Diversidade genética de populações naturais de Populus deltoides e Myrcia ovata e atividade antifúngica de óleos essenciais de M. ovata

• Ano de defesa: 2018
• Autor(a) principal: White, Larissa Alves Secundo
• Orientador(a): Blank, Arie Fitzgerald
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Agricultura e Biodiversidade
• Palavras-chave em Português: Diversidade biológica; Fungos fitopatogênicos; Essências e óleos essenciais; Populus deltoids; Myrcia ovata; Conservação e prospecção; Atividade antifúngica; Diversidade genética; Populus deltoides
• Palavras-chave em Inglês: Conservation and prospection; Antifungal activity; Genetic diversity
• Área do conhecimento CNPq: CIENCIAS AGRARIAS
• Link de acesso: http://ri.ufs.br/jspui/handle/riufs/11648

Populus deltoides is a native species widely distributed in the United States, commonly used in riparian recovery projects, being one of the main forest species used to obtain raw material to produce biofuels and cellulose. The first article aimed to evaluate the diversity and genetic structure of a natural population of P. deltoides using the Single Nucleotide Polymorphism (SNP) marker. For this purpose, DNA from lyophilized young leaves from 612 individuals distributed in 15 states of the central, southeastern, and eastern regions of the US was extracted and sequenced. Genetic diversity data were obtained by the SNPs. Myrcia ovata is a native species of the Brazilian Atlantic Forest. Studies on its medicinal properties began in 2010 and highlighted their economic potential. In the State of Sergipe, a few individuals were found in the municipality of Japaratuba-SE, in Restinga phytophysiognomy. A study has already been developed on their chemical characterization and antifungal activity. The second article aimed to evaluate the genetic diversity of the natural population of M. ovata by using Inter Simple Sequence Repeat (ISSR) markers. New leaves of 24 individuals were collected for DNA extraction, and the genetic diversity was performed using ISSR. This is the first report on the genetic characterization towards the exploration and conservation of this species. The similarity found between the individuals was considered as intermediate (0.38), and the MYRO-154, MYRO-175, and MYRO-175.1 individuals presented the highest variability. Finally, the third article aimed to evaluate the antifungal activity of five chemotypes of M. ovata essential oils, four major compounds, and three pure compounds. Leaves were dried in a kiln, and the essential oils were extracted by hydrodistillation with a modified Clevenger. After identification, the major compounds and the essential oils were analyzed for fungistatic and fungicidal potential against the fungi Colletotrichum acutatum, Plenodomus destruens, and Thielaviopsis paradoxa, respectively responsible for postbloom fruit drop (PFD), foot rot of sweet potato, and stem bleeding in coconut diseases. All treatments presented different toxicity levels against the three fungi. For C. acutatum, the essential oil from the individual MYRO-180 (nerolic acid + linalool chemotype) and its major compound showed lower Minimal Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC). For P. destruens, the essential oil from the individual MYRO-159 (nerolic acid chemotype) presented a lower MIC of 0.05 μL.mL-1, and the nerolic acid + linalool chemotype and its major compound presented an MCF of 0.07 μL.mL-1. For T. paradoxa, the major compound citral + (E)-nerolidol stood out with the lowest MIC and MFC. Linalool showed the lowest toxicity against the three tested fungi.