Polyploidisation or whole genome duplication (WGD), is a widespread phenomena amongst
Eukaryotes but is especially abundant in the plant lineage. The extra genome copy can open a road
to evolutionary success by providing genetic material that is free to evolve new functionalities.
Nevertheless, WGD is generally not well tolerated due to subsequent changes in cell geometry and
genomic shock. Consequently the successful establishment of polyploids is somewhat shrouded in
mystery. Previous work in our lab revealed that many plant polyploids became established during
the Cretaceaus-Paleogene mass extinction. Because present-day polyploids are especially
abundant in stressful environments as the arctic and polyploids might have a higher adaptive
potential due to their increased genetic variation and changes in gene expression, stressful
conditions could be a catalyst for the polyploid establishment. Here we propose the use of a long
term evolutionary experiment to test this hypothesis, to assess the effect of the evolutionary
distance between the two genomes brought together and to study the stabilisation of the
polyploid genome. First, we will construct polyploid strains. Second, we will subject them to a wide
variety of stressors and monitor their ploidy level and fitness. Finally a few successful lineages will
be selected and the genomic features that allow their success will be identified by sequencing
their complete genomes every few generations.