Name and publication

Phytophthora pseudorosacearum T.I. Burgess (2018) 

Burgess TI, Simamora AV, White D, Wiliams B, Schwager M, Stukely MJC, and Hardy GE StJ. 2018. New species from Phytophthora Clade clade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
6a: evidence for recent radiation. Persoonia 41: 1–17.

Corresponding author: ​tburgess@murdoch.edu.au

Nomenclature

from Burgess et al. (2018)

Mycobank

MB822013

Etymology

refers to close relationship to Phytophthora rosacearum

Typification

Type: AUSTRALIA, Western Australia, Jarrahdale, from rhizosphere soil of dying Persoonia longifolia, isolated by the VHS, 2013 (holotype MURU 478, dried culture on V8A, Herbarium of Murdoch University, Western Australia)

Ex-type: CBS 143061 and VHS 29592

Sequences for ex-type in original manuscript: as Phytophthora aff. rosacearum strain VHS 29592 = ITS KJ372267;  Phytophthora pseudorosacearum strain VHS 29592 = TUB MF326827, HSP MF326878, COX MF326858 and NADH MF326907

Ex-type in other collections

(ET) CBS 143061, VHS29592,  S&T BL 188 (Abad)  

Molecular identification

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

Phytophthora pseudorosacearum isolate VHS 29592 ITS rDNA KJ372267

Phytophthora pseudorosacearum isolate CPHST BL 188 (= VHS 29592) COI MH477757

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 pseudorosacearum CPHST BL 188 
• NCBI: Phytophthora pseudorosacearum VHS 29592 
• EPPO-Q-bank: Phytophthora pseudorosacearum
• BOLDSYSTEMS: Phytophthora pseudorosacearum

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
6a

Morphological identification

Colonies and cardinal temperatures

Colony colony:
assemblage of hyphae which usually develops form a single source and grows in a coordinated way
morphology on V8 agar, CA, and PDA was cottony with a slight petaloid pattern, growth was appressed with striations on MEA. Minimum growth temperature 4°C, optimum 30°C, and maximum 37.5°C.

Conditions for growth and sporulation

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
 are produced in water cultures (soil extract or river water) and not observed in solid media. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
are formed readily in single-strain culture on CA and V8 after about 14 d.

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)
, and predominantly ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
to elongated ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
in shape. 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
average 52.7 ± 10.0 x 34.1 ± 5.6 µm (overall range 32.7–59.3 x 19.4–38.3 µm). Sporangiophores simple with internal proliferationinternal proliferation:
internal proliferation occurs when the sporangiophore continues to grow through an empty sporangium
both nested and extended. Hyphal swellings predominantly spherical, 6.1–30.9 µm in diameter. 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
 present averaging 28.4 ± 5.3 µm in diameter.

Sexual phase

Homothallic. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
with wavy walls and sometimes a tapering base, average size 35.8 ± 4.9 µm (23.8–49.0). OosporesOospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
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)
, globoseglobose:
having a rounded form resembling that of a sphere
to eccentric turning golden brown on maturity, average size 30.8 ± 3.3 µm (22.3–38.1). AntheridiaAntheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
paragynousparagynous:
pertaining to the sexual stage in which the antheridium is attached to the side of the oogonium (cf. amphigynous)
.

Most typical characters

Phytophthora pseudorosacearum closely resembles Phytophthora rosacearum, Phytophthora condilina, and Phytophthora kwongonina. Its most distinguishing characteristic is the 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
.

Specimen(s) evaluated

Australia, Western Australia, Jarrahdale, from rhizosphere soil of dying Persoonia longifolia, isolated by the VHS, 2013 CBS 143061 = VHS 29592; Cooljarloo, from water baiting in native vegetation, 1998, R. Hart, HSA2350; Albany, from rhizosphere soil of dying Xanthorrhoea platyphylla, 2010, VHS, VHS 24266

Hosts and distribution

NOT FOUND as of June 2018 in U.S. National Fungus Collections Nomenclature Database.

Additional references and links

 

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

 

• Google All Phytophthora pseudorosacearum
• Google Images Phytophthora pseudorosacearum
• Google Scholar Phytophthora pseudorosacearum

Fact sheet authors

Treena Burgess, Ph.D., Phytophthora Science and Management, Harry Butler Institute, Murdoch University, Australia

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