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Understanding patterns of dispersal, the movement of individuals or propagules, among populations of riverine species is imperative to their management and conservation. However, directly estimating dispersal can often be difficult. Therefore, estimates of gene flow, the movement of genes, are often used to infer dispersal among natural populations. In riverine species, gene flow is determined by species biology, riverine architecture and flow regime. While many studies investigate the role of species dispersive strategies by comparing patterns of genetic structure in different species across the same geographic range, few also attempt to investigate the role of the non-biotic influences on gene flow in a comparative manner. Instead, studies regarding landscape processes (river architecture and hydrology) are based upon observations in a single riverine environment and not compared to other catchments that may differ in riverine architecture or hydrology. This study attempts to investigate all three factors influencing gene flow and genetic diversity using a comparative approach. This is done by contrasting two species of freshwater fish in two riverine systems that differ in their hydrological and structural makeup. By comparing patterns of genetic structure for each fish species, the role of species biology (behavioural and physical adaptations) can be explored. Then, by comparing patterns of genetic structure for each species, between riverine systems that differ in their landscape processes, the role of hydrology and riverine architecture in determining genetic structure can be explored. This study employed three different genetic markers to elucidate patterns of genetic structure and genetic diversity. These were, direct sequencing and screening of the control region of the mitochondrial DNA genome, microsatellite loci and allozymes...

Nous introduisons un ensemble de modèles à facteurs latents dédié à la génomique du paysage et aux tests d'associations écologiques. Cela comprend des méthodes statistiques pour corriger des effets d'autocorrélation spatiale sur les cartes de composantes principales en génétique des populations (spFA), des méthodes pour estimer rapidement et efficacement les coefficients de métissage individuel à partir de matrices de génotypes de grande taille et évaluer le nombre de populations ancestrales (sNMF) et des méthodes pour identifier les polymorphismes génétiques qui montrent de fortes corrélations avec des gradients environnementaux ou avec des variables utilisées comme des indicateurs pour des pressions écologiques (LFMM). Nous avons aussi développé un ensemble de logiciels libres associés à ces méthodes, basés sur des programmes optimisés en C qui peuvent passer à l'échelle avec la dimension de très grand jeu de données, afin d'effectuer des analyses de structures de population et des cribles génomiques pour l'adaptation locale. / We introduce a set of latent factor models dedicated to landscape genomics and ecological association tests. It includes statistical methods for correcting principal component maps for effects of spatial autocorrelation (spFA); methods for estimating ancestry coefficients from large genotypic matrices and evaluating the number of ancestral populations (sNMF); and methods for identifying genetic polymorphisms that exhibit high correlation with some environmental gradient or with the variables used as proxies for ecological pressures (LFMM). We also developed a set of open source softwares associated with the methods, based on optimized C programs that can scale with the dimension of very large data sets, to run analyses of population structure and genome scans for local adaptation.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-04-07T12:34:26Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Ferreira, D.M.C.-DELIMITAÇÃO DE ESPÉCIES E FILOGEOGRAFIA DO COMPLEXO Cryptanthus zonatus (Vis.) Vis. (BROMELIACEAE).pdf: 2597427 bytes, checksum: 104e86eeb5b9dc72d1a7d96ef9fa743f (MD5) / Made available in DSpace on 2017-04-07T12:34:26Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Ferreira, D.M.C.