The Effect of Mung Bean seed and wheat seed germination when given NaCl, KCl,
and distilled water
Mohammad Rizavi
Abstract
Mung bean seeds are types of seeds found in the legume family. Today, these
seeds are cultivated across India, Southeast Asia, and China. Mung bean seeds are
often used as an ingredient in sweet dishes. In order for the seeds to grow, they
must be left under four hours of daylight.
In this experiment, the objectives are to demonstrate how osmosis/diffusion
is performed while germinating mung bean seeds and the rate at which each seed
grows when given various solutions such as, sodium chloride (NaCl), potassium
chloride (KCl), and distilled water. 10 seeds were used for each solution. They were
wrapped inside a paper towel folded once and placed into Ziploc bags. Each bag was
given either NaCl, KCl, or distilled water. The bags were placed in a dark cabinet and
observed for seven days.
According to the results, the distilled water was the solution that germinated
the seeds at a faster rate than the other two solutions. The distilled water
germinated its seeds almost twice as fast. Also, the shoot lengths of the seeds that
were given distilled water were longer than the shoot lengths of the other two
solutions. This experiment proves that distilled water can freely move across the
permeable cell membrane of mung bean seeds faster than other solutions. This is
because osmosis is the diffusion of only water molecules through a selectively
permeable membrane.
Introduction
Mung Beans originated mainly from the Indian Subcontinent and China.
Mung Beans usually germinate with water in daylight for four hours. The beans
were first seen 4500 years ago in the Harappan civilization. They must be under
warm temperature for at least four hours and for the rest of they day, they spend it
in the night. Cultivation of mung bean seeds spread across India approximately
3500 years ago.
The hypothesis for this experiment can be stated that if Mung Beans are
mixed with sodium chloride (NaCl) and placed in a bag, then the mung beans will
grow at a faster rate in darkness. The control group of this experiment is the bag
containing water and ten Mung beans. The experimental group of this experiment is
the Sodium Chloride and ten Mung Beans. The independent variable would be the
mung beans exposed to Sodium Chloride. The dependent variable is the rate at
which the mung beans grow.
Osmosis is the diffusion of only water molecules across a selectively
permeable membrane from an area of low concentration to an area of high
concentration (Kannan, 2008). Simple diffusion is the diffusion of molecules across a
cell membrane from an area of low concentration to an area of high concentration.
The seeds in this experiment will be hypotonic towards the solution. The seed has
low concentration, which leads to the seed absorbing the solution. The effect of
Sodium Chloride on the mung bean could potentially result in the mung bean
increasing its rate of germination (Nakamura, 1990).
The overall purpose of this experiment is to allow the experimenter to
understand the process of osmosis and diffusion through the germination of mung
beans. It also serves as an example of how hypotonic, hypertonic, and isotonic
solutions work. These solutions are the measure of osmotic pressure of two
different solutions parted by a cell membrane. They determine the direction of
diffusion from the two solutions. The overall experiment involves the need for light
and whether it is under artificial or actual light, the substance should go through
plant growth.
Materials and Methods
This experiment included two Ziploc bags, a pipette, a 25 mL graduated
cylinder, 20 wheat seeds, paper towels, distilled water, and one solution that served
as the treatment group. The distilled water was used as the control group. The first
step for this experiment was placing 10 wheat seeds into two separate paper towels.
Each paper towel was folded once. One of the sets of paper towels containing 10
wheat seeds was drenched with distilled water and the other set was exposed to
0.25 M of sodium chloride (NaCl). A graduated cylinder was used to measure out
three mL of sodium chloride and a pipette was used to pour the three mL solution
onto the paper towel. Both sets of paper towels were stored inside separate zip log
bags. The two Ziploc bags were labeled accordingly depending on the solution that
the seeds were exposed to. Properly sealing the bags, they were then placed in a
dark environment (a drawer or a closet) and were observed every evening at 6:30
p.m.
Results:
In this experiment, wheat seeds and mung bean seeds were given sodium chloride
(NaCl), potassium chloride (KCl), and distilled water. When the seeds were exposed to
NaCl and KCl, only a few of the seeds germinated, whereas, when the seeds were given
distilled water, all the seeds germinated.
Effect of NaCl on Wheat Seed Germination
10
Number of Seeds Germinated
9
8
7
6
5
Control
4
NaCl
3
2
1
0
1
2
3
4
5
Number of Days
6
7
Figure 1 Average amount of wheat seeds germinated after given NaCl and distilled
water after 7 days of observation.
The 10 seeds that were given 0.25 M NaCl germinated at a slower rate than the 10
seeds that were given distilled water. The graph provides evidence of how seeds were
germinating twice as fast as the NaCl solution each day. The distilled water was able to
diffuse at a faster rate through the cell membrane than the NaCl solution.
