Plants and flowers make any house a home. They bring life and color to the room, instantly uplifting moods and providing beauty. While visiting a friend, a beautiful bouquet of flowers caught my attention and a curiosity arose of how long these flowers would last. Upon inquiry, sucrose was used to prolong the vase life of the flowers. Therefore, the research question for this experiment is:
Does sugar, or sucrose, prolong the vase life of cut Rosa Hybrid L flowers?
Quite simply, flowers make the seeds necessary for reproduction. The main parts of the flower are typically found in the center of the flower and are known as the carpel (which contains egg cells and is made up of the stigma, style, and ovary) and the stamen (which contains pollen cells and is made up of the anther and filament). The most common type of flower is from the division Magnoliphyta, otherwise known as angiosperms. In fact, angiosperms are the “largest and most diverse group within the kingdom Plantae” and “represent approximately 80 percent of all the known green plants now living”. Plants need water to survive, which allows the plant to “maintain turgor pressure,” which “helps to keep the plant erect and is accomplished when the plasma membrane pushes against the cell wall”. Water moves into the root hairs by osmosis that is needed in photosynthesis to combine with carbon dioxide to make glucose.
12H2O + 6CO2 6H2O + C6H12O6 + 6O2
Water and minerals enter the vascular tissue called xylem and is carried upward through transpiration and are taken to the leaves. Another vascular tissue called phloem is made of living cells that distribute the products of photosynthesis from the leaves to other parts of the plant. Plants “close their stomata” at night due to their inability to make food during this time. Therefore, photosynthesis occurs during the daytime because it requires light. In fact, photosynthesis literally means ‘putting together with light.’ In contrast to animals and humans, plants produce oxygen. This is done by combining carbon dioxide and water. The result is sugar and oxygen, which leaves through the stomata.
In this experiment, tulips were considered for the flower species to be tested. However, they are hard to control due to their phototropism characteristics and the fact that they are only available during the summer. Therefore, after further consideration, Rosa Hybrid L, was selected for use during the experiment. Furthermore, in order to test the prolonged lifespan possibility, sucrose was used as a carbohydrate for nourishment. Sucrose was selected because many studies have shown that supplying exogenous soluble sugars tend to increase cut flower vase life. This is because soluble sugars delay the cut flower senescence. In addition, the concentration of soluble carbohydrates is a factor that controls the vase life of cut roses because there is a limited carbon source inside the flower because of few leaves that process photosynthesis and gives product to glucose.
The purpose of this experiment is to observe if sucrose can prolong the life of cut roses. Therefore, the hypothesis and null hypothesis of this experiment is:
H0 — Soluble sucrose will not prolong the vase life of cut roses.
H1 — Soluble sucrose will prolong the vase life of cut roses.
Furthermore, in this experiment, sucrose is the independent variable and the longevity of the rose is the dependent variable. Acids and biocides, which are usually required as preservatives for cut flowers, are not going to be applied in this experiment. If the flower absorbs acids and biocides, the lifespan may be prolonged due to preservatives, which can produce erroneous results in the experiment. The only possible way the lifespan will be prolonged is due to the sucrose solution.
In this experiment, it is believed that the more sucrose added, the longer the lifespan of the flower. This is a direct result of the movement of water and minerals within the flower. Photosynthesis, which occurs in the leaves, produces glucose, water, and oxygen. Therefore, for the purposes of this experiment, all but two leaves are removed from the stem of the cut flowers. This will limit the amount of glucose produced. Glucose is stored as a starch and is distributed to the leaves and stems and is used to release energy through respiration. As a result of glucose limitation, there is an energy limitation as well.
If the stems of the roses are cut at a perpendicular angle, they will absorb the sucrose solution that is provided. This solution will move up the xylem vessels through transpiration. This will distribute the carbohydrate (sucrose) throughout the rose, prolonging its life and providing energy.
10% > 8% > 6% > 4% > 2% > 0% of sucrose solution
The purpose of this experiment was to determine the relationship between sucrose and cut roses. Specifically, the experiment was designed to discover if the use of sucrose would prolong the lifespan of cut roses in vases. The results show that the water solution in the beakers with the cut roses decreased daily. However, it was also determined that the decreasing of water was not consistent. It was further determined that 0% of sucrose in the solution absorbed more water than those that contain sucrose. The lowest absorption level was with 10% sucrose, followed by 8%, 6%, 4%, and 2%. In other words, the more sucrose that was contained in the water, the less water was absorbed by the roses.
