Cytokinins promote the growth of young leaves and delay the senescence of mature leaves, as well as having a nutrient mobilizing effect. Treatment of some leaves of cauliflower bean plugs with cytokinins showed significant differences in growth and senescence rates from untreated leaves.
Operation method
Experiments on the effect of cytokinins on the growth and senescence of leaves of the bean, Brassica napus L.
Principle
Cytokinins promote the growth of young leaves and delay the senescence of mature leaves, as well as having a nutrient mobilizing effect. Treatment of some leaves of cauliflower bean plugs with cytokinins showed significant differences in growth and senescence rates from untreated leaves.
Materials and Instruments
Vegetable Bean Seedling Move I. Materials and methods For more product details, please visit Aladdin Scientific website.
Scissors, beaker, brush, ruler.
Materials and equipment
Vegetable bean seedlings
1 pair of scissors, 5 500 ml beakers or wide-mouth jars, 1 brush, 1 small ruler.
30pp M BA solution, 0.3N KOH.
Experimental Steps
1. Cultivation of kidney bean seedlings
Select 100-150 seeds of cauliflower beans and sow them in pots filled with vermiculite. Place the pots in a greenhouse or growth chamber at 20-24°C with about 16 hours of sunlight length and 1500-2000 meter candles. Water the plants with tap water (do not use a nutrient solution).
2. Preparation of 30pp M BA solution
Dissolve 15 mg of BA in 1-2 ml of 0.3 N KOH, dilute to 500 ml with distilled water and add 0.05% Tween 20.
3. Treatment of plugs
About 14 days after sowing of vegetable beans, when the plants grew to a height of about 25 cm with two primary leaves and one unexpanded ternate leaf, the plants were cut from about 10 cm below the primary leaves and the cotyledons were quickly removed. Place 42 of these cuttings in seven wide-mouth bottles containing distilled water, six per bottle, making sure to soak the base of each cuttings in water.
Treat the plugs in each of the seven wide-mouthed bottles as follows:
Bottle No. 1 Control - no treatment
Vase No. 2 Cut off three leaves.
Vase 3 Apply BA solution to one of the two primary leaves.
Bottle #4 Cut off the ternate leaves and then treat one of the two primordial leaves with BA as in bottle #3.
Vial No. 5 Apply BA to one of the two primary leaves.
Vase No. 6 Apply BA to the three emergent leaves.
Vase No. 7 Cut off one leaflet in the middle of the two primary leaves and the three emergent leaves, and apply BA to one of the remaining two leaflets.
4. Management of cuttings
After the start of the experiment, observations were made twice a week and the following tasks were carried out each time:
(1) A small section of the base of the plug was cut off to keep the cut fresh and to remove adventitious roots and newly grown ternate leaves.
② Replace the distilled water in the bottle.
③ Repeat the application of BA solution to the leaves.
④ Observe the leaves of the plugs in each treatment showing signs of senescence and estimate the development of senescence by recording the color of the leaves such as changing to dark green (1), light green (2), yellow-green (3), or yellow (4), and the length of the two leaflets was measured as a sign of growth in vial #7.
III. Results Plotting and Measurements
① Plot a graph for each of the different treatments, marking the degree of senescence (1-4) on the vertical axis and the number of days on the horizontal axis, and plotting the changes in leaf senescence in each of the following treatments:
Vials 1, 2, 3, 4 and 6: Track senescence of two primary leaves.
Vial #5: two primordial leaves and three emergent leaves.
Vial #7: the two remaining leaflets of the triple emergent leaf.
(ii) Measure the size of the triple emergent leaves in vials 1, 3, 5 and 6, fill in the data in the table below, and write the calculated average on the board. 