Format: ORAL

Laura Albreht1, Nils Bourland2, Bente Klitgrd3, Rowan Schley4, Steven B. Janssens5, Olivier J. Hardy1

1 Université Libre de Bruxelles, Unit of Evolutionary Biology and Ecology, Brussels, Belgium 2 Royal Museum for Central Africa, Service of Wood Biology, Tervuren, Belgium 3 Royal Botanic Gardens, Accelerated Taxonomy Department, Kew, Richmond, UK 4 University of Exeter, Department of Geography, Exeter, UK 5 Meise Botanic Garden, Meise, Belgium

Reliable delimitation of species is fundamental for establishing sustainable and equitable harvesting guidelines of economically important organisms. Pterocarpus (Fabaceae) is a pantropical genus of trees including several highly valuable timber-producing species that face significant threats from intensive logging. However, a lack of taxonomic clarity has hindered the advance of logging regulations and has led to the inclusion of all African Pterocarpus populations under CITES (CoP19). In our study, we addressed this issue by reassessing species delimitation of all twelve accepted African Pterocarpus species, including neotropical samples of the two pantropical species. Based on DNA sequences obtained by Angiosperms353 probe set, we reconstructed a comprehensive phylogeny combining maximum likelihood and multispecies coalescence approaches. Additionally, we explored the potential of high-copy DNA for identifying African Pterocarpus species. This involved reconstructing chloroplast and ribosomal DNA phylogenies, using genome skimming and maximum likelihood approaches. Our results confirmed the monophyly of eleven Pterocarpus species and a paraphyletic P. rotundifolius, presenting one Angolan subclade with the remaining subclades further subdivided in three geographically coherent groups, suggesting the possibility of cryptic diversity within the complex. A similar situation arose in P. lucens, which exhibited two sister clades with disjunct distributions. Species delimitation based on high-copy DNA was congruent with the Angiosperms353 data for most species, indicating the reliability of chloroplast and ribosomal DNA markers for Pterocarpus species identification. Our findings give valuable insights into African Pterocarpus species delimitation, highlighting the need for further investigation of potential cryptic diversity within P. rotundifolius and P. lucens. Finally, our study lays the groundwork for developing DNA-based tools aimed at improving logging regulations for African Pterocarpus species. Contact (presenting author): Laura.Albreht@ulb.be/laura.albreht@gmail.com