Proposta de metodologia para mapeamento de locos controladores de características oligogênicas

• Ano de defesa: 2007
• Autor(a) principal: Rocha, Rodrigo Barros
• Orientador(a): Araujo, Elza Fernandes de
• Banca de defesa: Martins Filho, Sebastião , Abad, Júpiter Israel Muro
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Mapeamento genético; QTL; OTL; Máxima verossimilhança; Características oligogênicas
• Palavras-chave em Inglês: Genetic mapping; QTL; OTL; Maximum likehood; Oligogenic traits
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/1365

Oligogenic traits are distinguished by their heritage ruled by higher effect genes and by their importance for the cultivated plants, with emphasis to the plant disease resistance heritage. The qualitative nature and epistatic interaction of these traits results in a heritage pattern that should not be interpreted thought traditional methods for QTL (Quantitative Trait Loci) detection. The investigation of methods which allow a better interpretation of the genetic information produced during the recombination is still one of the major objectives of QTL detection. The objective of this work is to purpose a method for detection of important loci related with the expression of oligogenic traits OTL (Oligogenic Trait Loci). This method, defined as Oligogenic Trait Mapping Method (O.T.M.M.), uses maximum likehood probability functions to obtain the r estimates of better adjustment to the observed data from the conditional probabilities of occurrence between the molecular markers and the OTL. The results show that the method was adequate for OTL detection in backcrossing and F2 populations. Comparative analysis with others QTL detection methodologies shows that O.T.M.M. has the more accurate r estimates of the distance between the molecular markers and the OTL loci. The necessity of previous knowledge about the heritage pattern of the traits in one of the main limitations in the study of oligogenic traits, and the not proper definition of the correct heritage pattern results in a decrease in the accuracy of the methodology. The O.T.M.M. does not need previous information of the markers order in the linkage groups and are not influenced by the presence of two QTL in the same linkage group. The focus in the analysis presumptions of the oligogenic heritage, the higher accuracy of the r estimates, obtained from the information contained in all genotypic classes, and the position of the OTL in the map, contribute to make O.T.M.M. a powerful tool the analysis of oligogenic traits.