| Abstract Detail
Systematics Takawira-Nyenya, Ratidzayi [1], Mucina, Ladislav [2], Cardinal-McTeague, Warren [3], Thiele, Kevin [4]. Sansevieria (Snake plants) are a herbaceous clade within Dracaena (Dragon Trees): Inference from non-coding plastid and nuclear DNA sequence data. The evolutionary history of the dracaenoid genera Dracaena and Sansevieria (Asparagaceae, Nolinoideae) remains poorly resolved, despite their worldwide popularity as foliage ornamentals, indoor plants and medicinal plants. The aims of our study were to: shed light on the evolutionary relationships within and between Dracaena and Sansevieria using molecular phylogenetic inference of both nuclear (nDNA) and plastid (cpDNA) markers, to examine the infrageneric classifications of each genus, and to revise the circumscription of the dracaenoids in light of morphological and phylogenetic evidence. We sampled 21 accessions of Dracaena (ca. 19 species), 27 accessions of Sansevieria (ca. 26 species), and six outgroup taxa. We based Phylogenetic analyses on nucleotide sequences of two non-coding plastid DNA regions, the trnL-F region (trnL intron and trnL-trnF intergenic spacer) and rps16 intron, and the low-copy nuclear region At103. Phylogenetic hypotheses were constructed using maximum parsimony, maximum likelihood, and Bayesian inference. Individual datasets were analysed separately and as combined datasets after carrying out congruence tests. The dracaenoids constitute a strongly supported monophyletic group. Dracaena was resolved as a paraphyletic grade embedded with two clades of Sansevieria, a primary clade comprising most species, and a secondary clade including S. sambiranensis, a distinctive species from Madagascar. The backbone of our phylogeny was only resolved in nDNA analyses, but combined analyses recovered strongly supported species groups. Previously recognised infrageneric classifications were not supported supported by our phylogeny, and biogeographic groupings were frequently more significant than morphology. Based on our findings we support a recent proposal to recognise a broadened circumscription of Dracaena that includes Sansevieria. We provide a generic description for the recircumscribed Dracaena and new combinations for several species of Sansevieria in Dracaena. More work including expanded sampling and more DNA regions is underway to improve the resolution in our phylogeny and for furher uderstanding on the evolution and biogeographic patters in the newly circumscribed genus Dracaena
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1 - University of Oslo, Natural History Museum , , P.O. Box 1172, Blindern, 0218 Oslo, Oslo, Norway, +47
2 - Murdoch University , Harry Butler Institute, Building 390, Perth, Australia
3 - University of Ottawa , Department of Biology, Gendron Hall, 30 Marie Curie, Ottawa, Canada
4 - The University of Western Australia, School of Biological Sciences, 35 Stirling Highway, , Crawley, WA 6009, Perth, Australia
Keywords:
Africa
Chrysodracon
Hawaii
Kenya
Madagascar
Pleomele
zimbabwe.
Presentation Type: Oral Paper
Session: SYS5, Systematics V: Gymnosperms to Monocots part A
Location: Virtual/Virtual
Date: Friday, July 31st, 2020
Time: 1:15 PM
Number: SYS5004
Abstract ID:876
Candidate for Awards:None |
