Garlic Mustard Invasion

Experiment 2. Does garlic mustard produce chemicals that inhibit native seed germination?

Materials Needed (All items are contained in Kit unless noted):

Petri dishes
Filter paper
Plastic bottles
Plastic pipettes
Garlic mustard extract from a standard population (Urbana, IL)
Elymus hysterix (eastern bottlebrush grass)
Graduated cylinder
Purified water
Sharpie marker
Scissors (provided by you)
Garlic mustard plants collected from local woods (collected by you)
Balance - accurate to 0.1 g (provided by you)

Step 1: Make the chemical extracts from your locally collected garlic mustard plants.

Add 100mL of purified water (provided by INHS in kit) to each of the two plastic bottles.
Separate the roots and leaves for all of the plants.
Weigh out 1 g of root tissue (combining roots from multiple plants as needed to get to this amount).
Take the 1 g of root tissue and use the scissors to cut the roots into lengths < 1 cm long.
Add the cut up root fragments to one bottle of water and swirl the mixture a couple of times.
Label the bottle (Local Roots) and set aside.
Measure 1 g of leaves. Cut leaves into small sections (around 1 cm2 squares)
Add leaves to the second bottle of water, swirl, label, and set aside.
Let these mixtures sit overnight to allow the chemicals in the plant tissue to seep into the water.

Step 2. While the mixtures are sitting, prepare 16 Petri dishes.

Add a circle of filter paper to each dish – the circles are a little larger than the Petri dishes, so just crinkle the edges so that they fit. (This will prevent the seeds from slipping underneath the filter paper).
Label 4 of the Petri dishes “Water 1,” “Water 2,” “Water 3,” “Water 4.”
Repeat for: Local Roots, Local Leaves, and Standard GM (the extract provided from a standard population in Urbana, IL)
Label the 4 pipettes that were included in the kit, “Water,” “Local Root,” “Local Leaves,” “Standard”
Add 10 Elymus hysterix (eastern bottlebrush grass) seeds to each petri dish.

Step 3. Day 2: Adding the liquids - use the plastic pipettes to add 2 mL of the solution to the appropriate Petri dish.

Using the plastic funnel and a piece of filter paper, transfer the “Local Roots” extract into a clean, labeled bottle.
Using the plastic funnel and a fresh piece of filter paper, transfer the “Local Leaves” extract into another clean labeled bottle.
Using the “Water” pipette, add 2 mL of the purified water provided to each of the four “Water“ dishes.
Using the “Local Roots” pipette, add 2 mL of the purified water provided to each of the four “Local Roots “ dishes.
Using the “Local Leaves” pipette, add 2 mL of the purified water provided to each of the four “Local Leaves “ dishes.
Using the “Standard” pipette, add 2 mL of the purified water provided to each of the four “Standard “ dishes.

Step 4. Growing the seeds

Check seeds daily
Each day, add 1 mL of the appropriate solution (in other words, add water to the Water dishes, Local Root solution to the Local Root dishes, etc.) to keep the filter paper moist.
Each day, record the number of seeds that have germinated.
Continue this for two weeks or until all of the seeds have germinated.

Step 5. After two weeks, measure the length of the root and shoot on each germinated seedling in each Petri dish. Be sure to record the data in a way that it is clear from which Petri dish (treatment and replicate number) each seedling came.