Détail de l'auteur
Documents disponibles écrits par cet auteur (1)
Affiner la recherche
Molecular evidence for polyploid origins in Saxifraga (Saxifragaceae) : the narrow arctic endemic S. svalbardensis and its widespread allies / Christian Brochmann in American Journal of Botany, 85 (7) (07/1998)
Titre : Molecular evidence for polyploid origins in Saxifraga (Saxifragaceae) : the narrow arctic endemic S. svalbardensis and its widespread allies Type de document : Imprimé Auteurs : Christian Brochmann (1953-) ; Xiang ; Brunsfeld ; Douglas E. Soltis (1953-) ; Pamela S. Soltis (1957-) Année de publication : 1998 Article en page(s) : 135-143 Langues : Anglais (eng) Catégories : [Thématique] Variabilité, analyse de l'ADN, polymorphisme Mots-clés : Saxifraga Saxifraga svalbardensis Résumé : The recently described polyploid Saxifraga svalbardensis is endemic to the arctic archipelago of Svalbard. We investigated relationships among four closely related species of Saxifraga in Svalbard and tested three previously proposed hypotheses for the origin of S. svalbardensis: (1) differentiation from the morphologically and chromosomally variable polyploid S. cernua; (2) hybridization between the diploid S. hyperborea and S. cernua; and (3) hybridization between the tetraploid S. rivularis and S. cernua. Fifteen populations were analyzed using random amplified polymorphic DNAs (RAPDs) and nucleotide sequences of the chloroplast gene matK and the internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA). RAPD and matK data suggest that S. svalbardensis has originated from a hybrid with S. rivularis as the maternal parent and S. cernua as the paternal parent, possibly a single time, whereas ITS data could not be used to discriminate among the hypotheses. The data also suggest that the diploid S. hyperborea is a progenitor of the tetraploid S. rivularis. The four populations examined of S. svalbardensis were virtually identical for RAPD and ITS markers, whereas S. cernua showed high levels of variation, suggesting that the latter polyploid either has formed recurrently or has undergone considerable differentiation since its origin. Lien pérenne : DOI : 10.2307/2446562
in American Journal of Botany > 85 (7) (07/1998) . - 135-143Brochmann, C., Xiang, , Brunsfeld, , Soltis, DE., Soltis, PS. 1998. Molecular evidence for polyploid origins in Saxifraga (Saxifragaceae) : the narrow arctic endemic S. svalbardensis and its widespread allies. American Journal of Botany, 85(7): 135-143.