Phytophthora kelmanii

Name and publication

Phytophthora kelmanii Z.G. Abad, J.A. Abad, T.I. Burgess & Mostowf. (2021)

Mostowfizadeh Ghalamfarsa R, Burgess TI, Abad ZG, Abad JA. 2021. Phytophthora kelmanii Fungal Planet 1267. In: Crous PW et al. Fungal Planet Description Sheets 1182–1283. Persoonia 46: 313–528.

Nomenclature

Mycobank

MB838760

Etymology

Named to honour Dr Arthur Kelman, Emeritus Professor at the Department of Plant Pathology, North Carolina State University, USA, and mentor of Jorge and Gloria Abad during their time at NCSU. Arthur Kelman (11 Dec. 1918 – 29 June 2009) was one of the most influential plant pathologists of the twentieth century. He was a member of the National Academy of Sciences for his pioneering contributions to the study of phytobacteriology and received numerous awards including Fellow of the International Society of Plant Pathology, American Phytopathological Society, the American Association for the Advancement of Science, and the American Academy of Microbiology.

Typification

Type: Australia, Western Australia, Armadale, baited from rhizosphere soil of Ptilotus pyramidatus, collected by Giles Hardy 2016; holotype MURU485

Ex-type: CBS 146551

Sequences of ex-type in manuscript: ITS MT210487, ß-tubulin MT210491, HSP90 MT210495, cox1 MT210499, nadh1 MT210503 and LSU MT210486

Molecular identification

Position in ITS phylogenetic tree

Clade 8a

Morphological identification

Colonies and cardinal temperatures

Colony morphology on V8A, CA, and MEA was uniform, rosaceous pattern on PDA. Minimum growth temperature 4°C, optimum 25°C, and maximum 37.5°C.

Conditions for growth and sporulation

Sporangia are produced in water cultures (soil extract) and not observed in solid media. Oogonia formed readily in paired cultures on CA and V8 after about 14 d.

Asexual phase

Sporangia were non-papillate, persistent, and predominantly ovoid in shape with internal proliferation, both nested and extended. Sporangia averaged 46 x 31 µm (overall range 26–75 x 21–49 µm); Sporangiophores simple or loose sympodia. Hyphal swellings present, numerous, globose. Chlamydospores present.

Sexual phase

Heterothallic. Oogonia had wavy walls and size ranged from 27–44 µm. Oospores plerotic to slightly aplerotic, globose and golden brown on maturity, size ranged 24–40 µm. Antheridia amphigynous.

Most typical characters

Phytophthora kelmanii is closely related to P. pseudocryptogea and has frequently been classified as P. cryptogea. Morphologically it is very similar to other species in clade 8a, but is distinguished by masses of globose hyphal swellings.

Additional specimen(s) evaluated

Australia, Western Australia, Armadale, baited from rhizosphere soil of Ptilotus pyramidatus, G Hardy, 2016, CBS 146551; baited from rhizosphere soil of Xanthorrhea pressii, 2014, VHS30761; rhizosphere soil of Salvia rosmarinus, 2018, VHS38521; USA, California, 1992, SUC629; rhizosphere soil of Juglans nigra, 1995, SCRP209

Hosts and distribution

Distribution: cosmopolitan
Substrate: roots
Disease note: Phytophthora root rot
Host: broad, including Abies spp., Picea spp., native ecosystems, numerous ornamentals, tree crops

Additional references and links

none available

Fact sheet author

Treena Burgess, Ph.D., Phytophthora Science and Management, Harry Butler Institute, Murdoch University