Polyploidy (whole genome duplication via auto- or allopolyploidy) is an important process in angiosperm evolution. The here proposed project will use the impressive polyploid complex of the genus Leucanthemum (Compositae, Anthemideae) with 42 species representing an uninterrupted series of diploid to dodecaploid chromosome numbers as a model to investigate the genetic, genomic, biogeographical and ecological consequences of polyploidy. In a top-down approach we envisage (a) to prepare a hypothesis of the reticulate phylogeny of the whole genus using sequencing of nuclear and chloroplast markers and AFLP fingerprinting, along with an up-to-date taxonomic revision of the genus, and (b) to model eco-climatic niches of all species based on georeferenced herbarium specimens. Phylogenetic information and reconstructions of actual and potential eco-climatic niches will be then used to circumscribe the temporal, spatial and ecological diversification of the polyploidy complex. In a bottom-up approach, we will use the phylogentically distinct L. pluriflorum clan comprising diploid, tetraploid, and hexaploid species from Iberian coastal and inland habitats (a) to study the phylogeography of this group and (b) to assess the fate of duplicated candidate genes connected with salt tolerance by sequence comparisons and expression studies.
