Crop Physiology Lab Stomatal Morphology and Physiology Introduction: Stomata are the pores through which a plant exchanges gases with the atmosphere. Carbon dioxide and oxygen, which are involved in photosynthesis and respiration, enter and exit through these pores. The open stomata also provide a route for water to escape from the plant (transpiration). Hence, the stomata are ultimately responsible for the energy and water balances in the plant. It is not surprising that plants tightly control the stomatal aperture to regulate gas transfer. In this lab we will study some aspects of stomatal morphology and physiology. The following is a listing of activities related to this lab
Objectives:
Upon completion of this laboratory you should be able
to: 1.
prepare an epidermal leaf peel.
2.
determine the frequency of stomata on a leaf. 3. determine stomatal distribution/ frequency
I. Making an Epidermal Leaf Peel
1. Cut the epidermis between the major lateral veins along three sides of rectangle (approx. 2 x 3 mm) with a razor blade. 2. Make the cuts shallow so they do not go through the leaf. These cuts will serve to bound the sides of the leaf strip. 3. Insert a fine-tipped forceps (handle with care) just beneath the epidermis in the middle of the uncut end of the rectangle. .4Grasp the tissue firmly and pull
Note: The lower epidermis generally strips more easily than the upper epidermis. Some species are more difficult to strip than others. Vicia faba (broad bean) and Zebrina sp. (Wandering Jew) are especially easy to peel. II. Other Techniques Paint clear nail polish on the leaf surface and allow it to dry. To remove the leaf "cast", use a piece of clear cellophane tape which can then be taped to a microscope slide for viewing. In some cases, it is even possible to apply the tape directly to the leaf, rub it down and then remove it and transfer it to a microscope slide.
Monoco t
Dicot
Grass