Microsatellite Development and Flow Cytometry in the African Tree Genus Afzelia (Fabaceae, Caesalpinioideae) Reveal a Polyploid Complex

Premise of the study: Microsatellites were developed in the vulnerable African rainforest tree Afzelia bipindensis to investigate gene flow patterns. Methods and Results: Using 454 GS-FLX technique, 16 primer sets were identified and optimized, leading to 11 polymorphic and readable markers displaying each six to 25 alleles in a population. Up to four alleles per individual were found in each of the loci, without evidence of fixed heterozygosity, suggesting an autotetraploid genome. Cross-Amplification succeeded for all loci in the African rainforest species A. pachyloba and A. bella ,which appeared tetraploid, and for most loci in the African woodland species A. africana and A. quanzensis ,which appeared diploid, but failed in the Asian species A. xylocarpa Flow cytometry confirmed the suspected differences in ploidy. Conclusions: African Afzelia species are diploid or tetraploid, a situation rarely documented in tropical trees. These newly developed microsatellites will help in the study of their mating system and gene flow patterns.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Are we underestimating the number of plant species in the tropics? New insights from population genetics approaches applied on African forest trees

info:eu-repo/semantics/nonPublishe

Are there many cryptic plant species in the tropics? New insights from population genetics approaches applied on African rain forest trees

info:eu-repo/semantics/nonPublishe

Population genetics data reveal many new tree species in the African flora - cryptic and less cryptic ones

info:eu-repo/semantics/nonPublishe

Are we underestimating the number of plant species in the tropics? New insights from population genetics approaches applied on African forest trees

info:eu-repo/semantics/nonPublishe

Revealing hidden species diversity in closely related species using nuclear SNPs, SSRs and DNA sequences - a case study in the tree genus Milicia

Background: Species delimitation in closely related plant taxa can be challenging because (i) reproductive barriers are not always congruent with morphological differentiation, (ii) use of plastid sequences might lead to misinterpretation, (iii) rare species might not be sampled. We revisited molecular-based species delimitation in the African genus Milicia, currently divided into M. regia (West Africa) and M. excelsa (from West to East Africa). We used 435 samples collected in West, Central and East Africa. We genotyped SNP and SSR loci to identify genetic clusters, and sequenced two plastid regions (psbA-trnH, trnC-ycf6) and a nuclear gene (At103) to confirm species' divergence and compare species delimitation methods. We also examined whether ecological niche differentiation was congruent with sampled genetic structure. Results: West African M. regia, West African and East African M. excelsa samples constituted three well distinct genetic clusters according to SNPs and SSRs. In Central Africa, two genetic clusters were consistently inferred by both types of markers, while a few scattered samples, sympatric with the preceding clusters but exhibiting leaf traits of M. regia, were grouped with the West African M. regia cluster based on SNPs or formed a distinct cluster based on SSRs. SSR results were confirmed by sequence data from the nuclear region At103 which revealed three distinct ‘Fields For Recombination' corresponding to (i) West African M. regia, (ii) Central African samples with leaf traits of M. regia, and (iii) all M. excelsa samples. None of the plastid sequences provide indication of distinct clades of the three species-like units. Niche modelling techniques yielded a significant correlation between niche overlap and genetic distance. Conclusions: Our genetic data suggest that three species of Milicia could be recognized. It is surprising that the occurrence of two species in Central Africa was not reported for this well-known timber tree. Globally, our work highlights the importance of collecting samples in a systematic way and the need for combining different nuclear markers when dealing with species complexes. Recognizing cryptic species is particularly crucial for economically exploited species because some hidden taxa might actually be endangered as they are merged with more abundant species.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Seed and pollen dispersal of African timber tree species – implications for sustainable forest exploitation

info:eu-repo/semantics/nonPublishe

Population genetics data of tropical African trees suggest that species richness is largely underestimated due to cryptic species and taxonomic over-lumping

info:eu-repo/semantics/nonPublishe

History of the Guineo-Congolian forest: insights from phylogeographic patterns in plants

info:eu-repo/semantics/nonPublishe