Edge effects and mating patterns in a bumblebee-pollinated plant

Abstract

<jats:title>Abstract</jats:title> <jats:p>Researchers have long assumed that plant spatial location influences plant reproductive success and pollinator foraging behavior. For example, many flowering plant populations have small, linear, or irregular shapes that increase the proportion of plants on the edge, which may reduce mating opportunities through both male and female function. Additionally, plants that rely on pollinators may be particularly vulnerable to edge effects if those pollinators exhibit restricted foraging and pollen carryover is limited. To explore the effects of spatial location (edge vs. interior) on siring success, seed production, pollinator foraging patterns, and pollen-mediated gene dispersal, we established a square experimental array of 49 Mimulus ringens (monkeyflower) plants. We observed foraging patterns of pollinating bumblebees and used paternity analysis to quantify male and female reproductive success and mate diversity for plants on the edge vs. interior. We found no significant differences between edge and interior plants in the number of seeds sired, mothered, or the number sires per fruit. However, we found strong differences in pollinator behavior based on plant location, including 15% lower per flower visitation rates and substantially longer interplant moves for edge plants. This translated into 40% greater pollen-mediated gene dispersal for edge than for interior plants. Overall, our results suggest that edge effects are not as strong as is commonly assumed, and that different plant reproduction parameters respond to spatial location independently.</jats:p>

Propensity for selfing varies within a population of hermaphroditic snails: coexistence of selfers, outcrossers and mixed-mating individuals

“…We found that propensities for selfing differed substantially between the individuals of a single snail population. Variation among individuals in selfing propensity has not received much attention in the mating-system literature, which has traditionally been focused on comparing species [6][7][8][9] or populations [11,13].…”

“…In plants, many studies have also documented variability between populations of a single species (e.g. [2,[10][11][12]). For example, in 51% of 105 surveyed plant species, populations fell into several of the three mating-system categories defined above [13].…”