Aaron Cantor, Alison Hale, Justin Aaron, M. Brian Traw,
Susan Kalisz
By: Megan Kittleson
Low allelochemical concentrations detected in garlic mustard-invaded forest soils inhibit fungal growth and AMF spore germination
General Background•Garlic Mustard (Alliaria Petiolata)• Cool season biennial herb• Commonly found in moist, shaded soils•Native to Europe; introduced in 1800’s• Invasive species• Found to have antimicrobial effects
Experiment Specific Background• Inhibitory effects due to allelochemicals• Secondary compounds included cyanide, flavonoids, glucosinolates, and gyclosides• Concentrations of AITC in soil have been unknown•Highly potent anti-fungal properties•Many native plants rely on arbuscular mycorrhizal fungi (AMF)
Glucosinolates BITCAITC (allyl isothiocyanate)
Goals of the Experiment•Determine timing of release and natural concentrations of AITC•Quantify the impact of garlic mustard on fungal abundance•Determine the range of AITC concentrations that can suppress AMF spore germination
Methods• Two sites tested; established paired plots• Garlic mustard invaded• Garlic mustard absent (control)•Determined lowest level of AITC present in soil• Approx: 0.001 mM• Tested Glomus clarum spores against varied concentrations of AITC
Methods• Two trials of bioassay conducted• 2009 – 4 petri dishes per concentration• 2010 – 5 petri dishes per concentration• Spores washed twice in 2.5% chloramine-T salt hydride• 16-26 spores pipetted in each Petri dishes• Contained water-agarose media• AITC solutions of varied concentrations created• Commercial AITC and deionized water• Sterile deionized water was negative control• 6 ml of respective treatment pipetted to lid of inverted petri dish
Methods• Sealed all petri dishes twice with Parafilm• Placed in a 2% CO2 incubator at 28˚ C in the dark for 1 week• After 1 week collected data on spore germination using a dissecting scope•One-way ANOVA and pairwise comparisons in SAS
Results
Results• All concentrations of AITC significantly inhibited germination• 2009 trial• ANOVA: p < 0.0001• Pairwise comparison : all p < 0.0001 compared to control• 2010 trial• ANOVA: p < 0.0026• Pairwise comparison: all p < 0.01 • Percentage of G. clarum spores that germinated decreased as AITC increased• Lowest detected level of AITC caused 57% germination failure
My Research1. Does garlic mustard plant tissue show similar
inhibitory effects on bacteria?2. Are there any variations between first and second
year plants?
Questions?
Bibliography• Aaron, Cantor, Alison Hale, Justin Aaron, M. Brian Traw, and Susan
Kalisz. "Low Allelochemical Concentrations Detected in Garlic Mustard- invaded Forest Soils Inhibit Fungal Growth and AMF Spore
Germination."Academic Search Complete. EBSCO, 15 Nov. 2010. Web. 9 Oct. 2012.• "Garlic Mustard." Invasive Plant Atlas of the United States. The
University of Georgia - Center for Invasive Species and Ecosystem Health, 8 Sept. 2011. Web. 26 Nov. 2012. <http://www.invasiveplantatlas.org/>.• "Plants - Garlic Mustard (Alliaria Petiolata)." National Invasive Species
Information Center. USDA National Agriculture Library, 12 Aug. 2012. Web. 25 Nov. 2012. <http://www.invasivespeciesinfo.gov>.• Stinson, Kristina. "Garlic Mustard Suppression of Mutualistic Fungi
Stronger in North America Than Europe." Harvard Forest. Harvard University, 1 Apr. 2008. Web. 26 Nov. 2012. <http://harvardforest.fas.harvard.edu/>.• "Weed of the Week: Garlic Mustard." Forest Health Protection. USDA
Forest Service, 1 Aug. 2005. Web. 25 Nov. 2012. <http://na.fs.fed.us>.
