Phytophthora pisi

Name and publication

Phytophthora pisi Heyman (2013)

Heyman F, Blair JE, Persson L, and Wikström M. 2013. Root rot of pea and faba bean in southern Sweden caused by Phytophthora pisi sp. nov. Plant Dis. 97: 461–471.

Corresponding author: F. Heyman fredrik.heyman@slu.se

Nomenclature

from Heyman et al. (2013)

Mycobank

MB801280

Etymology

“Pisi” refers to the host plant pea, from which it was first isolated.

Typification

Type: SWEDEN, Skåne Län, Höganäs, isolated from roots of Pisum sativus, by M. Wikström in 1997; 97603 (?)

Ex-type: CBS 130350 and P19612 World Oomycete Collection

Ex-type in other collections

CBS 130350 = P19612 (WOC/WPC) = CPHST BL 133 (Abad), 60A4 (Yang)

Molecular identification

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

Phytophthora pisi isolate CPHST BL 133 (= P19612) ITS rDNA MG865567, COI MH477754

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

Clade 7b

Morphological identification

adapted from Heyman et al. (2013)

Colonies and cardinal temperatures

Colony morphology on V-8 agar, potato dextrose agar, and malt extract agar with no distinctive pattern and slow growth. Minimum temperature for growth 4°C, optimum 25–30°C, maximum 37°C.

Conditions for growth and sporulation

Sporangia and hyphal swellings produced in liquid media, and gametangia readily produced on culture media after 4 days.

Asexual phase

Sporangia nonpapillate; persistent; ovoid or ellipsoid (31–160 L x 17–45 W µm); showing occasionally internal nested or external proliferation and originated in unbranched or closely sympodial sporangiophores. Hyphal swellings globose and intercalary, formed in liquid cultures. Chlamydospores absent. 

Sexual phase

Homothallic. Oogonia smooth-walled, globose (24–47 µm diam.); antheridia amphigynous; oospores aplerotic (19–35 µm diam.).  

Most typical characters

Phytophthora pisi is characterized by the presence of nonpapillate sporangia and homothallic oogonia with aplerotic oospores.

Additional specimen(s) evaluated

Phytophthora pisi ex-type CPHST BL 133, duplicate of P19612 (World Phytophthora Collection)

Hosts and distribution

Distribution: Europe (Sweden)
Substrate: roots
Host: Pisum sativum (Fabaceae)

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

Additional references and links

Fact sheet author

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