Phytophthora ipomoeae

Name and publication

Phytophthora ipomoeae Flier & Grünwald (2013)

Grünwald NJ. 2013. Phytophthora ipomoea Flier & Grünwald, sp. nov. Fungal Planet 197. Persoonia 31: 264–265. In: Crous PW, et al. 2013. Fungal Planet description sheets: 154–213. Persoonia 31: 188–296.

Corresponding author: grunwald@science.oregonstate.edu

The holotype description of this previously published species P. ipomoeae Flier & Grünwald was invalid and is corrected here (Flier et al. 2002). 

Nomenclature

from Grünwald (2013)

Mycobank

MB805536

Typification

Type: MEXICO, Toluca, on leaves of Ipomoea longipedunculata (Convolvulaceae), 1999, W.G. Flier & N.J. Grünwald (holotype CBS H-21401)

Ex-type: CBS 109229 = PIC 99169 = MUCL 30219

Sequences for ex-type in original manuscript: CBS 109229 = ITS rDNA KF777191 and LSU KF777242 (provided by Nik Grunwald to G. Abad on 1.15.14 and not included in the 2013 Persoonia publication)

Sequence ITS rDNA AY770742 in the 2013 Persoonia publication is for selected specimen PIC 99165, not for the type PIC 99169. 

Ex-type in other collections

CBS 109229 = PIC 99169 = MUCL 30219 = P10225 (WOC/WPC), PD_00078, Fry 1-1, CPHST BL 21 (Abad), 31B5 (Yang)

Molecular identification

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

Phytophthora ipomoeae isolate CPHST BL 21 (= P10225 WPC) = ITS rDNA MG865518, COI MH136912

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

Clade 1c

Morphological identification

adapted from Grünwald (2013)

Colonies and cardinal temperatures

Species grows well on rye A agar (RA), cherry decoction agar (CA), potato dextrose agar (PDA), and oatmeal agar (OA). Growth inhibition is observed on V-8 Agar (V8). Minimum growth at approximately 11°C, optimum at 20°C, and maximum at 25°C.

Asexual phase

Sporangia semipapillate; caducous with short pedicel; ellipsoid, or obovoid (35–47.5 µm length); originated in compound sympodial and intermediate sporangiophore branches, with swellings where sporangia emerge. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth-walled, globose (32.5 µm diam.), frequently with tapered base; antheridia amphigynous; oospores plerotic (28.8 µm diam.).

Most typical characters

the presence of typical basal swellings on the sympodial sporangiophores

Additional specimen(s) evaluated

Phytophthora ipomoeae CPHST BL 21 = P10225 (World Phytophthora Collection)

Hosts and distribution

Distribution: North America (Mexico)
Substrate: leaves, stems
Disease note: leaf blight
Host: Ipomoea longipedunculata, Ipomoea purpurea (Convolvulaceae)

Retrieved January 31, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

Notes in Grünwald (2013): the holotype description of this previously published species P. ipomoeae Flier & Grünwald (Flier et al. 2002) was invalid and is corrected here. The species has more recently also been described on Ipomoea purpurea (Badillo-Ponce et al. 2004).

Flier WG, Grünwald NJ, Kroon LPNM, Van Den Bosch TBM, Garay-Serrano E, Lozoya-Saldana H, Bonants PJM, and Turkensteen LJ. 2002. Phytophthora ipomoeae sp. nov., a new homothallic species causing leaf blight on Ipomoea longipedunculata in the Toluca Valley of central Mexico. Mycol. Res. 106: 848–856.

Badillo-Ponce G, Fernández-Pavía SP, Grünwald NJ, Garay-Serrano E, Rodríguez-Alvarado G, and Lozoya-Saldaña H. 2004. First report of blight on Ipomoeae purpurea caused by Phytophthora ipomoeae. Plant Disease 88: 1283.

Fact sheet author

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