No abstract

No abstract

Twenty-seven accessions of Lippia alba Mill. collected in Rio Grande do Sul state, Brazil, were analysed by ISSR and RAPD markers to evaluate their genetic variability and relationships. Six ISSR primers and four RAPD primers generated 120 amplified fragments, most of which were polymorphics. The overall genetic variability among accessions was very high when compared with other plant species. The hierarchical analysis of molecular data (UPGMA) showed low relationship between accessions, and no grouping between accessions of the same chemotype. Canonical functions allowed identifying some variables related with the chemical characteristics of the essential oils. Both ISSR and RAPD markers were efficient to address the genetic diversity of L. alba, and may contribute to the conservation and breeding of this increasingly important aromatic and medicinal species.Keywords: molecular relationship, ISSR, RAPD, Lippia alba, Verbenaceae. Variabilidade genética entre acessos sul-brasileiros de Lippia alba Mill. (Verbenaceae) detectada por ISSR e RAPD ResumoVinte e sete acessos de Lippia alba Mill. coletados no Rio Grande do Sul, Brasil, foram analisados por marcadores ISSR e RAPD visando avaliar a variabilidade genética e as relações entre acessos. Seis sequencias iniciadoras de ISSR e quatro de RAPD geraram 120 fragmentos amplificados, a maior parte dos quais apresentaram algum grau de polimorfismo. A variabilidade genética geral entre acessos foi muito elevada quando comparada com outras espécies vegetais. A análise hierárquica dos dados moleculares (UPGMA) mostrou baixa relação entre acessos, e não houve formação de agrupamentos entre acessos pertencentes ao mesmo quimiotipo. Análise de funções canônicas permitiu identificar algumas variáveis relacionadas com as características químicas dos óleos essenciais. Tanto os marcadores ISSR como RAPD foram eficientes para avaliar a diversidade genética em L. alba e devem contribuir para a conservação e melhoramento desta importante espécie aromática e medicinal.

Essential oils of Baccharis uncinella DC and B. dracunculifolia DC collected from different wild populations growing in Bolivia, southern Brazil and Uruguay were analysed using gas chromatography and gas chromatographymass spectrometry techniques, to check for chemical variability. Cluster analysis led to the identi¼cation of two chemotypes for B. dracunculifolia, related to aromadendrane-or cadinane-derived components. As the timing of sampling of the plant material may have an in½uence on the composition of the essential oil isolated, the seasonal in½uence at the moment of harvesting was studied for two populations of each species. The results suggested that the ½owering season was optimal both species and this supported the practice of harvesting at the full bloom stage.

No abstract