Vol 44(2010) N 6 p. 883-897;
I.A. Milyutina1*, D.V. Goryunov2, M.S. Ignatov3, E.A. Ignatova3, A.V. Troitsky1
The Phylogeny of Schistidium (Bryophyta, Grimmiaceae) Based on the Primary and Secondary Structure of Nuclear rDNA Internal Transcribed Spacers1Belozersky Institute of Physical and Chemical Biology, Moscow State University, Moscow, 119899 Russia
2Tsytsin Main Botanical Garden, Russian Academy of Sciences, Moscow, 127276 Russia
3Biological Faculty, Moscow State University, Moscow, 119992 Russia
Received - 2010-05-11; Accepted - 2010-06-23
Phylogeny of Schistidium (Bryophyta, Grimmiaceae) was studied by comparing the nucleotide sequences of internal transcribed spacers ITS1-2 of nuclear rDNA and the trnT-trnD region of chloroplast DNA. Phylogenetic trees constructed based on nuclear and chloroplast sequences were consistent, comprising a basal grade and two large clades. Morphological characteristics specific for these clades were described. Secondary structures of ITS1 and ITS2 Schistidium species were modeled using thermodynamic criteria. Four different structures of the longest ITS1 hairpin were identified. These results were used to analyze possible paths of Schistidium evolution. Characteristics of the ITS2 secondary structure support the two major clades recognized in the phylogenetic trees.
Schistidium, ITS, trnT-D, secondary structure, inverted repeat, phylogeny