Phytophthora drechsleri (to be redescribed 2022)

Name and publication

Phytophthora drechsleri Tucker (1931)

Tucker CM. 1931. Taxonomy of the genus Phytophthora de Bary. Research Bulletin of the Missouri Agricultural Experiment Station 153: 1–208 (pg. 188).





≡ Phytophthora erythroseptica var. drechsleri (Tucker) Sarej., Annales de l'Institut Phytopathologique Benaki 2: 48 (1936) [MB353067]


from Tucker (1931)

Type: UNITED STATES OF AMERICA, Idaho, known only from the type isolated by Charles Drechsler from rotting tubers of Solanum tuberosum L, Tucker No 206 (according to Tucker 1931, original publication of the species)

Ex-type: LOST

Well-authenticated specimen(s) selected by Gloria Abad: CPHST BL 17 (A2) = P11637 (WPC) = Tucker, authentic isolate: UNITED STATES OF AMERICA, California, from Beta vulgaris var. altissima, collected by C.M. Tompkins, N0 114 = CBS 292.35, identified by C.M.Tucker, deposited by C.M. Tucker, Apr 1935

CPHST BL 140 (A1) = P1691 (WPC) from Chrysanthemum cinerariifolium, ARGENTINA

Tucker authentic isolate in other collections

CPHST BL 17 (Abad A2) = P11637 (WPC) = P1087 (WPC) = P11638 (WPC) = CBS 292.35ATCC 46724, P538 Cooke (SCRI), P41 (Gallegly), 23J5 (Yang)

NOTE: ATCC 46724 is P. cryptogea but was originally deposited as P. drechsleri.

CPHST BL 140 (Abad A1) = P1691 (WPC) = ATCC 15428, CBS 373.72, IMI 40499, Frezzi 619

Molecular identification

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

Phytophthora drechsleri isolate CPHST BL 17 (= P1087 WPC) = ITS rDNA MG865484, COI MH136879

Sequences for Tucker authentic specimen in other sources
Position in ITS phylogenetic tree

Clade 8a

Morphological identification

Colonies and cardinal temperatures

Colonies on V8-A, PDA, and MEA with no distinctive pattern, on PDA and MEA with very light chrysanthemum pattern. Minimum temperature for growth 3°C, optimum 27–33°C, and maximum 36°C.

Asexual phase

Sporangia nonpapillate, persistent, ellipsoid, ovoid, irregular shapes, and some with tapered bases (23–34 × 36–59 µm), showing internal and external proliferation, and originated in unbranched sporangiophores. Hyphal swellings globose, catenulate (rosary shape), and frequently clustered. Chlamydospores absent.

Sexual phase

Heterothallic. Oogonia with smooth wall, globose, some with slightly tapered bases (within antheridium), 25–40 µm diam.; antheridia amphigynous, oval (9–16 µm); oospores almost plerotic to aplerotic (22–35 µm diam) with thin walls (2.5 µm). 

Most typical characters

Phytophthora drechsleri is characterized by the typical hyphal swellings that are globose with rosary shape, frequently clustered, and produced in water cultures.

Specimen(s) evaluated

Phytophthora drechsleri CPHST BL 17 (A2), duplicate of P1087 (World Phytophthora Collection) (G. Abad selected specimen #1)

Phytophthora drechsleri selected specimen CPHST BL 140 (A1), duplicate of P1691 (World Phytophthora Collection) (G. Abad selected specimen #2)

Hosts and distribution

Distribution: cosmopolitan
Substrate: roots, stems, leaves, buds, flowers, fruits, tubers, bark of trunks
Disease note: primarily a root pathogen but also attacks ripening fruit for various crops; root rot, bark canker, fruit rot, stem rot, seedling blight
Hosts: multiple hosts. 113 genera in 40 families

Retrieved January 29, 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