Authors: Hernandez, K., Lane, B., Adhikari, A., Harmon, P.F., Goss, E.M.
Faculty Mentor: Erica Goss
College: College of Agricultural and Life Sciences
When an invasive species establishes in a new area it can gain a competitive advantage by being released from its natural pathogens. With time, pathogens may emerge on the invasive species and the competitive interactions may change. The Big Oaks National Wildlife Refuge in Madison, Indiana is home to native plant species and the invasive grass Microstegium vimineum. Multiple fungal pathogens have recently emerged on M. vimineum. In the summer of 2018, a new disease was observed on M. vimineum at our Big Oaks National Wildlife Refuge field site. The objective of this research was to identify the pathogen causing this new disease on M. vimineum. Symptomatic leaves exhibited diamond to elongated lesions isolated to the leaf tissue. A Pyricularia-like species was successfully isolated from 13 leaves. Conidia were pyriform with 2-3 cells per conidia. Conidia were15.16-16.97 μm in length (16.24 µm average) and 5.65-8.99 µm in width (7.53 µm average). We sequenced the internal transcribed spacer to identify the isolates. Comparison to sequences in the NCBI GenBank database revealed no matches with greater than 93% identity. Phylogenetic analysis revealed the pathogen as a previously uncharacterized Pyricularia-like species and may represent a new genera. This finding will contribute to ongoing research on the effects of emerging pathogens on invaded plant communities.