Fluxo gênico recíproco entre cultivares de soja sob a teoria de genética de populações

• Autor(a) principal: Pereira, Welison Andrade
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1310
• topic: Soja; Melhoramento genético; Genética de populações; Organismos transgênicos; Soybean; Genetic; Populations genetics; Transgenic organisms; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL

According to the literature, it isn't common that the natural hybridization rate in Glycine max exceeds the value 1%. With the arrival of transgenic cultivars, new researches has been done in order to investigate the allogamy of these cultivars. For seed producers for marketing is important to know this aspect of the cultivars, because genetic purity is the assurance of your product. Researches show that the fact of growing genetically modified to not change the existing expectation of cross-fertilization. In the knowledge that genetic purity is required for any variety, the objetctive was to assess the rate of reciprocal cross-fertilization involving two soybean cultivars, one conventional and one GM. Previously, we attempted to adjust methods of bioassay for the detection of soybean seeds of GM crops, and reflect the gene flow of soybean from the perspective of population genetics. From the adjustment of the methods of bioassays: i) seed germination in a substrate containing glyphosate, and ii) presoaking of seeds with the herbicide, followed by germination test, we obtained efficient protocols for detecting and quantification of GM soybean seeds of the soybean seeds. The method of wetting the substrate with germination herbicide solution, 0.03% of its acid equivalent at a ratio of 3 times the weight of dry paper was selected for the testing of natural hybridization. Faced with the prospect of population genetics, it was concluded that the chance of fixation of an allele in the gene pool of a population after gene flow is, among other factors, because of its relevance to the fitness of their bearers. In addition, the selection against a dominant allele needs only one generation to eliminate it from the gene pool of the population and that the dilution effect should be used for the dissemination of natural hybridization rates found in studies of this type. In the study of reciprocal cross-fertilization, different methods for the verification of natural hybridization, examining the color of the flower field, examining the color of the hypocotyls in a greenhouse, the spraying of seedlings with the herbicide in greenhouses, and the germination of seeds in contact with the herbicide in the laboratory seed analysis showed that the rates of outcrossing population were 0.05, 0.10, 0.39 and 0.22% respectively. Based on these results, it was found that the rate of natural hybridization reverse is not the same in both directions and that the application of the dilution effect is indispensable to present the results of studies on gene flow, since the population values are lower than those found in the rows studied.