Plant Systematics and Evolution

, Volume 225, Issue 1, pp 1–13

Nuclear ribosomal ITS sequences and phylogeny in East AsianAconitum subgenusAconitum (Ranunculaceae), with special reference to extensive polymorphism in individual plants

  • Y. Kita
  • M. Ito

DOI: 10.1007/BF00985455

Cite this article as:
Kita, Y. & Ito, M. Pl Syst Evol (2000) 225: 1. doi:10.1007/BF00985455


Internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA (nrDNA) were used to examine the phylogeny of East Asian aconites. Individual aconites were discovered to contain as many as eight different ITS sequences after cloning and PCR-SSCP (single-stranded conformational polymorphisms) analysis. We identified eight putative ITS pseudogenes from four taxa with low predicted secondary structure stability and high substitution rates. Maximum likelihood (ML) and neighbor-joining (NJ) methods were used for phylogenetic reconstruction. The ITS trees agree with the previous chloroplast DNA (cpDNA) tree for the vast majority of the taxa. We found two East Asian clades in the ITS trees: 1) a clade with the Chinese diploid,Aconitum volubile and East Asian tetraploids, and 2) a clade of East Asian diploids and Siberian tetraploids. In the former clade, most tetraploid taxa appear to be polyphyletic; sequences from individual plants did not correspond to recognized taxonomic units. This indicates a recent divergence of the East Asian tetraploids.

Key words

Ranunculaceae Aconitum ITS polymorphism pseudogenes phylogeny 

Copyright information

© Springer-Verlag 2000

Authors and Affiliations

  • Y. Kita
    • 1
  • M. Ito
    • 2
  1. 1.Department of Biological Sciences, Graduate School of ScienceUniversity of TokyoTokyoJapan
  2. 2.Department of Systems SciencesUniversity of TokyoKomaba, TokyoJapan

Personalised recommendations