Eurasian watermilfoil is an invasive freshwater plant heavily managed with herbicides to mitigate its ecological and economic impacts. Previous research has proven that while many genotypes are sensitive to herbicides, some exhibit resistance, but the mechanism(s) is unknown. One hypothesis is that resistant genotypes harbor microbial communities that block the uptake and/or metabolize herbicide, leading to reduce its efficacy. To test it, we studied four different genotypes known to exhibit different susceptibilities to the commonly used herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D). We exposed three clones of each genotype to 500μg L-1 2,4-D for 48 hours, and compared them to the control. We are currently extracting microbial DNA from their roots and shoots. We will use 16S DNA barcoding to determine the microbial composition using next-generation sequencing. The data will help determine if sensitive and resistant genotypes have predictably distinct microbial communities.
Faculty Mentor: Ryan Thum, Annis Water Resource Institute