-DELIMITAÇÃO DE ESPÉCIES E FILOGEOGRAFIA DO COMPLEXO Cryptanthus zonatus (Vis.) Vis. (BROMELIACEAE).pdf: 2597427 bytes, checksum: 104e86eeb5b9dc72d1a7d96ef9fa743f (MD5) Previous issue date: 2016-02-29 / CAPES / Cryptanthus Otto & A.Dietr. (Bromeliaceae, Bromelioideae) é um gênero endêmico do Brasil. Cryptanthus burle-marxii Leme e C. zonatus (Vis.) Vis. são restritas ao norte da Floresta Atlântica nordestina e não apresentam delimitação taxonômica bem definida, pois muitos de seus caracteres morfológicos se sobrepõem. Ambas as espécies compõem o complexo C. zonatus (Vis.) Vis.. O objetivo do presente estudo foi realizar a delimitação de espécies e descrever os padrões filogeográficos do complexo C. zonatus, utilizando dados morfológicos, moleculares e de modelagem de nicho ecológico. Para o estudo foram feitos testes de amplificação heteróloga em C. burle-marxii e C. zonatus, utilizando 38 locos de microssatélites nucleares de cinco espécies de Bromeliaceae. Dos 38 locos testados, 24 apresentaram amplificação positiva e 13 foram polimórficos. Dez locos polimórficos foram selecionados para serem amplificados e genotipados em 147 indivíduos de oito populações do complexo C. zonatus. O resultado da análise morfológica e de estrutura genética mostrou que C. burle-marxii e C. zonatus são dois nomes dados à mesma espécie. A análise filogeográfica mostrou que a distribuição geográfica e estrutura genética do complexo C. zonatus pode ter sofrido modificações no quaternário. No último máximo glacial a distribuição geográfica potencial do complexo era contínua e maior em algumas áreas que atualmente é mar, o que deve ter ocorrido provavelmente devido à regressão marinha neste local. No Holoceno médio houve a potencial separação da distribuição possivelmente devido a uma barreira ecológica que perdurou até o presente formando dois grupos geneticamente estruturados, um ao norte e outro ao sul. Para a conservação da espécie foram indicadas populações prioritárias para o estabelecimento de unidades de conservação. / Cryptanthus Otto & A.Dietr. (Bromeliaceae, Bromelioideae) is an endemic genus from Brazil. Cryptanthus burle-marxii Leme and C. zonatus (Vis.) Vis. are species restricted to the north of the northeastern Atlantic Forest and have no well-defined taxonomic delimitation due to overlaping of some morphological characters. Both species are included in the Cryptanthus zonatus complex. The main goal of this study was to delimit species boudaries and to describe the phylogeographic patterns of the complex C. zonatus using morphological, molecular and ecological niche modeling data. For this study were carried out cross-amplification tests in C. burle-marxii and C. zonatus using 38 loci of nuclear microsatellite of five species of Bromeliaceae. Of the 38 loci tested, 24 showed positive amplification and 13 were polymorphic. Ten polymorphic loci were selected to be amplified and genotypes in 147 individuals from eight populations of the complex C. zonatus. The results of the morphological and genetic structure analyses showed that C. burle-marxii and C. zonatus are two names given to the same species. The phylogeographic analysis showed that the geographic distribution and genetic structure of the complex C. zonatus may have been modified in the Quaternary. The potential geographic distribution of the complex in the last glacial maximum was continuous and larger in some areas which are sea in present, what have probably occurred due to marine regression at this location. In the middle Holocene, there was the potential separation of distribution, possibly due to an ecological barrier that lasted until the present, forming two genetically structured groups, one in the north and other in the south. For conservation of the species priority populations were indicated for the establishment of protected areas

Made available in DSpace on 2014-07-29T14:52:09Z (GMT). No. of bitstreams: 1 Tese thannya nascimento.pdf: 3166640 bytes, checksum: 0a9faeb659c9594423ee5e7f8b495662 (MD5) Previous issue date: 2009-01-22 / The goal of this study was to evaluate the genetic structure and the spatial pattern of intra and interpopulational gene flow of Dipteryx alata Vogel, based on nuclear and chloroplastidial microsatellite markers. Primers were developed based on sequencing of random fragments from a shotgun genomic library for detection of microsatellite regions. 12 microsatellites regions were obtained from 688 sequences, which allowed the construction of pairs of primers. These regions are composed of motifs with two to six nucleotides, ranging from 136 to 380 base pairs. This shows that the random sequencing strategy from shotgun libraries is interesting because it allows the achievement of primers for repetitive regions with different motifs. Two of these loci (Da_E06 e Da_E12) were polymorphic with three alleles each. He estimation for these loci showed satisfactory values (0.2946 and 0.2879, respectively), considering the number of alleles. Also, we used a transferred primer from the species Phaseolus vulgaris (BM164) for D. alata. Moreover, other two chloroplastidials microsatellite primers were used for molecular analyses of georeferenced subpopulations, totalizing 775 plants distributed over the natural occurrence area of Cerrado. 