RESUMEN
Loss of genetic diversity reduces the ability of species to evolve and respond to environmental change. Araucaria araucana is an emblematic conifer species from southern South America, with important ethnic value for the Mapuche people (Pehuenche); the Chilean Government has catalogued its conservation status as vulnerable. Climatic fluctuations were potentially a major impact in the genetic variation within many tree species. In this context, the restricted geographic distribution of A. araucana in Chile appears to be a consequence of the Last Glacial Maximum (LGM). During the past two centuries, strong human intervention has also affected the geographical distribution and population sizes of A. araucana. Reduction of population size may cause loss of genetic diversity, which could affect frequency of adaptive loci. The aims of this study were to know the existence of potential loci under selection and populations with genetic, demographic disequilibrium in the Chilean distribution of A. araucana. Based on 268 polymorphic AFLP loci, we have investigated potential loci under selection and genetic, demographic disequilibrium within seven Chilean populations of Araucaria araucana. Correlation of 41 outlier loci with the environmental variables of precipitation and temperature reveals signatures of selection, whereas 227 neutral loci provide estimates of demographic equilibrium and genetic population structure. Three populations are recommended as priorities for conservation.
RESUMEN
Introduction: Ugni molinae Turcz., Ugni candollei Barn. (Berg) and Ugni selkirkii (Hook. et Arn.) Berg are Chilean species that share morphological characteristics and they are distributed in geographic locations with very diverse habitats. Its is considered important for the characterization of the Chilean flora to determine if there are similarities in the sort of chemical compounds among species with close morphological relations, growing in different habitats and their consequent biological activity. Objective: to assess the chemical composition and the antioxidant capacity of leaf extracts from the Chilean species of the genus Ugni, and to compare with the U. molinae characteristics. Methods: composition of chemical compounds was determined by chromatographic methods (HPLC-ESI-MS). The antioxidant capacity was assessed by DPPH, ABTS and by stabilization of the hydroxyl radical. Results: as expected, given the great morphological similarity existing among the three species of Ugni that grow in Chile, similarities were found in their chemical composition. Nevertheless, it was also expectable to find variations among them. Thus, U. candollei and U. selkirkii are the species that present greater content and variety of phenolic and terpenic compounds. These species exert greater antioxidant capacity in comparison toU. molinae. U. candollei hightlights for its flavonoid content such as glycosides and quercetin derivatives, and the species U. selkirkii, is important in galotannins. U. molinae is characterized in ellagic acids derivatives. Conclusion: these data and the morphological characteristics could become a useful toll in order to determine the closeness degree among these species(AU
Introducción: Ugni molinae Turcz., Ugni candollei (Barn.) Berg y Ugni selkirkii (Hook. et Arn.) Berg son especies chilenas que comparten características morfológicas y se distribuyen en lugares geográficos con muy diversos hábitats. Se considera importante para la caracterización de la flora chilena determinar si hay similitudes en el tipo de compuestos químicos entre especies con relaciones morfológicas cercanas, que crecen en diferentes hábitats y su actividad biológica consecuente. Objetivo: evaluar la composición química y la capacidad antioxidante de extractos de hojas de las especies chilenas del género Ugni, y compararlas con las características de la especie U. molinae. Métodos: la composición química se determinó por métodos cromatográficos (HPLC-ESI-MS). La capacidad antioxidante se evaluó por los métodos DPPH, ABTS, y la estabilización del radical hidroxilo. Resultados: como era de esperar, dada la gran similitud morfológica existente entre las tres especies de Ugni que crecen en Chile, se encontraron similitudes en su composición química. Sin embargo, también era esperable encontrar variaciones entre ellas. Por lo tanto, U. candollei y U. selkirkii son las especies que presentan mayor contenido y variedad de compuestos fenólicos y terpénicos. Estas especies ejercen una mayor capacidad antioxidante en comparación con U. molinae. U. candollei se caracteriza por su contenido en flavonoides como quercetina glucósidos y sus derivados, y la especie U. selkirkii, por la presencia de galotaninos. U. molinae se caracteriza por contener derivados del ácido elágico. Conclusión: estos datos y las características morfológicas podrían convertirse en una herramienta útil para determinar el grado cercanía entre estas especies(AU)