Florivory and Clonal Reproduction of Clintonia borealis: A Study Using Modeling and a Natural Experiment
thesisposted on 2018-11-27, 00:00 authored by Jason Palagi
The balance of sexual and clonal reproduction has important implications for plant populations. While all plants reproduce sexually via flowers, most plants also have some form of clonal reproduction. Environmental factors such as florivory or geographic isolation can shift the reproductive balance of a population. This dissertation assesses the influence florivory and geographic isolation can have on the reproductive balance of the boreal forest plant species, Clintonia borealis (bluebead lily). While bluebead lily sexually reproduces via perfect flowers, the flowers are a preferred springtime forage of white-tailed deer. The effects of florivory on bluebead lily populations were estimated using an agent-based model with parameters based on previously published excavation studies. The model showed no influence on the number of ramets in populations with and without florivory, but an order of magnitude difference in the number of genets. The results of the model were tested against a natural experiment by sampling bluebead lily patches on Great Lakes islands with and without white-tailed deer populations. DNA microsatellite markers were developed using an Illumina Mi-Seq genome-wide shotgun sequencing run. The markers were used to identify genets among leaf samples taken from clonal patches. Patches on islands without deer had over three times the clonal richness and over twice the clonal diversity as patches on islands with deer. The Great Lakes islands samples were used to assess a small, isolated bluebead lily population in northwest Indiana. All ramets of the Indiana population were sampled and genotyped. The clonal richness and structure of the population was found to be similar to patches on islands with deer, suggesting that it may benefit from the introduction of new genets into the population, a conservation strategy known as translocation. Analyses of the genetics showed the Indiana population to be diverging from other sampled populations. Since local adaptations of the Indiana population are unlikely to migrate northward into the core species range, the lagging-edge assisted migration of seed was suggested as a way of preserving those adaptations. Overall, the findings in this dissertation suggest that florivory and isolation can have strong influences on the clonal structure of plant populations.