Phytophthora hibernalis (to be redescribed 2022)

Name and publication

Phytophthora hibernalis Carne (1926)

Carne WM. 1926. A brown rot of citrus in Australia (Phytophthora hibernalis n. sp.). Journal of the Royal Society of Western Australia 12: 13–42.





from Carne (1926)

Type: AUSTRALIA, on fruit, leaves, and smaller branches of Citrus spp. in Western Australia, South Australia, and probably Victoria, Queensland and Mediterranean Region (Carne 1925). The types of the new species are at present in the authors collections (page 43, Carne 1925).

Ex-type: LOST

Well-authenticated specimen selected by Gloria Abad: 
CPHST BL 41G = P3822 (WPC) from citrus (Citrus sinensis) AUSTRALIA

Selected specimen in other collections

CPHST BL 41G (Abad) = P3822 (WPC), CBS 114104, PD 011 050-11181, ATCC 56353, CMI13460, H. H. Ho, H17.1; Pinjarra, R. F. Dorpel WA648

Molecular identification

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

Phytophthora hibernalis isolate CPHST BL 41G (= P3822 WPC) = ITS rDNA MG865506, COI MH136900

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

Clade 8c

Genome sequence

Phytophthora hibernalis strain ex-epitype BL41G. Accession genome USDA_Phib_BL41_1.0 reference, BioProject PRJNA605765, USDA-APHIS-PPQ-S&T (2020), Srivastava et al 2022

Morphological identification

Colonies and cardinal temperatures

Colony morphology on V8-A, PDA, and MEA with no distinct pattern. Minimum growth temperature 6°C, optimum 15–21°C, and maximum 25°C.

Asexual phase

Sporangia semipapillate; caducous with medium to long pedicels (18–74 µm long); elongate, ellipsoid, ovoid, or obovoid (21–44 L x 13–22 W µm); produced in unbranched or in lax sympodial branching, or occasionally in umbellate sporangiophores. Hyphal swellings absent. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth-walled (24–36 µm diam); antheridia predominantly amphigynous, often intercalary, some with multiple radiating hyphae or spines; oospores plerotic (22–30 µm in diam).

Most typical characters

Phytophthora hibernalis is distinguished by the production of elongate, caducous sporangia with medium to long pedicels.

Specimen(s) evaluated

Phytophthora hibernalis CPHST BL 41G, duplicate of P3822 (World Oomycetes/Phytophthora Collection)

Hosts and distribution

Distribution: Africa (South Africa); Asia (Israel); Australasia; Europe; North America (USA: CA); Central America; Caribbean; South America (Argentina, Brazil, Venezuela)
Substrate: fruits, leaves, twigs
Disease note: brown rot of fruit; leaf and twig blight
Hosts: multiple hosts, foliage/fruits, primarily Citrus spp. (Rutaceae); on 11 genera in 9 families

Retrieved January 31, 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