Phytophthora sansomeana

Name and publication

Phytophthora sansomeana Hansen & Reeser (2009)

Hansen EM, Wilcox WF, Reeser PW, and Sutton W. 2009. Phytophthora rosacearum and P. sansomeana, new species segregated from the Phytophthora megasperma "complex". Mycologia 101: 129–135.

Corresponding author: hansene@science.oregonstate.edu

Nomenclature

from Hansen et al. (2009)

Mycobank

MB499443

Etymology

The name commemorates Dr Eva Sansome, whose astute cytological observations established the diploid nature of Phytophthora and other oomycetes.

Typification

Type: UNITED STATES OF AMERICA, collected from soybean in Indiana by Reeser, isolate OSU 1819B holotype in Herbarium OSC (dried culture)

Ex-type: ATCC MYA-4455

Sequences for ex-type in original manuscript: OSU 1819B = ITS rDNA EU925375

Ex-type in other collections

MYA-4455 (= 1819B) = P8051 (WOC/WPC), CPHST BL 55 (Abad), CBS 117693, 47H3 (Hong)

Molecular identification

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

Phytophthora sansomeana isolate CPHST BL 55 (= P8051 WPC) = ITS rDNA MG865585, COI MH136977

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

Clade 8a

Morphological identification

adapted from Hansen et al. (2009)

Colonies and cardinal temperatures

Colony after 7 days of growth on potato dextrose agar, malt extract agar with slight chrysanthemum pattern, and in V8 agar with no distinct pattern. Minimum growth temperature 3°C, optimum 24–30°C, and maximum 33°C.

Conditions for growth and sporulation

Sporangia form in water; hyphal swellings are sometimes observed in old water cultures.

Asexual phase

Sporangia nonpapillate, persistent; ovoid, obpyriform, ellipsoid, obovoid (30–53 L x 19–40 W µm) some with distorted shapes and some with tapered bases; presenting internal proliferation, produced on long, unbranched or loosely sympodial sporangiophores. Hyphal swellings globose, subglobose, with radiating hyphae produced on clusters or catenulated. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth-walled, globose (25–52 µm diam); antheridia small (6–24 L x 9–16 W µm) predominately amphigynous and sometimes with digitate projections; oospores globose (23–44µm diam) plerotic, aplerotic, or slightly aplerotic.

Additional specimen(s) evaluated

Phytophthora sansomeana ex-type CPHST BL 55, duplicate of P8051 (World Phytophthora Collection), which is a duplicate of ex-type ATCC MYA-4455

Hosts and distribution

Distribution: North America (USA), Asia (China)
Substrate: roots, collar
Disease note: root rot
Host: Glycine max (Fabaceae), various other hosts

Retrieved February 01, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional info:
Substrate:
rhizosphere

Additional references and links

Fact sheet author

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