BIOLOGY FINAL LAB REPORT PAPER

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National University

Final Lab Report

Seed Germination & Environmental Conditions

Jerry Shirey

BIO100A Survey of Bioscience Lab

Professor Gorman

September 24, 2020

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Introduction

Plants are an essential part of life on the planet, providing the needed building blocks for

all creatures to flourish and grow. These plants not only provide a portion of the air we breathe,

but also provide nutrients and other compounds we need to survive and grow. However, with the

changes in the conditions of the soil they grow in, we effect their ability to reproduce, thrive, and

grow. Salinity of the soil is one such change that can have lasting effects on plant life and

growth. Plants use a process known as osmosis, to control the process of water being taken in

through the roots, this process is controlled by the levels of salt in the soil and inside the plants;

when salt levels are too high this may cause water to be drawn from the plant back in to the soil

preventing growth, lowering the yield of crops by interfering with the nitrogen uptake process of

the plant (Queensland Government). When salt dissolves in a liquid solution such as water,

sodium chloride is separated into, sodium and chloride ions; chloride ions are easily absorbed by

the roots and build to highly toxic levels in the leaves, harming and even killing the plants

(Perry).

Due to the scarcity of fresh water, the effects of salinity reduce the ability for plants and

animals to survive. In an effort to better understand the salt tolerance of plants, we can test

different salt water solutions on seeds during their germination process to witness the effects of

salinity first hand. During the germination process, water uptake activates the processes in which

the seed grows. Higher salinity concentrations will inhibit this water uptake process, causing

these seeds not to begin the germination process and creating an environment that the seed is

unlikely to survive in. During this process we should see incremental decreases in the

germination level of the seeds as the salinity increases and at a certain salinity level we will also

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see the complete stop of the process. We will identify at what level salinity becomes high enough

to stop the germination process and result in failure for the plants to grow and thrive.

Methods and Materials

To prepare for the experiment we first had to gather all the required materials. A picture

of these materials can be found below labeled as Figure 1 and a complete listing of these items

labeled as Table 1. After compiling all these materials we began to prepare for the experiment.

The experiment was started by reading the

entire lab manual, and understanding the complete process. At this point using the indelible

marker we marked the paper coffee cups and Ziploc bags with their corresponding salinity

number. 100 ml of tap water was added to a 500 ml plastic bottle along with 4 tablespoons of Sea

Salt, this solution was stirred, swirled, and shaken to ensure as much salt as possible became

soluble into the solution. Once this was achieved, 1/4 cup or 59 ml was poured off the top of the

bottle. This solution was poured into the cup labeled 1/2. Another 1/4 cup of was added to this

cup and stirred to produce the desired 50% saturated solution. 1/4 cup of this solution was

removed and placed in the cup labeled 1/4, again another 1/4 cup of water was added and stirred

to produce a 25% saturated solution and a 1/4 cup of solution was removed and placed in the cup

marked 1/8.

Measuring Cups Measuring Spoons (6) Paper Coffee Cups

(6) Quart Sz. Ziploc Bags

Indelible Marker Ink Pen Final Lab Manual (12) Sheets of Paper

Towels Packet Watermelon Radish Seeds

Granulated Sea Salt

500ml Plastic Bottle (7) Plates

Figure 2: Experiment Materials

Table 1: Experiment Material List

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This same process was continued producing cups labeled 1/8, 1/16, and 1/32. This

produced saturated solutions of 12.5%, 6.3%, and 3.1%. After completing the mixing process for

these cups a final cup labeled 0, was made by adding 1/4 cup of water, this cup would serve as

our control with no salt. Once the solutions had been prepared a single sheet of paper towel was

folded and placed in each cup to absorb the solution, seen in Figure 2 below. The paper towels

would serve as the germination

media for the seeds in this

experiment.

At this time the Watermelon

radish seeds were placed on a clean

plate for inspection. All seeds of

different color, sizes, and shape were

removed to produce a grouping of

seeds with similar characteristics. This produced a total of 121 seeds, which were separated into

six piles of 20 seeds. Once the solution had fully penetrated the germination media, each piece

was placed on a separate, clean plate, and unfolded. Once

completed each plate received a total of 20 seeds placed around

the media as seen to the left in Figure 3. This media was then

folded and placed in the corresponding Ziploc bag marked for

its solution as seen in Figure 4 below. Once the process was

completed the bags were placed in a room at an average

temperature of 72 degrees Fahrenheit to begin the germination process. Each day at 6:00 PM the

Figure 2: Prepared Solution and Germination Media

Figure 3: Seeds on Germination Material

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germination material was removed from these Ziploc bags and inspected to document the

changes the seeds underwent over the next 4 days.

Results

During the experiment, as salinity levels increased a marked reduction in the process of

germination was seen over the four day period, as detailed below for each separate solution.

The 0% solution presented with the beginning of germination starting on day one, when

checked 4 seeds had begun to sprout and another 5 seeds had begun to split but did not show any

growth. On day two, 8 seeds were sprouting and 11 were beginning to split. Day three showed a

total of 19 seeds that had begun the germination process, along with a final seed that had no

activity. The seeds that had begun the germination process were in multiple forms with some

only showing the sprout of a white root and 6 seeds that were showing the beginning of leaves.

On day four all 19 sprouts were showing the formation of leaves and were substantially well

along in the germination process, see Figure 7 below.

