Diversidade e estrutura genética em uma população natural de Plathymenia reticulata Benth. no Sul do Espírito Santo

• Ano de defesa: 2017
• Autor(a) principal: Souza, Lucimara Cruz de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Genética e Melhoramento; UFES; Programa de Pós-Graduação em Genética e Melhoramento
• Palavras-chave em Português: Matrix trees; Molecular marker ISSR; Genetic variability; Forests – Conservation; Árvores matrizes; Marcadores moleculares ISSR; Variabilidade genética; Florestas - Conservação; Vinhático; Marcadores genéticos; 631.523
• Link de acesso: http://repositorio.ufes.br/handle/10/7848

Forest fragmentation and selective logging of certain species are responsible for the reduction of large continuous areas, leading to the reduction of genetic diversity. Therefore, it is necessary to define strategies for the conservation and management of forest remnants to ensure the survival and maintenance of reduced populations. Molecular markers stand out as interesting tools for these studies. The species Plathymenia reticulata Benth., popularly known as vinhático, belongs to the family Fabaceae. This species stands out for its economic and ecological importance due to high quality wood and the potential for use in the recovery and restoration of degraded áreas. The objective of this study was to characterize the diversity and genetic structure of a natural P. reticulata population in a seasonal semideciduous montane forest in the southern state of Espírito Santo, using molecular markers Inter Single Sequence Repeats (ISSR). DNA samples from 149 individuals were analyzed using ten ISSR primers, generating 156 fragments, of which 101 were polymorphic (64.74%). The sampled individuals were classified into three sample units: healthy and reproductive age adult trees (A), seedlings originated from seeds collected within the fragment - mixture of progenies (B) and young individuals in natural regeneration areas around the fragment (C). The polymorphic information content (PIC) for the markers revealed an average of 0.38, characterizing them as moderately informative. The number of loci used (n = 101) was greater than that established as optimal number (n = 88), indicating precision in the analyzes. High genetic diversity was found in the species, based on the values of the diversity index of Nei (H '= 0.407), Shannon index (I = 0.594) and the formation of distinct groups by the UPGMA method. In addition, through the diversity parameters evaluated, it was possible to confirm that in the areas of natural regeneration and progeny mix there is genetic diversity equivalent to that found in adults. The analysis of molecular variance indicated that most of the genetic variation is found within the groups (96.53%) and showed moderate differentiation between adults and regenerants and adults and mixture of progenies. Genetic differentiation among adult trees was low (FST = 0.03) indicating that high gene flow rates (Nm = 12.70) are negating the effects of genetic drift. These results were also confirmed by the Nei genetic distance analysis, principal coordinate analysis (PCoA) and the Bayesian approach performed by the STRUCTURE software. The data obtained allowed to evaluate the potential of adult trees as matrices to obtain seedlings with certified genetic variability