Distinguishing a friend from a foe: Unravelling the genetic basis and adaptive value of heterospecific pollen rejection

Shortly after the start of the spring season, wild meadow flowers rise from the ground.

Pollinators circulate from one flower type to another to collect nutrients, harvesting and depositing pollen grain from different plant species.

But, how do plants in such complex ecosystems ensure that the right pollen genotypes fertilize their ovules to avoid ´unproductive reproduction´?

Our previous observations and the work of others suggest that reproductive interference caused by heterospecific pollen transfer triggers the evolution of ´kin recognition mechanisms´ preventing the pollen of other species from fertilizing ovules.

Yet, we still know very little about the genetic factors and the evolutionary dynamics driving the establishment of heterospecific pollen rejection.We identified a pair of recently diverged species suffering from reproductive interference in sympatry in the process of evolving strong heterospecific pollen rejection mechanisms.

This gives a unique opportunity to 1) dissect the developmental and molecular processes involved in pollen recognition and rejection, 2) quantify the selective pressures driving their evolution, and, more globally, 3) assess the impact of reproductive interference on phenotypic evolution.

In pursuing these goals, we will combine molecular, quantitative and evolutionary genetics to provide new concepts and empirical measurements on how the composition of ecosystems influences phenotypic diversification and species interactions.