF, Reeser PW, and Sutton W. 2009. Phytophthora rosacearum and P. sansomeana, new species segregated from the Phytophthora megasperma "complex". Mycologia 101: 129–135.

Corresponding author: hansene@science.oregonstate.edu

Nomenclature

from Hansen et al. (2009)

Mycobank

MB499443

Etymology

The name commemorates Dr Eva Sansome, whose astute cytological observations established the diploid nature of Phytophthora and other oomycetes.

Typification

Type: UNITED STATES OF AMERICA, collected from soybean in Indiana by Reeser, isolate OSU 1819B holotype in Herbarium OSC (dried culture)

Ex-type: ATCC MYA-4455

Sequences for ex-type in original manuscript: OSU 1819B = ITS rDNA EU925375

Ex-type in other collections

(ET) CBS 117693, ATCC MYA-4455, WPC P8051, S&T BL 55, 47H3 (Hong) 

Molecular identification

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

Phytophthora sansomeana isolate CPHST BL 55 (= P8051 WPC) = ITS rDNA MG865585, COI MH136977

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 sansomeana CPHST BL 55
• EPPO-Q-bank: Phytophthora sansomeana CBS 117693 ITSrDNA, β-tub, TEF
• BOLDSYSTEMS: Phytophthora sansomeana (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
8a

Morphological identification

adapted from Hansen et al. (2009)

Colonies and cardinal temperatures

Colony colony:
assemblage of hyphae which usually develops form a single source and grows in a coordinated way
after 7 days of growth on potato dextrose agar, malt extract agar with slight chrysanthemum pattern, and in V8 agar with no distinct pattern. Minimum growth temperature 3°C, optimum 24–30°C, and maximum 33°C.

Conditions for growth and sporulation

Sporangia form in water; hyphal swellings are sometimes observed in old 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
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
, obpyriformobpyriform:
inversely pear-shaped, i.e. with the widest part at the point of attachment (cf. pyriform)
, 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
, obovoidobovoid:
inversely egg-shaped; ovoid, but with the widest part at the apex
(30–53 L x 19–40 W µm) some with distorted shapes and some with tapered bases; presenting internal proliferationinternal proliferation:
internal proliferation occurs when the sporangiophore continues to grow through an empty sporangium
, produced on long, unbranched or loosely sympodial sporangiophores. Hyphal swellings globoseglobose:
having a rounded form resembling that of a sphere
, subglobose, with radiating hyphaehyphae:
single, tubular filament of a fungal or oomycete thallus; the basic structural unit of a fungus or oomycete
produced on clusters or 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, globoseglobose:
having a rounded form resembling that of a sphere
(25–52 µm diam); antheridiaantheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
small (6–24 L x 9–16 W µm) predominately amphigynousamphigynous:
pertaining to the sexual stage in which the antheridium completely surrounds the stalk of the oogonium (cf. paragynous)
and sometimes with digitate projections; oosporesoospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
globoseglobose:
having a rounded form resembling that of a sphere
(23–44µm diam) 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)
, or 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)
.

Additional specimen(s) evaluated

Phytophthora sansomeana ex-type CPHST BL 55, duplicate of P8051 (World Phytophthora Collection), which is a duplicate of ex-type ATCC MYA-4455

Hosts and distribution

Distribution: North America (USA), Asia (China)
Substrate: roots, collar
Disease note: root rot
Host: Glycine max (Fabaceae), various other hosts

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

Additional info:
Substrate: rhizosphere

Additional references and links

 

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

 

• Google All Phytophthora sansomeana
• Google Images Phytophthora sansomeana
• Google Scholar Phytophthora sansomeana

Fact sheet author

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