Name and publication

Phytophthora asparagi Saude & Hausbeck (2012)

Granke LL, Saude C, Windstam ST, Webster BJ, and Hausbeck MK. 2012. Phytophthora asparagi Saude & Hausbeck, sp. nov. Persoonia 28: 146–147. In Crous et al. Fungal Planet description sheets: 107–127. Persoonia 28: 138–182

Nomenclature

Mycobank

MB569000

Etymology

named after the host from which it was isolated, Asparagus

Typification

Type: USA, Southwest Michigan, Asparagus officinalis, Spring 2006, C. Saude & M.K. Hausbeck, holotype CUP SP326 (Cornell herbarium)

Ex-type: SP326 = CBS 132095

Sequences for ex-type in original manuscript:  ITS EF185089, LSU JX064983

Ex-type in other collections

(ET) CBS 132095, NRRL 64320, ATCC MYA-4826, SP326, S&T BL 206 (Abad), 62C4 (Hong)

Molecular identification

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

Phytophthora asparagi ITS rDNA, COI

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 asparagi CBS 132095
• EPPO-Q-bank: Phytophthora asparagi
• BOLDSYSTEMS: Phytophthora asparagi

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
6e

Morphological identification

Colonies and cardinal temperatures

Colony colony:
assemblage of hyphae which usually develops form a single source and grows in a coordinated way
morphology appressed with stellate to rosaceous pattern on V8A. Minimum growth temperature 5°C, optimum 25°C, and maximum 30°C.

Conditions for growth and sporulation

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
produced on dilute V8 agar. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
are formed readily on V8A.

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
non-papillate, non-caducous, and predominantly ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
to obpryiform in shape. 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
ranged 20–60 x 10–35 µm;. Sporangiophores simple or loose sympodiasympodia:
a type of sporangiophore which appears simple, but where each successive sporangium develops on a branch behind and to one side of the previous apex, where growth has already ceased
. Hyphal swellings present. ChlamydosporesChlamydospores:
an asexual spore with a thickened inner wall that is delimited from the mycelium by a septum; may be terminal or intercalary, and survives for long periods in soil
absent.

Sexual phase

Homothallic. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
smooth-walled. OosporesOospores:
zygote or thick-walled spore that forms within the oogonium after fertilization by the antheridium; may be long-lived
pleroticplerotic:
pertaining to an oospore that fills the oogonium (cf. aplerotic)
, thick-walled, size ranged 25 – 45 µm. AntheridiaAntheridia:
the male gametangium; a multinucleate, swollen hyphal tip affixed firmly to the wall of the female gametangium (the oogonium)
amphigynousamphigynous:
pertaining to the sexual stage in which the antheridium completely surrounds the stalk of the oogonium (cf. paragynous)
.

Most typical characters

Morphologically similar to other species in Cladeclade:
a taxonomic group of organisms classified together on the basis of homologous features traced to a common ancestor
6.

Additional specimen(s) evaluated

USA, Southwest Michigan, Asparagus officinalis, 2004-2005, C. Saude & M.K. Hausbeck, 48 isolates (Saude et al. 2008)

Hosts and distribution

Distribution: USA, japan, China, Europe, Australia, New Zealand, South Africa
Substrate: crown, roots, and spear (Asparagus)
Disease note: water-soaked lesions on shoots slightly above or below the soil line (Asparagus)

Host: Asparagus (Asparagaceae), Pistacia lentiscus (Anacardiaceae), Juniperus phoenicea (Cupressaceae)

Additional references and links

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

Fact sheet author

Treena Burgess, Ph.D., Phytophthora Science and Management, Harry Butler Institute, Murdoch University, Australia

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