Coastal sand dunes are dynamic ecosystems with elevated levels of disturbance and are highly susceptible to plant invasions. One invasive plant that is of concern to the Great Lakes system is Gypsophila paniculata L. (perennial baby’s breath). The presence of G. paniculata negatively impacts native species and has the potential to alter ecosystem dynamics. Our research goals were to (1) estimate the genetic structure of invasive G. paniculata along the Michigan dune system and (2) identify landscape features that influence gene flow in this area. We analyzed 12 populations at 14 nuclear and two chloroplast microsatellite loci. We found strong genetic structure among populations (global F_ST = 0.228), and pairwise comparisons among all populations yielded significant F_ST values. Results from clustering analysis via STRUCTURE and discriminant analysis of principal components (DAPC) suggest two main genetic clusters that are separated by the Leelanau Peninsula, and this is supported by the distribution of chloroplast haplotypes. Land cover and topography better explained pairwise genetic distances than geographic distance alone, suggesting that these factors influence the genetic distribution of populations within the dunes system. Together, these data aid in our understanding of how invasive populations move through the dune landscape, providing valuable information for managing the spread of this species.

Premise of the Study: Gypsophila paniculata (baby's breath; Caryophyllaceae) is a herbaceous perennial that has invaded much of northern and western United States and Canada, outcompeting and crowding out native and endemic species. Microsatellite primers were developed to analyze the genetic structure of invasive populations. Methods and Results: We identified 16 polymorphic nuclear microsatellite loci for G. paniculata out of 73 loci that successfully amplified from a primer library created using Illumina sequencing technology. Microsatellite primers were developed to amplify di‐, tri‐, and tetranucleotide repeats and tested in three invasive populations in Michigan. Conclusions: These markers will be useful in characterizing the genetic structure of invasive populations throughout North America to aid targeted management efforts, and in native Eurasian populations to better understand invasion history. Five of these developed primers also amplified in G. elegans .

Premise of the study: Gypsophila paniculata L. (baby’s breath) is an herbaceous perennial that has invaded much of northern and western United States and Canada, outcompeting and crowding out native and endemic species. Microsatellite primers were developed to analyze the genetic structure of invasive populations. Methods and Results: We have identified 16 polymorphic nuclear microsatellite loci for G. paniculata out of 73 loci that successfully amplified from a primer library created using Illumina sequencing technology. The developed primers amplified microsatellite loci in 3 invasive populations in Michigan. Primers amplified di-, tri-, and tetra-nucleotide repeats. Conclusions: These markers will be useful in characterizing the genetic structure of invasive populations throughout North America to aid targeted management efforts, and in native Eurasian populations to better understand invasion history. Five of these developed primers also amplified in G. elegans .

Coastal sand dunes are dynamic ecosystems with elevated levels of disturbance, and as such they are highly susceptible to plant invasions. One such invasion that is of major concern to the Great Lakes dune systems is that of perennial baby’s breath ( Gypsophila paniculata ). The invasion of baby’s breath negatively impacts native species such as the federal threatened Pitcher’s thistle ( Cirsium pitcheri ) that occupy the open sand habitat of the Michigan dune system. Our research goals were to (1) quantify the genetic diversity of invasive baby’s breath populations in the Michigan dune system, and (2) estimate the genetic structure of these invasive populations. We analyzed 12 populations at 14 nuclear and 2 chloroplast microsatellite loci. We found strong genetic structure among populations of baby’s breath sampled along Michigan’s dunes (global F _ST = 0.228), and also among two geographic regions that are separated by the Leelanau peninsula. Pairwise comparisons using the nSSR data among all 12 populations yielded significant F _ST values. 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). Private nSSR alleles and cpSSR haplotypes within each cluster suggest the possibility of at least two separate introduction events to Michigan.