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

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