Variabilidade genética quantitativa e estrutura populacional de Dipteryx alata Vog. do cerrado

• Autor(a) principal: Mota, Elias Emanuel Silva
• Data de Publicação: 2017
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/13148
• topic: Baru; Parâmetros genéticos; QST; Estrutura genética; Conservação; Genetic parameters; Genetic structure; Conservation; CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::SILVICULTURA::GENETICA E MELHORAMENTO FLORESTAL

The objective of this study was to estimate genetic parameters for quantitative traits of Dipteryx alata; to infer about the influence of climatic, edaphic and geographic factors on the phenotypic divergence among subpopulations and to compare the population genetic structure of the species, based on quantitative and molecular data, to infer about the adaptive processes in the subpopulations. The germplasm collection consists of 600 plants in the field, in a randomized complete block design, with four replications and one plant per plot. Seedlings from the sowing in mid-October 2011 were transplanted to the field in March 2012. A phenotypic evaluation was also carried out in the 25 natural subpopulations, in which leaf and inflorescence data were collected from adult plants in six states of Central Brazil, sampling six plants per subpopulation. A composite sample of soil was also obtained with subsamples collected in the projection of the canopy of the plants. The evaluations of the plants from the germplasm collection, for the purposes of this study, began in March 2013, being the individual accessions characterized morphologically and agronomically. The quantitative data of the collection and the natural subpopulations were submitted to descriptive analysis, analysis of variance and correlation between the silvicultural characters. From the variance components, the genetic parameters of interest were also estimated. The comparison of the population genetic structure via microsatellite marker (FST) and quantitative data (QST) was performed based on the probability distributions of the values of the two estimates, which were generated by parametric bootstrap using 10000 resamples. There was significant variation between subpopulations and progenies within subpopulations, for most of the traits evaluated. There is genetic variability both among and within subpopulation, and its structuring is inherent to the evaluated variable. The traits, initial height, final height, initial diameter, final diameter, stem height and crown diameter showed higher heritability values, having a greater potential for genetic gain by selection and breeding. The geographic distances matrix showed low magnitude correlation only with the distances matrix of the phenotypic data of leaves and with the data matrix of the nutritional contents of leaves. The results of the Mantel tests suggested that the environmental factors (climate and soil), as well as the geographical distribution of the subpopulations are associated, even in small magnitude, with the phenotypic divergence among the subpopulations. Eighteen of the twenty seven characters evaluated for the species suggest that drift is the main cause of differentiation among subpopulations.