Phytophthora pseudolactucae


   Phytophthora  spp. in subclade 8b:  portion of the seven-loci ML phylogeny featuring the type cultures of 212 described species (by T. Bourret). Notice the position of   P. pseudolactucae  Ex-type CBS 137103 = S&T BL 118 . Gloria Abad, USDA S&T.
Phytophthora spp. in subclade 8b: portion of the seven-loci ML phylogeny featuring the type cultures of 212 described species (by T. Bourret). Notice the position of P. pseudolactucae Ex-type CBS 137103 = S&T BL 118. Gloria Abad, USDA S&T.
   Phytophthora  spp. in subclade 8b:  Morphological Tabular key (PDF) and Tabular key legends (PDF) in IDphy2 KEY SECTION. Notice the data of   P. pseudolactucae  Ex-type CBS 137103 = S&T BL 118 . Gloria Abad, USDA S&T.
Phytophthora spp. in subclade 8b: Morphological Tabular key (PDF) and Tabular key legends (PDF) in IDphy2 KEY SECTION. Notice the data of P. pseudolactucae Ex-type CBS 137103 = S&T BL 118. Gloria Abad, USDA S&T.

Name and publication

Phytophthora pseudolactucae M.Z. Rahman, S. Uematsu, Kanto, M. Kusunoki & Kageyama (2015)

Rahman MZ, Uematsu S, Kimishima E, Kanto T, Kusunoki M, Motohashi K, Ishiguro Y, Suga H, and Kageyama K. 2015. Two plant pathogenic species of Phytophthora associated with stem blight of Easter lily and crown rot of lettuce in Japan. Mycoscience 56: 419–433.

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

Nomenclature

from Rahman et al (2015)

Mycobank

MB807138

Etymology

refers to its high similarity with Phytophthora lactucae in the rRNA gene ITS region

Typification

Type: JAPAN, Kagawa, Onohara, in crowns of Lactuca sativa, 1 Feb, 2013, leg. M. Kusunoki holotype, NBRC H-13221 (freeze dried)

Ex-type: cultures, KPh 2013-2-1, NBRC 110060, CBS 137103

Sequences for ex-type in original manuscript: Phytophthora sp. KPh2013_2_1 = AB894388 (ITS rDNA), AB894396 (cox1)

Ex-type in other collections

(ET) CBS 137103, NBRC 110060, KPh 2013-2-1, WPC P19992, S&T BL 118 (Abad)

Molecular identification

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

Phytophthora pseudolactucae isolate CPHST BL 118 (= P19992 WPC) = ITS rDNA MG865573, COI MH136965

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
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
8b

Morphological identification

adapted from Rahman et al (2015)

Colonies and cardinal temperatures

Colony colony:
assemblage of hyphae which usually develops form a single source and grows in a coordinated way
morphology on CMA, V8A, and PDA with no defined pattern. Growth on V8A between 3°C and 25°C, with optimum at 20–23°C.

Conditions for growth and sporulation

Oogonia and oosporesoospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
produced abundantly in single cultures on grass leaf blade, V8A, and CMA.

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
semipapillatesemipapillate:
pertaining to the production of shallow having papilla that are not well developed, shallow and less nipple-like than fully papillate structures
; persistentpersistent:
pertaining to sporangia that remain attached to the sporangiophore and do not separate or detach easily (cf. caducous)
; ovoid-obpyriform, elongated 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
(av. 42 μm length X 30.4 μm width), without 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)
; originated on unbranched or simple sympodial or sporangiophores. 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
present.

Sexual phase

Homothallic. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
smooth, spherical or sub-spherical (av. diameter of 40 μm); antheridiaantheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
predominantly paragynousparagynous:
pertaining to the sexual stage in which the antheridium is attached to the side of the oogonium (cf. amphigynous)
, rarely amphigynousamphigynous:
pertaining to the sexual stage in which the antheridium completely surrounds the stalk of the oogonium (cf. paragynous)
, intercalaryintercalary:
positioned within a hypha (cf. terminal)
, regularly spherical; oosporesoospores:
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 (av. 33 μm diam).

Additional specimen(s) evaluated

Phytophthora pseudolactucae ex-type CPHST BL 118, duplicate of P19992 (World Phytophthora Collection)

Hosts and distribution

Distribution: Asia (Japan)
Substrate: stem, crown
Disease note: stem blight, crown rot
Host: Lactuca sativa (Asteraceae)

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

Additional info:
Host and geographic distribution in Japan: Lactuca sativa; Hyogo and Kagawa Prefectures

Additional references and links

 

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

 

Fact sheet author

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