Phytophthora pachypleura

Name and publication

Phytophthora pachypleura Henricot, Pérez Sierra & Jung (2014)

Henricot B, Pérez Sierra A, and Jung T. 2014. Phytophthora pachypleura sp. nov., a new species causing root rot of Aucuba japonica and other ornamentals in the United Kingdom. Plant Pathology 63: 1095–1109.

Corresponding author:,


from Henricot et al. (2014)



Fungal names



refers to the thick wall of the oospores (‘pachy’ = ‘thick’ and ‘pleura’ = ‘wall’ in Greek)


Type: UNITED KINGDOM, Cheshire, isolated from roots of Aucuba japonica, June 2008, B. Henricot; holotype IMI 502404 (preserved in a metabolically inactive state by deep-freezing in CABI, Egham, Surrey, UK)

Ex-type: culture IMI 502404

NOTE: Phytophthora pachypleura IMI 502404 not available at HerbIMI (1/28/2017)

Sequences for ex-type in original manuscript

Phytophthora sp. BH-2013 strain RHS 53593.1 = ITSrDNA KC855330, β-tub KC855354, TEF KC855378, Cox1 KC855426, NDH KC855402

Ex-type in other collections

Phytophthora pachypleura = sp. 1 BH-2013 strain RHS 53593.1 = IMI 502404 = P19987 (WPC), CPHST BL 146 (Abad), 61H7 (Yang)

Molecular identification

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

Phytophthora pachypleura isolate CPHST BL 146 (= P19987 WPC) = ITS rDNA MG865558, COI MH136948

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

Clade 2c

Morphological identification

adapted from Henricot et al. (2014)

Colonies and cardinal temperatures

Colonies on V-8 agar, potato dextrose agar, and malt extract agar with chrysanthemum pattern. Minimum temperature for growth 5°C, optimum 25°C, maximum 35°C.

Conditions for growth and sporulation

Sporangia produced abundantly on non-sterile soil extract, and gametangia readily produced on V8A within 7 days.

Asexual phase

Sporangia semipapillate, sometimes bipapillate; persistent; ovoid, ellipsoid, obpyriform, limoniform, and with irregular or distorted shapes (mouse-shaped) (30–84 L x 22–44 W µm); showing external proliferation close to the sporangial base resulting in loose sympodia or originated in unbranched sporangiophores. Hyphal swellings sometimes formed close to the sporangial base. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth-walled, globose to slightly subglobose (21–39 µm diam.), sometimes with tapering base; antheridia paragynous, obovoid, club-shaped, or irregular, usually attached close to the oogonial stalk and in some cases more than one antheridium per oogonium is observed; oospores predominantly plerotic and sometimes slightly aplerotic (17–30 µm diam.); oospores wall thick.

Additional specimen(s) evaluated

Phytophthora pachypleura ex-type CPHST BL 146, duplicate of P19987 (World Phytophthora Collection)

Hosts and distribution

Distribution: Europe (Italy, UK)
Substrate: roots
Disease note: root rot
Host: Aucuba japonica (Garryaceae)

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

Additional references and links

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

Fact sheet author

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