Efeito da saturação e do tamanho de populações F2 e de retrocruzamento sobre a acurácia do mapeamento genético

• Autor(a) principal: Cruz, Eduardo Machado
• Data de Publicação: 2006
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1394
• topic: Simulação; QTL; Melhoramento vegetal; Simulation; QTL; Plant Breeding; CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA QUANTITATIVA

The objective of this work was to generate and analyze data of simulated genomes of F2 and backcrossed populations, and based on these data, to evaluate the optimum size of population samples for genetic mapping studies. F2 and backcrossed populations with seven sample sizes (50, 100, 150, 200, 400, 600 and 800 individuals) and four levels of saturation were generated (5, 10, 15 and 20 markers in each of the 10 linkage groups of 100 centimorgans). Simulations were performed using the GQMOL software (2005) and analyzed with both GENES (2004) and GQMOL (2005) software developed by Professor Cosme Damião Cruz, from the Department of General Biology at the Federal University of Viçosa, Viçosa, MG. The results led to the conclusion that the use of small samples, approximately 50 individuals, is completely impracticable, even with saturation of 5 cM per linkage group, which was the highest level of saturation used in this work, as well as it is unnecessary the use of samples above 400 individuals to attain map accuracy. Samples with small number of individuals do not allow the recovering of the exact number of species linkage groups and the correct order, neither the accurate estimation of the distance between pairs of loci. For F2 populations, the smallest sample sizes of 100, 150 and 200 individuals can be used for a complete recovery of the genome with saturations of 5; 6.66; and 10 cM respectively, and for backcrossed populations of 200 individuals in the first three levels of saturation and 800 in the saturation of 20 cM. If few individuals exist, above 100 though, to carry out an evaluation, reliable maps can be constructed, since saturation above 5 cM is used.