Biodiversity drivers in Mediterranean-Type Ecosystems: Pollination and the evolution of mating phenotypes in yellow flaxes (Linum spp.)

The role of pollinators and plant sexual diversity in the evolution of Mediterranean-Type Ecosystems (MTE) floras is a silver bullet target for biodiversity research and conservation in Europe.

The setting of the floral sexual organs (the mating phenotype) has the most crucial implication in the function of the pollinator - flower interaction, i.e. in the efficiency of pollen transfer. However, it has never been studied quantitatively and in depth in evolutionary biology.

FLAXMaTE will approach the evolution of the mating phenotypes in Linum, an intrinsically Mediterranean genus and a classic study system for the evolution of heterostyly with all its polymorphic species located in two MTE regions: the Mediterranean Basin (MB) and the Cape Floristic Region (CFR).

In contrast with previous studies based in phenotypic categorisation or two-dimensional measures, I will for the first time characterize the mating phenotype of Linum species and their pollinators through an innovative three-dimensional geometric morphometric approach using computed tomography.

To disentangle the macroevolutionary patterns of the mating phenotypes in Linum and the convergence of polymorphisms in MTEs, I will build a phylogeny of Old World yellow flaxes and I will use comparative methods to relate the evolution of the mating phenotypes with the MTE distribution, the pollination niche of species, and the diversification rates of the clade.

The genomic basis of the convergence will be also studied through the sequencing of the S-locus in polymorphic MB and CFR species.

To test the role of pollinators and the mating function as biodiversity drivers and agents of the evolutionary convergence of stylar polymorphisms, I will test the similarity in the mating function of Linum in pairs of populations and species from the MB and CFR through pollen transfer experiments using a novel methodology based in quantum dots.