Estrutura genética, fluxo gênico e sistema reprodutivo de Anacardium occidentale L. do cerrado
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2014-11-22
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Universidade Federal de Goiás
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Because constant degradation of the Cerrado the persistence of long-term populations in their natural habitat may be compromised, as a result of loss of genetic variability. To gene-rate useful information for the implementation of conservation programs in situ and ex situ to Anacardium occidentale L. ecotype from Cerrado, species popularly known as cajuzinho-do-campo. This work had the objective: evaluate, based on microsatellite markers, the ma-ting system, spatial pattern of gene flow intra-population, genetic structure of spontaneous populations and the germplasm collection of the Federal University of Goiás and the landsca-pe influence the genetic structure of populations. For the difference in scale and type of analysis of populations, the work was separated into three chapters. In the first, titled "Ma-ting system, space genetic structure and contemporary gene flow in Anacardium occidentale L ", analyzes were made to answer questions related to the reproductive system and evoluti-onary processes that occur within a population of the species, individuals were sampled three stages of life. As a result it was observed that the species has mating system predomi-nantly outcrossing, the difference between multilocus and single locus outcrossing rate was positive and significant, indicating 16.4% of outcrossing between related individuals. Only 0.05% of the seeds were from selfing. Was assigned paternity to 45% of the seeds. In all ma-trices multiple paternity was observed with 6.7 effective number of pollen donors in each matrix. The pollen pool received by matriz had significant difference (фFT = 0.124). The pol-len dispersal occurred in greater proportion to short distances (41 m), but may reach distan-ces greater than 130 m. The effective area of pollination was 9410 m2 and the effective size of the neighborhood of 18 individuals. The seed dispersal probably occurs at distances grea-ter than the sampled area, which limited the powers of parents of juvenile individuals. Found high genetic diversity within the populationwith reduction the values of adults for seeds and increased inbreeding. The adults showed high genetic neighborhood (262 individuals), re-sulting from weak spatial genetic structure. In the second chapter, titled "Diversity and gene-tic structure of spontaneous populations and germplasm collection of Anacardium occiden-tale L. ecotype from Cerrado", populations were analyzed distributed in the Cerrado to as-sess the genetic variability and its structure between populations, was also analyzed the germplasm collection as the variability and its representation compared to the population. Was observed that the populations have high genetic variability and significant inbreeding. The geographical distribution of genetic diversity and allelic richness showed pattern central - peripheral. Genetic differentiation was weak and significant (RST = 0.095), with a pattern of isolation by distance. Populations with distance of up to 140 m are more similar than expec-ted by chance. There were no significant signs of genetic bottleneck. Individuals in the germ-plasm collection showed high genetic similarity, genetic differentiation was higher among offspring than between populations (θS = 184 and θP = 0.014, respectively). The variability of the collection is representative as the existing variability in spontaneous populations. Fi-nally, in the third chapter titled "Effects pattern of landscape on the variability and genetic structure of populations Anacardium occidentale L. ecotype from Cerrado", we analyzed the genetic structure at the landscape scale to Goiás state populations. Was observed that the main type of matrix around the populations are remaining natural vegetation and pasture, with great variation in the remaining percentage. There was a relationship between the change in allelic richness and remaining percentage of natural vegetation and predominant matrix around the populations in the lowest values were found when the predominant type of matrix is the pasture. Inbreeding was related to landscape when characterized for 2 km scale, where there was a higher inbreeding when the predominant type of matrix is the pas-ture. Due to anthropogenic changes in the landscape there was genetic discontinuity between eight pairs of populations. These results indicate that the fragmentation and change in land use are influencing the genetic variability and gene flow of populations.
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OLIVEIRA, L. K. Estrutura genética, fluxo gênico e sistema reprodutivo de Anacardium occidentale L. do cerrado. 2014. 205 f. Tese (Doutorado em Genética e Melhoramento de Plantas) - Universidade Federal de Goiás, Goiânia, 2014.