PARENT SESSION
Monday, August 7, 5:00-6:30 pm
Poster Session 2 - Invasive species
Exhibit Hall, Ballroom Level, Cook Convention Center
Intergenerational differences in defensive chemical production in Alliaria petiolata.
Abts, Anna *,2, Lang, Kimberly *,2, Vaughn, Steven 1, Morris, Sherri 2, McConnaughay, Kelly 2, 2 Bradley University, Peoria, IL1 United States Department of Agriculture, Peoria, IL
ABSTRACT- Alliaria petiolata (garlic mustard) is an invasive species in temperate forests throughout North America that leads to decreases in species diversity. Garlic mustard produces an arsenal of secondary chemicals in the glucosinolate family that serve as defenses against herbivores. We previously hypothesized that carbon and nitrogen availabilities in the environment modulate internal (tissue level) C and N availability, which in turn modulate glucosinolate production. We examined variability in plant growth and in tissue carbon, nitrogen, and glucosinolate (specifically sinigrin and glucotropaeolin) profiles in natural populations of garlic mustard from five forest sites that vary in light availability, soil pH, and soil nitrogen availability. Our data are partially consistent with our original hypothesis, but obvious and unpredicted differences in sinigrin production between first- and second-year plants were observed. Sinigrin production in first-year plants was highest in sites where sinigrin production was least for second-year plants and vice versa. First-year plants with the highest levels of sinigrin grew in sites with high soil nitrogen availability, consistent with the Carbon/Nutrient Balance Hypothesis. In contrast, glucotropaeolin production was high in sites with limited light availability and reduced growth for first- and second-year plants, consistent with the Resource Availability Hypothesis. We propose that glucosinolate profiles of garlic mustard plants are determined by a complex interplay of resource availability, induction via herbivores, and intergenerational dynamics. Understanding the factors that regulate the cache of glucosinolates in garlic mustard will improve our ability to manage systems that are, or could become, dominated by this aggressive invader. ©
Key words: Alliaria petiolata, Invasive species, Glucosinolates