Dan Martin

ROOT DEFENSE AGAINST NATIVE FUNGI IN GARLIC MUSTARD. Dan Martin¹, Laura Beaton¹, and Tiffany M. Knight; Washington University, Department of Biology, St. Louis, MO¹.

Alliaria petiolata, a biennial member of the Brassicicae family commonly termed “Garlic Mustard,” is an important invasive species in North American temparate forests. Highly shade tolerant, A. petiolata is able to penetrate established forest ecosystems at a rapid rate, displacing the native plant community. Garlic mustard’s root exudates have detrimental effects (Prati, 2004) on both the plant and the mychorrizal community. Here, we consider the possible role garlic mustard's root exudates may play in defense against fungal infection. We hypothesized that binding the root exudates of A. petiolata with activated carbon would increase garlic mustard’s susceptibility to fungal infection. Transplanted first-year rosettes were grown with or without activated carbon and with or without fungicide. After 8 weeks, the plants were harvested and the degree of fungal root infection was assessed by grinding and plating root material on mycological agar according to the methods of Nan et al. (Nan, 1991). Examination of colony growth on the plates revealed no significant effect of activated carbon on fungal infection rate, indicating that garlic mustard's root exudates have no clear anti-fungal purpose.