Name and publication
Phytophthora podocarpi K. Dobbie, R.L. McDougal & P.M. Scott (2022)
Dobbie K, Scott P, Taylor P, Panda P, Sen D, Dick M, McDougal R. 2022. Phytophthora podocarpi sp. nov. from siseased needles and shoots of Podocarpus in New Zealand. Forests 13 (2): 214
Nomenclature
Mycobank
MB841407
Etymology
‘podocarpi’ refers to Podocarpus, the host genus of this oomycete
Typification
Type: NEW ZEALAND, Gisborne, Hampton Forest, from needles of Podocarpus totara, July 2011, BJ Rogan. holotype NZFRIM 5991
Ex-type: ICMP 24118 = NZFS 3642
Sequences of ex-type in manuscript: genome sequence GenBank LGSN00000000
Molecular identification
Position in ITS phylogenetic tree
Clade 15
Morphological identification
Colonies and cardinal temperatures
Very slow growing, slightly felted with slight striate pattern on CA. Minimum growth temperature 2°C, optimum 17°C, and maximum 25°C.
Conditions for growth and sporulation
Sporangia are produced after 24–36 h in pond water. Oogonia rare in single-strain culture on CA and V8 after about 8 weeks.
Asexual phase
Sporangia were non to semi-papillate, both persistent and caducous, and predominantly ovoid in shape with no proliferation. Sporangia averaged 55.7 x 37 µm (overall range 47.6–64.5 x 31.3–41.1 µm). Sporangiophores simple or loose sympodia. Hyphal swellings present. Chlamydospores absent.
Sexual phase
Homothallic. Oogonia had smooth walls and size ranged from 25–30 µm Oospores plerotic, globose often with a tapering base and light golden brown on maturity, size ranged 22–27 µm. Oogonial stalk often globose, occasionally with digitate projections. Antheridia absent or paragynous.
Most typical characters
In phylogenetic analysis, P. podocarpi falls between clade 3 and clade 5 and has been placed in the new clade 15 along with Perenospora hyoscyami.
Additional specimen(s) evaluated
New Zealand, Gibsborne, Hampton Forest, Western Cape Province, from needles of Podocarpus totara, 2011, NZFS 3603, NZFS 3645, NZFS 3768; Gisborne, Mata Forest, 2012, NZFS 3702; 2014, NZFS 4074; Northland, Pipiwai Forest, 2012, NZFS 3727; Taranaki, Otunui Forest, 2017, NZFS 4473; Hawkes Bay, Crystals Forest, 2017, NZFS 4525; Bay of Plenty, Kinleith Forest, NZFS 4526
Hosts and distribution
Distribution: New Zealand
Substrate: leaves (needles)
Disease note: needle and shoot blight of Podocarpus totara
Host: Podocarpus totara
Additional references and links
none available
Fact sheet author
Treena Burgess, Ph.D., Phytophthora Science and Management, Harry Butler Institute, Murdoch University