Name and publication
Phytophthora gibbosa Jung, Stukely & Burgess (2011)
Jung T, Stukely MJC, Hardy GE StJ, White MD, Paap T, Dunstan WA, and Burgess TI. 2011. Multiple new Phytophthora species from ITS Clade 6 associated with natural ecosystems in Australia: evolutionary and ecological implications. Persoonia 13: 13–39.
Nomenclature
from Jung et al. (2011)
Mycobank
Etymology
refers to the gibbous ornamented surface of the oogonia (gibbosa Latin = gibbous, knaggy)
Typification
Type: WESTERN AUSTRALIA, Scott River ironstones, from rhizosphere soil of dying Acacia pycnantha, 2009, VHS, holotype MURU 461 (dried culture on V8A, Herbarium of Murdoch University, Western Australia)
Ex-type: CBS 127951 and VHS 21998
Sequences for ex-type in original manuscript: CBS 127951 = ITS rDNA HQ012933, HSP90 HQ012892, cox1 HQ012846
Ex-type in other collections
CBS 127951 = VHS 21998 = P19586 (WOC/WPC), CPHST BL 65 (Abad), 62B8 (Yang)
Molecular identification
Voucher sequences for barcoding genes (ITS rDNA and COI) of the ex-type (see Molecular protocols page)
Phytophthora gibbosa isolate CPHST BL 65 (= P19586 WPC) = ITS rDNA MG865499, COI MH136894
Sequences for ex-type in other sources
- NCBI: Phytophthora gibbosa CPHST BL 65
- NCBI: Phytophthora gibbosa CBS 127951
- Phytophthora DATABASE: Phytophthora gibbosa PD_02711
- EPPO-Q-bank: Phytophthora gibbosa CBS 127951
- BOLDSYSTEMS: Phytophthora gibbosa (barcoding COI & ITS)
Position in ITS phylogenetic tree
Clade 6b
Morphological identification
Colonies and cardinal temperatures
Colony morphology is uniform on V8A, CA, MEA, and PDA. Minimum growth temperature 7.5°C, optimum 30°C, and maximum 32.5°C.
Conditions for growth and sporulation
Sporangia are produced in water cultures (soil extract or river water) and not observed in solid media. Oogonia are formed readily in single-strain culture on CA and V8A after about 20 d.
Asexual phase
Sporangia are non-papillate, persistent, and ovoid or ellipsoid in shape. Sporangia average 48.8 ± 9.6 × 30.8 ± 5.4 μm (overall range 24.8–71.1 × 17.4–48.0 μm). Sporangiophores usually in simple sympodia with internal extended proliferation. External proliferation also observed leading to lax sympodia. Hyphal swellings are common. Chlamydospores absent.
Sexual phase
Homothallic. Oogonia are globose with wavy to ornamented gibbous walls turning golden-brown on maturity, average size 38.1 ± 5.4 mm (27.0–49.9 µm). Oospores are aplerotic, globose, with a large ooplast and thick walls, average size 31.4± 4.6 µm (18.9–39.4). Antheridia amphigynous.
Most typical characters
Phytophthora gibbosa can be easily differentiated from all other species from ITS Clade 6 (except Phytophthora ornamentata) by the production of ornamented (gibbous) oogonia in single culture. In addition, it can be separated from Phytophthora gregata and P. taxon raspberry by the lack of nested proliferation of sporangia.
Specimen(s) evaluated
Australia, Western Australia, Scott River ironstones, from rhizosphere soil of dying Acacia pycnantha, 2009, CBS 127951 = VHS 21998; VHS 22007; from dying Xanthorrhoea gracilis, VHS 21999; from a dying Grevillea sp., VHS 22008
CPHST BL 65 = P19586 WPC
Hosts and distribution
Distribution: Australia
Substrate: soil associated with dying plants, roots
Retrieved January 30, 2018 from U.S. National Fungus Collections Nomenclature Database.
Additional info:
Distribution: Western Australia
Substrate: roots, collars, and rhizosphere soil
Disease note: no pathogenicity trials have been conducted
Hosts: Acacia pycnantha, Xanthorrhoea gracilis, Grevillea sp.
Additional references and links
Burgess TI, Webster JL, Ciampini JA, White DW, Hardy GESJ, Stukely MJC. 2009. Re-evaluation of Phytophthora species isolated during 30 years of vegetation health surveys in Western Australia using molecular techniques. Plant Disease 93: 215–223.
- Phytophthora DATABASE: Phytophthora gibbosa
- EPPO-Q-bank: Phytophthora gibbosa
- SMML USDA-ARS: Phytophthora gibbosa
- EPPO Global Database: Phytophthora gibbosa
- Forest Phytophthoras of the world: Phytophthora gibbosa
- CABI Invasive Species Compendium: Phytophthora gibbosa
- Encyclopedia of Life (EOL): Phytophthora gibbosa
- Index Fungorum (IF): Phytophthora gibbosa
- Plantwise Knowledge Bank: Phytophthora gibbosa
- Google All Phytophthora gibbosa
- Google Images Phytophthora gibbosa
- Google Scholar Phytophthora gibbosa
Fact sheet authors
Treena Burgess, Ph.D., Centre for Phytophthora Science and Management, School of Biological Sciences and Biotechnology, Murdoch University, Australia; Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America