Phytophthora cathayensis

Name and publication

Phytophthora cathayensis C. Morales-Rodríguez, Y. Wang & A. Vannini, sp. nov. (2021)

Morales-Rodríguez C, Wang Y, Martignoni D, Vannini A. 2021. Phytophthora cathayensis sp. nov., a new species pathogenic to Chinese Hickory (Carya cathayensis) in southeast China. Fungal Systematics and Evolution 7 (1): 99–111.

Nomenclature

Mycobank

MB834619

Etymology

name refers to Carya cathayensis, the host plant from which all isolates were obtained

Typification

Type: CHINA, Zhejiang, Hangzhou, Lina, Tuankou, isolated from small pieces of cambium and adjacent xylem tissue from Carya cathayensis tree with collar canker, 2017, C. Morales-Rodríguez; CGMCC No. 19655 (preserved as metabolically inactive culture, China General Microbial Culture Collection, CGMCC No. 19655)

Ex-type: CP30 = CGMCC No. 19655

Sequences of Ex-type in manuscript: ITS MN385741, cox1 MN692211, ß-tubulin MT063102, HSP90 MT063109

Molecular identification

Position in ITS phylogenetic tree

Clade 2d

Morphological identification

Colonies and cardinal temperatures

Colony morphology stellate on MEA, stoloniferous felty colonies on PDA, and uniform on V8A. Minimum growth temperature 7.5°C, optimum 25°C, and maximum 30°C.

Conditions for growth and sporulation

Sporangia produced on soil extract after 24–36 hours in the dark. Oogonia are formed readily in single cultures on V8A after 15–20 days.

Asexual phase

Sporangia were papillate, persistent, and predominantly ovoid in shape. Sporangia averaged 27.3 x 18.6 µm (overall range 28–85 x 21–50 µm). Sporangiophores simple.Hyphal swellings present. Chlamydospores present, rare.

Sexual phase

Homothallic. Oogonia smooth-walled, size ranged from 20–29 µm. Oospores mostly plerotic, size ranged 18–25 µm. Antheridia paragynous.

Most typical characters

Morphologically similar to other species in Clade 4. A single isolate from the USA recovered from pecans, informally known as P. sp. pecan has identical sequence to P. cathayensis.

Additional specimen(s) evaluated

CHINA, Zhejiang, Hangzhou, Lina, Tuankou, isolated from small pieces of cambium and adjacent xylem tissue from Carya cathayensis tree with collar canker, 2017, C. Morales-Rodríguez, CP29; CP31

Hosts and distribution

Distribution: China
Substrate: tree collar
Disease note: trunk lesions of Carya cathayensis leading to a severe decline and dieback
Host: Carya cathayensis

Additional references and links

none available

Fact sheet author

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