Name and publication

Phytophthora richardiae Buisman (1927)

Buisman CJ. 1927. Root rots caused by Phycomycetes. Mededeelingen van bet Phytopathologisch Laboratorium "Willie Commelin Scholten", Baarn, 11: 1–51.

or

Buisman C. 1927. Root rots caused by Phycomycetes. Thesis University of Utrecht 88, 51pp. Meded. pkytopath: lab. Willie Commelin Scholten 11: 7.

Nomenclature

Mycobank

MB276520

Typification

from Buisman (1927)

Type: NETHERLANDS collected from calla lily (Zantedeschia aethiopica) showing decay in nurseries.

Ex-type: no code indicated in original manuscript, Buisman 1927

Well-authenticated specimen selected by Gloria Abad:
CPHST BL 76 = P7789 (WPC) = from Zantedeschia aethiopica

Well-authenticated selected specimen in other collections

IMI340618 = P7789 (WPC), CPHST BL 76 (Abad) (in Cladeclade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
10a)

NOTE: Original publication of Phytophthora richardiae indicates the origin in the Netherlands, and Index Fungorum ("Citations in published lists or literature: Petrak's Lists volume 3 Page Image in Published List") also indicates the Netherlands. 

Specimens CBS 240.30, ATCC 60353, P642, and 45F5 (Yang et al. 2017) indicate origin in the USA, and sequences indicate the position in Cladeclade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
8a. Nomenclature of P. richardiae is under revision.

NOTE: IMI 340618 indicates that "a culture is available from the CABI Culture Collection", but no culture for Phytophthora richardiae was available at CABI Collection (3.21.18).

Ex-type in other collections

(ET) CBS 149410, NRRL 64472, CABI IMI340618 (AVA), WPC P7789,  S&T BL 76 (Abad) 

Molecular identification

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

Phytophthora richardiae isolate CPHST BL 76 ( = P7789 ) ITS rDNA MK496521, COI MH136974

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 richardiae CPHST BL 76
• NCBI: Phytophthora richardiae P7789
• BOLDSYSTEMS: Phytophthora richardiae (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
9c

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 on PDA, V8, and MEA with non-distinct pattern. Minimum growth temperature 10°C, optimum 25°C, and maximum 32°C.

Conditions for growth and sporulation

Sporangia produced on plugs of culture media flooded in soil extract.

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)
; globoseglobose:
having a rounded form resembling that of a sphere
, 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
(22–71 L x 15–40 W µm), some with tapered basetapered base:
pertaining to the base of a sporangium or oogonium; funnel-shaped
; showing nested and extended internal proliferationinternal proliferation:
internal proliferation occurs when the sporangiophore continues to grow through an empty sporangium
; originated in unbranched or in simple sympodial sporangiophores. Hyphal swellings globoseglobose:
having a rounded form resembling that of a sphere
, subglobose, sometimes with radiating hyphaehyphae:
single, tubular filament of a fungal or oomycete thallus; the basic structural unit of a fungus or oomycete
, sometimes catenulatecatenulate:
having a chain-like form
. 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
 smooth-walled, globoseglobose:
having a rounded form resembling that of a sphere
(29–48 µm diam); antheridiaantheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
predominantly amphigynousamphigynous:
pertaining to the sexual stage in which the antheridium completely surrounds the stalk of the oogonium (cf. paragynous)
and occasionally paragynousparagynous:
pertaining to the sexual stage in which the antheridium is attached to the side of the oogonium (cf. amphigynous)
, spherical, ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
, club-shaped sometimes with digitate projections; oosporesoospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
 plerotic (26–45 µm diam), oosporeoospore:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
wall thick.

Most typical characters

Phytophthora richardiae is characterized by the 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
shape and proliferationproliferation:
formation of a sporangium within an empty sporangium that has previously emitted zoospores (internal or nested) or after the sporangiophore has emerged from the empty sporangium (external)
, and the morphological characters of the antheridiaantheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
.

Specimen(s) evaluated

Phytophthora richardiae CPHST BL 76, duplicate of P7789 (World Phytophthora Collection)

Hosts and distribution

Distribution: Asia, Australia, Europe, North America (USA)
Substrate: roots
Disease Note: root rot
Host: Zantedeschia spp. (Araceae); also Robinia (Fabaceae), Asparagus (Asparagaceae), Daucus carota (carrot, Apiaceae), and Solanum lycopersicum (tomato, Solanaceae) (Erwin & Ribeiro 1996)

Retrieved February 01, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional info:
Host: Zantedeschia aethiopica

Additional references and links

 

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

 

• Google All Phytophthora richardiae
• Google Images Phytophthora richardiae
• Google Scholar Phytophthora richardiae

Fact sheet author

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