Abstract Detail

Systematics Section/ASPT

Waterway, Marcia J. [1], Prado, Alberto [2], Bruhl, Jeremy [3], Gehrke, Berit [4], Hoshino, Takuji [5], Jin, Xiao-Feng [6], Luceño, Modesto [7], Masaki, Tomomi [8], Phulphong, Kamolhathai [9], Simpson, David [10], Wilson, Karen [11], Zhang, Shuren [12].

Testing sectional monophyly in Carex (Cyperaceae).

Classification of diverse, species-rich genera into sections gives useful perspectives on the distribution of this diversity across global geographic and ecological gradients and aids in identification of unknown samples. Sectional classification within Carex (Cyperaceae) has a long, confusing history and many of the currently recognized sections appear to be paraphyletic or polyphyletic based on recent molecular studies. To develop a new sectional classification that better represents evolutionary relationships, we need a phylogenetic framework. We present here a phylogenetic hypothesis for about 1/8^th of the species of Carex and its embedded segregate genera based on 9 DNA regions: two nuclear ribosomal spacers (ETS, ITS), two plastid coding genes (matK, rbcL), and five plastid introns or spacers, comprising a total of more than 8000 aligned positions, with 45% of the informative characters from ITS and ETS, 15% from coding genes, and 40% from plastid introns and spacer regions, with only 2% missing data. The tree comprises 250 species including 8 outgroups and representative sampling from the major Carex clades: Core Carex (153 spp.), Core Vignea (39 spp.), Core Unispicate (27 spp.), Schoenoxiphium clade (16 spp.), and Siderostictae clade (7 Spp.). Taxon sampling was designed to represent as many sections as possible and to represent six continents in proportions roughly equivalent to the actual distribution pattern, but North America remains over-represented and Asia under-represented. The resulting phylogenetic tree provides very strong support for all major clades and the relationships among them, with the Asian Siderostictae clade sister to the rest of the group, and Asian subclades as the earliest diverging lineages in both the Core Carex and Core Vignea clades. We use this tree to test sectional monophyly by adding samples with more complete taxon sampling of the target section(s) but fewer DNA regions per species, and reanalyzing the data. We illustrate three examples of polyphyletic groupings: sections Hymenochlaenae, Mitratae, and subgenus Vigneastra, as well as three examples where species from multiple sections form strongly supported subclades within the Core Carex clade: the Laxiforae/Paniceae/Bicolores group and the Griseae/ Careyanae/ Granulares group. We invite discussion on criteria for developing new, more natural sectional circumscriptions.

1 - McGill University, Plant Science-Macdonald Campus, 21111Lakeshore, Ste-Anne-de-Bellevue, QC, H9X 3V9, Canada
2 - McGill University, Plant Science-Macdonald Campus, 21111 Lakeshore, Ste-Anne-de-Bellevue, QC, H9X 3V9, Canada
3 - University of New England, Botany, N.C.W. Beadle Herbarium, Armidale, NSW, 2351, Australia
4 - Johannes Gutenberg Universitat, Institut fur Spezielle Botanik und Botanischer Garten, Mainz, 55099, Germany
5 - Okayama University Of Science, Faculty Of Informatics, Kitaku, Ridai-cho, 1-1, Okayama, N/A, 700-0005, Japan
6 - Hangzhou Normal University, Life and Environmental Science, 16 Xuelin St., Hangzhou, Zhejiang, 310036, P.R. China
7 - Universidad Pablo de Olavide, Molecular Biology and Biochemical Engineering, Carretera de Utrera sn, Seville, 41013, Spain
8 - Okayama University of Science, Biosphere-Geosphere Science, Ridai-cho 1-1, Kita-ku, Okayama-shi, Okayama, 700-0005, Japan
9 - Mahasarakham University, Biology, Mueang Maha Sarakham District, Maha Sarakham, 44150, Thailand
10 - Royal Botanic Gardens, Kew, Herbarium, Richmond, Surry, TW9 3AB, UK
11 - Royal Botanic Gardens & Domain Trust, Mrs Macquaries Road, Sydney, N/A, NSW 2000, Australia
12 - Institute of Botany, Chinese Academy of Sciences, State Key Laboratory of Systematics & Evolutionary Biology, Xiangshan, Beijing, 100093, P.R. China

Keywords:
Carex
Cyperaceae
molecular phylogeny
infrageneric classification.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PSY015
Abstract ID:1038
Candidate for Awards:None