Name and publication

Phytophthora flexuosa T. Jung, M. Horta Jung, Scanu & Bakonyi (2017) 

Jung T, Jung MH, Scanu B, Seress D, Kovács GM, Maia C, Pérez-Sierra A, Chang T-T, Chandelier A, Heungens K, van Poucke K, Abad-Campos P, Léon M, Cacciola SO, and Bakonyi J. 2017 Six new Phytophthora species from ITS Cladeclade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
7a including two sexually functional heterothallicheterothallic:
pertaining to sexual reproduction in which conjugation is possible only through interaction of different thalli (i.e. different mating types) (cf. homothallic)
hybrid species detected in natural ecosystems in Taiwan. Persoonia 38: 100–135.

Corresponding author: trjung@ualg.pt, thomas.jung@mendelu.cz

Nomenclature

from Jung et al. (2017)

Mycobank

MB816571

Etymology

refers to the flexuose oogonial walls (flexuosa Lat = flexuose, bulged)

Typification

Type: TAIWAN, Taiping Mountain, isolated from rhizosphere soil of a mature Fagus hayatae tree, T. Jung, 2013 (CBS H-22550 holotype, dried culture on V8A, Herbarium CBS-KNAW Fungal Biodiversity Centre)

Ex-type: CBS 141201 = TW78

Sequences for ex-type in original manuscript: Phytophthora flexuosa isolate TW78 = ITSrDNA KU517152, cox1 KU517146

Ex-type in other collections

(ET) CBS 141201, NRRL 64130,  TW78, S&T BL 211 (Abad), 67C3 (Hong)

Molecular identification

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

Phytophthora flexuosa isolate TW78 ITS rDNA KU517152

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 flexuosa TW78
• EPPO-Q-bank: Phytophthora flexuosa
• BOLDSYSTEMS: Phytophthora flexuosa

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
7a

Morphological identification

adapted from Jung et al. (2017)

Colonies and cardinal temperatures

Colony colony:
assemblage of hyphae which usually develops form a single source and grows in a coordinated way
morphology on V8A and MEA is uniform, and on PDA dome-shaped woolly. Minimum growth temperature 5°C, optimum 25°C, and maximum 35°C.

Conditions for growth and sporulation

Sporangia not observed on solid agar but produced abundantly in non-sterile soil extract; gametangiagametangia:
part of hypha specialized for fusion in sexual reproduction (see antheridium and oogonium)
produced in single culture on V8A within 5 days. Hyphal swellings regularly formed in liquid culture and solid agar.

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
, elongate, 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
, obpyriformobpyriform:
inversely pear-shaped, i.e. with the widest part at the point of attachment (cf. pyriform)
, and limoniform (34.9–74.8 μm length × 22.8–49.7 μm width); presenting internal nested and extended proliferationextended proliferation:
a type of internal proliferation in which the sporangiophore originates from inside of an empty sporangium, and continues to grow through and out of the old sporangium
; borne on unbranched sporangiophores. Hyphal swellings inflated, tubular to coralloid. 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

Homothallichomothallic:
pertaining to sexual reproduction that can take place within a single thallus (i.e. self-fertile, non-outcrossing) (cf. heterothallic).
. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
with ornamented walls and sometimes smooth-walled, globoseglobose:
having a rounded form resembling that of a sphere
, subglobose (25.7–42.8 μm diam.), flexuose, or elongated, often with long tapering to funnel-like and curved bases; 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)
, clavate, subglobose to cylindrical, often with finger-like hyphal projections; 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)
, globoseglobose:
having a rounded form resembling that of a sphere
or elongated and containing a large ooplast and often two nuclei (22.7–37.7 μm diam.) and with thick walls.

Hosts and distribution

Distribution: Asia (Taiwan)
Substrate: rhizosphere soil
Host: Fagus hayatae (Fagaceae)

Retrieved January 30, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

 

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

 

• Google All Phytophthora flexuosa
• Google Images Phytophthora flexuosa
• Google Scholar Phytophthora flexuosa

Fact sheet author

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