Name and publication
Phytophthora oreophila I. Khaliq and T.I Burgess (2019)
Khaliq I, Hardy GE, McDougall KL, Burgess TI. 2019. Phytophthora species isolated from alpine and sub-alpine regions of Australia, including the description of two new species; Phytophthora cacuminis sp. nov and Phytophthora oreophila sp. nov. Fungal Biology 123 (1): 29–41.
‘oreos’ refers to a Greek word for a mountain and ‘phila’ means loving. The name is given to the species due to its mountainous origin, and its ability to grow at extremely low temperatures (less than 4°C).
Type: Australia: New South Wales, Merritts Creek; by baiting rhizosphere soil and associated roots collected from a disturbed alpine herbfield, Jan 2016. Collected by Keith McDougall, isolated by I. Khaliq. Holotype MURU 483 (dried culture on V8A, Herbarium of Murdoch University, Western Australia)
Ex-type: culture CBS 144708 = U11
Sequences of ex-type in manuscript: ITS MG542976, β-tubulin MG543037, HSP90 MG543025, cox1 MG543002, nadh1 MG543013
Position in ITS phylogenetic tree
Colonies and cardinal temperatures
Colony morphology on V8 agar and CA was slightly petaloid, and rosaceous on PDA. Minimum growth temperature 4°C, optimum 20°C, and maximum 32.5°C.
Conditions for growth and sporulation
Sporangia were non-papillate, persistent, and predominantly ovoid in shape with internal proliferation, both nested and extended. Sporangia averaged 40.9 x 26.7 µm (overall range 19.9–59.9 x 13.4–38.5 µm). Sporangiophores simple. Hyphal swellings present. Chlamydospores absent.
Homothallic. Oogonia had wavy walls and size ranged from 29.3–48.1 µm Oospores plerotic, globose with a large ooplast and pale on maturity, size ranged 26.8–42 µm. 90% of oospores aborted after formation of the walls. Antheridia paragynous often with multiple antheridia.
Most typical characters
Phytophthora oreophila is closely related to and morphologically resembles P. rosacearum and P. pseudorosacerum; the most distinguishing characteristics are the lower temperature optima and faster growth.
Hosts and distribution
Disease note: no known disease
Host: native vegetation
Additional references and links
Fact sheet author
Treena Burgess, Ph.D., Phytophthora Science and Management, Harry Butler Institute, Murdoch University