Abstract Detail

Reproductive Processes

Pearson, Avery [1], Zelman, Zeke [1], Hill, Lauryn [1], Stevens, Mia [1], Jackson, Evan [1], Incarnato, Miyauna Monique Nicole [1], Johnson, Ren [1], Wagenius, Stuart [2], Ison, Jennifer [3].

Bee taxa differ in their pollen movement patterns and contribution to the male fitness of a self-incompatible prairie perennial.

Many flowering plants are visited and pollinated by a diverse array of insects. These visitors often differ in how they move pollen within and between conspecific plants, thus directly influencing an individual plant’s reproductive fitness. Yet most studies of plant fitness measure only female reproductive fitness, which reflects only pollen receipt. In this study, we quantify male reproductive fitness and pollen removal rates using a novel field method with paternity analysis to measure how visits by different pollinating taxa impact the siring success of Echinacea angustifolia, a hermaphroditic self-incompatible prairie perennial. In western Minnesota, Echinacea is pollinated by a diverse set of native bees. While Echinacea has hermaphroditic flowers, we treated the flowering plants (n = 200) in our study population as functionally dioecious—we permitted only one bee taxon to visit each ‘male’ plant, while any bee could visit our ‘female’ plants. We genotyped 403 offspring from the ‘female’ plants and all flowering plants at ten microsatellite loci. We identified the likely pollen donor for each offspring, which informed us which bee taxon successfully moved the pollen. We also measured the pre-visit pollen removal (n = 183) for each bee taxon to determine the rate of pollen depletion in the population. We found that visits by the coneflower specialist bee, Andrena helianthiformis, and the generalist bee, Augochlorella aurata remove significantly more pollen per visit than other bee visitors. The genotyping data revealed that most visits across all bee taxa resulted in no offspring sired on ‘female’ plants. Previous research found that visits by A. helianthiformis increased Echinacea’s female fitness. Similarly, we found that visits by A. helianthiformis lead to higher siring success than by any other bee taxa. Therefore, a visit by A. helianthiformis can increase an Echinacea plant’s male and female fitness. Unfortunately, this coneflower-specialist bee appears largely absent from the small prairie remnants in our study area, highlighting the importance of preserving specialist pollinators. Our work also illustrates the value of directly quantifying both female and male fitness in plants

1 - The College Of Wooster, Biology Department, 1189 Beall Ave., Wooster, OH, 44691, USA
2 - Chicago Botanic Garden, Conservation Science, 1000 Lake Cook Road, Glencoe, IL, 60022, United States
3 - The College Of Wooster, Biology Department, 1189 Beall Ave., Wooster, OH, 44691, United States

Keywords:
plant-pollinator interactions
male fitness
Pollination
Echinacea angustifolia
Bees
tallgrass prairie
paternity
pollinator effectiveness.

Presentation Type: Oral Paper
Number: RP3003
Abstract ID:241
Candidate for Awards:None