Periodic Reporting for period 2 - FLAXMATE (Biodiversity drivers in Mediterranean-Type Ecosystems: Pollination and the evolution of mating phenotypes in yellow flaxes (Linum spp.))
Reporting period: 2023-03-01 to 2024-02-29
Biodiversity embodies the evolutionary potential of Life against global change. Among the most biodiverse regions of our planet, called diversity hotspots, are the five existing Mediterranean regions (MTEs, Mediterranean-Type Ecosystems). Among them, due to their number of species, the Mediterranean Basin (MB, Mediterranean Basin) and the Cape Region in South Africa (CFR, Cape Floristic Region) stand out.
One of the great drivers of biodiversity on our planet is the coevolution between flowers and pollinators. Particularly, the fit of the floral sexual organs (i.e. the mating phenotype) with the pollinator body has the most crucial implication in the function of the pollinator-flower interaction. Therefore, the role of pollinators and plant sexual diversity in the evolution of Mediterranean-Type Ecosystems floras is a silver bullet target for biodiversity research and conservation in Europe.
The FLAXMaTE project has investigated how the reproductive traits of flowers and pollinators promote biodiversity in MTEs. To do this, a group of 74 species of yellow flaxes (Linum spp.), wild relatives of cultivated flax, which are distributed from the MB to the CFR, passing through eastern Africa, were studied. Within this group, there is a convergence in the appearance of floral polymorphisms in the two study MTEs. It was observed that the pollination system of species determines the evolution of their mating phenotype, in a way that suggest that pollination precision is the main underlying evolutionary force. The biogeographý of species plays a role in the evolution of mating phenotypes and in the appearance of heterostyly. The occurrence of species in biodiversity hotspots, including Mediterranean-type ecosystems, does not seem to be related to the evolution of this mating system,
One of the great drivers of biodiversity on our planet is the coevolution between flowers and pollinators. Particularly, the fit of the floral sexual organs (i.e. the mating phenotype) with the pollinator body has the most crucial implication in the function of the pollinator-flower interaction. Therefore, the role of pollinators and plant sexual diversity in the evolution of Mediterranean-Type Ecosystems floras is a silver bullet target for biodiversity research and conservation in Europe.
The FLAXMaTE project has investigated how the reproductive traits of flowers and pollinators promote biodiversity in MTEs. To do this, a group of 74 species of yellow flaxes (Linum spp.), wild relatives of cultivated flax, which are distributed from the MB to the CFR, passing through eastern Africa, were studied. Within this group, there is a convergence in the appearance of floral polymorphisms in the two study MTEs. It was observed that the pollination system of species determines the evolution of their mating phenotype, in a way that suggest that pollination precision is the main underlying evolutionary force. The biogeographý of species plays a role in the evolution of mating phenotypes and in the appearance of heterostyly. The occurrence of species in biodiversity hotspots, including Mediterranean-type ecosystems, does not seem to be related to the evolution of this mating system,
A phylogeny of Linum was built with next-generation genotyping, following an ambitous sampling of Linum leaf material through field campaigns in Spain, France, Italy, South Africa, along with networking with target Botanical Gardens, Seed banks and experts in various parts of the world.
A parallel sampling of flowers for each species enabled their phenotypic analyses and quantitative description of their mating phenotype. The performance of pollinator censuses and pollinator sampling, with up to to 800 hours of censuses in 22 Linum species, revealed the high diversity and, sometimes, specificity of pollinators in this genus.
Analysing all the above data jointly enabled to prove the role of pollinators and their floral fit in the evolution of the mating phenotypes of MTE Linum species, and hence their role in promoting biodiversity.
Finally, the novel Qdots pollen labelling technique was implemented to prove the efficiency of pollen transfer as a function of the mating phenotype and pollinator fit in linum species with contrasting mating phenotypes.
A parallel sampling of flowers for each species enabled their phenotypic analyses and quantitative description of their mating phenotype. The performance of pollinator censuses and pollinator sampling, with up to to 800 hours of censuses in 22 Linum species, revealed the high diversity and, sometimes, specificity of pollinators in this genus.
Analysing all the above data jointly enabled to prove the role of pollinators and their floral fit in the evolution of the mating phenotypes of MTE Linum species, and hence their role in promoting biodiversity.
Finally, the novel Qdots pollen labelling technique was implemented to prove the efficiency of pollen transfer as a function of the mating phenotype and pollinator fit in linum species with contrasting mating phenotypes.
FLAXMaTE has progressed the research on sexual flower polymorphisms beyond the previous state-of-the-art, focusing for the first time on the 2D quantitative characterisation of the mating phenotype and its functional implications for the pollinator fit and pollen transfer efficiency. FLAXMaTE implemented the use of new methodologies such as Geometric morphometrics, to analyse the mating phenotype of flowers, and Quantum dots, to analyse pollen transfer efficiency. A direct observation of the mechanisms of coevolution between pollinators and flowers helps to understand the mechanisms that promote biodiversity.
The data generated during this project for wild Linum populations and their pollinators in Europe and South Africa may be useful for future assessments of the conservation status for this genus and functional animal group. In addition, identifying and characterising the ecology and reproductive function of flax wild relatives that are suitable for crop diversification is a means for the long-term preservation of flax as an important worldwide crop, keeping natural diversity for breeders to deal with upcoming environmental change, helping in its sustainable cultivation and potentially increasing nutritional benefits for humans and renewable raw materials benefits for industry.
The data generated during this project for wild Linum populations and their pollinators in Europe and South Africa may be useful for future assessments of the conservation status for this genus and functional animal group. In addition, identifying and characterising the ecology and reproductive function of flax wild relatives that are suitable for crop diversification is a means for the long-term preservation of flax as an important worldwide crop, keeping natural diversity for breeders to deal with upcoming environmental change, helping in its sustainable cultivation and potentially increasing nutritional benefits for humans and renewable raw materials benefits for industry.