Distribuição da variabilidade genética e fluxo de pólen em subpopulações de Annona crassiflora Mart. (Annonaceae)
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2015-12-21
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Universidade Federal de Goiás
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The Annona crassiflora Mart. species (Annonaceae) is a fruit plant native from Cerrado, widely distributed throughout the biome. The goal here was evaluate the spatial distribution of genetic variability in natural subpopulations of the species, geographically, and relate the genetic diversity levels with climatic and landscape profile, furthermore the pollen dispersal within a subpopulation. We used here six pair of microsatellite primers. To evaluate thedistribution of genetic variability we sampled 25 natural subpopulations, 30.6 plants per subpopulation, on average. We estimate the genetic diversity (He), allelic richness (Ar), fixation index (f), genetic structure, using coancestry coefficient (θ) and inbreeding coefficient of overall population (F). The spatial pattern the genetic variability was evaluated by Mantel test, Moran's I index and linear regression of genetic parameter with two spatial dimensions (latitude and longitude). We correlate He, Ar and f with climate suitability and the percentage of Cerrado vegetation around subpopulations. Furthermore we evaluated the pollen dispersal by paternity analysis, using 572 plants, including 460 seeds, 20 mother plants and 92 pollen donors candidate, within a natural subpopulation. The outcrossing rates were also evaluated in maternal families using the mixed mating model. The outcrossing rates indicate mating system with prevalence of allogamy. The assignment of paternity indicated that gene flow mainly occurs in short distances, until 360 meters, in the subpopulation evaluated. The 25 subpopulations have moderate genetic diversity levels and strong genetic structure. We found inbreeding due to the subdivision, but not in mating within subpopulations. The demes belongs to two consistent groups with genetic discontinuity between the northwest and southeast subpopulations distribution. The genetic diversity and allelic richness showed strong relationship with longitude, suggesting a range expansion in the southeastern direction. We noted that spatial distribution of genetic diversity and allelic richness are related to suitability at the last glacial maximum, by an indirect effect of geographical distances, whereas no relationship was observed regarding present suitability. The percentage of cover natural vegetation, in turn not explain the spatial distribution of genetic diversity, allelic richness and inbreeding coefficient.
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ALMEIDA JÚNIOR, E. B. Distribuição da variabilidade genética e fluxo de pólen em subpopulações de Annona crassiflora Mart. (Annonaceae). 2015. 153 f. Tese (Doutorado em Genética e Melhoramento de Plantas) - Universidade Federal de Goiás, Goiânia, 2015.