Phytophthora captiosa

Name and publication

Phytophthora captiosa Dick & Dobbie (2006)

Dick MA, Dobbie K, Cooke DEL, and Brasier CM. 2006. Phytophthora captiosa sp. nov. and P. fallax sp. nov. causing crown dieback of Eucalyptus in New Zealand. Mycol. Res. 110: 393–404.

Corresponding author e-mail: margaret.dick@ensisjv.co.nz

Nomenclature

from Dick et al. (2006)

Mycobank

MB356996

Etymology

‘captiosa’ = deceitful, referring to the deceitful nature of this pathogen and the disease it causes

Typification

Type: NEW ZEALAND, Bay of Plenty, Rotoehu Forest, from leaves of Eucalyptus salignae, 7 August 1992, C. Barr, NZFRI-M 5215 (New Zealand Forest Research Institute Herbarium – Mycology dry sample from C24242 = NZFS 310C)

Ex-type: NZFS 310C deposited at the New Zealand Forest Research Institute Culture Collection, Rotorua; also deposited at the International Collection of Micro-organisms from Plants, Auckland (ICMP 15576) and the World Phytophthora Collection, California (P10719)

Sequences for ex-type in original manuscript: Phytophthora captiosa NZFS 310C ITSrDNA DQ297402

Ex-type in other collections

NZFS 310C = P10719 (WPC) = CBS 119107, ICMP 15576, C24242, CPHST BL 11 (Abad), 46H7 (Yang)

Molecular identification

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

Phytophthora captiosa isolate CPHST BL 11 (= P10719 WPC) = ITS rDNA MG865469, COI MH136865

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

Clade 10a

Morphological identification

adapted from Dick et al. (2006)

Colonies and cardinal temperatures

Colonies on CA with stellate to rosaceous pattern. Minimal growth was seen at 2°C, optimum ca 25°C, and maximum 30°C.

Asexual phase

Sporangia nonpapillate, persistent; ovoid, ellipsoid (30–41 x 20–30 µm), showing both internal and external proliferation, originated in unbrached sporangiophores. No hyphal swellings or chlamydospores observed.

Sexual phase

Homothallic. Oogonia spherical, smooth-walled (30–43 µm diam), often exhibiting a tapered base; antheridia amphigynous, cylindrical to conical often with coiled hyphae at the base, occasionally two-celled (17–23 x 12–17 µm); oospores predominantly plerotic with thick wall up to 3 µm.

Most typical characters

Phytophthora captiosa is homothallic with amphigynous conical antheridia and nonpapillate sporangia

Additional specimen(s) evaluated

Phytophthora captiosa ex-type CPHST BL 11 duplicate of P10719 (World Phytophthora Collection)

Hosts and distribution

Distribution: New Zealand
Substrate: living leaves; also twigs, petioles, seed capsules, and peduncles
Disease note: associated with crown disease; causes premature leaf drop and twig dieback upon inoculation
Hosts: Eucalyptus botryoidesEucalyptus saligna (Myrtaceae)

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

Additional information:

P. captiosa causes a crown disease of Eucalyptus botryoides and E. saligna. Symptoms include leaf spots, petiole infection, and twig and small branch lesions.

Quarantine status

USA: This species was listed as a species of concern during the 2009 Phytophthora prioritization project conducted by USDA APHIS PPQ CPHST PERAL (Schwartzburg et al.).

Additional references and links

Fact sheet author

Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America