Principle Investigators: Morgan Hiler-
Carrie Martin-
Hannah Leirmoe-
Topic:
In our experiment we will endeavor to determine if seeds planted beneath the surface of agar will be able to germinate, and if their shoots will break through the agar.
Background Research:
In the natural habitats of the seeds of the Arabidopsis plant are wind distributed. Where the seeds land on the surface of soil is where they experience dormancy and will eventually germinate. The Arabidopsis is the ideal plant for experimentation, because it is a low maintenance plant that can grow in multiple environments such as green houses in soil and laboratory Petri dishes in agar. In order for germination to occur in an Arabidopsis seed there has to be period of dormancy for the seeds, that is broken by imbibing the seeds for 2-4 days. It is also best if the seeds have a high humidity level while germinating. The ideal temperature is between 16-25° C, and photoperiods of 16 hours of light and 8 hours of dark. ( Arabidopsis: A Lab Manual)
We were unable to locate experiments pertaining to the inability of Arabidopsis seeds to grow when planted too deeply in soil, or any other growing solution. However, an article about planting Arabidopsis stated, “the seeds should not be covered over with more soil since the seeds require light to germinate.” ( This experiment is to help further our understanding of the germination requirements of Arabidopsis seeds.
Hypothesis:
Arabidopsis seeds are planted below the surface of the agar will germinate, but the shoots will not be able to break to surface of the agar before the plant dies.
Materials:
1. 8 Petri dishes
2. 120 Arabidopsis seeds ( Columbia)
3. Agar - 5oz, 0.8% agar to fill Petri dishes
- 0.5 oz, 0.1% agar for imbibtion during the dormancy period
5. Room at about 70° F
6. Light lamp set on light and dark cycles of 16hrs light and 8 hrs dark
7. 3 Pipettes
8. 1 Small test tube
Method:
Preparation:
1. Fill small tube with 0.1% agar and pour all Arabidopsis seeds into the tube.
2. Seal the tube and shake. After shaking place tube in a refrigerator.
3. Leave seeds in fridge for two days to break dormancy.
4. Use 0.8% agar to fill the 4 Petri dishes half full, lay them flat to cool so that agar is even.
5. Fill other 4 dishes ¼ full and let cool. Remove the solid agar from these dishes.
Setting up Experiment:
1. After two days remove the tube from the refrigerator lay out 4 Petri dishes ½ full of agar.
2. Use a pipette and place three rows of 5 seeds evenly spaced across the surface of the agar in four Petri dishes.
3. Then use the 4, ¼ full solid agar “patties” that was removed from dishes and place them on top of the other 4 dishes. The seeds below the agar will be experimental group.
4. Use pipettes to place three rows of 5 seeds across the top of agar the strips. Be sure to place seeds between rows already below agar. This will be your control group.
6. Label dishes A- 1, 2, 3, and 4. Observe the seeds growth for two weeks.
5. After two weeks remove seeds from agar and tape them on pieces of copy paper correctly labeled.
6. Measure growth of shoot and root growth of all and if any plants died.
7. Compile data and draw conclusions.
There could be several confounding factors in this experiment, such as the surface seeds receiving more oxygen than the seeds below the surface of the agar. The seeds below the agar will also not be receiving direct light like the seeds on the surface. When removing the seeds for measurement they could break and an accurate measurement may not possible. Some seeds could fail to germinate at all. Finally the roots of seeds could become tangled in each other.
Anticipated Results:
There are several graphs we indeed to produce the first will be an graph showing germination of the seeds, whether they did or did not germinate. The second will be a graph showing whether the seeds lived or died once they germinated. The third will be a graph showing the root growth of the seeds above the agar(control group). A fourth will be a graph showing the root growth of the seeds below the agar(experimental group). A fifth graph will show the shoot growth of the seeds above the agar, and a sixth graph will show the shoot growth of the seeds below the agar.
One possible outcome of this experiment is that the seeds in the control group, on top of the agar, will germinate and grow viable roots and shoots. Also that the seeds in the experimental group, in the agar, will germinate, and live long enough to break the surface of the agar. If this happens it would be inconsistent with our hypothesis
A second possible outcome is that the control group will germinate and grow into viable plants. However, the experimental group could germinate, but the shoot may not be able to break the surface of the agar and die. If this occurs the results would thereby be consistent with our hypothesis.