Análise molecular de espécies perenes e anuais do gênero Dicerandra (Lamiaceae) baseada em marcadores ISSR

• Ano de defesa: 2007
• Autor(a) principal: Martins, Fernanda Louback de Castro
• Orientador(a): Oliveira, Luiz Orlando de
• Banca de defesa: Ribon, Andréa de Oliveira Barros , Otoni, Wagner Campos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Bioquímica Agrícola
• Departamento: Bioquímica e Biologia molecular de plantas; Bioquímica e Biologia molecular animal
• País: BR
• Palavras-chave em Português: Dicerandra; Marcadores ISSR; Espécies perenes e anuais
• Palavras-chave em Inglês: Dicerandra; ISSR marks; Perennials and annuals species
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA::BIOLOGIA MOLECULAR
• Link de acesso: http://locus.ufv.br/handle/123456789/2390

Dicerandra is a genus formed by five perennials and four annuals species. All species are endemics of the southeastern United States and restricted to sandhill vegetation and a mosaic of scrub habitats. The majority of these species presents restricted geographic distribution and their habitats have suffered extent antropic modifications. Because of these, five species from Dicerandra are endangered or threatened. The perturbations suffered by Dicerandra habitats were presumably preponderant in the complex relation between their taxa. This complexity is verified by the demonstrated differences among morphologic, ecologic and genetic classifications. Although some species present perennial life cycle, they show more similarity with annuals species when compared by chloroplastic genome. This study aimed to evaluate the genetic variability distributed within and among the annuals and perennials species constituents of the Dicerandra genus, and to improve the understanding of the relation inside this genus as well as its evolutionary history, using ISSR markers. For this proposal were analyzed six taxa, four perennials (D. cornutissima, D. thinicola, D.frutescens modesta e D. frutescens frutescens) and two annuals (D. densiflora e D. linearifolia linearifolia), comprising 92 individuals distributed in 14 populations of the southeastern United States. Seven ISSR primers were selected for this study. Using these primers was possible to generate 103 bands with 100% of polymorphism at total ensemble level. The annuals taxa group demonstrated more genetic variability and differentiation among their taxa than perennials group, excluding Dicerandra cornutissima (COR). The COR inclusion raised the genetic diversity of the perennials group. This group, without COR, had over 60% of the total molecular variance attributed to the variability inter individuals within taxa, whereas the total variance in the annuals taxa group was equally divided among the taxa and among the individuals within taxa. Phenogram and principal coordinates analyzes permitted the identification of four major groups. Only the group comprised by D. frutescens frutescens, D. thinicola e D. frutescens modesta taxa demonstrated heterogeneity suggesting more genetic proximity among them. The results still revealed that the nuclear genome of COR was originated from annuals ancestors, however it has more genetic proximity with the perennials taxa. Furthermore, the exclusive bands presented by COR in the band analyzes excluded the hypothesis in which COR made part of one hybrid zone originated from a recent crossing among annuals and perennials parental.