Evolution in African tropical trees displaying ploidy-habitat association: The genus Afzelia (Leguminosae)
| Autor: | Jérémy Migliore, Dominique Champluvier, Jean-Louis Doucet, Kasso Daïnou, Olivier J. Hardy, Armel S L Donkpegan, Jan J. Wieringa, Jérôme Duminil, Rosalía Piñeiro |
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| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
0301 basic medicine Time Factors DNA Plant 010603 evolutionary biology 01 natural sciences Trees Polyploidy 03 medical and health sciences Species Specificity Polyploid Phylogenetics Genus Afzelia Botany Genetics Molecular Biology Ecosystem Phylogeny Ecology Evolution Behavior and Systematics NdhF Polymorphism Genetic Geography biology fungi food and beverages Fabaceae Sequence Analysis DNA biology.organism_classification Biological Evolution Nuclear DNA 030104 developmental biology Africa Molecular phylogenetics Ploidy |
| Zdroj: | Molecular Phylogenetics and Evolution. 107:270-281 |
| ISSN: | 1055-7903 |
| DOI: | 10.1016/j.ympev.2016.11.004 |
| Popis: | Polyploidy has rarely been documented in rain forest trees but it has recently been found in African species of the genus Afzelia (Leguminosae), which is composed of four tetraploid rain forest species and two diploid dry forest species. The genus Afzelia thus provides an opportunity to examine how and when polyploidy and habitat shift occurred in Africa, and whether they are associated. In this study, we combined three plastid markers (psbA, trnL, ndhF), two nuclear markers (ribosomal ITS and the single-copy PEPC E7 gene), plastomes (obtained by High Throughput Sequencing) and morphological traits, with an extensive taxonomic and geographic sampling to explore the evolutionary history of Afzelia. Both nuclear DNA and morphological vegetative characters separated diploid from tetraploid lineages. Although the two African diploid species were well differentiated genetically and morphologically, the relationships among the tetraploid species were not resolved. In contrast to the nuclear markers, plastid markers revealed that one of the diploid species forms a well-supported clade with the tetraploids, suggesting historical hybridisation, possibly in relation with genome duplication (polyploidization) and habitat shift from dry to rain forests. Molecular dating based on fossil-anchored gene phylogenies indicates that extant Afzelia started diverging c. 14.5 or 20 Ma while extant tetraploid species started diverging c. 7.0 or 9.4 Ma according to plastid and nuclear DNA, respectively. Additional studies of tropical polyploid plants are needed to assess whether the ploidy-habitat association observed in African Afzelia would reflect a role of polyploidization in niche divergence in the tropics. |
| Databáze: | OpenAIRE |
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