Date of Award

8-2018

Degree Type

Thesis

Degree Name

Biology (M.S.)

Department

Biology

First Advisor

Charlyn Partridge

Second Advisor

James McNair

Third Advisor

Timothy Evans

Academic Year

2017/2018

Abstract

Invasive species can reduce biodiversity of a system by outcompeting native species for resources, changing the physical characteristics of a habitat, and altering natural disturbance regimes. Coastal sand dune ecosystems are dynamic with elevated levels of disturbance, and as such they are highly susceptible to plant invasions. The topography, geographic distribution of preferred habitat, and disturbance regime in an ecosystem can influence where an invasive plant becomes established, its dispersal patterns, and how densely it grows. One such invasion that is of major concern to the Great Lakes dune systems is baby’s breath (Gypsophila paniculata). The invasion of baby’s breath negatively impacts native species, including rare ones such as Pitcher’s thistle (Cirsium pitcheri). Estimating the genetic variation and structure of invasive populations can lead to a better understanding of the invasion history, and the factors influencing invasion success. Microsatellite genetic markers can be beneficial for estimating levels of diversity present within and among populations. Our research goals were to develop microsatellite primers to analyze invasive populations, quantify the genetic diversity and estimate the genetic structure of these invasive populations of baby’s breath in the Michigan dune system. We identified 16 polymorphic nuclear microsatellite loci for baby’s breath out of 73 loci that successfully amplified from a primer library created using Illumina sequencing technology. We analyzed 12 populations at 14 nuclear and 2 chloroplast microsatellite loci and found moderate genetic diversity, strong genetic structure among the populations (global FST = 0.228), and also among two geographic regions that are separated by the Leelanau peninsula. Results from a Bayesian clustering analysis suggest two main population clusters. Isolation by distance was found over all 12 populations (R = 0.755, P < 0.001) and when only cluster 2 populations were included (R = 0.523, P = 0.030); populations within cluster 1 revealed no significant relationship (R = 0.205, P = 0.494). The results suggest the possibility of at least two separate introduction events to Michigan. These results provide an understanding of the invasion history and factors contributing to invasion success. Management of invasive populations can use this to identify populations of high priority.

Available for download on Monday, September 13, 2021

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