Morphologische und molekularsystematische Untersuchungen an der Centaurea stoebe L. Gruppe (Asteraceae-Cardueae) in Europa
The polymorphic genus Centaurea with its c. 600 species comprises a number of groups, which can be classified with classical methods with difficulties only. Chloroplast DNA spacer and internal transcribed spacer (ITS 1 and 2) of the ribosomal repeat of nuclear DNA turned out to be too invariable for phylogenetic analyses within the Centaurea stoebe group. Therefore parts of the distinctly more variable intergenic spacer (IGS) of the ribosomal repeat of nuclear DNA were sequenced. Two regions were developed and established as new markers. By a combination of ITS 1 and the two IGS regions a phylogenetic analysis of the investigation group consisting of 22 taxa was possible. Additionally, RAPD analysis was used to estimate the infraspecific variation and to clarify the origin of introduced plants.