Number of Seeds Germinated
Effect of KCl on Seed Germination
10
9
8
7
6
5
4
3
2
1
0
Control
KCl
1
2
3
4
5
Number of Days
6
7
Figure 2 Average amount of wheat seeds germinated when given KCl solution and
distilled water after 7 days of observation.
The seeds that were given distilled water germinated at a faster rater than the
seeds given KCl solution. This was because the cell membranes of the seeds that were
given distilled water diffused faster than the seeds given KCL solution. When comparing
the effect of NaCl on seed germination (Figure 1) to the effect of KCl on seed
germination (Figure 2), the KCl solution germinated faster than the NaCl solution.
Average Shoot Length of Seeds
Stem Length (cm)
3
2.5
2
1.5
Series1
1
0.5
0
control
NaCl
Solutions
KCl
Figure 3 Average length of the stems on the seeds germinated after given distilled water,
NaCl , and KCl for 7 days.
Since the seeds of the distilled water grew at a faster rate, the stems of the seeds
were taller than the other two solutions. Also, the KCl solution germinated seeds faster
than the NaCl, which also meant that the lengths of the stems were taller than the stems
of the NaCl. There is a positive correlation between the rate at which a seed germinates
and the length of the shoot.
Average Seed Germination
10
Effects of Different Solutions on
Control
Seed Germination
9
KCl
8
7
6
5
NaCl
4
3
2
1
0
1
2
3
4
Days
5
6
7
Figure 4 Average amount of wheat seeds germinated using NaCl, KCl, and distilled
water for 7 days.
During the 7 days of observation, more wheat seeds grew when given distilled
water than the other two solutions. This is because distilled water was able to move faster
across the seeds’ permeable cell membrane rather than the NaCl and KCl solutions. The
results of this experiment proved that the hypothesis was incorrect because the wheat
seeds did not grow at a faster rate than the distilled water when given either NaCl and/or
KCl.
Control
G.
NaCl
KCl
2
0
4
2
9
4
10
5
10
5
10
6
10
6
Figure 5 Number of seeds germinated for each
solution after 7 days of observation.
0
0
0
2
5
6
7
Discussions:
The objectives of this experiment were to compare/contrast diffusion and osmosis
by germinating seeds. Seeds that were given distilled water germinated as quick as the
first day of observation which meant that water can move across a cell membrane at a fast
rate. However, when the mung bean seeds and the wheat seeds were given two different
solutions, NaCl and KCl, the rate of diffusion was slower. This experiment proved that
the hypothesis stated earlier was incorrect and that if mung bean seeds are given NaCl or
KCl, then the rate of germination will be slower than the rate of distilled water.
According to a similar experiment performed by Islamia University, the seeds that
were given NaCl did not grow faster than the seeds given water. However, experimenters
modified the amount of NaCl solution given to seeds by adding more of the solution.
When the seeds were given more of the solution, the rate of seed germination increased
(Ashraf and others, 1999).
Another experiment was conducted at the Universite catholique de Louvain where
seeds were given water, NaCl, and PEG solution. The length of the shoot was taller from
the seeds that were given water after 6 days than the seeds that were given NaCl and
PEG. This proves that water also travels faster through the permeable cell membrane,
which makes the seeds grow faster (Almansouri, 2001).
This experiment demonstrated the diffusion of water molecules across a cell
membrane. Specifically, distilled water had a faster rate of diffusion across the cell
membrane. The significance of this experiment was that water is simply the best solution
for a faster growth of seeds when compared to other solutions. This information can help
plantation owners grow their seeds at a faster rate.
References
Almansouri, M., J.M. Kinet, and S. Lutts. Effect of salt and osmotic stresses on
germination in durum wheat (Triticum durum Desf.). N.p., Apr. 2001. VCU Database.
Web. 17 Oct. 2014.
<http://link.springer.com/article/10.1023%2FA%3A1010378409663>.
Ashraf, Mohammad, Nasim Akhtar, Firdous Tahira, and Faiz-ul-Hassan Nasim. Effect of
NaCl Pretreatment on the Germination and Emergence of Seven Cultivars of Wheat
Seeds. Pakistan Journal of Biological Sciences, 1999. VCU Database. Web. 17 Oct.
2014. <http://www.scialert.net/abstract/?doi=pjbs.1999.1594.1597>.
Kannan, A., & Upreti, R. K. (2008). Influence of distillery effluent on germination and
growth of mung bean (vigna radiata) seeds. Journal of Hazardous Materials, 153 (1-2)
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