Name and publication

Phytophthora urerae G.A. Forbes & Grünwald (2019)

Grünwald NJ, Forbes GA, Perez‐Barrera W, Stewart JE, Fieland VJ, Larsen MM. 2019. Phytophthora urerae sp. nov., a new cladeclade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
1c relative of the Irish famine pathogen Phytophthora infestans from South America. Plant Pathology 68 (3): 557–65.

Corresponding author: nik.grunwald@ars.usda.gov

Nomenclature

Mycobank

MB 828472

Etymology

referring to the host plant Urera laciniata from which it was first isolated and which was validated as a host plant following Koch’s postulates

Typification

Type: Peru, San Ramon, Junin, isolated from plant host Urera laciniata in Peru, Collected by W. Perez-Barrera, holotype BPI893220

Ex-type: culture PSR27

Sequences for ex-type in original manuscript:  PSR27; ITS KR632862, cox1 KR632858, PITG11126 KR632939, ypt1 KR632913, β-tubulin KR632888

Ex-type in other collections

(ET) CBS 148929, NRRL 64200, PSR27, S&T BL 203 (Abad), VJF-2015a  

Molecular identification

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

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

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
1c

Morphological identification

Colonies and cardinal temperatures

Colonies smooth to slightly stellate on rye B and V8A, and appeared cottony and petallate to stellate on PDA. Minimum growth temperature 6°C, optimum 20–25°C, and maximum 28°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 on solid V8A. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
are formed readily on agar within 7 days when paired with opposite mating typemating type:
molecular mechanisms that regulate compatibility in sexual reproduction in heterothallic species (also referred to as compatibility type); typically denoted as A1 or A2
.

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 semi-papillate to 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 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
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 30 x 18 µm (overall range 20–36 x 14–22 µm). Hyphal swellings absent. 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

Heterothallic. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
smooth-walled, size ranged from 22–40 µm. OosporesOospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
pleroticplerotic:
pertaining to an oospore that fills the oogonium (cf. aplerotic)
, size ranged 18–35 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

Morphologically similar to other species in Cladeclade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
1c. Can be distinguished as it can only cause symptoms on a single host Urera laciniata.

Additional specimen(s) evaluated

Peru, San Ramon, Junin, foliage of Urera laciniata, collected by W. Perez-Barrera, PSR26; PSR28; PSR29; PSR30; PSR31

Hosts and distribution

Distribution: Peru
Substrate: leaf
Disease note: foliar blight on leaves of native plant Urera laciniata in Peru
Host: Urera laciniata

Additional references and links

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

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.