Abstract
Chromosome number change is a driver of speciation in eukaryotic organisms. Carnivorous sundews in the plant genus Drosera L. exhibit single chromosome number variation both among and within species, especially in the Australian Drosera subg. Ergaleium D.C., potentially linked to atypical centromeres that span much of the length of the chromosomes. We critically reviewed the literature on chromosome counts in Drosera, verified the taxonomy and quality of the original counts, and reconstructed dated phylogenies. We used the BiChrom model to test whether rates of single chromosome number increase and decrease, and chromosome number doubling differed between D. subg. Ergaleium and the other subgenera and between self-compatible and self-incompatible lineages. The best model for chromosome evolution among subgenera had equal rates of chromosome number doubling but higher rates of single chromosome number change in D. subg. Ergaleium than in the other subgenera. Contrary to expectation, self-incompatible lineages had a significantly higher rate of single chromosome loss than self-compatible lineages. We found no evidence for an association between differences in single chromosome number changes and diploidization after polyploidy or centromere type. This study presents an exemplar for critically examining published cytological data and rigorously testing factors that may impact the rates of chromosome number evolution.
Original language | English |
---|---|
Pages (from-to) | 2314-2325 |
Number of pages | 12 |
Journal | Evolution |
Volume | 77 |
Issue number | 10 |
DOIs | |
State | Published - Oct 2023 |
Bibliographical note
Publisher Copyright:© The Author(s) 2023.
Funding
The authors thank Fernando Rivadavia for verifying vouchers and feedback on the manuscript, Alex Eilts and the College of Biological Sciences Conservatory, University of Minnesota for their assistance in growing plants for genome size estimation, Aaron Lee and Yaniv Brandvain for their feedback on the manuscript, the University of Western Australia library for access to Lin Chen’s Thesis, Sergey Matveev for translating literature from Russian, and Virginia’s Department of Conservation and Recreation and Darren Loomis for permits and assistance with access to the Cherry Orchard Bog Natural Area Preserve. The work is supported by the National Science Foundation (DEB 2015210), the Fulbright Futures Program, and the Botanical Society of America.
Funders | Funder number |
---|---|
Virginia’s Department of Conservation and Recreation and Darren Loomis | |
Botanical Society of America | |
Fulbright Futures Program | |
National Science Foundation Arctic Social Science Program | DEB 2015210 |
National Science Foundation Arctic Social Science Program |
Keywords
- BiChrom model
- RevBayes
- carnivorous plants
- chromosome number change
- diploidization
- holocentric chromosomes
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Genetics
- General Agricultural and Biological Sciences