Name and publication

Phytophthora chrysanthemi M. Naher, H. Watan., Chikuo & K. Kageyama (2011)

Naher M, Motohash K, Watanabe H, Chikuo Y, Senda M, Suga H, Brasier C, and Kageyama K. 2011. Phytophthora chrysanthemi sp. nov., a new species causing root rot of chrysanthemum in Japan. Mycol. Prog. 10: 21–31.

Corresponding author: kageyama@green.gifu-u.ac.jp

Nomenclature

from Naher et al. (2011)

Mycobank

MB560577

Etymology

refers to the original host plant of this pathogen

Typification

Type: JAPAN, Gifu, Minokamo (36°N, 137°E), from root rot of potting chrysanthemum (Chrysanthemum X morifolium), 2000, collector H. Watanabe, isolate NBRC 104917 (deep-freezing) deposited at the National Institute of Technology and Evaluation - Biological Resource Center, Japan

Ex-type: CBS 123163 = GF749

Sequences for ex-type in original manuscript: Phytophthora chrysanthemi GF749 = ITS AB437135, β-tub AB511995, TEF 1α AB511925, LSU AB465349, HS 90 AB511987, L10 AB511926

Ex-type in other collections

(ET) CBS 123163, S&T BL 94 (Abad), GF749, 61F1 (Hong)

Molecular identification

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

Phytophthora chrysanthemi isolate CPHST BL 94 (= P19843 WPC) = ITS rDNA MG865472, COI MH136868

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 chrysanthemi CPHST BL 94
• NCBI: Phytophthora chrysanthemi GF749
• BOLDSYSTEMS: Phytophthora chrysanthemi (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
9a

Morphological identification

adapted from Naher et al. (2011)

Colonies and cardinal temperatures

Colonies on V8-A, PDA, and MEA with no distinctive pattern. Minimum temperature for growth 6°C, optimum 30°C, and maximum 35°C.

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)
; 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
, ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
, or pyriformpyriform:
pear-shaped, with the narrowest part at the base (cf. obpyriform)
(24–59 μm long ×16–43 μm wide); with extended, nested, or internal proliferationinternal proliferation:
internal proliferation occurs when the sporangiophore continues to grow through an empty sporangium
with 3 to 8 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
. 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 single or sympodial sporangiophores. Hyphal swellings elongated, irregular to globoseglobose:
having a rounded form resembling that of a sphere
, produced lateral and intercalaryintercalary:
positioned within a hypha (cf. terminal)
(up to 67 μm). 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
spherical terminal, lateral, or intercalaryintercalary:
positioned within a hypha (cf. terminal)
(27–46 μm diam.).

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
terminal, often laterally sessile and intercalaryintercalary:
positioned within a hypha (cf. terminal)
with smooth walls; mostly spherical or nearly spherical, and occasionally possessing a distinct funnel-shaped stalk (26–46 μm diam.), acquiring a golden brown color with aging; antheridiaantheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
mostly terminal and occasionally intercalaryintercalary:
positioned within a hypha (cf. terminal)
and predominantly paragynousparagynous:
pertaining to the sexual stage in which the antheridium is attached to the side of the oogonium (cf. amphigynous)
but sometimes amphigynousamphigynous:
pertaining to the sexual stage in which the antheridium completely surrounds the stalk of the oogonium (cf. paragynous)
; oosporeoospore:
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)
, spherical (19–35 μm diam.).

Additional specimen(s) evaluated

Phytophthora chrysanthemi CPHST BL 94 = P19843 (World Phytophthora Collection)

Hosts and distribution

Distribution: Asia (Japan), Europe (Croatia, Germany), North America (USA)
Substrate: stems, roots
Disease note: stem and root rot
Hosts: Chysanthemum (Asteraceae)

Retrieved January 29, 2018 from U.S. National Fungus Collections Nomenclature Database.

Quarantine status

Phytophthora chrysanthemi is listed in the U.S. Regulated Plant Pest Table (last modified Nov. 15, 2017).

Additional references and links

 

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

 

• Google All Phytophthora chrysanthemi
• Google Images Phytophthora chrysanthemi
• Google Scholar Phytophthora chrysanthemi

Fact sheet author

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