Name and publication

Phytophthora pseudokernoviae T. Jung, M. Horta Jung, A. Durán & E. Sanfuentes (2022)

Jung T, Milenković I, Corcobado T. et al. 2022. Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Clade clade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
10 and its evolutionary implications. Persoonia-Molecular Phylogeny and Evolution of Fungi 49: 1–57.

Corresponding authors: thomas.jung@mendelu.cz and dr.t.jung@gmail.com

Nomenclature

Mycobank

MB843149

Etymology

Name refers to the morphological similarity to P. kernoviae.

Typification

Type: Chile, Parque Oncol, isolated from a naturally fallen necrotic leaf of Drimys winteri in a Valdivian rainforest,, Nov. 2014, T. Jung, A. Durán & E. Sanfuentes, holotype HNHM-MYC-009707, dried culture on V8A, Herbarium of the Hungarian Natural History Museum, Budapest

Ex-type: culture CBS 148796 = NRRL 64351 = CL012

Sequences for ex-type in original manuscript:  LSU ON000686, ITS ON000780, β-tubulin OM975959, hsp90 OM976476, tigA OM974653, rpl10 OM974513, tef-1a OM984939, enolase OM976570, cox1 ON013846, ypt1 ON024996, nadh1 OM976955, rps10 OM976714

Ex-type in other collections

 (ET) CBS 148796, NRRL 64351, CL012 

Molecular identification

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

Phytophthora pseudokernoviae ITS rDNA, COI

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 pseudokernoviae
• EPPO-Q-bank: Phytophthora pseudokernoviae
• BOLDSYSTEMS: Phytophthora pseudokernoviae

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
10a

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 appressed uniform to faintly striate on V8A and faintly radiate on CA, dense-woolly and faintly petaloid on PDA. Optimum growth temperature 15°C and maximum 25°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
produced in non-sterile soil extract after 1–2d. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
produced readily in single culture on V8A after 2–3 weeks.

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
were papillatepapillate:
pertaining to the production of a distinct papilla at the distal end of the sporangium (cf. nonpapillate and semipapillate)
, caducouscaducous:
pertaining to sporangia that become dislodged readily (i.e. deciduous) and separate from the sporangiophore (cf. persistent)
, and predominantly 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
averaged 42.7 x 29.7 µm (overall range 30.5–55.0 x 21.3–35.7 µm), external proliferationexternal proliferation:
formation of a sporangium after a sporangiophore has emerged from beneath and external to an empty sporangium that has previously emitted its zoospores (cf. internal proliferation)
. Sporangiophores dense sympodiasympodia:
a type of sporangiophore which appears simple, but where each successive sporangium develops on a branch behind and to one side of the previous apex, where growth has already ceased
. Hyphal swellings rare. 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. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
smooth-walled mostly with a tapering base turning golden brown with age, 19–39 µm. OosporesOospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
predominantly pleroticplerotic:
pertaining to an oospore that fills the oogonium (cf. aplerotic)
, size ranged 16–36 µm. AntheridiaAntheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
amphigynousamphigynous:
pertaining to the sexual stage in which the antheridium completely surrounds the stalk of the oogonium (cf. paragynous)
.

Most typical characters

Resides in phylogenetic cladeclade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
10a and is closely related to P. chilensis, P. kernoviae and P. pseudochilensis. These species have similar morphology and low temperature optima and maxima.

Additional specimen(s) evaluated

Chile, Parque Oncol, isolated from a naturally fallen necrotic leaf of D. winteri in a Valdivian rainforest, Nov. 2014, T. Jung, A. Durán & E. Sanfuentes, CL013; isolated from a stream running through a Valdivian rainforest using a Nothofagus obliqua leaf as bait, CL156.

Hosts and distribution

Distribution: Chile
Substrate: fallen leaves and forest stream
Disease note: no known disease
Host: no known host

Additional references and links

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

Fact sheet author

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.