What's Wrong with the Plants?
Leaf Microorganism Identification--This technique can be used to determine if there are any microscopic organisms on the leaves.
1. If you suspect organisms on the leaves may be causing the disease symptoms scrape off any suspected material onto a microscope slide and make a wet mount.
2. Examine under the microscope and determine if there are any living organisms. Use the guides available to identify anything you observe.
Root Extraction Technique--This technique can be used to loosen some materials that may adhere to the roots.
1. Cut a few roots from the healthy plant and place them in the test tube. Fill the tube with about 10 ml of 20% bleach solution. Place the stopper tightly into the tube and shake vigorously for 90 sec. Quickly add 10 ml of water to the tube, close and gently shake a few times. Repeat with diseased plant. Label both tubes.
2. Pour the contents of each tube in culture dishes and observe under dissecting scope. Make wet mounts of the cultures and observe under the compound scope.
3. Record your observations.
Soil Extracting Technique--This technique can be used to filter some organisms out of the soil.
1. Take 4-5 tablespoons of soil that was surrounding the roots of one plant. Place on ä Scotties tissue that has been placed over the screen in the Baermann-type filter. Fold the tissue over the soil. Gently add enough water to immerse only the bottom of the soil. Do not totally cover the soil with water. Place the lid on the filter dish. Label. Repeat for the second plant.
Describe any other techniques you used to examine the plant:
The University of Arizona
Department of Biochemistry and Molecular Biophysics
General Biology Program for Secondary Teachers