Association of Rhizoctonia theobromae with cassava witches’ broom outbreak in Brazil and genetic relatedness to Southeast Asian isolates
5 affiliations
- 1Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ), Inhoffenstraße 7B, 38124 Braunschweig, Germany
- 2Embrapa Mandioca e Fruticultura, Rua Embrapa, s/n, Centro, 44380000 Cruz das Almas, Brazil
- 3Embrapa Pecuária Sul, BR 153 Km 633 Vila Industrial, 96401970 Bagé, Brazil
- 4Embrapa Amapá, Rodovia Josmar Chaves Pinto, Km-5 n.2600, 68903419 Macapá, Brazil
- 5Embrapa Pesca e Aquicultura, Avenida ‘NS 10’ com a ‘LO 18’, Loteamento Água Fria 77008900 Palmas, Brazil
Abstract
Background: A new cassava disease outbreak was identified in indigenous communities in Oiapoque, Amapá, Brazil, characterized by stunting, proliferation of thin shoots, broom-like leaf formations, and apical dieback. These symptoms are consistent with Cassava Witches' Broom Disease (CWBD), previously reported in other regions of South America and Asia. Methods: Metagenomic profiling, molecular diagnostics, phylogenetic analyses, and multilocus genotyping were used to investigate microbial communities associated with symptomatic cassava plants. Results: Rhizoctonia (Ceratobasidium) theobromae was identified as the predominant fungal species associated with symptomatic plants. Genetic analyses indicated a close relationship between Brazilian isolates and Asian reference strains, suggesting a possible transcontinental introduction and supporting an association between R. theobromae and CWBD. This represents the first confirmed report of R. theobromae in Brazil, expanding its known geographic distribution in the Americas. Conclusion: The detection of this quarantine pathogen represents a potential threat to cassava production, food security, and preservation of indigenous cassava landraces in Brazil. These findings reinforce the need for surveillance, phytosanitary measures, and further studies on emerging fungal pathogens associated with cassava diseases.
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BibTeX
@article{oliveira2026association,
title = {{Association of Rhizoctonia theobromae with cassava witches’ broom outbreak in Brazil and genetic relatedness to Southeast Asian isolates}},
author = {Saulo Alves Santos de Oliveira and Samar Sheat and Paolo Margaria and Adilson Lopes Lima and Jackson de Araujo dos Santos and H. S. Rocha and Helton Fleck Silveira and Cristiane Ramos de Jesus and Stephan Winter},
journal = {Frontiers in Plant Science},
year = {2026},
month = may,
doi = {10.3389/fpls.2026.1799146},
url = {https://doi.org/10.3389/fpls.2026.1799146},
note = {CC BY},
}
RIS
TY - JOUR
TI - Association of Rhizoctonia theobromae with cassava witches’ broom outbreak in Brazil and genetic relatedness to Southeast Asian isolates
AU - Saulo Alves Santos de Oliveira
AU - Samar Sheat
AU - Paolo Margaria
AU - Adilson Lopes Lima
AU - Jackson de Araujo dos Santos
AU - H. S. Rocha
AU - Helton Fleck Silveira
AU - Cristiane Ramos de Jesus
AU - Stephan Winter
PY - 2026
DA - 2026/05/28
JO - Frontiers in Plant Science
DO - 10.3389/fpls.2026.1799146
UR - https://doi.org/10.3389/fpls.2026.1799146
AB - Background: A new cassava disease outbreak was identified in indigenous communities in Oiapoque, Amapá, Brazil, characterized by stunting, proliferation of thin shoots, broom-like leaf formations, and apical dieback. These symptoms are consistent with Cassava Witches' Broom Disease (CWBD), previously reported in other regions of South America and Asia. Methods: Metagenomic profiling, molecular diagnostics, phylogenetic analyses, and multilocus genotyping were used to investigate microbial communities associated with symptomatic cassava plants. Results: Rhizoctonia (Ceratobasidium) theobromae was identified as the predominant fungal species associated with symptomatic plants. Genetic analyses indicated a close relationship between Brazilian isolates and Asian reference strains, suggesting a possible transcontinental introduction and supporting an association between R. theobromae and CWBD. This represents the first confirmed report of R. theobromae in Brazil, expanding its known geographic distribution in the Americas. Conclusion: The detection of this quarantine pathogen represents a potential threat to cassava production, food security, and preservation of indigenous cassava landraces in Brazil. These findings reinforce the need for surveillance, phytosanitary measures, and further studies on emerging fungal pathogens associated with cassava diseases.
SN - 1664-462X
ER -