Phytophthora caryae

Name and publication

Phytophthora caryae Brazee, Yang & Hong (2016)

Brazee NJ, Yang X, and Hong CX. 2016. Phytophthora caryae sp. nov., a new species recovered from streams and rivers in the eastern United States. Plant Pathology 66: 805–817.

Corresponding author:


from Brazee et al. (2016)




refers to Carya, the first host genus discovered


Type: UNITED STATES OF AMERICA collected in Deerfield, Massachusetts, baited with a rhododendron leaf from the Connecticut River, June 2013, N.J. Brazee; holotype ATCC TSD-54

Ex-type: NJB2013-AF-08, 67F4

Sequences for ex-type in original manuscript: isolate NJB2013-AF-08 ITS KJ631538, β-Tub KJ631572, TEF KU695515, COX1 KJ631586, Nadh1 KU695483

Ex-type in other collections

NJB2013-AF-08 = 67F4 

Molecular identification

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

Phytophthora caryae isolate NJB2013-AF-08 ITS rDNA KJ631538

Sequences for ex-type in other sources
  • NCBI: Phytophthora caryae NJB2013-AF-08
  • Phytophthora DATABASE: Phytophthora caryae 
  • EPPO-Q-bank: Phytophthora caryae 
  • BOLDSYSTEMS: Phytophthora caryae (barcoding COI & ITS)
Position in ITS phylogenetic tree

Clade 2c

Morphological identification

adapted from Brazee et al. (2016)

Cardinal temperatures

Minimum temparature to grow 10°C, optimum 22–25°C, maximum 35°C.

Conditions for growth and sporulation

Phytophthora caryae produce abundant sporangia after being submerged in 1.5% soil water extract for 15–20 h under light. Abundant gametangia produced in cV8A after 7 days.

Asexual phase

Sporangia semipapillate, sometimes bipapillate; persistent; ovoid, ellipsoid, obpyriform and with distorted shapes including peanut-shaped (33–82.6 µm length x 20.3–47.7 µm width); originated in simple sympodial sporangiophore; external proliferation common. Hyphal swellings common, and chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth-walled, frequently with tapered base (21.6–34.7 µm diam.); antheridia paragynous, globose to oval; oospores predominantly plerotic (18.2–29.4 µm diam.) and sometimes slightly aplerotic.

Hosts and distribution

Distribution: North America (USA: MA, NC)
Substrate: isolated from water
Disease note: mildly pathogenic on Carya (Juglandaceae) in innoculation experiments
Hosts: Carya (Juglandaceae)

Retrieved January 29, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

  • Phytophthora DATABASE: Phytophthora caryae
  • EPPO-Q-bank: Phytophthora caryae
  • SMML USDA-ARS: Phytophthora caryae
  • EPPO Global Database: Phytophthora caryae
  • CABI Invasive Species Compendium: Phytophthora caryae
  • Encyclopedia of Life (EOL): Phytophthora caryae
  • Index Fungorum (IF): Phytophthora caryae
  • Plantwise Knowledge Bank: Phytophthora caryae

Fact sheet author

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