Name and publication
Phytophthora cactorum (Lebert & Cohn) Schröter (1886)
Schröter J. 1886. pp. 129–256 (236). In: F. Cohn, Kryptogamen-Flora von Schlesien. Band 3, Heft 3, Pilze J.U. Kern's Verlag, Breslau, 1889, pp. 1–814.
Nomenclature
from Schroeter (1886)
Mycobank
Synonym(s)
≡ Peronospora cactorum Lebert & Cohn, Beiträge zur Biologie der Pflanzen 1: 182 (1872) [MB166699]
≡ Nozemia cactorum (Lebert & Cohn) Pethybr., Scientific Proceedings of the Royal Dublin Society 13: 566 (1913) [MB562134]
≡ Phloeophthora cactorum (Lebert & Cohn) G.W. Wilson, Mycologia 6 (2): 80 (1914) [MB453641]
= Phytophthora paeoniae D.C. Cooper & Porter, Phytopathology 18: 881 (1928) [MB273265]
Typification
Type: SLOVAKIA, Bratislava, in the garden of Jacobi, Type Figures: Peronospora cactorum was first identified on cacti in 1870 by Lebert and Cohn. Habitat, intercellular in the parequima of various diseased rotten cacti. Observed in the host 1868/9.
Ex-type: LOST
Well-authenticated specimen selected by Gloria Abad: CPHST BL 9 = P0714 (WPC) (Collection MUCL 9638)
Selected specimens in other collections
CPHST BL 9 (Abad) = P0714 (WPC) = CBS 231.30, ATCC200785, ATCC10091, Gallegly N93, MUCL 9638
Molecular identification
Voucher sequences for barcoding genes (ITS rDNA and COI) of selected specimens (see Molecular protocols page)
Phytophthora cactorum isolate CPHST BL 9 (= P0714 WPC) = ITS rDNA MG783385, COI MH136858
Additional sequences for molecular identification
ITS rDNA HQ261514 (isolate P0714), COI HQ261261 (isolate P0714)
Sequences for ex-epitype in other sources
- NCBI: Phytophthora cactorum CPHST BL 9
- NCBI: Phytophthora cactorum P0714
- NCBI: Phytophthora cactorum CBS 231.30
- Phytophthora DATABASE: Phytophthora cactorum PD00929 = P0714
- EPPO-Q-bank: Phytophthora cactorum CBS 231.30
- BOLDSYSTEMS: Phytophthora cactorum OOMYA2078-10 = CBS 231.30, PHYTO008-10 = P0714 (barcoding COI & ITS)
Position in ITS phylogenetic tree
Clade 1a
Morphological identification
Colonies and cardinal temperatures
Colonies in V8 agar, potato dextrose agar, and malt extract agar with no distinct pattern. The minimum temperature for growth is 4°C, the optimum 24°C, and the maximum 30°C.
Asexual phase
Sporangia papillate, caducous with short pedicels (less than 4 μm in length), ellipsoidal, obpyriform, ovoid, or globose (24–50 L x 19–36 W μm) borne in simple or in close or lax sympodial sporangiophores. Hyphal swellings absent. Chlamydospores terminal and intercalary, globose (17–55 μm diam).
Sexual phase
Homothallic. Oogonia smooth-walled and usually hyaline (19–38 µm diam); antheridia paragynous, nearly spherical to club-shaped, and nearly always applied close to the oogonial stalk; oospores plerotic and aplerotic (20–26 µm diam), with an average wall thickness of 2 μm.
Most typical characters
Phytophthora cactorum is characterized by its production of caducous sporangia with short pedicels and paragynous antheridia.
Specimen(s) evaluated
Phytophthora cactorum CPHST BL 9 (Abad) = P0714 [World Phytophthora Collection (WPC) California, USA]
Hosts and distribution
Distribution: cosmopolitan
Substrate: leaves, stems, fruits, roots
Disease note: damping off of seedlings, fruit rot, leaf and stem rot, collar and crown rot, stem canker, root rot (Waterhouse & Waterston 1966)
Host: at least 154 genera of vascular plants in 54 families (Waterhouse & Waterston 1966)
Retrieved May 18, 2018 from U.S. National Fungus Collections Nomenclature Database.
Quarantine status
There is no quarantine for Phytophthora cactorum, as it is very prevalent and widely distributed around the world.
Additional references and links
Phytophthora cactorum in OSU Phytophthora Online course: Training for Nursery Growers. Oregon State University.
- Phytophthora DATABASE: Phytophthora cactorum
- EPPO-Q-bank: Phytophthora cactorum
- SMML USDA-ARS: Phytophthora cactorum
- EPPO Global Database: Phytophthora cactorum
- Forest Phytophthoras of the world: Phytophthora cactorum
- CABI Invasive Species Compendium: Phytophthora cactorum
- Encyclopedia of Life (EOL): Phytophthora cactorum
- Index Fungorum (IF): Phytophthora cactorum
- Plantwise Knowledge Bank: Phytophthora cactorum
- Google All Phytophthora cactorum
- Google Images Phytophthora cactorum
- Google Scholar Phytophthora cactorum
Fact sheet author
Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America