Desequilíbrio de ligação e mapeamento associativo em populações de milho-pipoca relacionadas por ciclos de seleção

• Ano de defesa: 2014
• Autor(a) principal: Paes, Geísa Pinheiro
• Orientador(a): Viana, José Marcelo Soriano
• Banca de defesa: Nascimento, Moysés
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Milho - Qualidade; Milho - Melhoramento genético; Desequilíbrio de fase ganética; SNP; Detecção de QTL
• Palavras-chave em Inglês: Corn - Quality; Corn - Breeding; Ganética phase imbalance; SNP; Detection of QTLs
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/4806

Linkage disequilibrium (LD) is defined as the non-random association between alleles of different loci in a population and association mapping (MA) refers to a statistically significant association between molecular marker and phenotypic trait. The objectives of this study were: (1) estimate the linkage disequilibrium in populations of popcorn related by cycles of selection using SNP markers, (2) compare the populations in the degree of LD, (3) evaluate changes in allele frequencies and (4) identify significant associations between markers and quality related characteristics of popcorn. In total 465 samples were evaluated, with 354 samples belonging to the population 'Viçosa' and 111 samples belonging to the population eija- asm Improvement Program popcorn, Federal University of Viçosa. The populations were subjected to the following cycles of selection: Viçosa cycle 1 and cycle 1 Beija-Flor, obtained after one cycle of selection among and within half-sib families, Viçosa cycle 4, obtained after four cycles of selection among and within half-sib families, Viçosa cycle 2 full-sib families (FIC), obtained after two cycles of selection among and within full-sib families, Viçosa S4, obtained by selection of progeny S4. Ninety-six SNPs markers in properly selected QTL regions for quality, already identified above were used. The following characters were measured: capacity expansion (ml/g), grain density (g/ml), sphericity of grains and 100 grains weight (g). In comparison the Viçosa c0 used as the reference population for the highest mean values for LD linking group found in Viçosa c2 fic (D' = 0,8911; r 2 = 0,1905) as well as to related and unrelated SNPs (D' = 0,8911, r 2 = 0,1905) . Regarding the MA significant associations (p < 0.05) were found for all traits, with thirteen associations related to the feature expandability, twenty three with the sphericity of the grains, eight with the weight of 100 grains and seventeen density of the grains.