Variabilidade genética quantitativa e molecular em uma coleção de germoplasma de Eugenia dysenterica DC. (Myrtaceae)

• Autor(a) principal: Almeida Júnior, Edivaldo Barbosa de
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/3532
• topic: Caracteres quantitativos; Conservação; Diversidade genética; Marcadores moleculares; Conservation; Gene diversity; Molecular markers; Quantitative traits; GENETICA::GENETICA VEGETAL

The cagaiteira (Eugenia dysenterica DC)., is a native species of Cerrado. The plant is known for fruit production, which are used in natura or processed in several ways. It also provides food for the local fauna and, therefore, it conservation is important for maintenance for the communities. In order to maintain the productivity potential of the species, we should invest on plant breeding programs. To support these programs and help the species conservation, it is important to characterize the genetic variability available to breeders, both in germplasm collections and natural populations. This could also help to recommend priority areas to collect and conserve the germplasm. Neutral molecular markers have been used to evaluate the distribution of genetic variability in natural populations. The genetic structure of populations is the result of historical interaction between genetic drift, mutation, and gene flow. To detect the influence of adaptive processes in the genetic differentiation of populations we used index. The comparison of to the , for neutral loci, provides values to test hypotheses about the role of natural selection. Therefore, the aim of this study was to characterize the germplasm collection of the cagaiteira from the EA/UFG. We used quantitative traits and microsatellite markers to make inferences about the role of natural selection in the differentiation of the cagaiteira subpopulations of Goiás, Southeast Brazil. Data collected from the quantitative traits were: plant height (AB), height of the first bifurcation (AB), the stem circumference (CC) and mean diameter of the crown projection (DC), leaf length (CL), leaf width (LL), leaf format (FF) and footstalk length (CP). Molecular data were obtained by amplification of eight microsatellite loci. We estimated the following quantitative genetic parameters: heritability and genetic variation coefficient, and the molecular parameters: gene diversity and allelic richness. We compared the probability distributions of the genetic structure parameters for both, quantitative and molecular data ( vs. ). From the quantitative genetic parameters we found modest responses to selection for the traits: AP, CC and DC; and significant responses for CL, LL, FF and CP. It was observed that the samples collected in natural populations are well represented in the germplasm collection, supported by molecular gene diversity. The traits AP, DC and DC are under convergent natural selection, and the traits CL, LL, FF and CP are under divergent natural selection into the cagaiteira subpopulations of Southeast Goiás.