Phytophthora versiformis

Name and publication

Phytophthora versiformis Paap and Burgess (2017)

Paap T, Croeser L, White D, Aghighi S, Barber PA, Hardy GES, Burgess TI. 2017. Phytophthora versiformis sp nov., a new species from Australia related to P. quercina. Australasian Plant Pathology 46: 369–378.

Corresponding author:





named after the highly variable morphology of the sporangia


Type:  AUSTRALIA, Western Australia, Williams, from rhizosphere soil of Corymbia calophylla, March 2013; collected by Trudy Paap, holotype MURU 474 (dried culture on V8A, Herbarium of Murdoch University, Western Australia)

Ex-type: CBS 142005 = TP13.46

Sequences for ex-type in original manuscript: Phytophthora versiformis strain TP13.46 = ITS KX011279, β-tubulin KX011321, HSP90 KX011256coxKX011222, and NADH KX011302 

Ex-type in other collections

CBS 142005 = TP13.46

Molecular identification

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

Phytophthora versiformis isolate TP13.46 = ITS rDNA KX011279,

Phytophthora versiformis isolate CPHST BL 189 (TP13.46) = COI MH477760

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

Clade 3b

Genome sequence

Phytophthora versiformis strain ex-type ST_20190930 (= BL 189). Accession genome ASM1470621v1 reference, BioProject PRJNA640137, USDA-APHIS-PPQ-S&T (2020)

Morphological identification

Colonies and cardinal temperatures

Colony morphology on V8, PDA, MEA, and CA are uniform, appressed, with regular smooth margins. Growth is very slow on all media. Minimum growth temperature 4°C, optimum 20°C, and maximum 28°C.

Conditions for growth and sporulation

Sporangia are produced in water cultures (soil extract or river water) and not observed in solid media. Oogonia are formed irregularly in single-strain culture on CA and V8 after about 20 d.

Asexual phase

Sporangia papillate or semipapillate, and often displaced; predominantly ovoid, but broad-ovoid, obpyriform, ellipsoid, globose, and distorted shapes also observed. Sporangia averaged 36.6 ± 11.2 x 24.2 ± 4.6 µm and ranged 19.7–81.1 x 14.5–36.9 µm. Sporangiophores simple, often with a swollen base, with no proliferation. Hyphal swellings of various shapes and often branched. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia average 33.3 ± 2.9 µm (27.6–39 µm). Oospores thick-walled and turn golden brown on maturity, average size was 29.5 ± 2.9 µm (24.8–35.7 µm). Antheridia paragynous.

Most typical characters

The most typical features for Phytophthora versiformis are sporangia with highly variable shapes and its slow growth rate.

Specimen(s) evaluated

Australia; Western Australia all from rhizosphere soil and roots of Corymbia calophylla, collected by Trudy Paap in 2013, Williams, CBS 142005 = TP13.46; Tenterton, TP13.05; Albany, TP13.07; Marradong, TP13.14; Cape Naturaliste, TP13.29; Jurien, TP13.42; collected by Louise Croeser in Perup, March 2013, MJ5; collected by Paul Barber in Perth, March 2011, PAB11.87

Hosts and distribution

Distribution: Australia
Substrate: roots, rhizosphere soil
Disease note: pathogenicity doubtful
Host: Corymbia calophylla (Myrtaceae)

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

Additional info:
Western Australia
Substrate: roots and rhizosphere soil
Disease Note: can infect host, and cause small lesions on fine roots, but does not kill the host
Hosts: Corymbia calophylla

Additional references and links

Barber PA, Paap T, Burgess TI, Dunstan WA, Hardy GES. 2013. A diverse range of Phytophthora species are associated with dying urban trees in an Australian capital city. Urban Forestry and Urban Greening 12: 569–575.

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

Fact sheet authors

Treena Burgess, Ph.D., Centre for Phytophthora Science and Management, School of Biological Sciences and Biotechnology, Murdoch University, Australia; Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America