The 3.1% solution presented with the beginning of germination starting on day one, when

checked 2 seeds had begun to sprout and another 3 seeds had begun to split but did not show any

growth. On day two, 16 seeds were sprouting and 1 was beginning to split, and 3 were showing

Figure 4: Individual Seed Germination Media in Bags

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no activity. Day three showed a total of 18 seeds that had begun the germination process, along

with a final seed that had no activity. The seeds that had begun the germination process were in

multiple forms with some only showing the sprout of a white root and 4 seeds that were showing

the beginning of leaves. On day four all 19 sprouts were showing the formation of leaves and

were substantially well along in the germination process, see Figure 7 below.

The 6.3% solution presented with the beginning of germination starting on day one, when

checked 1 seed had begun to sprout and another 1 seed had begun to split but did not show any

growth. On day two, results remained the same as seen on day one. Day three showed a total of 6

seeds that had begun the germination process, along with a 14 seeds that had no activity. The

seeds that had begun the germination process were in the early stages presenting with only very

small amounts of growth that was only visible with close examination. On day four a total of 7

sprouts were present, however, very little growth was seen outside the initial splitting and a small

root, see Figure 6 below.

The 12.5% solution presented with no germination starting on day one, when checked 2

seeds had begun to split. On day two, results remained the same as seen on day one with no

seeds beginning to produce noticeable changes and only 3 seeds showing the signs of splitting.

Day three showed the same 3 seeds swollen and appearing to split with no growth, the remainder

of the 17 seeds appeared dormant with no activity. On day four no changes were seen in these

seeds, see Figure 5 below.

The 25% solution presented with no germination starting on day one, when checked 1

seed appeared to be splitting open. On day two, results remained the same as seen on day one

with no seeds beginning to produce noticeable changes and only 2 seeds showing the signs of

splitting. Day three showed the same 2 seeds swollen and appearing to split with no growth, the

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remainder of the 18 seeds appeared dormant with no activity. On day four no changes were seen

in these seeds, see Figure 7 below.

The 50% solution presented with no change to any of the seeds. On day two, results

remained the same as seen on day one with no seeds beginning to produce noticeable changes.

On day three, results remained the same as seen on day one with no seeds beginning to produce

noticeable changes. On day four, these results continued the same no seeds beginning to produce

noticeable changes, see Figure 5 below.

An observational note on the 25% and 50% solution occurred on days 3 and 4. These

salinity solutions appeared by observation of the germination media to be absorbing the nutrients

out of the seeds and into the solution, this was observable by a noticed color change to the media

directly surrounding these seeds, which appeared as a lightly brown or reddish color.

Discussion

During the experiment we produced an inhospitable environment for the germination

process through the use of solutions with high levels of salt. With this we were able to observe

that as the salinity level rises, plants show a marked reduction in the germination and growth

Figure 7: 50% & 25% Solution Figure 6: 12.5% & 6.3% Solution Figure 5: 3.1% & 0% Solution

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process. At a certain point of salinity, 6.3% in this experiment all growth is stopped. Further at

salinity levels of 25% or higher we see the seeds being destroyed and nutrients being depleted

from them by the salinity. As noted in the introduction, plants use a process known as osmosis,

to control the process of water being taken in through the roots, this process is controlled by the

levels of salt in the soil and inside the plants; when salt levels are too high this may cause water

to be drawn from the plant back in to the soil preventing growth, lowering the yield of crops by

interfering with the nitrogen uptake process of the plant (Queensland Government). These toxic

levels of sodium chloride prohibit the germination.

“It has been estimated that more than 20% of all cultivated lands around the world

contain salt levels high enough to cause salt stress to crop plants” (Kaymakanova). With this in

mind, we see the ramifications of the infiltration of salt into the world’s water supplies, due to

our own actions, as being a possible game changer in agriculture. With knowing this information

we must be aware of the changes we make to the environment through items such as agriculture,

and ensure we ourselves are not destroying the ability for soil to be viable. Even small changes to

the salinity level of land can have huge consequences in the future on food production in general.

We expected during this experiment to see an incremental reduction in the germination

process across the different levels of salinity. However, we actual saw the complete halting of

the germination process over a 3.1% level. This shows us how fragile the germination process is

in regards to salinity levels. With this in mind further research will need to be conducted to

narrow the exact point of salinity that germination failure occurs. This can be done by

formulating an experiment for every 0.5% of salinity between the levels of 0 and 6%.

Overall, these results are shocking, to say the least, about what a small amount of salinity

will trigger the failure of germination and plant growth overall.

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Works Cited Kaymakanova, Mira. "Effects of Salinity on Germination and Seed Physiology in Bean (Phaseolus Vulgaris

L.)." Biotechnology & Biotechnological Equipment 23.1 (2009): 326-329. Web. 24 September 2020. <https://www.tandfonline.com/doi/pdf/10.1080/13102818.2009.10818430#:~:text=Salinity%20 can%20affect%20germination%20of,on%20embryo%20viability%20(7).&text=Many%20studies %20on%20seedling%20growth,germinated%20under%20non%2Dsaline%20conditions.>.

Perry, Dr. Leonard. "Salt Damage to Plants." n.d. University of Vermont. Web. 24 September 2020. <http://www.uvm.edu/pss/ppp/articles/salt1.htm#:~:text=When%20salt%20dissolves%20in%20 water,the%20characteristic%20marginal%20leaf%20scorch.>.

Queensland Government. "Impacts of Salinity." 01 October 2013. Queensland Government. Web. 24 September 2020. <https://www.qld.gov.au/environment/land/management/soil/salinity/impacts#:~:text=If%20th e%20level%20of%20salts,salinity%20may%20not%20be%20obvious.>.