210 of these plants were collected and georeferenced one by one along the margins of the Araguaia River in the states of Mato-Grosso (RAMT) and Goiás (RAGO) for spatial distribution of genetic variability in local scale analysis. The relationship between estimations of genetic diversity parameters with patterns of potential distribution of species was evaluated. This was used to test the hypothesis that the genetic variability of D. alata populations is distributed according to the central-periphery model. D. alata subpopulations showed considerable high levels of genetic variability that was significantly structured among subpopulations and well structured in space, both for nuclear and chloroplastidial data. The estimation of the apparent cross-fertilization rate (ta = 1.0575) indicates that the species is allogamous. Estimations of migration rates by pollen and by seeds were lower than one, indicating that seed dispersal contributes more effectively for total gene flow. Estimates of the genetic diversity parameters from the Araguaia River population showed similar values between both margins. The estimation of the apparent cross-fertilization rate (0.9434) indicated that the Araguaia River is not a physical barrier to effective gene flow. The effective size of the neighborhood, i.e., the mean number of individuals in an area where panmixia occurs was 85.64 and 22.99 for nuclear and chloroplastidial data, respectively, indicating that seed dispersal is more restricted. The correlogram generated with chloroplastidial data presented a cline pattern of variance more evident than with nuclear data, suggesting that the presence of spatial genetic structure is being more influenced by seed dispersal. We observed that the genetic parameters do not follow a classical central-periphery model, because peripheral population (according to geographical distribution of sampling locations) tended to demonstrate higher values for these estimations, mainly the South and Western subpopulations. The relationship found between the fixation index (f) with human impact indicated that the subpopulations evaluated can be affected by fragmentation process and land use, probably caused by the recent human colonization in Cerrado biome. / O objetivo geral deste estudo foi avaliar a estrutura genética e o padrão espacial do fluxo gênico intra e interpopulacional de Dipteryx alata Vogel, com base em marcadores microssatélites nucleares e cloroplastidiais. Foi utilizada uma estratégia de desenvolvimento de iniciadores que se baseia no seqüenciamento aleatório de fragmentos provenientes de uma biblioteca genômica shotgun para a detecção de regiões microssatélites, em barueiro. Das 668 sequências obtidas, foram encontradas 12 regiões microssatélites que possibilitaram a construção dos pares de iniciadores. Estas regiões são compostas por motivos com dois a seis nucleotídeos, que variam entre 136 a 380 pb. Isto mostra que a estratégia de sequenciamento aleatório a partir de bibliotecas shotgun é interessante por possibilitar a obtenção de iniciadores para regiões repetitivas com diferentes motivos. Dois destes locos (Da_E06 e Da_E12) foram polimórficos, apresentando três alelos cada. As estimativas de He para estes locos apresentaram valores satisfatórios, considerando o número de alelos, e foram iguais a 0,2946 e 0,2879, respectivamente. Isto indica que os iniciadores desenvolvidos e padronizados com sucesso neste trabalho podem ser utilizados para estudos genético-populacionais. Juntamente com estes dois iniciadores desenvolvidos, foi utilizado outro transferido da espécie Phaseolus vulgaris (BM164) para D. alata, além de outros dois iniciadores microssatélites cloroplastidiais para análises moleculares de 23 subpopulações georeferenciadas, totalizando 775 plantas, distribuídas ao longo da área de ocorrência natural do Cerrado. Destas plantas, 210 foram coletadas e georreferenciadas uma a uma, ao longo das margens do alto rio Araguaia nos estados de Mato-Grosso (RAMT) e Goiás (RAGO), para análises de distribuição espacial da variabilidade genética em escala local. Para testar a hipótese de que a variabilidade genética das subpopulações de D. alata se distribui conforme o modelo central-periférico, foram avaliadas as relações entre as