Identificação e patogenicidade de Choanephoraceae

• Ano de defesa: 2023
• Autor(a) principal: Ulsenheimer, Isabela
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Mato Grosso; Brasil; Instituto de Ciências Agrárias e Ambientais (ICAA) – Sinop; UFMT CUS - Sinop; Programa de Pós-Graduação em Agronomia
• Palavras-chave em Português: Filogenia; Gossypium hirsutum; Adenium obesium; Choanephora sp.; Regiões gênicas; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA; Phylogeny; Gene regions
• Link de acesso: http://ri.ufmt.br/handle/1/5689

The genus Choanephora was first described in 1873 (Currey) and belongs to the family Choanephoraceae. Studies show that only conserved gene regions are used to identify Choanephora spp. and therefore, using non-conserved regions is important to verify the genetic diversity that the genus may have. Choanephora spp. have been reported in several hosts, causing major crop damage. Thus, the work was carried out with the objective of seeking alternative genomic regions for the identification of species of the Choanephoraceae family from 26 isolates, in addition to verifying the pathogenicity of Choanephora sp. nov., C. infundibulifera, C. cucurbitarum, Poitrasia circinans and Blakeslea trispora in cotton and Choanephora sp. nov. in desert rose. In the molecular analyses, monohyphal cultures were used for DNA extraction and amplification of the following regions: ITS, LSU, ACT, RPB2 and MCM7. Pathogenicity was performed by inoculation of mycelium discs in cotton plants and spore suspension in desert rose plants. The molecular analysis revealed the occurrence of the species: Blakeslea trispora, Poitrasia circinans, Choanephora infundibulifera and C. cucurbitarum, but in addition, it proposed the existence of a new species of the genus Choanephora sp. nov. Regarding pathogenicity, C. cucurbitarum, C. infundibulifera and Choanephora sp. nov. were pathogenic to cotton, causing abortion of apples (66.66%, 58.33% and 75.00%, respectively). The symptoms in cotton were wilting and watery rot of flowers and miscarriage of apples. The presence of signs of the phytopathogen was also observed. This test, together with the phylogeny, allows us to confirm the first report of pathogenicity of C. infundibulifera, C. cucurbitarum and Choanephora sp. nov. in cotton cultivation in Brazil. In desert rose, Choanephora sp. nov. caused destruction of flowers and flower buds in three days, with significant miscarriage of these structures above 65%. Symptoms of rot and discoloration were also observed.