Abstract
Genetic variation is a key determinant of population resilience and evolutionary potential. Genetic variation is maintained in populations through factors such as gene flow and genetic recombination as a result of sexual reproduction. The self-incompatible, spring ephemeral herbs, Dicentra canadensis (Squirrel Corn) and D. cucullaria (Dutchman’s Breeches) rely solely on pollination by bumblebee queens for sexual reproduction. However, the species are also clonal and can produce genetically identical offspring through vegetative propagation. The distribution of clones in a population may alter the success of outcrossing if bumblebee queens move pollen between clonal mates. Low outcrossing success can negatively impact a population’s genetic variation. Therefore, to learn more about sexual reproduction in Dicentra species, we aimed to study (1) pollen dispersal distance in D. canadensis, and (2) clonal extent in D. cucullaria. To study pollen dispersal, we dyed the pollen grains of D. canadensis using quantum dot nanoparticles in order to measure their movement from donor to recipient flowers. To study clonal extent, we hand crossed D. cucullaria flowers with sires from various distances and compared the sexual reproductive success of the crosses using ovule and seed production. We found that queen bumblebees mostly move pollen less than 2 meters between inflorescences, meaning pollen is most likely not being dispersed between D. canadensis populations. We also found that D. cucullaria populations exhibit low clonal spread, as crosses from sires of any distance showed higher reproductive success than self-crosses. With this information, we can infer that although queen bumblebees are only moving pollen short distances within a population, they are likely carrying pollen between genetically distinct individuals, allowing for successful reproduction and the maintenance of the population. In the face of a changing climate, understanding plant-pollinator systems and the factors affecting reproductive success can allow us to better conserve these species.
Advisor
Ison, Jennifer
Department
Biology
Recommended Citation
Davis, Aubrey E., "Game of Clones: Pollen Dispersal, Clonal Spread, and their Implications for Genetic Variation in Two Spring Ephemeral Dicentra Species" (2025). Senior Independent Study Theses. Paper 11289.
https://openworks.wooster.edu/independentstudy/11289
Publication Date
2025
Degree Granted
Bachelor of Arts
Document Type
Senior Independent Study Thesis
© Copyright 2025 Aubrey E. Davis