estimativas de parâmetro genético de diversidade com os padrões de distribuição potencial da espécie. Foi observado que as subpopulações de D. alata apresentam consideráveis níveis de variabilidade genética que se encontra significativamente estruturada entre as subpopulações, tanto para os dados nucleares quanto para os cloroplastidiais, apresentando-se também estruturada no espaço. A estimativa da taxa de fecundação cruzada aparente (ta = 1,0575) indica que a espécie seja alógama. As estimativas das razões de migração via pólen e via semente foram menores do que 1, o que indica que a dispersão de sementes contribui mais efetivamente para o fluxo gênico total em escala regional. As estimativas dos parâmetros genéticos de diversidade referentes à população contígua ao Rio Araguaia mostraram valores semelhantes entre as margens do rio. A estimativa da taxa de fecundação cruzada aparente (0,9434) confirma a reprodução por alogamia no barueiro. O baixo nível de diferenciação entre as subpopulações das duas margens do rio indica que o rio Araguaia não confere uma barreira física efetiva ao fluxo gênico. O tamanho efetivo de vizinhança, ou seja, o número médio de indivíduos numa área onde ocorre panmixia, para os dados nucleares e cloroplastidiais foi igual a 85,64 e 22,99, respectivamente, indicando que a dispersão de sementes é mais restrita em escala local. O correlograma gerado a partir dos dados cloroplastidiais apresenta um padrão clinal de variação mais evidente do que o proveniente dos dados nucleares, o que sugere que a presença da estrutura genética espacial deve estar sendo mais influenciada pelo padrão de dispersão da semente. Foi observado que parâmetros genéticos estimados para D. alata não se enquadram no clássico modelo central-periférico, pois as populações tidas como periféricas (de acordo com a distribuição geográfica dos pontos de coleta) tendem a exibir maiores valores para estas estimativas, com destaque para as as subpopulações das bordas Sul e Oeste do bioma. A relação encontrada entre os valores estimados para o índice de fixação intrapopulacional (f) com o impacto humano indica que as subpopulações estudadas podem estar sofrendo as conseqüências dos processos de fragmentação e uso da terra na variabilidade genética, causado provavelmente pelo recente processo de ocupação do Cerrado.

The genetic diversity and genetic structure of populations, and the processes shaping gene flow within and between populations, are influenced by the landscapes they occur within. Within terrestrial landscapes, rivers and their riparian habitat are among the most dynamic, diverse and complex of landscapes and their linear structure appears as an interlinking feature across large landscapes. This thesis took a landscape genetics approach to examine the influence of river landscape features on Alnus glutinosa populations, a widespread keystone tree species of European riparian ecosystems. By accounting for the differing dispersal mechanisms of A. glutinosa (wind and water), landscape effects on seed- and pollen-mediated gene flow, genetic diversity, demographic and genetic structure were identified at different spatial scales of a large UK river catchment. Widespread gene flow within and between A. glutinosa populations was identified with no apparent limitation of wind-mediated pollen dispersal. Hydrochorous dispersal of seed between populations was evident, and found to increase genetic connectivity between riparian populations; however an isolation by distance effect was identified between populations located further apart from each other. No pattern of genetic diversity was found, with high levels of genetic diversity identified at all spatial and temporal scales. At the river-catchment scale no genetic clustering was observed, either within or between the six rivers studied. Demographic structuring within A. glutinosa populations was evident, and correlated with distance from the main river channel. Interactions between seed dispersal, hydrological disturbance, colonisation, and historical influences are discussed in relation to fine-scale spatial genetic structure between A. glutinosa sapling and adult generations. Central to the landscape genetics approach taken in this thesis was the incorporation of key A. glutinosa life history attributes. By incorporating gene flow analyses, species ecology and landscape features, the research presented here furthers our understanding of riverine landscape influences on their riparian populations at different spatial scales and can be used to inform management principles.

