Experiment a. Plasmolysis and Deplasmolysis in Epidermal Tissue Objective : To see the events of plasmolysis and deplasmolysis in epidermal tissue. Materials and tools: Plant material :Rhoe discolor Chemical material : Sucrose 1M, or NaCl 1M. Tools : Microscope, object glass and cover, razor blade, dropper pipettes Ways of working: 1. Take a thin layer of the lower epidermis surfaceRhoe discolor Use a razor blade measuring 1-3 cm2 2. The piece is placed in a preparation glass and dripped with 2-3 drops of water 3. After covering with a cover glass, observe under a microscope at low magnification 4. Colored cells near the edge of the section are observed, including non-pigmented cells, nuclei and other subcellular particles in the cells. 5. Then add 2 or 3 drops of 1M sucrose between the preparation glass and the cover glass through one side. 6. Excessive water is absorbed by the tissue paper on the opposite edge of the cover glass 7. Continue adding drops of sucrose solution so that they are absorbed by the tissue paper into the glass 8. Observe the decrease in protoplast volume and note the unpigmented cytoplasmic threads remaining attached to the cell wall and note the time for this process. 9. Now place a piece of tissue paper to absorb the sucrose solution and add a few more drops of water on the opposite side of the glass 10. Observe the deplasmolysis process that occurs and note the time required for this process to take place in one cell. 11. Perform procedures 5-10 for 1M NaCl solution. Experiment b. Determination of Cell Fluid Osmosic Pressure Objective: Calculating the osmotic pressure of cell fluids Materials and tools: Plant material: Leaf Rhoe discolor which is still fresh. Chemical material : Glucose or Sucrose solution with concentration 0.24 :0.22 :0.20 :0.18 :0.16 :0.14 :0.12 :0.10 M Tools: Razor blade, test tube, tweezers, object glass Ways of working: 1. Prepare seven test tubes and then fill about 1/3 of the glucose or sucrose solution into the tubes, one test tube for one concentration. 2. Cut the colored epidermis layer of the plant using a razor blade, try to cut only one layer. 3. Check under the microscope whether your incision is good enough to use. 4. If it is representative enough, count the number of intact purple cells and place the incision into a test tube and record the time the immersion starts. 5. Leave the incision in the solution for 30 minutes. 6. After 30 minutes, examine the epidermal incision under a microscope with the sucrose solution reagent where the incision was kept, then count the cells with a purple color that are still intact. 7. Look for the sucrose concentration where 50% of the epidermal cells have been plasmolyzed. This condition is called Incipient Plasmolysis. The percentage of cells that experience plasmolysis is calculated using the equation: % plasmolysis =Σ early purple cells - Σ late purple cells X 100% Σ cells are colored initial purple 8. Cells in the Incipient Plasmolysis state have an osmotic potential equal to the osmotic potential of the solution used. Experiment c. Measuring Tissue Water Potential Using the Chardakov Method Objective: To find out how to measure water potential using the Chardakov method Materials and Tools: Plant material : Tubers of several types of plants Chemical material : 0.1 sucrose solution; 0.2 ; 0.3 ; 0.4 ; 0.5 ; 0.6 M, methylene blue (methylene blue) Tools : Six pipettes with a capacity of 10 mL, 6 test tubes, tools cork drill, micropipette or syringe 6 pieces Ways of working: 1. Fill the test tube with sucrose solution according to the concentration of 10 mL 2. Make a cut of the tuber whose water potential will be measured using a cork drill 3. Put 10 pieces of tissue into each test tube 4. The test tube is closed and left for 80 minutes 5. Every 20 minutes the test tube is shaken slowly to speed up equilibrium 6. After 80 minutes, remove the tuber pieces from the test tube using tweezers or a needle with a stem, for each tube use different tweezers 7. Next, the remaining solution is tested with the original solution of the same concentration and has been stained with methylene blue 8. Using a pipette or syringe, drop the test solution into the remaining solution slowly in the middle of the solution and observe the movement of the test solution; If the test solution falls to the bottom of the remaining solution, it means that the remaining solution has become dilute. If the test solution is reflected upwards again, it means that the remaining solution has become more concentrated than before. Look for the remaining solution where the test solution floats in the remaining soaking solution. 9. The solution in which the test solution floats shows that the solution has not changed during immersion in the tissue, which means that the tissue is in equilibrium with the sucrose solution used, which also means that the water potential of the leaves is the same as the water potential of the solution.