Name and publication
Phytophthora insulinativitatica Q.N. Dang, G. Hardy 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.
Nomenclature
Mycobank
MB836442
Etymology
referring to the locality (Christmas Island) where this species was recovered
Typification
Type: AUSTRALIA, Christmas Island, rhizosphere soil from disturbed rainforest, March 2016, G. Hardy, holotype MURU468
Ex-type: culture CBS 146553
Sequences of ex-type in manuscript: ITS KY212028, β-tubulin MT583631, hsp90 MT583676, cox1 MT583646, cox2 MT583661, nadh1 MT583691, rps10 MT583707
Molecular identification
Position in ITS phylogenetic tree
Clade 2a
Morphological identification
Colonies and cardinal temperatures
Colony morphology smooth and uniform on PDA, cottony and uniform on CA, stellate on MEA, produced a pattern of concentric circles on V8A. Minimum growth temperature 4°C, optimum 30°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 are formed readily in paired cultures on V8A after about 21 d.
Asexual phase
Sporangia were semi-papillate, caducous, and predominantly limoniform with no proliferation. Sporangia averaged 34.1 x 21.5 µm (overall range 25.4–45 x 16.1–28.8 µm). Sporangiophores umbellate and compound sympodia. Hyphal swellings present. Chlamydospores present.
Sexual phase
Heterothallic. Oogonia had smooth walls and size ranged from 20.3–32.5 µm. Oospores plerotic to semi-aplerotic, globose, size ranged 18.3–30.5 µm. Antheridia amphigynous.
Most typical characters
Phytophthora insulinativitatica resides in clade 2a most closely related to P. botryosa. The feature that most distinguishes P. insulinativitatica is the umbellate and compound symposia.
Additional specimen(s) evaluated
Australia, Christmas Island, rhizosphere soil from disturbed rainforest, 2016, G. Hardy, CBS 146553; CI21A
Hosts and distribution
Distribution: Australia (Christmas Island)
Substrate: rhizosphere soil
Disease note: no known disease
Host: disturbed rainforest vegetation
Additional references and links
none available
Fact sheet author
Treena Burgess, Ph.D., Phytophthora Science and Management, Harry Butler Institute, Murdoch University