Abstract Many waders are in decline, and the number of endangered species and populations is increasing. Their protection and management requires knowledge of both ecological and genetic state of the populations. In this thesis, I studied the distribution-wide genetic variation, structure and phylogeography of the Temminck’s Stint (Calidris temminckii) and Terek Sandpiper (Xenus cinereus) using microsatellites and sequence data from the mitochondrial control region and cytochrome oxidase I gene. I compared these regionally endangered species to other waders with varying evolutionary histories, breeding systems and habitat preferences to examine the levels of genetic variation and structure at different spatial scales. In addition, I studied the genetic structure of the endangered Baltic population of the Southern Dunlin (Calidris alpina schinzii) with microsatellites. I used genetic information in all three study species to determine units for conservation. The Temminck’s Stint and Terek Sandpiper, both not restricted to the Arctic, had low distribution-wide structuring. They also had quite low levels of variation when compared to other species breeding at similar latitudes, indicating reductions in population sizes during past climate changes. Especially the peripheral breeding populations were differentiated and showed signs of inbreeding and genetic drift when compared to the main range. The Temminck’s Stint populations at the Bothnian Bay and Yakutia, and Terek Sandpiper populations in Finland and Belarus, should be treated as separate management units. The broader interspecific comparison of waders suggests that habitat availability, mating system and the extent of philopatry may affect the genetic composition of species. The genetic analyses of the Southern Dunlin indicated strong effects of philopatry and inbreeding throughout the range. Local subpopulations at the Bothnian Bay and in Sweden need to be considered as separate management units. Management efforts at the Baltic should be focused on increasing connectivity and providing large enough breeding habitats for potential immigrants and recruits. / Tiivistelmä Useat kahlaajapopulaatiot ovat pienentyneet ja uhanalaistuneet maailmanlaajuisesti. Lajien ja populaatioiden ekologiaa ja genetiikkaa on tunnettava, jotta suojelutoimia voidaan kohdistaa oikein. Tutkin väitöskirjassani lapinsirrin (Calidris temminckii) ja rantakurvin (Xenus cinereus) geneettistä rakennetta, muuntelua ja fylogeografiaa levinneisyysalueen laajuisesti mikrosatelliittien ja mitokondrion kontrollialueen ja sytokromioksidaasi I -geenin sekvenssien avulla. Tutkin, mitkä tekijät vaikuttavat geneettisen rakenteeseen ja muunteluun vertaamalla näitä lajeja muihin kahlaajiin, joilla on erilaisia lisääntymisstrategioita, jotka pesivät vaihtelevissa ympäristöissä ja joista monet eroavat toisistaan myös fylogeografialtaan. Lisäksi tutkin Itämeren rannalla pesivän etelänsuosirrin (Calidris alpina schinzii) geneettistä populaatiorakennetta mikrosatelliittien avulla. Käytin geneettistä tietoa hyväksi luonnonsuojeluyksikköjen määrittämisessä kaikille kolmelle tutkimuslajilleni. Lapinsirrin ja rantakurvin fylogeografinen historia oli samankaltainen. Geneettisen muuntelun määrä oli vähäisempää verrattuna muihin, samankaltaisissa ympäristöissä pesiviin kahlaajiin. Molemmat lajit ovat todennäköisesti kärsineet historiallisten ilmaston-muutosten aiheuttamasta populaatioiden pienenemisestä. Erityisesti levinneisyysalueen reunoilla pesivät populaatiot olivat erilaistuneita, ja niissä näkyi sukusiitoksen ja geneettisen satunnaisajautumisen merkkejä. Perämeren ja Jakutian lapinsirri- sekä Valko-Venäjän ja Suomen rantakurvipopulaatioita tulee kohdella erillisinä suojeluyksiköinään. Vertailu muihin kahlaajiin osoitti, että niin pesimä- ja talvehtimisalueiden laajuus kuin lisääntymisstrategiat ja paikkauskollisuus voivat vaikuttaa lajien geneettiseen koostumukseen. Etelänsuosirrin geneettiset analyysit paljastivat merkkejä sukusiitoksesta, joita paikkauskollisuus ja populaatioiden pienuus ovat voimistaneet. Perämeren ja Ruotsin populaatioita tulee kohdella erillisinä suojeluyksiköinään. Suojelutoimet on kohdistettava tarpeeksi suurien, hyvälaatuisten pesimäpaikkaverkostojen ylläpitämiseen.

