Resolving the Phylogeny of the Olive Family (Oleaceae): Confronting Information from Organellar and Nuclear Genomes

• Main Authors: Julia Dupin, Pauline Raimondeau, Cynthia Hong-Wa, Sophie Manzi, Myriam Gaudeul, Guillaume Besnard
• Format: Article in Journal/Newspaper
• Language: English
• Published: Zenodo 2020
• Subjects: herbarium; museum collection; mitochondrial DNA; plastome; nuclear ribosomal DNA; phytochromes; low-copy genes; taxonomy; polyploidy; Antarc*; Antarctica
• Online Access: https://doi.org/10.5281/zenodo.7445727

The olive family, Oleaceae, is a group of woody plants comprising 28 genera andca. 700 species, distributed on all continents (except Antarctica) in both temperate and tropicalenvironments. It includes several genera of major economic and ecological importance such as olives,ash trees, jasmines, forsythias, osmanthuses, privets and lilacs. The natural history of the group is notcompletely understood yet, but its diversification seems to be associated with polyploidisation eventsand the evolution of various reproductive and dispersal strategies. In addition, some taxonomicalissues still need to be resolved, particularly in the paleopolyploid tribe Oleeae. Reconstructinga robust phylogenetic hypothesis is thus an important step toward a better comprehension ofOleaceae’s diversity. Here, we reconstructed phylogenies of the olive family using 80 plastidcoding sequences, 37 mitochondrial genes, the complete nuclear ribosomal cluster and a smallmultigene family encoding phytochromes ( phyB and phyE ) of 61 representative species. Tribes andsubtribes were strongly supported by all phylogenetic reconstructions, while a few Oleeae generaare still polyphyletic ( Chionanthus, Olea, Osmanthus, Nestegis ) or paraphyletic ( Schrebera, Syringa ).Some phylogenetic relationships among tribes remain poorly resolved with conflicts betweentopologies reconstructed from different genomic regions. The use of nuclear data remains animportant challenge especially in a group with ploidy changes (both paleo- and neo-polyploids).This work provides new genomic datasets that will assist the study of the biogeography and taxonomyof the whole Oleaceae.