Phytophthora infestans (to be updated 2022)

Name and publication

Phytophthora infestans (Mont.) de Bary (1876)

De Bary A. 1876. Researches into the nature of the potato fungus – Phytophthora infestans. Journal of the Royal Agricultural Society XII (IX): 240–242 (pg. 240).





Botrytis infestans Mont., Bulletin de la Société Philomatique de Paris 13: 313 (1845) [MB226630]
Peronospora infestans (Mont.) Casp. (1852) [MB179737]


Holotype for Botrytis infestans: FRANCE, from leaves of Solanum tuberosum “Sur les fanes de pomme de terre” M. Vernois, collected by Herbier Montagne, deposited by Hi. C. Montagne on 18.8.1845 FUSION94490 in Muséum d´e histoire naturelle de Paris

Ex-type: LOST

Well-authenticated specimen selected by Gloria Abad: 
CPHST BL 142 (Abad) = P1381 (WPC)

Molecular identification

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

Phytophthora infestans isolate CPHST BL 142 (= P1381 WPC) = ITS rDNA MG865512, COI MH136906

Phytophthora infestans isolate CPHST BL 143 (= P19941 WPC) = ITS rDNA MG865513, COI MH136907

Phytophthora infestans isolate CPHST BL 19 (= P10650 WPC) = ITS rDNA MG865514, COI MH136908

Sequences for selected specimens in other sources
Position in phylogenetic tree

Clade 1c

Genome sequence

Phytophthora infestans strain ex-epitype T30-4. Accession genome ASM14294v1 reference, BioProject PRJNA17665, Broad Institute of MIT and Harvard (2009), Haas et al. 2009

Haas, B.J., Kamoun, S., Zody, M.C., et al. 2009. Genome sequence and analysis of the Irish potato famine pathogen Phytophthora infestans. Nature 461: 393–398.

Morphological identification

Colonies and cardinal temperatures

Colony morphology on V8-A, PDA, and MEA with non-distinct pattern and slow growth. The minimum temperature for growth is 4°C, optimum 18°C, and maximum 24°C.

Asexual phase

Sporangia semipapillate; caducous with short pedicelovoid, ellipsoid or limoniform (15–48 µm long x 12–30 µm wide); some intercalary sporangia; sporangia originated in compound sympodial sporangiophores. Hyphal swellings small, typically produced in the sporangiophoresChlamydospores absent.

Sexual phase

Heterothallic. Oogonia smooth-walled (22–43 µm diam.); antheridia amphyginous, elongated cylindrical or ellipsoid; oospores predominantly plerotic (20–40 µm diam.).

Specimen(s) evaluated

Phytophthora infestans CPHST BL 142 = P1381 (World Phytophthora Collection)

CPHST BL 19 = P10650 (WPC)

CPHST BL 143 = P19941 (WPC)

Hosts and distribution

Distribution: cosmopolitan
Substrate: tubers, leaves, haulms of potato and tomato; also stems, flowers, fruits, buds on other hosts
Disease note: late blight of potato and tomato; overwinters in tubers; several races occur; also causes leaf blights and, rarely, damping off, flower, and fruit blight in a wide range of hosts
Host: Principal hosts are Solanaceae including Solanum spp. (potato) and Lycopersicon esculentum (tomato). Also occurs on hosts in 15 other genera and in ten other families (Erwin & Ribeiro 1996).

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

Additional references and links

De Bary A. 1876. Researches into the nature of the potato fungus – Phytophthora infestans. Journal of the Royal Agricultural Society XII (IX): 239–268 (pg. 240).

Berkeley MJ. 1846. Observations, botanical and physiological on the potato murain. J. Hortic. Soc. Lond. 1: 9–34.

Montagne C. 1845. Sur la maladie qui ravage les pommes de terre. L´Institut (Journal universel des Sciences et Sociétés savants françaises et étrangéres, 1re sect. Sciences mathématiques, physiques et naturelles) 13: 312–314.

Semal J, Joly P, Lamy D. 1982. Etude de l'herbier de Camille Montagne relatif au Phytophthora infestans (Mont.) de Bary (Botrytis infestans Mont.). Bulletin des recherches agronomiques de Gembloux 17: 295–306.

Fact sheet author

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