Phytophthora vignae (to be redescribed 2022)

Name and publication

Phytophthora vignae Purss (1957)

Purss GS. 1957. Stem rot, a disease of cowpeas caused by an undescribed species of Phytophthora. Queensland J. Agric. Anim. Sci. 14: 125–154.

Nomenclature

Mycobank

MB 303625

Typification

from Purss (1957)

Type: AUSTRALIA, collected from stem and root tissue of cowpea [Vigna sinensis (L.) Endl. Ex Hassk.] in Stuart Valley, Queensland

Ex-type: LOST

Well-authenticated specimen(s) selected by Gloria Abad: 
Selected specimen #1: CPHST BL 30 = P3019 (WPC) from AUSTRALIA in Vigna unguiculata (race 1)

Selected specimen in other collections

P3019 (WPC) = Pegg 20853 (race 1), CPHST BL 30 (Abad)

Molecular identification

Voucher sequences for barcoding genes (ITS rDNA and COI) of selected specimens (see Molecular protocols page)

Phytophthora vignae isolate CPHST BL 30 (= P3019 WPC) = ITS rDNA MG865598, COI MH136989

Sequences for selected specimen in other sources
Position in ITS phylogenetic tree

Clade 7b

Morphological identification

Colonies and cardinal temperatures

Colony morphology on CMA, PDA, V-8 with no distinct pattern. Minimum growth temperature 10°C, optimum 24°C, and maximum 32°C.

Conditions for growth and sporulation

Sporangia produced in distilled water following growth in pea broth. Chlamydospores and hyphal swellings produced in CMA and oat meal agar. Sexual stage produced abundantly in host tissue, oat meal agar, and corn meal agar.

Asexual phase

Sporangia nonpapillate; persistent; ovoid to obpyriform (27–72 µm length x 15–54 µm width) with tapered base and showing nested and extended proliferation; produced in unbranched and sometimes in simple sympodial sporangiophores. Hyphal swellings irregular, terminal, and intercalary. Chlamydospores terminal and intercalary, globose (12–21 µm).

Sexual phase

Homothallic. Oogonia smooth-walled (27–42 µm diam.); antheridia amphigynous, spherical to ovate; oospores aplerotic (24–32 µm diam.).

Specimen(s) evaluated

Phytophthora vignae CPHST BL 30, duplicate of P3019 (World Phytophthora Collection)

Hosts and distribution

Distribution: Asia, Australia
Substrate: stems, soil; also leaves, roots
Disease note: stem rot, leaf spot, may completely destroy root system
Host: natural hosts: Vigna unguiculata (Vigna sinensis, Fabaceae); Vigna angularis; (=Phaseolus angularis, Fabaceae, sometimes referred to Phytophthora vignae f.sp. adzukicola. Malus domestica (apple, Rosaceae) fruits can be infected when inoculated. Reports from a few other taxa.

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

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