Phytophthora pini

Name and publication

Phytophthora pini Leonian (1925)

Leonian LH. 1925. Physiological studies on the genus Phytophthora. American Journal of Botany 12: 444–498.




Synonym: Phytophthora citricola 


from Leonian (1925)

Holotype: UNITED STATES OF AMERICA, isolated from the roots of pinus (Pinus resinosa) in Minnesota by Roy G. Pierce in 1925 and sent to Leonian by Annie R. Gravatt; No. 372 (Leonian); VTMH 11737 (holotype) a dried culture deposited at the Massey Herbarium of Virginia Polytechnic Institute and State University in Blacksburg, Virginia

Isotype: CBS H-7639 deposited by L.H. Leonian, April 1925

Ex-isotype: CBS 181.25

Ex-isotype in other collections

CBS 181.25 = P3274 (WOC/WPC), ATCC 64532, VTMH 11737, IMI 77970, PD 06 03209133, P343 (WVU), CPHST BL 48 (Abad), 33J1 and 45F1 (Yang)

Molecular identification

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

Phytophthora pini isolate CPHST BL 48 (= P3274 WPC) = ITS rDNA MG865565, COI MH136957

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

Clade 2c

Morphological identification

Colonies and cardinal temperatures

Colony morphology after 7 days of growth on V8 agar and potato dextrose agar with no distinct pattern, and on malt extract agar with chrysanthemum pattern. Minimum temperature for growth is 5°C, optimum 25°C, and maximum 30°C. 

Conditions for growth and sporulation

Gametangia formed in different agar including V-8 clarified as well as in hemp seed agar, and in soil solution or in distilled water.

Asexual phase

Sporangia semipapillate; persistent; ovoid, globose, ellipsoid, bluntly ellipsoid, and irregular shapes (30–90 µm L x 22–50 µm W); produced in unbranched or in simple sympodial loose sporangiophore. Hyphal swellings small and irregular. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth-walled (22–42 µm diam.) sometimes with slight tapered base; antheridia predominantly paragynous, occasionally two or three antheridia per oogonium may be observed; oospores predominantly plerotic (20–34 µm diam.).

Specimen(s) evaluated

Phytophthora pini ex-type CPHST BL 48, duplicate of P3274 (World Phytophthora Collection), which is a duplicate of ex-type CBS 181.25

Hosts and distribution

Distribution: widespread
Substrate: roots
Disease note: root rot, canker
Host: Pinaceae

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