Université de Montréal
Candidat Postdoctoral fellow
superviseur(e): Simon Joly
Dr. Muthama Muasya
Début: 2017-01-15
Fin: 2019-01-15
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Projet

Speciation and genome sizes in Schoenus (tribe Schoeneae)
Differences in genome sizes can be used to suggest which plant taxa have hybridized to create subsequent polyploids. For example, preliminary screening for differences in genome sizes in the ‘Schoenus’ clade of tribe Schoeneae of Cyperaceae (sedges) indicates that genomes are much larger within compared to outside of the clade, suggesting the existence of hybridization and polyploidy among these species (preliminary data). In addition, evolutionary relationships among ‘Schoenus’ species are predicted to be complex as hybridization is likely among them and because the clade is relatively young and most of the species are endemic to a relatively small area in southern Africa. Objectives: The general objective of this study is to determine the relative contribution of polyploidy and hybridization in the evolution of the ‘Schoenus’ clade. To address this, intensive study of morphological differences among ‘Schoenus’ sedges is critical to identify proper species and help in deciphering the evolutionary relationships within the clade. More specifically, this study aims to do the following: 1) to obtain genome size data for all species of the ‘Schoenus’ clade native to southern Africa; 2) to acquire chromosome number data for all species of the ‘Schoenus’ clade native to southern Africa; 3) to revise the taxonomy of the South African ‘Schoenus’ clade of sedges; and 4) to decipher evolutionary relationships within the ‘Schoenus’ clade of sedges in southern Africa.

Mots-clés

taxonomy, plants, South Africa, genome sizes, chromosome number, polyploidy, Cyperaceae, Schoenus

Publications

1- Challenges to barcoding an entire flora
Elliott, Tammy L., T. Jonathan Davies
2014 Molecular Ecology Resources

2- Effects of Simulated Grazing in Ungrazed Wet Sedge Tundra in the High Arctic
Elliott, Tammy L., Gregory H. R. Henry
2011 Arctic, Antarctic, and Alpine Research

3- Community restructuring can maintain diversity across a severity gradient in the absence of foundation species
Harris, Liam W., Tammy L. Elliott, T. Jonathan Davies
2014 Ecosphere

4- Contrasting lineage-specific patterns conceal community phylogenetic structure in larger clades
Elliott, Tammy L., Marcia J. Waterway, T. Jonathan Davies,
2016 Journal of Vegetation Science

5- Taxonomic realignment in the southern African Tetraria (Cyperaceae, tribe Schoeneae; Schoenus clade)
Elliott, T.L., A.M. Muasya
2017 South African Journal of Botany

6- Jointly modeling niche width and phylogenetic distance to explain species co-occurrence
Elliott, Tammy L., T. Jonathan Davies
2017 Ecosphere

7- Understanding the Processes Underpinning Patterns of Phylogenetic Regionalization
Daru, Barnabas H., Tammy L. Elliott, Daniel S. Park, T. Jonathan Davies
2017 Trends in Ecology & Evolution