Phytophthora thermophila

Name and publication

Phytophthora thermophila Jung, Stukely, Burgess (2011)

Jung T, Stukely MJC, Hardy GE St, White MD, Paap T, Dunstan WA, and Burgess TI. 2011. Multiple new Phytophthora species from ITS Clade 6 associated with natural ecosystems in Australia: evolutionary and ecological implications. Persoonia 13: 13–39.


from Jung et al. (2011)




Type: AUSTRALIA, Western Australia, Dwellingup, from rhizosphere soil of declining Eucalyptus marginata, 2004, holotype MURU 464 (dried culture on V8A, Herbarium of Murdoch University, Western Australia)

Ex-type: CBS 127954 = VHS 13530

Sequences for ex-type in original manuscript: CBS 127954 = HSP90 HQ012916, cox1 HQ012872

Ex-type in other collections

CBS 127954 & VHS 13530 = P19593 (WOC/WPC), CPHST BL 77 (Abad), 55C1 (Yang)

Molecular identification

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

Phytophthora thermophila isolate CPHST BL 77 (= P19593 WPC) = ITS rDNA MG865593, COI MH136985

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

Clade 6b

Morphological identification

Colonies and cardinal temperatures

Colony morphology is stellate to petaloid on V8A, CA, and MEA. Colonies are irregular and dense-felty on PDA. Minimum growth temperature 10°C, optimum 33°C, and maximum 35°C.

Conditions for growth and sporulation

Sporangia are produced in water cultures (soil extract or river water) and not observed in solid media. Oogonia observed for one isolate when flooded with nonsterile soil filtrate.

Asexual phase

Sporangia are nonpapillate, persistent, ovoid to elongated ovoid, or limoniform with average dimensions of 44.8 ± 6.3 x 25.7 ± 3.9 µm (overall range 29.0–64.8 x 15.6–39.3 µm). Sporangiophores in simple sympodia, and internal proliferation, both nested and extended, occurs in chains. Hyphal swellings globose or elongated. Chlamydospores globose, 41.5 ± 14.7 µm.

Sexual phase

Homothallic although oogonia only observed for one isolate. Oogonia with wavy walls, average size 31.1 ± 2.5 mm (27.2–38.0 µm) Oospores are highly aplerotic, globose, average size 23.6 ± 2.2 µm (0.4–29.7). Antheridia are paragynous.

Most typical characters

Phytophthora thermophila is in a species cluster with P. amnicola, P. fluvialis, P. moyootj, and P. litoralis, all recovered from waterways in Western Australia. Of all these species, P. thermophila is the only one to occasionally reproduce sexually in culture.

Specimen(s) evaluated

Australia, Western Australia, Dwellingup, from rhizosphere soil of declining Eucalyptus marginata, 2004; VHS 13530 = CBS 127954; VHS 21998 = CBS 127951; VHS 13567; VHS 13761; Pemberton, from rhizosphere soil of dying Banksia grandis, 2006, VHS 16164; Quinninup, from native forest, 1998, VHS 3655; Manjimup, from native forest, 2000; VHS 7474; Brunswick, from stream baiting, 2008, MUCC 764

ex-type CPHST BL 77 = P19593 (WPC)

Hosts and distribution

Distribution: Australia
Substrate: soil associated with dying plants

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

Additional info:
Distribution: Western Australia, Tasmania
Substrate: roots, collars and rhizosphere soil
Disease note: no pathogenicity trials have been conducted
Hosts: commonly isolated in association with other Phytophthora species in rhizosphere soil collected in wetter areas

Additional references and links

Burgess TI, Webster JL, Ciampini JA, White DW, Hardy GESJ, Stukely MJC (2009) Re-evaluation of Phytophthora species isolated during 30 years of vegetation health surveys in Western Australia using molecular techniques. Plant Disease 93, 215-223.

Hüberli D, Hardy GESJ, White D, Williams N, Burgess TI (2013) Fishing for Phytophthora from Western Australia's waterways: A distribution and diversity survey. Australasian Plant Pathology 42: 251-260.

Nagel JH, Gryzenhout M, Slippers B, Wingfield MJ, Hardy GESJ, Stukely MJC, Burgess TI (2013) Characterization of Phytophthora hybrids from ITS clade 6 associated with riparian ecosystems in South Africa and Australia. Fungal Biology 117: 329-347.

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