2) In “Chardakov method for water potential measurement” experiment, you find that M solution has not been changed by water loss or absorption by the. Chardakov Technique. Plant Physiology. UNI. Incubating tissue in solution. Pre- incubation. Incubation. Post-incubation. Save for later measurement. Did solution change concentration? Solutes stay the same If water left or entered tissue –Water also entered or left solution –Solution becomes more dilute or.
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The Chardokov method provides a quick means to determine plant tissue water potentials. OK Any substance that can change shape or flow easily. At this point, the water potential of the solution equals the water potential of the potato cores.
Investigating osmosis: measuring the water potential of a potato cell
In both techniques, tissue samples are incubated in a series of solutions of known osmotic water potential. Boy, Oh Buoyancy Does it Float? Incubate the cores for 1. Dispense 10 mL of water or a sucrose solution 0. Change in weight of potato cores incubated in sucrose solutions. Repeat for all solutions.
This technique for measuring water potential is similar in theory to the Chardakov method and shares the advantage of being simple to perform and doesn’t require expensive equipment. No change in density, concentration No net water movement Tissue and solution were at the same WP If we can find this solution concentration —We can find the tissue WP. In this method, tissue samples are weighed before and after incubation in a series of solutions of known osmotic water potential.
Cut them to the same length ca. Be sure not to include any fragments of the skin. Chardakov Method for Determining Water Potential. Work quickly to minimize evaporation and keep the tissue wrapped in a moist towel.
Does it correspond to the value obtained by the Chardakov technique? Water potential values determined by this method may be slightly more negative than those obtained by the Chardokov method. Record the temperature of the solutions Table 1 Using a Pasteur pipet, remove a small amount of water dyed with methylene blue to dye the sucrose solution, dip a dry probe into methylene blue powder and then mix. If necessary, add more of the appropriate solution to completely submerge the cores but the final volume in each tube must be the same.
The water potential of the tissue is considered to be equal the osmotic potential of the incubating solution at which there is no change in tissue weight i.
Put two or preferably three potato cores in each solution water or sucrose. Registration Forgot your password? Do the cores show various degrees of turgor?
Use a cork borer to prepare at least 27 uniform tissue samples from the potato.
Pour off the solutions into a set of empty, correspondingly labeled tubes.
The solution gains or looses water depending on the water potential of the tissue. Alternately, for a more accurate measurement of changes in the solution density, a refractometer can be used.
Draw the best fit line for your data. Then remove the tissues, gently blot on paper towels and reweigh. Change in Weight final – initial g. Incubate the cores for at least 1. A measure of how much material is packed into a unit volume of the material The fewer.
Two ways to move water Bulk flow Osmosis Both move water from high energy to methoe Differences —Source of energy difference. Density changes can be observed by watching whether a drop of the original solution floats or sinks in the test solution after tissue incubation. Weigh the cores to the nearest 0.