Phytophthora attenuata

Name and publication

Phytophthora attenuata Jung, 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, Bakonyi J. 2017. Six new Phytophthora species from ITS Clade 7a including two sexually functional heterothallic hybrid species detected in natural ecosystems in Taiwan. Persoonia 38: 100–135.

Corresponding author:,


from Jung et al. (2017)




refers to the tapering oogonial stalks (attenuata Lat. = tapering)


Type: TAIWAN, Sheipa National Park, isolated from rhizosphere soil of a mature Castanopsis carlesii tree, T. Jung, 2013 (CBS H-22552 holotype, dried culture on V8A, Herbarium CBS-KNAW Fungal Biodiversity Centre)

Ex-type: CBS 141199 = TW129.

Sequences for ex-type: Phytophthora attenuata isolate TW129 ITS KU517154, cox1 KU517148

Ex-type in other collections

CBS 141199 = TW129 

Molecular identification

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

Phytophthora attenuata isolate TW129 ITS rDNA KU517154

Sequences for ex-type in other sources:
  • NCBI: Phytophthora attenuata TW129 
  • Phytophthora DATABASE: Phytophthora attenuata 
  • EPPO-Q-bank: Phytophthora attenuata 
  • BOLDSYSTEMS: Phytophthora attenuata 
Position in ITS phylogenetic tree

Clade 7a

Morphological identification

adapted from Jung et al. (2017)

Colony and cardinal temperature

Colony morphology on V8 agar is faintly striate with limited aerial mycelium, while on malt extract agar and potato dextrose agar it is uniform. Minimum growth temperature 5°C, optimum 25°C, and maximum 30–35°C.

Conditions for growth and sporulation

Sporangia produced abundantly in nonsterile soil extract. Gametangia readily produced on V8A.

Asexual phase

Sporangia nonpapillate; persistent; ovoid, elongated, obpyriform, limoniform, ellipsoid, and subglobose (18–79 L x 14-46 W μm); showing internal and extended proliferation and rarely external proliferation; originated mainly on unbranched sporangiophores and in lax sympodiaHyphal swellings small, limoniform, infrequently observed on sporangiophores. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth-walled or sometimes with flexuose or ornamented walls and tapering, often long bases (29–56 μm diam.); antheridia predominately paragynous; oospores aplerotic (26–45 μm) globose or rarely elongated.

Hosts and distribution

Distribution: Asia (Taiwan)
Substrate: isolated from rhizosphere soil
Hosts: Castanopsis carlesii (Fagaceae), Chamaecyparis formosensis (Cupressaceae)

Retrieved January 18, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

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

Fact sheet author

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