Name and publication

Phytophthora himalsilva Vettraino, Brasier & A. Vannini (2011)

Vettraino AM, Brasier CM, Brown AV, and Vannini A. 2011. Phytophthora himalsilva sp. nov. an unusually phenotypically variable species from a remote forest in Nepal. Fungal Biol. 115: 275–287.

Corresponding author: vannini@unitus.it

Nomenclature

from Vettraino et al. 2011

Mycobank

MB517974

Etymology

refers to the area from which it was first isolated and described

Typification

Type: NEPAL, close to Seri, Bajura (district) isolated from rhizosphere of Quercus leuchotricophora in Oct. 2005. NP44. Holotype: CBS 128767

Ex-type: CBS 128753 and CBS 128754 (listed as isotypes)

Sequences for ex-type in original manuscript: Phytophthora himalsilva isolate 44 = ITS HM752784, β-tub HM752790, Cox1 HM752796

Ex-type in other collections

(ET) CBS 128767, WPC P19820, NP44,  S&T BL 102 (Abad), 61G2 (Hong) 

Molecular identification

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

Phytophthora himalsilva isolate CPHST BL 102 (= P19820 WPC) = ITS rDNA MG865507, COI MH136901

Voucher sequences for Molecular Toolbox with seven genes (ITS, β-tub, COI, EF1α, HSP90, L10, and YPT1

(see Molecular protocols page) (In Progress)

Voucher sequences for Metabarcoding High-throughput Sequencing (HTS) Technologies [Molecular Operational Taxonomic Unit (MOTU)]

(see Molecular protocols page) (In Progress)

Sequences with multiple genes for ex-type in other sources

• NCBI: Phytophthora himalsilva CPHST BL 102
• NCBI: Phytophthora himalsilva isolate 44
• EPPO-Q-bank: Phytophthora himalsilva CBS 128767
• BOLDSYSTEMS: Phytophthora himalsilva (barcoding COI & ITS)

Position in multigenic phylogeny with 7 genes (ITS, β-tub, COI, EF1α, HSP90, L10, and YPT1)

Clade clade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
2a

Morphological identification

adapted from Vettraino et al. (2011)

Colonies and cardinal temperatures

Colonies in PDA, V8A, or MEA with stellate to chrysanthemum pattern. Minimum temperature 9°C, optimum 20–27°C, maximum 31°C.

Conditions for growth and sporulation

Sporangia formed in pondwater or unsterilised soil leachate.

Asexual phase

SporangiaSporangia:
sac within which zoospores form, especially when water is cooled to about 10°C below ambient temperature; in solid substrates, sporangia usually germinate by germ tubes
papillatepapillate:
pertaining to the production of a distinct papilla at the distal end of the sporangium (cf. nonpapillate and semipapillate)
, sometimes bipapillate; frequently caducouscaducous:
pertaining to sporangia that become dislodged readily (i.e. deciduous) and separate from the sporangiophore (cf. persistent)
, with medium and short pedicels (5–17 µm long), subterminal or lateral; elongate, obpyriformobpyriform:
inversely pear-shaped, i.e. with the widest part at the point of attachment (cf. pyriform)
, limoniform, mouse-shaped, some with tapered bases; originated in unbranched or branched sporangiophores. Hyphal swellings absent. Chlamydospores absent.

Sexual phase

Homothallic. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
smooth-walled (27–28 µm diam); antheridiaantheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
spherical, either paragynousparagynous:
pertaining to the sexual stage in which the antheridium is attached to the side of the oogonium (cf. amphigynous)
or amphigynousamphigynous:
pertaining to the sexual stage in which the antheridium completely surrounds the stalk of the oogonium (cf. paragynous)
, rarely both; oosporesoospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
apleroticaplerotic:
pertaining to a mature oospore that does not fill the oogonium; i.e. there is room left between the oospore wall and oogonium wall (cf. plerotic)
, spherical (23–24 µm diam).

Most typical characters

Phytophthora himalsilva is characterized by the shape of the spherical small antheridiaantheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
and the sporangiasporangia:
sac within which zoospores form, especially when water is cooled to about 10°C below ambient temperature; in solid substrates, sporangia usually germinate by germ tubes
frequently with medium pedicels.

Additional specimen(s) evaluated

Phytophthora himalsilva ex-type CPHST BL 102, duplicate of P19820 (World Phytophthora Collection)

Hosts and distribution

Distribution: Asia (Nepal)
Substrate: rhizosphere soil
Host: Quercus leucotrichophora, Castanopsis (Fagaceae); Carpinus (Betulaceae); Cupressus (Cupressaceae)

Retrieved January 31, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

 

• SMML USDA-ARS: Phytophthora himalsilva
• EPPO Global Database: Phytophthora himalsilva
• Forest Phytophthoras of the world: Phytophthora himalsilva
• CABI Digital Library: Phytophthora himalsilva
• Encyclopedia of Life (EOL): Phytophthora himalsilva
• Index Fungorum (IF): Phytophthora himalsilva

 

• Google All Phytophthora himalsilva
• Google Images Phytophthora himalsilva
• Google Scholar Phytophthora himalsilva

Fact sheet author

Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Plant Pathogen Confirmatory Diagnostics Laboratory (PPCDL), United States of America.