Phytophthora pseudolactucae

Name and publication

Phytophthora pseudolactucae Rahman, Uematsu, Kanto, 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:


from Rahman et al (2015)




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


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

KPh 2013-2-1, NBRC 110060, CBS 137103 = P19992 (WPC), CPHST 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

Sequences for ex-type in other sources
Position in ITS phylogenetic tree

Clade 8b

Morphological identification

adapted from Rahman et al (2015)

Colonies and cardinal temperatures

Colony 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 oospores produced abundantly in single cultures on grass leaf blade, V8A, and CMA.

Asexual phase

Sporangia semipapillate; persistent; ovoid-obpyriform, elongated ellipsoid (av. 42 μm length X 30.4 μm width), without proliferation; originated on unbranched or simple sympodial or sporangiophores. Chlamydospores present.

Sexual phase

Homothallic. Oogonia smooth, spherical or sub-spherical (av. diameter of 40 μm); antheridia predominantly paragynous, rarely amphigynous, intercalary, regularly spherical; oospores aplerotic, 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

  • Phytophthora DATABASE: Phytophthora pseudolactucae
  • EPPO-Q-bank: Phytophthora pseudolactucae
  • SMML USDA-ARS: Phytophthora pseudolactucae
  • EPPO Global Database: Phytophthora pseudolactucae
  • CABI Invasive Species Compendium: Phytophthora pseudolactucae
  • Encyclopedia of Life (EOL): Phytophthora pseudolactucae
  • Index Fungorum (IF): Phytophthora pseudolactucae
  • Plantwise Knowledge Bank: Phytophthora pseudolactucae

Fact sheet author

Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America