Variação da diversidade genética de populações de Epidendrum secundum (Orchidaceae) associadas aos afloramentos rochosos próximos ao litoral e localizados no interior do continente

• Autor(a) principal: Lima, Juliana da Silva [UNESP]
• Data de Publicação: 2018
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/203576; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2019-07-19/000918200.pdf
• topic: Variação genética; Orquídea; Afloramento (Geologia); Filogeografia

Glacial and interglacial periods had a profound impact on the distribution of plant communities, especially in South America. During glacial periods, grassland and shrub communities expanded as rain forests were more fragmented. The inverse process occurred during interglacial periods, where the expansion of rain forests and the consequent fragmentation of grasslands and open plant communities, such as restingas and high altitude grasslands, are clearly evident. However, there is evidence of greater stability of plant communities near the coast where the effects of the climatic oscillations would have been less drastic than in the inner part of the continent. Phylogeography studies also suggest a greater stability of the populations located near the coast, which tend to exhibit a greater genetic diversity than the populations located in the interior of the continent. The objective of this work is to use populations of the species Epidendrum secundum (Orchidaceae) as a biological model to test the hypothesis of a longitudinal gradient of diversity in populations distributed at different distances from the coast. The loci's amplification and characterization of alleles followed the methodology described for Epidendrum, and for the statistic analysis, the RAREFAC v. 3.5, PERMUT/CpSSR and Arlequin 3.5 software were used. The results of this study are also discussed considering the effects of historical climatic oscillations on the genetic structure of these populations and the evolutionary processes that shaped the high biodiversity observed in Atlantic Forest plant communities. This way the present study suggests that phylogeographic and genetic analysis may help to understand the impacta of genetic drift on the populations and conservation of these species of Epidendrum for studies of evolution in the Neotropical region