Name and publication
Phytophthora siskiyouensis Reeser & Hansen (2008)
Reeser PW, Hansen EM, and Sutton W. 2008. Phytophthora siskiyouensis, a new species from soil, water, myrtlewood (Umbellularia californica), and tanoak (Lithocarpus densiflorus) in southwestern Oregon. Mycologia 99: 639–643.
Corresponding author: reeserp@science.oregonstate.edu
Nomenclature
from Reeser et al. (2008)
Mycobank
Etymology
refers to the Siskiyou Mountains in SW Oregon where the new species was first identified
Typification
Type: UNITED STATES OF AMERICA collected from a seasonal tributary to the Chetco River, Curry County, Oregon in March 2003; type: WA5-030403
Ex-type: ATCC MYA-4187 = WA5-30403 = CBS 122779, P15122 WPC
Sequences for ex-type in original manuscript: WA5-030403 = ITS rDNA EF523386
Ex-type in other collections
ATCC MYA-4187 = WA5-30403 = CBS 122779, P15122 (WPC) = CPHST BL 56 (Abad), 41B7 (Yang)
Molecular identification
Voucher sequences for barcoding genes (ITS rDNA and COI) of the ex-type (see Molecular protocols page)
Phytophthora siskiyouensis isolate CPHST BL 56 (= P15122 WPC) = ITS rDNA MG865586, COI MH136978
Sequences for ex-type in other sources
- NCBI: Phytophthora siskiyouensis CPHST BL 56
- NCBI: Phytophthora siskiyouensis P15122 WPC
- Phytophthora Database: Phytophthora siskiyouensis PD_01635 = P15122
- EPPO-Q-bank: Phytophthora siskiyouensis CBS 122779
- BOLDSYSTEMS: Phytophthora siskiyouensis (barcoding COI & ITS)
Position in ITS phylogenetic tree
Clade 2
Morphological identification
adapted from Reeser et al. (2008)
Colonies and cardinal temperatures
Colony after 7 days of growth on potato dextrose agar, malt extract agar, and V8A with chrysanthemum pattern. Minimum growth temperature 3°C, optimum 21–25°C, and maximum 27°C.
Conditions for growth and sporulation
Sporangia formed abundantly on agar culture pieces placed in stream water; oogonia formed abundantly on V8A.
Asexual phase
Sporangia semipapillate, some with two and more rarely with three papilla; persistent or caducous with variable pedicel length (2–66 µm L); ovoid, ellipsoid, reniform (or kidney), distorted shapes (26–95 L x 23–50 W µm); hyphal swellings small, often associated with sporangiophore; sporangia originated terminal but often subterminal and occasionally intercalary in unbranched or simple sympodial sporangiophores. Hyphal swellings absent. Chlamydospores absent.
Sexual phase
Homothallic. Oogonia globose to subglobose (23–42 µm diam), occasionally much elongated or with a funnel shape tapering toward the stalk, frequently sessile and occasionally laterally intercalary; antheridia predominately paragynous, spherical, ellipsoid or ovoid, club-shaped (10–18 L x 8–13 W µm), terminal, occasionally intercalary and usually diclinous, attached anywhere on the oogonium; oospores globose to subglobose (19–33 µm diam) and usually aplerotic.
Most typical characters
Phytophthora siskiyouensis can be distinguished by the shape of the terminal and intercalary sporangia, and the shape of the antheridia.
Additional specimen(s) evaluated
Phytophthora siskiyouensis CPHST BL 56, duplicate of ex-type P15122 (World Phytophthora Collection)
Hosts and distribution
Distribution: Europe (England), North America (USA: OR)
Substrate: stems
Disease note: associated with cankers, pathogenicity little known
Host: Lithocarpus densiflorus (Fagaceae), Umbellularia californica (Lauraceae)
Retrieved February 01, 2018 from U.S. National Fungus Collections Nomenclature Database.
Additional info:
Substrate: rhizosphere
Additional references and links
- Phytophthora DATABASE: Phytophthora siskiyouensis
- EPPO-Q-bank: Phytophthora siskiyouensis
- SMML USDA-ARS: Phytophthora siskiyouensis
- EPPO Global Database: Phytophthora siskiyouensis
- Forest Phytophthoras of the world: Phytophthora siskiyouensis
- CABI Invasive Species Compendium: Phytophthora siskiyouensis
- Encyclopedia of Life (EOL): Phytophthora siskiyouensis
- Index Fungorum (IF): Phytophthora siskiyouensis
- Plantwise Knowledge Bank: Phytophthora siskiyouensis
- Google All Phytophthora siskiyouensis
- Google Images Phytophthora siskiyouensis
- Google Scholar Phytophthora siskiyouensis
Fact sheet author
Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America