THE MONOPHYLY AND RAPID EVOLUTION OF GENTIANA SECT CHONDROPHYLLAE-BUNGE S-L (GENTIANACEAE) - EVIDENCE FROM THE NUCLEOTIDE-SEQUENCES OF THE INTERNAL TRANSCRIBED SPACERS OF NUCLEAR RIBOSOMAL DNA

The nucleotide sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA of 24 representative species of sect. Chondrophy llae s.l. have been determined and analysed phylogenetically, together with some species of other sections of the genus Gentiana. The ITS se quences strongly support the monophyly of the sect. Chondrophyllae s.l . as a whole complex including various different dysploid cytotypes. S pecies, such as G. boryi and G. pyrenaica: that had been split into di stinct genera by some cytotaxonomists have been proven to be closely r elated. However, the ITS sequences do not provide sufficient informati on to make a robust estimation of the phylogenetic relationships among the closely related species and dysploid cytotypes of the complex, be yond recognizing their monophyly and rapid evolution. (C) 1997 The Lin nean Society of London.