2024-09-272024-09-272024-04-30Valdés Florido, A., González Toral, C., Maguilla Salado, E., Cires, E., Díaz Lifante, Z.M., Andrés Camacho, M.C.,...,Escudero Lirio, M. (2024). Polyploidy and hybridization in the Mediterranean: unravelling the evolutionary history of Centaurium (Gentianaceae).. Annals of Botany, 134 (2), 247-262. https://doi.org/10.1093/aob/mcae066.0305-73641095-8290https://hdl.handle.net/11441/162980• Background and Aims Polyploidy is considered one of the main mechanisms of plant evolution and speciation. In the Mediterranean Basin, polyploidy has contributed to making this region a biodiversity hotspot, along with its geological and climatic history and other ecological and biogeographical factors. The Mediterranean genus Centaurium (Gentianaceae) comprises ~25 species, of which 60 % are polyploids, including tetraploids and hexaploids. To date, the evolutionary history of centauries has been studied using Sanger sequencing phylogenies, which have been insuffcient to fully understand the phylogenetic relationships in this lineage. The goal of this study is to gain a better understanding of the evolutionary history of Centaurium by exploring the mechanisms that have driven its diversifcation, specifcally hybridization and polyploidy. We aim to identify the parentage of hybrid species, at the species or clade level, as well as assessing whether morphological traits are associated with particular ploidy levels. • Methods We sequenced RADseq markers from 42 samples of 28 Centaurium taxa, and performed phylogenomic analyses using maximum likelihood, summary coalescent SVDquartets and Neighbor-Net approaches. To identify hybrid taxa, we used PhyloNetworks and the fastSTRUCTURE algorithm. To infer the putative parental species of the allopolyploids, we employed genomic analyses (SNIPloid). The association between different traits and particular ploidy levels was explored with non-metric multidimensional scaling. • Key Results Our phylogenetic analyses confrmed the long-suspected occurrence of recurrent hybridization. The allopolyploid origin of the tetraploid C. serpentinicola and the hexaploids C. mairei, C. malzacianum and C. centaurioides was also confrmed, unlike that of C. discolor. We inferred additional signatures of hybridization events within the genus and identifed morphological traits differentially distributed in different ploidy levels. • Conclusions This study highlights the important role that hybridization has played in the evolution of a Mediterranean genus such as Centaurium, leading to a polyploid complex, which facilitated its diversifcation and may exemplify that of other Mediterranean groups.application/pdf16 p.engAtribución 4.0 Internacionalhttp://creativecommons.org/licenses/by/4.0/AllopolyploidycentaurieshybridizationMediterraneanplant evolutionpolyploidyRADseqinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess10.1093/aob/mcae066