Sucrose absorption can be affected by two factors:
Vascular occlusion prevents water transpiration inside the xylem. Research has shown that one of the primary causes of the short lifespan of cut roses is the result of blocked xylem vessels, constricting water supply. Furthermore, vascular occlusion occurs when the water is too sweet for the bacteria or microorganisms to grow in the vase water. These bacteria or microorganisms feed off of sweetened water, which decreases the amount of sucrose contained within the solution. Therefore, in order to limit the growth of harmful microorganisms, the pH of the water must be lowered and a biocide must be added to the solution. Research shows that flowers rehydrate best in acid water with a pH of 3.5 to 4.0. The growth of harmful bacteria was also promoted because the vase water was not changed throughout the experiment. As a result of these bacteria, the water supply became inadequate for the cut roses, thus causing them to wilt.
The sugar molecules were not absorbed by the cut stem. This can also cause an occlusion, limiting transpiration. Transpiration begins with osmosis. As the sucrose molecules in the water were increased, the ability of the plant to absorb the water decreased. This is clearly shown in the results because the solution that contained 10% sucrose had the least water uptake. This was further proved because the most water uptake was when there was no sucrose in the solution whatsoever. This was followed by 2%, 4%, 6%, and 8% respectively. Therefore, the results prove that sucrose molecules can cause vascular occlusion. In other words, sugar prevents osmosis because if the concentration of sugar outside the plant is greater than the concentration inside the plant.
The results of the experiment also show that the amount of sucrose that was left was comparative to the amount of sucrose that was in the original solution. This suggests that little absorption of sucrose. Therefore, as the sucrose increased, the less water was absorbed, resulting in a shorter lifespan of the rose.
The lack of water uptake resulted in a lack of fresh weight. This contributed to early wilting of the rose. This wilting includes the hardening of the leaves and the petals falling off the rose. In addition, wilting can be caused by the stored sugar being used until no more remained. The stored sugar weight was included during the original weighing of the rose.
The early introduction of the plant hormone ethylene (death or ripening hormone) was unexpected. Therefore, the roses with the sucrose solution of 2%, 4%, 6%, and 8% were terminated before the rose with 0%. This termination was a direct result of the ethylene hormone gas spreading to surrounding roses. As a result, the roses with the sucrose solution of 0% and 10% were the least affected.
There were errors in the experiment that affected the final results. To begin with, the water measurements were not obtained on the weekends. This affected the averages of water absorption. Second, the wilted leaves fell into the beakers. This may have affected water absorption. The reason for this is that the leaves may have absorbed water. Since the leaf is independent of the plant, it would not benefit the rose. Third, it is possible that some sugar molecules evaporated, rather than were absorbed. Fourth, miscalculations may have occurred due to uncertainties in measuring the amount of solution inside the beaker and weighing them.
Wilting is defined as the deepening of the plant color from green to brown. The leaves shrivel, harden and fall off. Bent neck, causes by inadequate water transport, may occur. The petals of the rose may shrivel, harden, and fall off as well. The final stage typically occurs with the hardening of the entire plant. This process may happen gradually or rapidly.
The roses wilted at various intervals, affecting the results. For example, the roses with 2%, 4%, 6%, and 8% sucrose solution wilted at day 7. The rose at 0% wilted at day 12 to 13. The rose at 10% did not wilt. The final results showed that the hypothesis was correct. The reason for this is that the rose in 0% sucrose solution wilted before the rose in 10% sucrose solution wilted. Thus, sucrose does prolong the vase life of a cut rose.
The experiment also proved that sucrose affects the amount of water that is absorbed by the plant. The sugar molecules create a blockade, known as a vascular occlusion, which prevents water from being absorbed. Furthermore, this blockade can make the plant vulnerable to air embolisms, which can also affect the lifespan of the plant.
As can be seen, there were many uncertainties regarding this experiment that may have adversely affected the result. To obtain more accurate results, it may be necessary to repeat the experiment while altering the pH level of the water, location of the plants to prevent wilting due to the plant hormone ethylene, and multiple plants with the same sucrose solution. In addition, it may be wise to conduct the experiment using a variety of different plants to see how each plant reacts to the sucrose solution.
For now, it is known that the vase lifespan of cut roses is longer due to the inclusion of a sucrose solution of 10%.
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