DIMENSIONS: COLLABORATIVE RESEARCH: The evolution of pollination syndrome diversity in Penstemon

University Of Kansas Center For Research Inc, Lawrence KS

Investigators

Abstract

Ecosystem health and productivity depend on co-evolved species interactions. In terrestrial ecosystems a key interaction is between flowers and pollinators, and changes in the relative abundances of different pollinators (e.g., bees, birds) are thought to impose selective pressures that can shift floral pollination strategies and shape flowering plant communities. However, multiple forces may act to constrain the ability of a flowering plant lineage to evolve a new pollination strategy under changing environmental conditions. This research will model the rate of pollination strategy transitions in the largest flowering plant genus endemic to North America (Penstemon), and will determine both ecological and genetic processes that constrain and shape the rate of pollination strategy diversification. Understanding the forces that maintain diversity in pollination strategies informs food security and agricultural management issues. The research integrates phylogenetic, ecological, and genetic approaches to understand the processes that determine pollination diversity. The research will test whether Penstemon has reached an evolutionary equilibrium in the relative frequencies of bee and hummingbird pollination syndromes. Additionally, the planned experiments will determine ecological and genetic processes responsible for asymmetries in pollination syndrome transitions, and in syndrome-specific speciation, and extinction rates. Field experiments will test whether interactions among floral traits constrain shifts from hummingbird to bee pollination. Genetic experiments will test whether loss-of-function mutations critical for shifts to hummingbird pollination also constrain reverse shifts from hummingbird to bee pollination. The integration of these experimental approaches will elucidate processes that determine pollination syndrome diversity in plant community assemblages.