Título:	Caracterização morfo-molecular e patogenicidade dos isolados de Phytophthora e Lasiodiplodia causando doenças em cacaueiro no Equador
Outros títulos:	Morpho-Molecular characterization and pathogenicity of Phytophthora and Lasiodiplodia isolates causing cocoa tree diseases in Ecuador
Autor(es):	Zambrano, Sergio Miguel Vélez
Orientador(es):	Pinho, Danilo Batista
Assunto:	Cacaueiro - doenças e pragas Phytophthora Lasiodiplodia theobromae Equador
Data de publicação:	6-Ago-2025
Data de defesa:	5-Abr-2024
Referência:	ZAMBRANO, Sergio Miguel Vélez. Caracterização morfo-molecular e patogenicidade dos isolados de Phytophthora e Lasiodiplodia causando doenças em cacaueiro no Equador. 2024. 145 f., il. Tese (Doutorado em Fitopatologia) — Universidade de Brasília, Brasília, 2024.
Abstract:	The cocoa tree (Theobroma cacao L.) is the most important species of the genus Theobroma due to its wide geographical distribution and global marketing of chocolate produced from the pods. Ecuador occupies the seventh position in the world among cocoa producing countries. The Coast region is the main cocoa producing region of Ecuador, with its culture cultivated in 16 of 24 provinces. Cocoa grown in the coastal region has high productivity and incidence of diseases such as black pod rot and dieback. Black pod rot and canker are caused by Phytophthora spp., while a complex of Lasiodiplodia spp. causes dieback. The precise identification of these pathogens has been carried out by comparison of morphological characteristics in combination with molecular data from different genomic regions. This approach reveals the discovery of new species and/or new of pathogens in various agricultural cultures. Based on this information, it is believed that black pod and dieback of cacao in Ecuador are caused by different species of Phytophthora and Lasiodiplodia, respectively. Therefore, the objectives of this work are: (i) identify the species of Phytophthora associated with the black pod, (ii) identify the species of Lasiodiplodia associated with dieback, (iii) determine the pathogenicity and aggressiveness of the isolates of Phytophthora and Lasiodiplodia and (iv) update the list of pathogens associated with cocoa in Ecuador. Pods with symptoms of black pod and plant tissues with symptoms of dieback were collected in the provinces of Esmeraldas, Guayas, Los Ríos, Manabí, Morona Santiago, Pichincha, and Santo Domingo de los Tsáchilas for indirect isolation. For prior identification, the partial region of the β-tubulin gene (Phytophthora spp.) or elongation factor (Lasiodiplodia spp.) was amplified and sequenced. Subsequently, representative isolates were selected for additional sequencing of the genomic regions ITS and COX2 for Phytophthora spp., and ITS, β -TUB, and RPB2 for Lasiodiplodia spp. The nucleotide sequences were compared and added to the GenBank database for Bayesian Inference (BI) analyses. Among the 181 isolates of Phytophthora collected from pods and stems, only P. palmivora was identified. Phylogenetic analyses confirm that the 166 isolates of Lasiodiplodia belong to the species L. theobromae, L. pseudotheobromae, L. brasiliensis, and L. laeliocattleyae, being that the last two were only reported for the first time as the causal agent of dieback of cacao. All species found were pathogenic. The clarification of the etiology of black pod rot, canker, and dieback is essential for the direction of the programs of improvement and efficient control of cacao diseases in Ecuador.
Unidade Acadêmica:	Instituto de Ciências Biológicas (IB) Departamento de Fitopatologia (IB FIT)
Informações adicionais:	Tese (doutorado) — Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Fitopatologia, 2024.
Programa de pós-graduação:	Programa de Pós-Graduação em Fitopatologia
Licença:	A concessão da licença deste item refere-se ao termo de autorização impresso assinado pelo autor com as seguintes condições: Na qualidade de titular dos direitos de autor da publicação, autorizo a Universidade de Brasília e o IBICT a disponibilizar por meio dos sites www.bce.unb.br, www.ibict.br, http://hercules.vtls.com/cgi-bin/ndltd/chameleon?lng=pt&skin=ndltd sem ressarcimento dos direitos autorais, de acordo com a Lei nº 9610/98, o texto integral da obra disponibilizada, conforme permissões assinaladas, para fins de leitura, impressão e/ou download, a título de divulgação da produção científica brasileira, a partir desta data.
Agência financiadora:	Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) e Organização dos Estados Americanos (OEA).
Aparece nas coleções:	Teses, dissertações e produtos pós-doutorado

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