DIVERSIDAD GENÉTICA Y MEJORAMIENTO DE PLANTAS MEDICINALES:

The study of recently formed species is important because it can help us to better understand organismal divergence and the speciation process. However, these species often present difficult challenges in the field of mol. phylogenetics because the processes that drive mol. divergence can lag behind phenotypic divergence. The current study shows that species of the recently diverged North American endemic genus of purple coneflower, Echinacea, have low levels of mol. divergence. Data from 3 nuclear loci and 2 plastid loci provide neither resolved topologies nor congruent hypotheses about species-level relationships. This lack of phylogenetic resoln. is likely due to the combined effects of incomplete lineage sorting, hybridization, and backcrossing following secondary contact. The poor resoln. provided by mol. markers contrasts previous studies that found well-resolved and taxonomically supported relationships from metabolic and morphol. data. These results suggest that phenotypic canalization, resulting in identifiable morphol. species, has occurred rapidly within Echinacea. Conversely, mol. signals have been distorted by gene flow and incomplete lineage sorting. The impact of natural history on the genetic organization and phylogenetic relationships of Echinacea is discussed. Sequence data are deposited in GenBank/EMBL/DDBJ under accession nos. EU423445-EU423852, EU440074-EU440323, and EU586829-EU586891. 

PARTE UTILIZADA= Used part: Toda la planta. 

ACCIÓN FARMACOLÓGICA= Pharmacological action: Antipalúdico. 

COMPOSICIÓN QUÍMICA= Chemical composition: The novel elemanolide sesquiterpenes I [R = COCMe:CH2, (E)-MeCH:CMeCO] were isolated, together with the known compd. zinaflorin III, from Z. peruviana and their structures were detd. by spectral anal. 

ZONA GEOGRÁFICA= Geografical zone: región central de Argentina. 

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3) FLAGEL, Lex E., et al. Phylogenetic, morphological, and chemotaxonomic incongruence in the North American endemic genus Echinacea. American Journal of Botany . 2008, vol.95, nº6, p.756-765.