Phytophthora elongata

Name and publication

Phytophthora elongata Rea, Stukely & Jung (2010)

Rea AJ, Jung T, Burgess TI, Stukely MJC, Giles E, and Hardy GE StJ. 2010. Phytophthora elongata sp. nov., a novel pathogen from the Eucalyptus marginata forest of Western Australia. Australas. Plant Path. 39: 477–491.

Corresponding author: tburgess@murdoch.edu.au

Nomenclature

from Rea et al. (2010)

Mycobank

MB515142

Synonymy

was referred to as P. sp.2 by Burgess et al. 2009

Etymology

refers to the occurrence of elongated sporangia

Typification

Type: WESTERN AUSTRALIA, Dwellingup, isolated from the rhizosphere of Eucalyptus marginata, April 2004, M. Stukely, MURU 453 dry culture in V8A agar preserved at Herbarium of Murdoch University, Western Australia

Ex-type: CBS 125799 (= VHS 13482)

Sequences for ex-type in original manuscript: Phytophthora elongata VHS 13482 = ITS rDNA GQ847754, CBS 125799 = COI: GQ847764 (deposited as COI but amplified with FM82, FM83 Martin and Tooley 2003, it should be called Cox1)

Ex-type in other collections

CBS 125799 = VHS 13482 = P19596 (WPC), CPHST BL 62 (Abad), 55C4 (Yang)

Molecular identification

Voucher sequences for barcoding genes (ITS rDNA and COI) of the ex-type (see Molecular protocols page)

Phytophthora elongata isolate CPHST BL 62 (= P19596 WPC) = ITS rDNA MG865485, COI MH136881

Sequences for ex-type in other sources
Position in ITS phylogenetic tree

Clade 2d

Morphological identification

Colonies and cardinal temperatures

Colony morphology is petaloid on CA, V8A, MEA, and PDA. Minimum growth temperature 5°C, optimum 25°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 14 d.

Asexual phase

Sporangia are semipapillate, persistent with varied shapes including markedly elongated. Normal sporangia average 45.8 ± 6.3 x 28.4 ± 3.5 mm (overall range 26–76 x 19–42 µm), elongated sporangia average 58.2 ± 12.7 mm x 24.5 ± 4.3 mm (overall range 34–90 x 16–40 µm). Sporangiophores in simple or lax sympodia with external proliferation. Hyphal swellings ellipsoid, but rare. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia are smooth-walled, often with a tapering base and long stalks, average size 31.2 ± 3.2 mm (20.9–41.5 µm). Oospores are both plerotic and aplerotic, globose, turning golden-brown on maturity, average size 27.4 ± 3.3 µm (17.9–37.8). Antheridia are paragynous.

Most typical characters

The most distinguishing feature of Phytopthora elongata are the unusually elongated sporangia after which it is named.

Specimen(s) evaluated

Australia; Western Australia, Dwellingup, from rhizosphere soil of dying Eucalyptus marginata, April 2004, M. Stukely, CBS 125799 = VHS 13482; VHS 13615; VHS 15078; VHS 13559; VHS 13663; from rhizosphere soil of Leucopogon propinquus, VHS 7134; Bridgetown, from rhizosphere soil of Patersonia xanthina, 1999, VHS 6362; Pemberton, from rhizosphere soil of Banksia grandis, 2006, VHS 16103

WPC = P19596, CPHST BL 62

Hosts and distribution

Distribution Australia (Western Australia and Victoria)
Substrate: roots, collars, and rhizosphere soil
Disease note: wilting, dieback
Hosts: numerous; including Eucalyptus marginata, Corymbia calophylla, Banksia grandis, Leucopogon propinquus, Dryandra squarrosa, Xanthorrhoea preissii, X. gracilis and Patersonia xanthina; wide host range

Retrieved January 29, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional info: pathogenic toward Eucalyptus marginata and Banksia grandis

Additional references and links

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