Desenvolvimento de um modelo para construção de mapas genéticos em autopoliploides, com aplicações em cana-de-açúcar / Development of a model to build genetic maps in autopolyploides, with applications in sugarcane

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

29/05/2012

RESUMO

Autopolyploid species are extremely important in agriculture. However, the complex structure of their genomes is not well understood. Despite all advances in genetic mapping of autotetraploids, the vast majority of the models used for autopolyploid species with high ploidy level, such as sugarcane, are approximations of those used in diploid organisms. Thus, the aim of this work was to develop a new model to build genetic linkage maps in autopolyploid species with any ploidy level, including markers with all possible dosages. For doing so, hiddenMarkov model technology was used. The new model presented herein can be applied to dominant and codominantmarkers data, with biallelic or multiallelic behavior. The method is based on the calculation of conditional probabilities that comprise the transition matrix followed by a reduction of its dimension using a computer-based approach. An application of the method was illustrated with a sugarcane mapping population derived from a cross between two pre-commercial varieties (IACSP 95-3018 × IACSP 93-3046), scored with three types of markers: SNPs, microssatellite and AFLPs. The results indicate that the new method is very efficient in obtaining genetic maps, even for high ploidy levels and for markers with high dosages, particularly when these markers have codominant behavior. It was also possible to estimate the likelihood, the recombination fractions and the linkage phases between allmarkers using themultipoint approach, which takes into account all markers of the linkage group simultaneously. The new model proposed in this work represents a major step towards the location of genomic regions associated with variation in quantitative traits and its genetic architecture, and assembling autopoliploid genome sequences.

ASSUNTO(S)

cana-de-açúcar genetic mapping mapeamento genético marcador molecular molecular marker nucleotídeos nucleotides polimorfismo polimorphism poliploides polyploids sugarcane

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