Phytophthora theobromicola

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.

Nomenclature

Mycobank

MB833783

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

Molecular identification

Position in ITS phylogenetic tree

Clade 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

Sporangia are produced in water cultures (non-sterile soil extract) after 24 h. Oogonia were not produced in paired cultures using several known tester strains.

Asexual phase

Sporangia were papillate, non-caducous, and predominantly obpyriform or ovoid in shape. Sporangia averaged 52.3 x 21.5 µm (overall range 27–76 x 21.5–45.5 µm). Sporangiophores simple. Hyphal swellings absent. Chlamydospores 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

none available

Fact sheet author

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