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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Gen?tica e biologia reprodutiva de vriesea minarum (Bromeliaceae): em busca de estrat?gias de conserva??o no quadril?tero ferr?fero, minas gerais

Rolim, P?mela Lavor 11 March 2013 (has links)
Made available in DSpace on 2014-12-17T15:49:13Z (GMT). No. of bitstreams: 1 PamelaLR_DISSERT.pdf: 3477786 bytes, checksum: e908a438292b6fd69e56fc50da98d37c (MD5) Previous issue date: 2013-03-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Vriesea minarum is a rupiculous bromeliad species, with naturally fragmented populations, restricted to the Iron Quadrangle, Minas Gerais, Brazil. It is a threatened species, which is suffering from habitat loss due to the growth of cities and mining activities. The knowledge of genetic variability in plant populations is one of the main branches of conservation genetics, linking genetic data to conservation strategies while the knowledge about plant reproductive biology can aid in understanding key aspects of their life story, as well as in the comprehension of their distribution and survival strategies. Thus, the study of diversity, richness, and genetic structure, as well as the reproductive biology of populations of V. minarum can contribute to the development of conservation actions. Chapter 1 presents the transferability of 14 microsatellite loci for V. minarum. Among the results of this chapter, we highlight the successful transferability of 10 microsatellite loci described for other species of Bromeliaceae, all of which are polymorphic. In Chapter 2, we present the genetic analyses of 12 populations of V. minarum that are distributed throughout the Iron Quadrangle. We used the 10 microsatellite loci tested in Chapter 1. The results show a low population structuring (Fst = 0.088), but with different values of genetic richness (mean = 2.566) and gene diversity (mean = 0.635) for all populations; and a high inbreeding coefficient (Gis = 0.376). These may be the result of pollinators action and/or efficient seed dispersal, thus allowing a high connectivity among populations of naturally fragmented outcrops. The reproductive biology and floral morphology of a population of V. minarum, located in the Parque Estadual da Serra do Rola-Mo?a, are studied in Chapter 3. This reserve is the only public environmental protection area where the species occurs. As a result of field experiments and observations, we found that the species has its flowering period from January to March, with flowers that last for two days and that it has a mixed pollination syndrome. It is primarily alogamous, but also has the capacity to be self-ferilized. It is expected that data obtained in chapters 1, 2 and 3 serve as basis for other studies with species from the ferruginous rocky fields, since until now, to our knowledge, there are no other survey of endemic species from the Iron Quadrangle, seeking to merge the genetic knowledge, with the data of the reproductive biology, with the ultimate aim of biodiversity conservation. Considering the great habitat loss for the species by mining, it becomes crucial to analyze the creation of new protected areas for its conservation / Vriesea minarum ? uma esp?cie de brom?lias rup?cola, com popula??es naturalmente fragmentadas, restrita a regi?o do Quadril?tero Ferr?fero, em Minas Gerais, Brasil. ? uma esp?cie amea?ada, que est? sofrendo com a perda de habitat devido ao crescimento das cidades e ?s atividades de minera??o. O conhecimento da variabilidade gen?tica em popula??es de plantas ? um dos principais ramos de gen?tica da conserva??o, associando dados gen?ticos para as estrat?gias de conserva??o, enquanto que o conhecimento sobre a biologia reprodutiva pode ajudar na compreens?o de aspectos fundamentais da hist?ria de vida, distribui??o e estrat?gias de sobreviv?ncia das plantas. Assim, o estudo da diversidade, riqueza, estrutura gen?tica e biologia reprodutiva das popula??es de V. minarum podem contribuir para o desenvolvimento de a??es de conserva??o. O cap?tulo 1 apresenta a transferabilidade de 14 loci de microssat?lites para V. minarum. Entre os resultados desse cap?tulo, destaca-se o sucesso da transferabilidade de 10 loci de microssat?lites descritos para outras esp?cies de Bromeliaceae, sendo todos eles polim?rficos. No cap?tulo 2, ? apresentada a gen?tica de 12 popula??es de V. minarum que se distribuem por todo o Quadril?tero Ferr?fero. Os resultados obtidos mostram pouca estrutura??o entre as popula??es (Fst = 0,088), mas com diferentes valores de riqueza (m?dia = 2.566) e diversidade gen?tica (m?dia = 0.635) para todas as popula??es; o coeficiente de endogamia foi alto (Gis = 0.376). Estes dados podem ser resultado da a??o de polinizadores e/ou dispers?o de sementes eficientes, j? que as popula??es s?o naturalmente fragmentadas. No cap?tulo 3, ? estudada a biologia reprodutiva e morfologia floral de uma popula??o de V. minarum, situada no Parque Estadual da Serra do Rola-Mo?a, Minas Gerais. Como resultado, foi poss?vel identificar que a esp?cie possui flora??o de janeiro a mar?o; com flores que duram dois dias; s?ndrome mista de poliniza??o; sendo primariamente al?gama, mas tamb?m tem capacidade para ser auto fecundada. Espera-se que dados obtidos nos cap?tulos 1, 2 e 3 sirvam como base para outros estudos com esp?cies de campos rupestres ferruginosos, j? que at? o presente momento, n?o ? de nosso conhecimento a exist?ncia de registros de outras pesquisas feitas com esp?cies end?micas do Quadril?tero Ferr?fero, que busquem conciliar o entendimento da gen?tica, com os dados da biologia reprodutiva, tendo como alvo a conserva??o da biodiversidade neste h?bitat altamente amea?ado pela minera??o. Torna-se crucial uma an?lise cuidadosa para a cria??o de novas ?reas de prote??o, para conserva??o das popula??es da esp?cie

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