Donkpegan A. S. L., Doucet J. L., Migliore J., Duminil Jérôme, Dainou K., Pineiro R., Wieringa J. J., Champluvier D., Hardy O. J. (2017). Evolution in African tropical trees displaying ploidy-habitat association : the genus Afzelia (Leguminosae). Molecular Phylogenetics and Evolution, 107, p. 270-281. ISSN 1055-7903.
Titre du document
Evolution in African tropical trees displaying ploidy-habitat association : the genus Afzelia (Leguminosae)
Année de publication
2017
Auteurs
Donkpegan A. S. L., Doucet J. L., Migliore J., Duminil Jérôme, Dainou K., Pineiro R., Wieringa J. J., Champluvier D., Hardy O. J.
Source
Molecular Phylogenetics and Evolution, 2017,
107, p. 270-281 ISSN 1055-7903
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 Glade 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.
Plan de classement
Sciences du monde végétal [076]
;
Etudes, transformation, conservation du milieu naturel [082]
Localisation
Fonds IRD [F B010069387]
Identifiant IRD
fdi:010069387
