Coding of intraspecific nucleotide polymorphisms: A tool to resolve reticulate evolutionary relationships in the ITS of beech trees (Fagus L., Fagaceae) |
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Authors: | Guido W Grimm Thomas Denk Vera Hemleben |
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Institution: | 1. Department of General Genetics, Centre of Plant Molecular Biology (ZMBP) , Eberhard Karls University , Auf der Morgenstelle 28, Tübingen, 72076, Germany E-mail: vera.hemleben@uni‐tuebingen.de;2. Department of Palaeobotany , Swedish Museum of Natural History , Box 50007, Stockholm, 104 05, Sweden |
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Abstract: | The internal transcribed spacers ITS1 and ITS2 of the nuclear ribosomal DNA (rDNA) have recently been found to display remarkable intraspecific polymorphism, a feature suggested as limiting their value for phylogenetic reconstructions. A comparative study of oligonucleotide motives and intraindividual nucleotide variability across all species of the tree genus Fagus (beech) shows, however, that this intraspecific ITS polymorphism follows a particular pattern, which can be used to detect reticulation and ancient polymorphism within the genus. Coding ITS polymorphisms as phylogenetically informative characters, moreover, resulted in better‐resolved phylogenies than traditional ‘base‐per‐base’ maximum parsimony and maximum likelihood analyses. |
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Keywords: | ITS intraspecific variability molecular evolution phylogeny reticulate evolution |
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