Linking pollinator behavior to selfing rate for three distinct pollinators

Insect pollinators are important to seed production but little is known about their impact on pollen dispersal and the amount of selfed seeds produced on a plant.  Selfing can decrease the level of heterozygosity within populations and increase genetic differences among populations. High selfing can reduce fitness and yield, especially when inbreeding depression is high.  Pollinator movements on a plant affect selfing rate.  We examined how distinct pollinators affect selfing rate in alfalfa and how the differences among pollinators in foraging behavior and pollen deposition patterns can affect a plant's selfing rate. Selfing rate was measured on an alfalfa field pollinated with distinct pollinators. Field wide selfing rate was estimated at 27%.  To compare the impact of these pollinators on selfing rate in alfalfa, we conducted individual greenhouse experiments with honey bees, common eastern bumble bees, and leaffcutting bees. We measured the number of open flowers per raceme, and the number of racemes per plant to assess the effect of different floral displays on bee behavior and their impact on selfing rate. This study will shed light on how distinct pollinators affect plant mating systems and the genetic structure of plant populations.