Estimation of phylogenetic relationships among some Hypericum (Hypericaceae) species using internal transcribed spacer sequences

Abstract

Thirty-four taxa representing 12 sections of the genus Hypericum were analyzed along with two representatives of Thornea using nuclear internal transcribed spacer (ITS) sequences in order to assess the scope of phylogenetic relationships in this species-rich genus. The resulting parsimony analysis corroborates the actual classification and interspecific affinities. The molecular data provide support for the monophyletic assemblage of the sections Androsaemum, Hypericum, Olympia, and Drosocarpium and for the polyphyletic origin of Ascyreia, Taeniocarpium, Myriandra, and Adenosepalum. The earlier evolutionary hypotheses concerning the origin of Hypericum balearicum and Hypericum calycinum, and the relatedness of Adenosepalum representatives, are not supported by our data analysis as well as hybrid origin of Hypericum perforatum. The obtained results encourage the use of ITS sequence analysis in resolving the phylogenetic relationships within the member-rich genus Hypericum.

Keywords:

• Hypericum
• ITS
• maximum parsimony
• molecular phylogeny

Acknowledgements

The authors would like to thank N. Ljubešić and H. Fulgosi of the Laboratory of Electron Microscopy, Division of Molecular Biology at Ruđer Bošković Institute for kindly providing laboratory facilities. The authors thank V. Magnus for helpful suggestions and critically reading the manuscript, and the reviewer for his constructive comments and suggestion to improve the manuscript. The authors are also grateful to all institutions that helped with seeds from their collections. The Croatian Ministry of Science, Education and Sports supported this research, Project no. 006-0061117-1239.