Phytophthora docyniae

Name and publication

Phytophthora docyniae Q.N. Dang, T.H. Nguyen & T.I. Burgess (2021)

Quynh. N. Dang, Thu. H. Nguyen, Hung. X. Tran & Thu. Q. Pham, Burgess TI. 2021. Phytophthora docyniae. Fungal Planet 1374. in Crous et al. Fungal Planet Description Sheets 1284–1382. Persoonia 47: 1–150.

Nomenclature

Mycobank

MB840241

Etymology

refers to the genus name of the only known host, Docynia indica

Typification

Type: Vietnam, Yen Bai province, Mu Cang Chai, isolated from the soil and root of Docynia indica, collected by VL Binh & XT Hung, Oct. 2019, holotype CBS H-24780

Ex-type: culture CBS 148031

Sequences for ex-type in original manuscript:  ITS MZ420209, β-tubulin MZ435255, cox1 MZ435257, LSU MZ435254

Molecular identification

Position in ITS phylogenetic tree

Clade 9c

Morphological identification

Colony and cardinal temperatures

Colony have a chrysanthemum pattern on PDA and V8A and are uniform on CA. Minimum growth temperature 15°C, optimum 27.5°C, and maximum 35°C.

Conditions for growth and sporulation

Sporangia are produced in water cultures (soil extract) and not observed in solid media. Oogonia not formed in single or paired cultures.

Asexual phase

Sporangia were non-papillate, persistent, and predominantly ellipsoid to ovoid in shape with internal proliferation, both nested and extended. Sporangia averaged 34.5 x 23.8 µm (overall range 30–39.5 x 19.8–27.9 µm), direct germination of sporangia with unusual shapes was observed. Sporangiophores simple. Hyphal swellings present. Chlamydospores present.

Sexual phase

Sterile in culture

Most typical characters

Phytophthora docyniae resides in clade 9c most closely related to P. macrochlamydospora and P. quininea. Compared to the other species it has very small sporangia which often directly germinate before releasing zoospores.

Additional specimen(s) evaluated

Vietnam, Yen Bai province, Mu Cang Chai, isolated from the soil and root of Docynia indica, VL Binh & XT Hung, 2019, CBS 148031; FP78

Hosts and distribution

Distribution: Vietnam
Substrate: roots
Disease note: root rot of Docynia indica
Host: Docynia indica

Additional references and links

none available

Fact sheet author

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