Influence of putative forest refugia and biogeographic barriers on the level and distribution of genetic variation in an African savannah tree, Khaya senegalensis (Desr.) A. Juss

cg.contactg.sexton@uq.edu.auen_US
cg.contributor.centerUniversity of Queensland - UQen_US
cg.contributor.centerUniversity of the Sunshine Coast, Faculty of Science, Health, Education and Engineering, GeneCology Research Centre and Animal Health Innovationen_US
cg.contributor.centerWorld Agroforestry Center - ICRAFen_US
cg.contributor.centerLes Amis de la Natureen_US
cg.contributor.centerUniversity of Adelaide, The Environment Institute, School of Earth and Environmental Sciences - Adelaide - Environment - SoE&ESen_US
cg.contributor.centerUniversity of Queensland, Queensland Alliance for Agriculture and Food Innovation - UQ - Qaafien_US
cg.contributor.crpCGIAR Research Program on Dryland Systems - DSen_US
cg.contributor.funderGovernament of Finlanden_US
cg.contributor.projectBuilding Biocarbon and Rural Development in West Africa - BIODEVen_US
cg.contributor.project-lead-instituteWorld Agroforestry Center - ICRAFen_US
cg.coverage.countryAOen_US
cg.coverage.countryBJen_US
cg.coverage.countryBWen_US
cg.coverage.countryBIen_US
cg.coverage.countryCMen_US
cg.coverage.countryCFen_US
cg.coverage.countryTDen_US
cg.coverage.countryCIen_US
cg.coverage.countryCDen_US
cg.coverage.countryETen_US
cg.coverage.countryGHen_US
cg.coverage.countryGNen_US
cg.coverage.countryKEen_US
cg.coverage.countryLRen_US
cg.coverage.countryMWen_US
cg.coverage.countryMZen_US
cg.coverage.countryNGen_US
cg.coverage.countryRWen_US
cg.coverage.countrySLen_US
cg.coverage.countrySOen_US
cg.coverage.countryZAen_US
cg.coverage.countryTZen_US
cg.coverage.countryTGen_US
cg.coverage.countryUGen_US
cg.coverage.countryZMen_US
cg.coverage.countryZWen_US
cg.coverage.countrySDen_US
cg.coverage.regionMiddle Africaen_US
cg.coverage.regionWestern Africaen_US
cg.coverage.regionSouthern Africaen_US
cg.coverage.regionEastern Africaen_US
cg.coverage.regionNorthern Africaen_US
cg.date.embargo-end-dateTimelessen_US
cg.identifier.doihttps://dx.doi.org/10.1007/s11295-015-0933-3en_US
cg.isijournalISI Journalen_US
cg.issn1614-2942en_US
cg.journalTree Genetics and Genomesen_US
cg.subject.agrovocafricaen_US
cg.volume11:103en_US
dc.contributorFrere, Celineen_US
dc.contributorKalinganire, Antoineen_US
dc.contributorUwamariya, A.en_US
dc.contributorLowe, Andrewen_US
dc.contributorGodwin, Ianen_US
dc.contributorPrentis, Peteren_US
dc.contributorDieters, M.en_US
dc.creatorSexton, Garyen_US
dc.date.accessioned2016-02-28T12:50:39Z
dc.date.available2016-02-28T12:50:39Z
dc.description.abstractPhylogeographic studies of tropical and subtropical tree species provide an ideal method to study the role of forest refugia in the structuring of genetic diversity in contemporary populations. To date, most studies have examined rainforestdependent trees, yet the influence of forest refugia on savannah forest and woodland trees remains poorly understood despite their potentially important role in forest assemblages during the last glacial maximum. Here, we examine the level and structuring of genetic diversity across the geographic range of the savannah woodland tree, Khaya senegalensis— African mahogany, from Senegal to Uganda (>5000 km) and from the steppes of the Sahara desert to the fringes of Africa’s equatorial rainforests (700 km). Three chloroplast (cpDNA) loci and 13 nuclear microsatellite (nSSR) loci were genotyped in 503 individuals. Individual-based clustering of nSSR genotypes identified that all samples formed two populations that showed no pattern of geographic structuring. Population level analysis of nSSR data revealed only very weak genetic structure (FST=0.013) with most of the genetic diversity contained within populations. Geographical differentiation (GST=0.096) was low for the 14 haplotypes identified. However, whereas all haplotypes occurred in the western populations (including Cameroon), only two cosmopolitan haplotypes were found in central-eastern populations. Geographically restricted lowfrequency haplotypes were found in eight western populations. Higher genetic diversity in western populations was confirmed by patterns of allelic richness, which were lower in central-eastern populations. Taken together, these results indicate that K. senegalensis displays very little genetic differentiation across its geographic range and that previously identified barriers to dispersal across the northern savannah belt of tropical Africa (e.g. the Dahomey Gap, Mega Lake Chad and the Adamawa Highlands) have not impeded contemporary gene dispersal in this species. Nevertheless, clustering of rare haplotypes indicates that the Dahomey Gap has likely been an important historical barrier to genetic connectivity between western and eastern regions of the species and that it is likely that this savannah tree also experienced range contraction around major forest refugial fringes or riparian incursions during the last glacial maximum (LGM).en_US
dc.formatPDFen_US
dc.identifierhttps://mel.cgiar.org/dspace/limiteden_US
dc.identifierhttps://link.springer.com/article/10.1007/s11295-015-0933-3en_US
dc.identifier.citationGary Sexton, Celine Frere, Antoine Kalinganire, A. Uwamariya, Andrew Lowe, Ian Godwin, Peter Prentis, M. Dieters. (31/10/2015). Influence of putative forest refugia and biogeographic barriers on the level and distribution of genetic variation in an African savannah tree, Khaya senegalensis (Desr. ) A. Juss. Tree Genetics and Genomes, 11: 103.en_US
dc.identifier.statusTimeless limited accessen_US
dc.identifier.urihttps://hdl.handle.net/20.500.11766/4558
dc.languageenen_US
dc.publisherSpringer Verlag (Germany)en_US
dc.rightsCC-BY-NC-4.0en_US
dc.sourceTree Genetics and Genomes; 11:103,(2015)en_US
dc.subjectgenetic diversityen_US
dc.subjectcpdnaen_US
dc.subjectnssrsen_US
dc.subjectkhaya senegalensisen_US
dc.subjecttropicaen_US
dc.subjectsavannahen_US
dc.titleInfluence of putative forest refugia and biogeographic barriers on the level and distribution of genetic variation in an African savannah tree, Khaya senegalensis (Desr.) A. Jussen_US
dc.typeJournal Articleen_US
dcterms.available2015-09-22en_US
dcterms.issued2015-10-31en_US
mel.impact-factor1.829en_US
mel.project.openhttp://worldagroforestry.org/climatechange/projects/biodeven_US

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