Chromosomal stasis in diploids contrasts with genome restructuring in auto- and allopolyploid taxa of Hepatica (Ranunculaceae)
Polyploidization and chromosomal rearrangements are recognized as major forces in plant evolution. Their role is investigated in the disjunctly distributed northern hemisphere Hepatica (Ranunculaceae). Chromosome numbers, karyotype morphology, banding patterns, 5S and 35S rDNA localization in all kn...
| Veröffentlicht in: | The New phytologist. - 1979. - 174(2007), 3 vom: 01., Seite 669-682 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2007
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't DNA, Plant DNA, Ribosomal DNA, Ribosomal Spacer RNA, Ribosomal, 5S |
| Zusammenfassung: | Polyploidization and chromosomal rearrangements are recognized as major forces in plant evolution. Their role is investigated in the disjunctly distributed northern hemisphere Hepatica (Ranunculaceae). Chromosome numbers, karyotype morphology, banding patterns, 5S and 35S rDNA localization in all known species were investigated and interpreted in a phylogenetic context established from nuclear internal transcribed spacer (ITS) and plastid matK sequences. All species had a chromosome base number of x = 7. The karyotype was symmetric and showed little variation among diploids with one locus each of 5S and 35S rDNA, except for interpopulational variation concerning 35S rDNA loci number and localization in H. asiatica. Tetraploids exhibited chromosomal changes, including asymmetry and/or loss of rDNA loci. Nuclear and plastid sequences resulted in incongruent topologies because of the positions of some tetraploid taxa. The diversification of Hepatica occurred not earlier than the Pliocene. Genome restructuring, especially involving 35S rDNA, within a few million yr or less characterizes evolution of both auto- and allopolyploids and of the diploid species H. asiatica, which is the presumptive ancestor of two other diploid species |
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| Beschreibung: | Date Completed 23.10.2007 Date Revised 14.04.2021 published: Print Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/j.1469-8137.2007.02019.x |