Alexandre Antonelli1,2,3, James J Clarkson1, Kent Kainulainen4, Olivier Maurin1, Grace E Brewer1, Aaron P Davis1, Niroshini Epitawalage1, David J Goyder1, Tatyana Livshultz5, Claes Persson2, Lisa Pokorny1, Shannon C K Straub6, Lena Struwe7, Alexandre R Zuntini1, Félix Forest1, William J Baker1. 1. Royal Botanic Gardens, Kew, TW9 3AE, UK. 2. Gothenburg Global Biodiversity Centre, Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, 405 30, Sweden. 3. Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK. 4. Gothenburg Botanical Garden, Carl Skottsbergs gata 22 A, Gothenburg, 413 19, Sweden. 5. Department of Biodiversity Earth and Environmental Sciences and Academy of Natural Sciences, Drexel University, 1900 Benjamin Franklin Parkway, Philadelphia, PA, 19103, USA. 6. Department of Biology, Hobart and William Smith Colleges, 300 Pulteney Street, Geneva, NY, 14456, USA. 7. Department of Ecology, Evolution, and Natural Resources & Department of Plant Biology, Rutgers University, 59 Dudley Road, New Brunswick, NJ, 08901, USA.
Abstract
PREMISE: Comprising five families that vastly differ in species richness-ranging from Gelsemiaceae with 13 species to the Rubiaceae with 13,775 species-members of the Gentianales are often among the most species-rich and abundant plants in tropical forests. Despite considerable phylogenetic work within particular families and genera, several alternative topologies for family-level relationships within Gentianales have been presented in previous studies. METHODS: Here we present a phylogenomic analysis based on nuclear genes targeted by the Angiosperms353 probe set for approximately 150 species, representing all families and approximately 85% of the formally recognized tribes. We were able to retrieve partial plastomes from off-target reads for most taxa and infer phylogenetic trees for comparison with the nuclear-derived trees. RESULTS: We recovered high support for over 80% of all nodes. The plastid and nuclear data are largely in agreement, except for some weakly to moderately supported relationships. We discuss the implications of our results for the order's classification, highlighting points of increased support for previously uncertain relationships. Rubiaceae is sister to a clade comprising (Gentianaceae + Gelsemiaceae) + (Apocynaceae + Loganiaceae). CONCLUSIONS: The higher-level phylogenetic relationships within Gentianales are confidently resolved. In contrast to recent studies, our results support the division of Rubiaceae into two subfamilies: Cinchonoideae and Rubioideae. We do not formally recognize Coptosapelteae and Luculieae within any particular subfamily but treat them as incertae sedis. Our framework paves the way for further work on the phylogenetics, biogeography, morphological evolution, and macroecology of this important group of flowering plants.
PREMISE: Comprising five families that vastly differ in species richness-ranging from Gelsemiaceae with 13 species to the Rubiaceae with 13,775 species-members of the Gentianales are often among the most species-rich and abundant plants in tropical forests. Despite considerable phylogenetic work within particular families and genera, several alternative topologies for family-level relationships within Gentianales have been presented in previous studies. METHODS: Here we present a phylogenomic analysis based on nuclear genes targeted by the Angiosperms353 probe set for approximately 150 species, representing all families and approximately 85% of the formally recognized tribes. We were able to retrieve partial plastomes from off-target reads for most taxa and infer phylogenetic trees for comparison with the nuclear-derived trees. RESULTS: We recovered high support for over 80% of all nodes. The plastid and nuclear data are largely in agreement, except for some weakly to moderately supported relationships. We discuss the implications of our results for the order's classification, highlighting points of increased support for previously uncertain relationships. Rubiaceae is sister to a clade comprising (Gentianaceae + Gelsemiaceae) + (Apocynaceae + Loganiaceae). CONCLUSIONS: The higher-level phylogenetic relationships within Gentianales are confidently resolved. In contrast to recent studies, our results support the division of Rubiaceae into two subfamilies: Cinchonoideae and Rubioideae. We do not formally recognize Coptosapelteae and Luculieae within any particular subfamily but treat them as incertae sedis. Our framework paves the way for further work on the phylogenetics, biogeography, morphological evolution, and macroecology of this important group of flowering plants.
Authors: In-Su Choi; Domingos Cardoso; Luciano P de Queiroz; Haroldo C de Lima; Chaehee Lee; Tracey A Ruhlman; Robert K Jansen; Martin F Wojciechowski Journal: Front Plant Sci Date: 2022-02-23 Impact factor: 5.753