The effect of auxin on seed germination

The effect of auxin on seed germination

1. Principle
Auxins and artificially synthesized similar substances such as naphthalene acetic acid have a great regulatory effect on plant growth, and their effects on plant growth are also different at different concentrations. Generally speaking, low concentrations of auxin promote growth, and high concentrations inhibit growth. Different plant organs respond differently to auxin. Usually roots are more sensitive to auxin than buds and stems. In this experiment, we observe the effects of different concentrations of NAA on the growth of different plant organs during seed germination.
2. Materials, equipment and reagents
(1) Material: wheat seeds.
(2) Instruments and equipment: incubator, petri dish, transfer pipette, tweezers, filter paper, ruler.
(3) Reagents: 10mg/L naphthalene acetic acid, 0.1% mercury.
Three, experimental steps
1. Take wheat seeds, sterilize them with 0.1% mercury liters for 15 minutes, rinse them with tap water and distilled water 3 times each, and place them in a 22°C incubator for 2 days.
2. Take 7 sets of 9cm clean petri dishes and number them. [ Sterile Petri Dish,Petri-Dish,Petri Dish Plastic,Petri Dish 90mm Sterile ] Add 10 mL of 10 mg/L naphthalene acetic acid to No. 1 petri dish, then draw 1 mL from it and place it in No. 2 petri dish, add 9 mL of distilled water and mix well to form a 1 mg/L naphthalene acetic acid solution. [ Sterile Petri Dish,Petri-Dish,Petri Dish Plastic,Petri Dish 90mm Sterile ] After diluting to Petri dish No. 6 (finally take out 1mL from Petri dish No. 6 and discard it), the concentration of naphthalene acetic acid in Petri dish No. 1 to No. 6 is 10 mg/L, 1 mg/L, and 0.1 mg. /L, 0.01 mg/L, 0.001 mg/L, 0.0001 mg/L. 9 mL of distilled water was added to the No. 7 petri dish as a control.[ Sterile Petri Dish,Petri-Dish,Petri Dish Plastic,Petri Dish 90mm Sterile ]
3. Put a piece of filter paper the same size as the bottom of the petri dish into each petri dish, select 10 germinated wheat seeds, arrange them neatly in the petri dish with tweezers, make the bud tip up and make the embryo The part facing the same side, after covering the lid, place it in the incubator at 22°C for 3 days in the dark.
4. Measure the average length of sprouts and roots of wheat in the petri dish and the number of roots.
4. Calculation and analysis of experimental results
Take the material in distilled water as a control, calculate the increase or decrease value of wheat sprout and root length in different concentrations of naphthalene acetic acid solution, and fill in the table for comparative analysis.