Marylaure De La Harpe

Master Student

The current master project is entitled “Phylogeography and biogeograohy of the polyploidy complex of the polyploidy complex of Alyssum montanum L. (Brassicaceae) focusing on the relationships between Alyssum cuneifolium L . and Alyssum loiseleurii P. Fourn.”. It is about solving the relationship between two plants species which are amount the  same polyploid taxa :  Alyssum cueifolium L. and Alyssum loiseleurii P.Fourn. (Brassicacea). Both share similar morphologies and ploidy levels, namely 2n = 4x. But they are growing at two different vegetation stages in a substrate under the similar pedogenetic dynamic. Alyssum cuneifolium is an orophyt growing on the calcareous screes above 1800 m and Alyssum loiseleurii is an arenicol species growing on the sand dunes of the Atlantic Coast.  Their geographical distribution (Pyrennee and Gascogne Gulf) let to think that one plant could have evolved from the other during the last interglacial period about 10,000 years ago. Note that at least one other species from the alpine zone of the Pyrenees already has an adjoining taxa on the sand dune in the Region of the Gascogne Gulf : Jasione crispa (Pourr.) Samp. var. atlantica (Ball) P.Küpfer.

The aim of this master project is to conduct a classical phylo - and bio - geographical study in order to retrace the evolutionary relationships between plant populations in regard to their ecological preferences (i.e.  growth substrate) and their current European geographical distribution.
For this purpose, chromosomal (flow cytometry and chromosomal count), molecular (genome fingerprinting: AFLP and genome sequencing: cpDNA) and mapping data (ArcGIS) are analyzed.  The field work was performed during the summer 2011 in order to collect the plant material (dryed silica-gel leaves and fixed flower buds) from various region of Europe. The molecular and the chromosomal analyses are running at the University of Lausanne, Neuchatel and Bratislava.
This master project was suggested by Prof. hon. Philippe Küpfer and I am supervised by Dr. Nadir Alvarez of the Departement of Evolution and Ecology (DEE) of the University of Lausanne and by Prof. Jean-Michel Gobat of the Laboratory of Soil and Vegetation of the University of Neuchâtel in the master cursus Biogeosciences.  The sampling and molecular analysis is done in collaboration with the group Prof. Karol Marhold of the Botanical Institute of Bratislava (SL), and Dr. Bozo Frajmann research group of the University of Innsbruck (AU).