Experiments for the identification of plant resistance
Experiments for the identification of plant resistance
The study of plant stress tolerance is important in scientific research and is closely related to production, so it is often necessary to measure the magnitude of stress tolerance. In this experiment, we practiced the technique of determining the change in cell permeability based on the change in electrical conductivity (the change in permeability responds to the magnitude of stress tolerance), and observed the effect of drought, high temperature, and other factors on the cell permeability to provide the conditions for in-depth research on stress tolerance.
Operation method
Experiments for the identification of plant resistance
Principle
When the plant tissue by drought or other adverse conditions such as high temperature, low temperature, etc., often can harm the structure of the protoplasmic body and cause increased permeability, the results of the cell contents will have different degrees of extravasation, so that the extravasation of the conductivity of the liquid increases, with the conductivity of the meter can be clearly determined, the greater the change in permeability, indicating that the more serious the injuries, the more resistance to the weaker. Move I. Materials and equipment For more product details, please visit Aladdin Scientific website.
1. Plant material: Wheat, corn or other crop leaves.
2. Instruments and appliances: (1) 1 conductivity meter (DDS-11 type or DDS-11A type); (2) 1 analytical balance (sense of one ten-thousandth); (3) 1 warming box; (4) 1 vacuum pump; (5) 1 vacuum desiccator; (6) 1 constant-temperature water bath; (7) 10 beakers, 50 ml; (8) Measuring flasks: 6 for 100 ml, and 1 for 1000 ml; ( (9) 1 set of glass distiller or ion exchange water purifier; (10) 10 glass rods; (11) a number of filter paper; (12) 1 wash bottle; (13) 1 pair of dissecting scissors.
3 Reagents:
(1) Redistilled or nonionized water;
(2) 100 ppm sodium chloride standard solution: take 100 mg of analytically pure sodium chloride, first dissolve in a small amount of non-ionized or redistilled water, and then set the volume in a 1000 ml measuring flask and shake well;
(3) Sulfuric acid - potassium dichromate washing solution appropriate amount.
Second, the operation steps
1. cleaning utensils, due to the conductivity changes are extremely sensitive, a slight impurity that produces a large error, so cleaning is an important step, so the glass utensils need to be washed with soap, and then washed with a new washing solution, and then with tap water, non-ionized water (or redistilled water) washed four or five times (and finally containers down with water), and then poured in the wash and padded with clean filter paper in the plate, on a clean gauze or glass plate cover, need to be If it is dry, it can be dried in the oven.
2. Make a standard curve: If you need to quantitatively determine the change of permeability, analytically pure NaCl can be used to form a standard solution of 0, 10, 20, 40, 60, 80, 100 ppm, at a constant temperature of 20 ~ 25 ℃ to determine the conductivity, conductivity reading, and made into a standard curve, such as only qualitative, then make a standard curve of this step can be omitted.
3. Prepare test materials:
Selection of wheat or other plants in certain parts of the growth and leaf age similar to a number of leaves, cut off the first gauze wash and wipe clean, take 2 copies, each weighing 2 grams, one in the 40 ℃ temperature box wilted half to 1 hour, a part of the insertion of the water cup to do the control. After treatment were rinsed twice with distilled water, and absorb with clean filter paper, and then cut into small segments of about 1 cm in length, into a small rigid glass cup (the size of the degree of tolerance of electrodes), and pressed with a glass rod, in the beaker accurately add 10-15 ml of non-ionized water to submerge the leaves. Then put into the vacuum desiccator and pumped with an air extractor for 7-8 minutes to draw out the air in the interstitial space of the cells. Then the air was slowly put in, and the water was penetrated into the tissue and made the leaves translucent. Note that during the whole process, the blade and the utensils in contact with the blade must be absolutely clean, and should not directly touch the blade with their hands to avoid contamination. In addition, it should prevent the CO2 exhaled from the mouth from dissolving in the cup.
4. Put the water cup with leaves into the constant temperature water bath: maintain the water temperature 20-25 ℃, 1 hour later, with a clean glass rod gently stirred, and then gently clamped out of the leaves, still at the original temperature with a conductivity meter to determine, record the readings. Comparison with the standard curve, you can find out the solution exuded electrolyte equivalent to the ppm number of NaCl. Another cup of water without leaves and the same treatment for the blank determination. The value of the blank determination was subtracted from the formal determination to give the amount of leaf exudation. If only qualitative determinations were made, a direct comparison between the two treatments was sufficient. The effect of drought and high temperature can be seen by comparing the results of the wilting treatment and the control. Three replicates are required.