Phytophthora variabilis

Name and publication

Phytophthora variabilis T. Jung, M. Horta Jung & I. Milenković (2022)

Chen Q, Bakhshi M, Balci Y, Broders KD, Cheewangkoon R, Chen SF, Fan XL, Gramaje D, Halleen F, Horta Jung M, Jiang N, Jung T, Májek T, Marincowitz S, Milenković I, Mostert L, Nakashima C, Nurul Faziha I, Pan M, Raza M, Scanu B, Spies CFJ, Suhaizan L, Suzuki H, Tian CM, Tomšovský M, Úrbez-Torres JR, Wang W, Wingfield BD, Wingfield MJ, Yang Q, Yang X, Zare R, Zhao P, Groenewald JZ, Cai L, Crous PW. 2022. Genera of phytopathogenic fungi: GOPHY 4. Studies in Mycology 101: 417–564.

Nomenclature

Mycobank

MB840174

Etymology

refers to the variable shapes of the oogonia with both amphigynous and paragynous antheridia

Typification

Type: SLOVAKIA, Bratislava, Marianka, isolated from a commercial tree planting substrate, Jun. 2013, T. Jung (holotype CBS H-24772, dried culture on V8A

Ex-type: culture CBS 147923 = TJ915

Sequences for ex-type in original manuscript:  ITS MZ753930, cox1 MZ736447, β-tubulin MZ736472, tigA MZ7364501

Molecular identification

Position in ITS phylogenetic tree

Clade 7b

Morphological identification

Colonies and cardinal temperatures

Colony morphology radiate on V8A, uniform on CA, and uniform and cottony on PDA. Minimum growth temperature <10°C, optimum 27.5°C, and maximum 5°C.

Conditions for growth and sporulation

Sporangia produced on non-sterile soil extract. Oogonia are formed readily in single culture.

Asexual phase

Sporangia were non-papillate, persistent and predominantly ovoid in shape. Proliferation both external and internal nested and extended. Sporangia averaged 61 x 37.7 µm (overall range 47.2–82.5 x 25.3–48 µm). Sporangiophores unbranched. Hyphal swellings absent. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth-walled, variable shapes, size ranged from 24–50 µm. Oospores aplerotic, turning brown after 4 weeks. Antheridia amphigynous and paragynous.

Most typical characters

Most distinguishing feature is the variable shape of oogonia.

Additional specimen(s) evaluated

SLOVAKIA, Bratislava, Marianka, isolated from a commercial tree planting substrate, Jun. 2013, T. Jung; CBS 147924 = TJ1495; TJ1496; TJ1497; TJ1498

Hosts and distribution

Distribution: Slovakia
Substrate: potting mix
Disease note: none known
Host: none known

Additional references and links

none available

Fact sheet author

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