Name and publication

Phytophthora intercalaris Xiao Yang, Balci, Brazee, Loyd & C.X. Hong (2016)

Yang X, Balci Y, Brazee NJ, Loyd AL, and Hong CX. 2015. A unique species in Phytophthora Clade 10: Phytophthora intercalaris sp. nov. recovered from stream and irrigation water in eastern United States. International Journal of Systematic and Evolutionary Microbiology 66: 845–855.

Correspondence author: Xiao Yang yxiao9@vt.edu

Nomenclature

from Yang et al. (2016)

Mycobank

MB812881

Etymology

refers to the abundant intercalaryintercalary:
positioned within a hypha (cf. terminal)
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
produced in hemp seed agar and carrot agar

Typification

Type: UNITED OF STATES OF AMERICA, recovered from Rapidan Stream, Virginia, USA, July 2007, deposited in the American Type Culture Collection (ATCC), Manassas, VA, USA, as ATCC TSD-7T (isolate 45B7T)

Ex-type: CBS 140632 (ex-type) deposited at the Centraalbureau voor Schimmelcultures (CBS) Fungal Biodiversity Centre, Utrecht, The Netherlands

Sequences for ex-type: Phytophthora intercalaris isolate 45B7T: ITS rDNA KT163268, cox1 KT163315, and β-tubulin KT163336

Ex-type in other collections

(ET) CBS 140632, TSD-7, 45B7 (Hong)

Molecular identification

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

Phytophthora ipomoeae isolate CPHST BL 21 (= P10225 WPC) = ITS rDNA MG865518, COI MH136912

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 ipomoeae CPHST BL 21 
• NCBI: Phytophthora ipomoea P10225
• NCBI: Phytophthora ipomoeae PD-00078 (P10225)
• NCBI: Phytophthora ipomoea CBS 109229 ITS in 2013 manuscript
• EPPO-Q-bank: Phytophthora ipomoea CBS 109229
• BOLDSYSTEMS: Phytophthora ipomoeae PHYTO022-10 (= P10225) (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
1c

Morphological identification

adapted from Yang et al. (2016)

Colonies and cardinal temperatures

Colony colony:
assemblage of hyphae which usually develops form a single source and grows in a coordinated way
morphology after 10 days of growth in carrot agar, V8 agar, and hemp seed agar with stellate pattern. Minimum growth temperature 5°C, optimum 25–30°C, maximum 32°C.

Conditions for growth and sporulation

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
of Phytophthora intercalaris produced from fresh mycelial plugs grown in cV8A after they were submerged in 1.5 % soil water extract for approximately 20 hours. Isolates of A1 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
observed in original publication, oosporesoospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
produced in pairing with Phytophthora cinnamomi A2 tester. Chamydospores abundantly produced in HSA and CA after 10 days.

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)
but occasionally caducouscaducous:
pertaining to sporangia that become dislodged readily (i.e. deciduous) and separate from the sporangiophore (cf. persistent)
with long pedicels (19–64 μm); ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
, 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
, limoniform, pyriformpyriform:
pear-shaped, with the narrowest part at the base (cf. obpyriform)
, or obpyriformobpyriform:
inversely pear-shaped, i.e. with the widest part at the point of attachment (cf. pyriform)
(25–52.5 x 19–37 μm) showing nested or extended internal proliferations; originated in unbrached and sometimes on simple sympodial sporangiophores. Hyphal swellings rarely produced in cV8A, while abundant in both young and aged cultures grown in hemp seed agar (HSA) and carrot agar (CA). Chlamydospores globose globose:
having a rounded form resembling that of a sphere
(25–63 μm diam) thin-walled, intercalaryintercalary:
positioned within a hypha (cf. terminal)
, occasionally terminal, and rarely lateral.

Sexual phase

Heterothallic. Oogonia with ornamented walls with abundant to few protuberances (34–47 μm diam); antheridiaantheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
amphigynous amphigynous:
pertaining to the sexual stage in which the antheridium completely surrounds the stalk of the oogonium (cf. paragynous)
(20 x 16 μm); oospores aborted (30–41 μm diam).

Hosts and distribution

Distribution: North America (USA: MA, MD, NC, VA, WV)
Substrate: isolated from stream and irrigation water

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

Additional info:
Collected from stream and nursery irrigation water in Maryland, Massachusetts, North Carolina, Virginia and West Virginia in the USA.

Additional references and links

 

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

 

• Google All Phytophthora intercalaris
• Google Images Phytophthora intercalaris
• Google Scholar Phytophthora intercalaris

Fact sheet author

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