Gentiana sect. Calathiana comprises approximately 17 species (22 subspecies) which are mainly distributed in the European mountain ranges. These very small gentians are hardly distinguished by morphology. In the project various regions of the chloroplast DNA are used for phylogenetic analyses and DNA barcoding. Similar to other groups, the variation of chloroplast DNA is too low for species identification, however, sufficient enough to distinguish species groups. DNA barcodes can be applied for identification of juvenile plants and hybrids in mixed populations in further research projects.

Hybridization between sympatric species of the section makes the identification of species with cpDNA barcodes difficult, since hybridization (historical or current) leads to ‘chloroplast capture’, a common phenomenon in plant species. Since not only chloroplast markers but also gene regions of the nuclear genome, especially the genes or non-coding region of the ribisomal DNA (‘Intergenic Transcribed Spacer 1 & 2, ITS) are frequently used, these barcode markers were tested in this model group. The determination with ITS barcodes is more specific than with cpDNA barcodes, since almost all taxa can be determined with them. Furthermore, it could be shown that the cpDNA standard sequences (MatK & RbCl) are less suitable for barcoding than other cpDNA regions.