Name and publication
Phytophthora × vanyenensis Q.N. Dang and T. I. Burgess (2021)
Dang QN, Pham TQ, Arentz F, Hardy GE, Burgess TI. 2021. New Phytophthora species in clade 2a from the Asia-Pacific region including a re-examination of P. colocasiae and P. meadii. Mycological Progress 20 (2): 111–129.
referring to the locality (Van Yen) where this species was recovered
Type: VIETNAM, Yen Bai, Van Yen, water from Cinnamomum cassia plantation, Sep. 2018, Q.N. Dang, Holotype MURU488
Ex-type: culture CBS 146554
Sequences of ex-type in manuscript: ITS MT568651, β-tubulin MT583634, hsp90 MT583680, cox1 MT583648, cox2 MT583665, nadh1 MT583695, rps10 MT583709
Position in ITS phylogenetic tree
Colonies and cardinal temperatures
Colony morphology cottony and stellate on CA, dense and stellate on PDA, smooth and thin on MEA, and submerged and stellate on V8A. Minimum growth temperature 4°C, optimum 30°C, and maximum 32.5°C.
Conditions for growth and sporulation
Sporangia were semi-papillate to papillate often bipapillate, mostly persistent, and variable in shape with external proliferation. Sporangia averaged 52.8 x 33.5 µm (overall range 36.4–74.3 x 19.6–51.7 µm). Sporangiophores simple. Hyphal swellings rare. Chlamydospores absent.
Heterothallic. Oogonia had smooth walls, and size ranged from 20–26.9 µm. Oospores plerotic to semi-aplerotic, globose, size ranged 17.1–24.8 µm. Copious oospores produced but about 60% aborted after the formation the wall. Oospores often aborted after formation of the walls. Antheridia amphigynous often with digitate projections.
Most typical characters
Additional specimen(s) evaluated
Viet Nam, Yen Bai, Van Yen, rhizosphere soil from Cinnamomum cassia plantations, 2018, Q.N. Dang, QD12; water from Cinnamomum cassia plantations QD30; QD32
Hosts and distribution
Disease note: root rot of Cinnamomum cassia, in conjunction with P. cinnamomi
Host: Cinnamomum cassia
Additional references and links
Fact sheet author
Treena Burgess, Ph.D., Phytophthora Science and Management, Harry Butler Institute, Murdoch University