Name and publication

Phytophthora theobromicola Pinho, Ramos-Sobrinho and Marelli (2021)

Decloquement J, Ramos-Sobrinho R, Elias SG, Britto DS, Puig AS, Reis A, Da Silva RA, Honorato-Júnior J, Luz ED, Pinho DB, Marelli JP. 2021. Phytophthora theobromicola sp. nov.: a new species causing black pod disease on cacao in Brazil. Frontiers in Microbiology 12: 537399.

Corresponding author: Danilo Batista Pinho danilopinho@unb.br; Jean-Philippe Marelli jean-philippe.marelli@effem.com

Nomenclature

Mycobank

MB 833783

Etymology

refers to only known host so far, Theobroma cacao

Typification

Type: BRAZIL, Bahia: Eunápolis, on pods of Theobroma cacao, July 2017, collected by R. Ramos-Sobrinho, holotype UB23904

Ex-type: culture CCUB1091

Sequences for ex-type in original manuscript: CCUB1091; ITS MT074263, β-tubulin MT074223, cox1 MW597344, HSP90 MT074287, EF1α MT074279, coxII MT074271

Ex-type in other collections

(ET) CCUB1091, ATCC 64859, ubadn 950

Molecular identification

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

Phytophthora theobromicola 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 theobromicola
• EPPO-Q-bank: Phytophthora theobromicola
• BOLDSYSTEMS: Phytophthora theobromicola

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
2b

Morphological identification

Colonies and cardinal temperatures

Colonies have chrysanthemum pattern on PDA, MEA, and V8A, and radiate on CA. Minimum growth temperature 10°C, optimum 25–30°C, and maximum 33°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
are produced in water cultures (non-sterile soil extract) after 24 h. OogoniaOogonia:
the female gametangium in which the oospore forms after fertilization by the antheridium
were not produced in paired cultures using several known tester strains.

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
were papillatepapillate:
pertaining to the production of a distinct papilla at the distal end of the sporangium (cf. nonpapillate and semipapillate)
, non-caducous, and predominantly obpyriformobpyriform:
inversely pear-shaped, i.e. with the widest part at the point of attachment (cf. pyriform)
or ovoidovoid:
egg-shaped, with the widest part at the base of the sporangium and the narrow part at the apex
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
averaged 52.3 x 21.5 µm (overall range 27–76 x 21.5–45.5 µm). Sporangiophores simple. Hyphal swellings absent. 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
present, abundant.

Sexual phase

Sterile in culture.

Most typical characters

Phytophthora theobromicola sp. nov. was historically recognized as P. citrophthora due to similar mycelial growth in different culture media and temperatures.

Additional specimen(s) evaluated

Brazil, Bahia: Igrapiúna, on pods of Theobroma cacao, July 2017, collector J. Honorato Júnior, culture CCUB1205; Porto Seguro, collector D. B. Pinho, culture CCUB1285; Barro Preto, collector J. Decloquement, culture CCUB1151

Hosts and distribution

Distribution: Brazil
Substrate: pods
Disease note: black pod disease of Theobroma cacao
Host: Theobroma cacao

Additional references and links

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

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.