Natural History and Breeding System of Maguire Primrose

• Main Author: Davidson, Jacob B.
• Format: Others
• Published: DigitalCommons@USU 2010
• Subjects: conservation; endemic plant; phenology; pollination; pollinator; primula; Ecology and Evolutionary Biology
• Online Access: https://digitalcommons.usu.edu/etd/696; https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1692&context=etd

The goal of this thesis was to examine the breeding system and natural history of the Maguire primrose (Primula cusickiana var. maguirei). Maguire primrose is an endemic, threatened subspecies found only along a narrow corridor within Logan Canyon in northern Utah, USA. This plant displays distinct flower distyly, with clear distinction of pin and thrum morphologies (morphs). The timing of Maguire primrose flower blooms was disparate between upper and lower canyon populations, and the flowers experienced cool temperatures occasionally. I captured eight different species of flying insects visiting Maguire primrose flowers, and made 67 observations of insect visitation. Inter-morph outcrossing hand pollinations were the most successful hand pollinations performed, but were usually not as successful as those that were naturally pollinated. Selfing rates were quite low compared to outcrossing reproductive scenarios. Morph-specific fecundity differences were detected in my hand pollinations, but not in the naturally pollinated maternal plants. I did not observe clear fecundity differences based on the canyon location of Maguire primrose.