Si les patrons d'expression de la diversité génétique des essences forestières à distribution grégaire des forêts tropicales humides ont fait l'objet de nombreuses études, les connaissances sur les essences forestières disséminées et représentées à très faible densité à l'hectare (dites rares) restent encore embryonnaires. Ces dernières suivent elles les mêmes patrons de distribution de la diversité génétique? Quels facteurs biotiques et abiotiques régissent l'organisation spatiale et l'évolution de la diversité génétique chez ce type d'espèce ? Afin d'améliorer les connaissances sur la biologie des espèces rares, nous nous proposons au travers de marqueurs microsatellites nucléaires(nuc) et chloroplastiques(cp) (i) d'analyser le régime de reproduction chez une espèce rare (ii) d'évaluer sa capacité de dispersion des gènes via les graines et le pollen , et enfin de(iii) décrire l'organisation spatiale de la diversité génétique à fine et à large échelle. Nous avons abordé ces questions avec Baillonella toxisperma (le Moabi), une essence commerciale dite rare (1 adulte/15ha à 20 ha), à multi- usages, représentée à travers les différentes écozones du bassin du Congo. Trois résultats majeurs découlent de nos travaux : (i) En dépit d'un isolement prononcé des adultes, B. toxisperma présente un régime de reproduction allogame prépondérant (tm ≈ 98%) avec des taux réduits d'autofécondation (1 - tm < 3%) probablement favorisé par la protandrie. (ii) Comme attendu dans le cas d'arbres disséminés, l'intensité de sa structure génétique spatiale à fine échelle est faible (Spnuc = 0.003 ; Spcp = 0.015) et reflète bien les flux de gènes à longues distances mesurés via le pollen [σp = 9.8 km à 10.8 km] et les graines [σs = 4.0 km à 6.3 km], probablement dû aux disperseurs efficaces que sont la chauve-souris, l'éléphant et l'homme. A large échelle spatiale, un signal phylogéographique a été détecté entre les individus situés de part et d'autre de l'équateur thermique, notamment entre ceux du massif forestier Camerounais et du Gabon (Rst = 0.313 > Rstp = 0.115, P < 0.001). Deux sous-groupes du massif forestier gabonais qui séparent les individus des forêts côtières de l'Ouest, de ceux des forêts planitaires de l'intérieur des terre, à l'Est, ont également été détectés, et présentent une différenciation génétique modérée (FST = 0.068, P < 0.001). La divergence génétique entre ces trois groupes pourrait s'expliquer par un isolement géographique qui remonterait aux perturbations climatiques du pléistocène et de l'Holocène sur la forêt tropicale humide africaine, et qui serait encore aujourd'hui maintenu par un isolement dans la reproduction du fait d'un asynchronisme dans la période de floraison entre leurs individus. La mise en évidence de ces trois groupes génétiques suggère une répartition biogéographique de B. toxisperma dans le bassin du Congo en partie façonnée par le climat actuel et passé. Nos conclusions peuvent servir d'outils d'aide à la décision pour les programmes de conservation et d'aménagement durable de la biodiversité en Afrique centrale. / If genetic diversity patterns of gregarious rainforest forest trees are well known, few knowledges are available about low density tree species. Does those last one follow the same genetic distribution pattern? Which biotic and abiotic factors underline the spatial structure and evolution of the genetic diversity of such species? In order to improve the knowledge of the biology of such species, we have propose through nuclear microsatellite(nuc) and chlorosplastic (cp) markers to (i) analyse the reproductive system of a low density tree species, (ii) assess its dispersal capacity through seeds and pollen, and finally to (iii) describe the spatial genetic structure at a fine and large scale. We have addressed those questions with Baillonella toxisperma Pierre (commonly named Moabi), a commercial tree of many uses, known to be rare (1 ind/15ha à 20 ha) and distributed through different ecologicals areas of Congo basin. Three main results rise from our study: (i) Despite a strong isolation of the adults, B. toxisperma has a dominant allogamous reproductive system (tm ≈ 98%) with a reduce rate of self-pollination (1- tm< 3%) which is probably due to occurrence of protandry. (ii) As expected in the case of low density trees, the spatial statistic (Sp) of the fine spatial genetic structure is very low [Spnuc = 0.003 ; Spcp = 0.015]. Those reflected a very high gene flow mediated through pollen [σp = 9.8 km à 10.8 km] and seeds [σs = 4.0 km à 6.3 km], that probably mediated by efficient dispersal vectors like bats, human and elephant. At a large scale, a phylogenetic signal has been detected between individuals located in both side of the thermic equator, mainly between those from the block forest of Cameroon and Gabon [RST = 0.313 > RSTp = 0.115, P < 0.001]. Two discretes genetics units from the Gabon block forest which separate individuals of the West coastal forests from the lowland forest ones (in the inland) have also been detected and showed a moderate genetic differentiation [FST = 0.068, P < 0.001]. The genetic differentiation between these three units could be explained by a geographical isolation during past climatic disturbances in the African rainforest, occurred in the Pleistocene and Holocene, and which will be still maintained up to date by a reproductive isolation caused by flowering asynchrony periods among individuals. The occurrence of these three genetic units suggests a biogeographical repartition of B. toxisperma in the Congo basin that is mainly due to the past and current climate. Our conclusions may lead to implement conservation strategies and sustainable management programm for biodiversity in Central Africa.