Eficiência do tamanho de populações F2 na análise de QTL

• Autor(a) principal: Ferreira, Eliel Alves
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1346
• topic: Característica quantitativa; Tamanhos populacionais; QTL fantasma; Quantitative traits; Population size; Ghost QTL; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL

Since the work done by Mendel, genetics has been developing quickly. Were established relations between chromosomes and genes, the molecular markers association and phenotypic characteristics, production of gene maps, detection of genes controlling quantitative traits (QTL), among others with the advent of genomics. Studies using molecular markers, especially when it seeks to detect QTL, population size is of paramount importance, because the higher the population the more accurate detection. Another important point is to prevent ghost QTL detection, which is a false positive. The objective this work was to study the QTLs detection, using simulated data, referent to population size and prevention of ghost QTLs in F2 populations. Two scenarios were simulated. zTo determine what population size is more efficient, four sizes were simulated (200, 400, 600 and 1000 individuals) with the same characteristics, for the first scenario. Were simulated, for the second scenario, a population of 1000 individuals. It was simulated a genotype with four linkage groups containing two QTLs in three groups and in one group does not contain QTL. In linkage groups 1, 2 and 3, contained two QTLs of large effect, one large and one small end and two small effect, respectively. For QTLs detection, it were used the methodologies of simple mark, simple and composite interval. Were observed that the larger the population size, the better was positioning of QTL and therefore that of 1000 individuals achieved the best results. In the second scenario, it was found that the method of composite interval is more effective in preventing ghost QTL and that the smaller the effect of the QTL more probability find ghost QTL.