Phytophthora tonkinensis

Name and publication

Phytophthora tonkinensis T. Jung, N.M. Chi, Scanu & I. Milenković (2022)

Jung T, Milenković I, Corcobado T. et al. 2022. Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Clade 10 and its evolutionary implications. Persoonia-Molecular Phylogeny and Evolution of Fungi 49: 1–57.

Nomenclature

Mycobank

MB843135

Etymology

Name refers to the origin of all known isolates in northern Vietnam (Tonkin is a previous name for the three northernmost regions of Vietnam).

Typification

Type: Vietnam, Sapa, isolated from a fallen leaf in a stream running through an evergreen cloud forest, 2017, T. Jung & N.M. Chi, holotype HNHM-MYC-009701, dried culture on V8A, Herbarium of the Hungarian Natural History Museum, Budapest, Hungary

Ex-type: CBS 148852 = NRRL 64356 = VN859

Sequences for ex-type in original manuscript:  LSU ON000705, ITS ON000799, β-tubulin OM975978, hsp90 OM976495, tigA OM974672, rpl10 OM97532, tef-1a OM984958, enolase OM976589, cox1 ON013865, ypt1 ON025015, nadh1 OM976974, rps10 OM976733

Molecular identification

Position in ITS phylogenetic tree

Clade 10b

Morphological identification

Colonies and cardinal temperatures

Colony morphology uniform on V8A and with faintly striate and dendroid sectors on CA; minimal growth on PDA. Optimum growth temperature 20°C and maximum 22.5°C.

Conditions for growth and sporulation

Sporangia produced in non-sterile soil extract after 2–4d. Oogonia produced readily in single culture on V8A after 2–3 weeks.

Asexual phase

Sporangia were nonpapillate, persistent, and predominantly ovoid to broad ovoid and subglobose in shape. Sporangia averaged 59.2 x 37.1 µm (overall range 35.5–72.4 x 28.3–50.8 µm), proliferation internal, nested, and extended. Sporangiophores unbranched. Hyphae irregular and coralloid with dense aggregations; hyphal swellings absent. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth to wavy walls, golden brown with age, 30–59 µm. Oospores predominantly plerotic, thin-walled, size ranged 28–57 µm. Antheridia paragynous.

Most typical characters

Resides in phylogenetic clade 10b, most typical character is the coralloid hyphae and low maximum temperature.

Additional specimen(s) evaluated

Vietnam, Sapa, isolated from a fallen leaf in a stream running through an evergreen cloud forest, 2017, T. Jung & N.M. Chi, VN1106, VN1107, VN1108, VN1109

Hosts and distribution

Distribution: Vietnam
Substrate: fallen leaf in stream
Disease note: no known disease
Host: no known host

Additional references and links

none available

Fact sheet author

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