Andrew Palmer and Phoebe Bruffett completing DNA Extraction of Lonicera Maackii

Author: Phoebe Bruffett | Majors: Biology and Psychology

The mechanisms underlying the continual spread of invasive plants within their respective non-native ranges is a major focal point to invasion research. Many theories have been proposed to understand these invasions, each with different implications for the predicted range for invasive plants. Lonicera maackii, also known as bush honeysuckle, provides an exceptional opportunity to examine the effectiveness of these theories to explain the trends of invasive plants. Lonicera maackii is native to eastern Asia, but has invaded much of the eastern United States, presenting a severe threat to the health of forest and other natural areas. I conduct a targeted phylogenetic analysis of L. maackii populations to investigate the natural and invasive history of the plant through DNA capture and analysis from herbarium samples. Leaf tissues from 95 individuals collected from major herbaria around the country were used to develop an intraspecific phylogeny to provide an evolutionary context for the success of L. maackii in its invasive range. The implications of this research can have a significant impact across the field of invasive biology and land management techniques. Understanding the invasive mechanisms of L. maackii can help individuals predict future invasions and range expansions of this species and others. This research can assist land managers in making more confident decisions regarding environmental management.

I found Dr. Beaulieu’s research lab by looking through the UARK research directory under biology professors who were conducting research. I knew I was interested specifically in biology and wanted to work in research pertaining to plants. The summer between my freshman and sophomore year I contacted Dr. Beaulieu and started in his lab fall of 2019. When I first started in the lab I attended lab meetings and worked on projects with other members in the lab to see what specifically I was interested in studying. I chose my topic by working with another student in the lab, Andrew Palmer, and a PhD student, Katy Dupree who were both conducting research pertaining to bush honeysuckle. Andrew focused specifically on the climatic envelopes of bush honeysuckle and uncovered a significant separation between the environmental conditions of the native east Asian L. maackii points and the invasive North American points.

Several challenges were presented to me throughout my research, for instance it was difficult to produce an effective protocol for DNA amplification and sequencing. I overcame this obstacle by working with Katy and Dr. Beaulieu who were very patient with me and help me figure out the most efficient protocol. Likewise, collecting viable DNA amplification from herbarium specimens is extremely challenging. With the guidance of Katy and Dr. Beaulieu, we were able to collect plenty of data to produce a phylogenetic tree, which describes the relationship among species that refers to the evolutionary history and development of those populations.

To assess the samples being used in this research, Dr. Beaulieu and I traveled to the University of Arkansas Herbarium. It was a wonderful experience; it is so amazing to think that DNA was collected from samples of this invasive species that date as far back as 1966. A picture of preserved plant specimens is shown below in Figure 1.

Through this honors college grant I was able to produce a phylogenetic tree as shown in Figure 2. Across the 95 leaf samples taken from herbarium specimens, we were able to not only amplify DNA for 35 of these specimens, but we were also able to sequence a common marker for phylogenetic analysis. This is a clear demonstration of the utility of historical collections, such as herbarium specimens, for addressing biogeographical and historical questions. This grant allowed me to have a whole new appreciation for these historical collections as well as an increased desire to understand invasive species more in order to predict future invasions and range expansions of ecologically damaging species such as L. maackii.