Gregory W Stull1, Rodrigo Duno de Stefano2, Douglas E Soltis3, Pamela S Soltis4. 1. Department of Biology, University of Florida, Gainesville, Florida 32611-8525 USA Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800 USA gwstull@gmail.com. 2. Herbario CICY, Centro de Investigación Científicas de Yucatán A. C., Mérida, Yucatán 97200 Mexico. 3. Department of Biology, University of Florida, Gainesville, Florida 32611-8525 USA Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800 USA. 4. Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800 USA.
Abstract
PREMISE OF THE STUDY: Major relationships within Lamiidae, an asterid clade with ∼40000 species, have largely eluded resolution despite two decades of intensive study. The phylogenetic positions of Icacinaceae and other early-diverging lamiid clades (Garryales, Metteniusaceae, and Oncothecaceae) have been particularly problematic, hindering classification and impeding our understanding of early lamiid (and euasterid) character evolution. METHODS: To resolve basal lamiid phylogeny, we sequenced 50 plastid genomes using the Illumina sequencing platform and combined these with available asterid plastome sequence data for more comprehensive phylogenetic analyses. KEY RESULTS: Our analyses resolved basal lamiid relationships with strong support, including the circumscription and phylogenetic position of the enigmatic Icacinaceae. This greatly improved basal lamiid phylogeny offers insight into character evolution and facilitates an updated classification for this clade, which we present here, including phylogenetic definitions for 10 new or converted clade names. We also offer recommendations for applying this classification to the Angiosperm Phylogeny Group (APG) system, including the recognition of a reduced Icacinaceae, an expanded Metteniusaceae, and two orders new to APG: Icacinales (Icacinaceae + Oncothecaceae) and Metteniusales (Metteniusaceae). CONCLUSIONS: The lamiids possibly radiated from an ancestry of tropical trees with inconspicuous flowers and large, drupaceous fruits, given that these morphological characters are distributed across a grade of lineages (Icacinaceae, Oncothecaceae, Metteniusaceae) subtending the core lamiid clade (Boraginales, Gentianales, Lamiales, Solanales, Vahlia). Furthermore, the presence of similar morphological features among members of Aquifoliales suggests these characters might be ancestral for the Gentianidae (euasterids) as a whole.
PREMISE OF THE STUDY: Major relationships within Lamiidae, an asterid clade with ∼40000 species, have largely eluded resolution despite two decades of intensive study. The phylogenetic positions of Icacinaceae and other early-diverging lamiid clades (Garryales, Metteniusaceae, and Oncothecaceae) have been particularly problematic, hindering classification and impeding our understanding of early lamiid (and euasterid) character evolution. METHODS: To resolve basal lamiid phylogeny, we sequenced 50 plastid genomes using the Illumina sequencing platform and combined these with available asterid plastome sequence data for more comprehensive phylogenetic analyses. KEY RESULTS: Our analyses resolved basal lamiid relationships with strong support, including the circumscription and phylogenetic position of the enigmatic Icacinaceae. This greatly improved basal lamiid phylogeny offers insight into character evolution and facilitates an updated classification for this clade, which we present here, including phylogenetic definitions for 10 new or converted clade names. We also offer recommendations for applying this classification to the Angiosperm Phylogeny Group (APG) system, including the recognition of a reduced Icacinaceae, an expanded Metteniusaceae, and two orders new to APG: Icacinales (Icacinaceae + Oncothecaceae) and Metteniusales (Metteniusaceae). CONCLUSIONS: The lamiids possibly radiated from an ancestry of tropical trees with inconspicuous flowers and large, drupaceous fruits, given that these morphological characters are distributed across a grade of lineages (Icacinaceae, Oncothecaceae, Metteniusaceae) subtending the core lamiid clade (Boraginales, Gentianales, Lamiales, Solanales, Vahlia). Furthermore, the presence of similar morphological features among members of Aquifoliales suggests these characters might be ancestral for the Gentianidae (euasterids) as a whole.
Authors: Tristan Charles-Dominique; T Jonathan Davies; Gareth P Hempson; Bezeng S Bezeng; Barnabas H Daru; Ronny M Kabongo; Olivier Maurin; A Muthama Muasya; Michelle van der Bank; William J Bond Journal: Proc Natl Acad Sci U S A Date: 2016-09-06 Impact factor: 11.205
Authors: Patrick P Edger; Ronald Smith; Michael R McKain; Arielle M Cooley; Mario Vallejo-Marin; Yaowu Yuan; Adam J Bewick; Lexiang Ji; Adrian E Platts; Megan J Bowman; Kevin L Childs; Jacob D Washburn; Robert J Schmitz; Gregory D Smith; J Chris Pires; Joshua R Puzey Journal: Plant Cell Date: 2017-08-16 Impact factor: 11.277
Authors: Nan Lin; Michael J Moore; Tao Deng; Hang Sun; Lin-Sen Yang; Yan-Xia Sun; Heng-Chang Wang Journal: Appl Plant Sci Date: 2018-04-27 Impact factor: 1.936