The genetics of adaptation under divergent selection by pollinators.

• Applicants: Professor Dr. Michael Lenhard; Dr. Mathias Scharmann
• Subject Area: Plant Genetics and Genomics ; Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 576084974

This project aims to understand how flowering plants adapt to changing environments by studying the genetics and ecology of floral variation in the South African plant genus Hemimeris. Our focus is on how different arrangements of female and male flower organs (style and stamen orientation) have evolved as adaptations to different pollinator environments, in particular the abundance of oil-collecting bees. Some Hemimeris populations show two flower forms (inversostyly), while others have only one (homostyly). Here, we wish to elucidate (1) how these flower forms affect pollination and mating patterns, and whether they promote outcrossing, (2) whether rare flower forms have an advantage because they get more visits from pollinators, (3) how repeated changes between the two flower types have happened across the evolutionary history of the group, (4) which ecological factors, like pollinator abundance, drive these switches, and if plants adapt to a lack of pollinators by evolving to self-pollinate, (5) how inversostyly is controlled at the genomic level across the genus. In particular, our preliminary work suggests that inversostyly is controlled by a “supergene”, and we will study (6) if similar or different component genes are responsible for parallel changes in different populations. To achieve these aims, the project combines field experiments, ecological modelling, genome sequencing, and population-genetic analysis. The results will improve our understanding of how plants evolve in response to environmental change, how genetic diversity is maintained, and what happens when pollinators become scarce. This work offers broader insights into adaptation, biodiversity, and the consequences of pollinator decline for ecosystems.

• DFG Programme: Research Grants
• International Connection: South Africa
• International Co-Applicant: Professor Dr. Anton Pauw