Abstract
Germination rates of the mung bean seeds differ when planted in different concentrations of salt. A decision to set up an experiment to investigate these claims was reached. For this experiment, Petri dishes containing 20 seeds of mung bean seeds were placed in 5 separate dishes. The other components included distilled water used as a control and 0.1, 0.25, 0.4, and 0.5 millimeters solution of KCL placed in the five dishes. Salinity in this experiment was represented by KCL concentration to prove that salty components in the soil could potentially inhibit growth.
The objective of this experiment was to establish the impacts of the saline conditions on germination. The aim was to establish the effects of an increased concentration of KCL on the mung seeds as they germinate.
This experiment predicted the impact of saline condition on the seeds growth. The osmotic pressure experienced by the seeds showed stunted growth. With the different samples the growth rate of the mung seed was tested. The increase in KCL concentration showed slowed seed germination rate, lower number of seeds germinated, the average germination time and reduced stem length and health.
Introduction
Germination requires several favorable environmental factors. Plants and seeds require certain compounds and environments to grow (Aslam 76). Plants require water, oxygen, and right temperatures in addition to the nutrients for growth. These factors were similar in the entire sample, and that means that they did not affect the results of the experiment. It can be noted that different plants react differently with different temperatures and alkalinity.
Extreme conditions are not conducive for growth. Very cold and very hot environments are unfavorable for germination. Salty soil or environment inhibits the growth of plants. The decrease in plant growth, stomata conductance, leaf area, and transpiration rate are some of the consequences of high salt presence (Zahedi et al. 27). The plants that are unable to change and adapt to the external environments do not survive.
According to Aslam salts have a negative effect on plants growth (23). The high concentration of salt inside the plant’s cells makes it harder for the plants to absorb water. This mechanism is referred to as osmotic effect. All major processes of the plant are affected by the salt concentration. Reduction in the leaf surface, protein synthesis, and metabolism are some of the noticeable effects. Plants exposed to salinity for a longer period do not survive for long (Baskin and Jerry 31).
Germination
Germination occurs when a seed has been transported to a favorable environment, and all the environmental dynamics are stable (Aslam 18). The process of growth resumption after dormancy can be referred to as germination (Parida and Das 20). Germination was followed by growth of the seeds slowly to their full size. In normal circumstances, these parameters are present or may be present but in large quantities that may not be favorable for growth. In such cases, the seeds might not germinate well as the environment is not conducive.
Osmosis
The movement of free water to a low free water concentration from a higher free water concentration referred to as osmosis (Brandenburg and Kleier 90). All organisms must closely regulate the amount of salts in their tissues. When a cell is surrounded by a saline concentration, it absorbs the salt, and the concentration inside the cells becomes either higher or equal to that of the outside environment.
This means that the osmosis process were not able to take place as the concentration was equal on both sides and thus the cells did not absorb the required components for germination. When there is a difference in concentration between the cells and the external environment, stagnated growth occurs. During germination, this process occurs for a seed to sprout and grow. The seed has a lower concentration and thus water from the environment enters the seed and triggers germination. Osmosis mechanism is used by plants to absorb water for growth (Zahedi et al. 30).
The objective of this experiment was to establish the impacts of these saline conditions on germination and establish the impact of the germination rate. A prediction on the effects of an increased concentration of KCL on the mung seeds would inhibit growth.
In light of the above, a decision to conduct an experiment to verify these facts was reached. The mung bean seeds were used as the test seeds and observations were done on their growth, while the soils had different concentration levels and all the other factors were similar. The various concentration solutions of KCL were used and germination rates were measured every day for a week. The results are recorded every day for analysis at the end of the experiment.
Methods and Materials
This experiment was done in a full laboratory environment, and no special conditions were provided. To set up the experiment the following items were required: five sets of Petri dishes each containing 20 mung bean seeds and a filter paper on each dish. The four Petri dishes had different concentration solution of KCL as shown below:
Table 1: shows the sample concentration levels.
The dishes were then wrapped with a film and put in a dark drawer. The average temperature of the room was set to around 26 degrees Celsius. Observations were made every day on the number of the seeds that had a root protruding as below table shows.
Table 2: show a record of the germinated seeds percentage per day in the various samples
Observations and measurements were done every day and were recorded. Within a week, results for the experiment were all recorded. The above table 2 shows these facts.
Results
Plant growth inhibition was observed in similar experiments using different salts. The trend and effect on germination and growth were also similar. In this experiment, the results were in line with the previous experiments done. These results proved that an increased salinity concentration in the soil or germination media caused retarded germination and growth. In summary, the ability of mung bean seeds to germinate faster and in a higher percentage of test seeds was because of increased KCL concentrations.
The experiment showed that it took the seeds different number of days to germinate with the concentration and the number of the seeds that germinated varied. As seen in the table 2 above, the concentration of 0.5mm KCL slowed down germination by five days while it took only one day for the seeds in both distilled water sample and 0.1mm concentration to germinate. The germination rate of seeds in distilled water and 0.10M of KCL were faster than the other KCL solutions of 0.25M, 0.4M, and 0.5M. KCL solution of 0.10M had the highest germination rate among the other concentrations of KCL solution and 0.5M had the lowest rate of germinated seeds on the 7-day experiment.
In general, the ability of mung bean seeds to germinate faster and in a higher percentage of test seeds was because of the increased KCL concentrations. These changes were illustrated in a graphical form below:
The growth of seeds was seen, and a conclusion was made that the concentration levels certainly affected the germination rates of seeds. The table 2 above shows the comparison of the germination rates with the control sample of water only. However, it was noted that water-controlled environment took only five days for all the seeds to germinate. And only 3.33% of the seeds in the 0.5mm KCL concentration germinated at the end of the week.
The table one above shows that the germination rates varied as the above parameters were affected by the external environment thus affecting the germination rates. As the plant germinated and was exposed to more saline environment, the necessary components of growth were limited. Due to the salinity differences between the seeds, the environment was different, and thus the plant did not get the necessary components for growth.
In the experiment, table 1 showed that the germination rates of the seeds in concentrations of 0.1M were higher as compared to the other samples with a higher level of KCL concentration. The osmotic pressure in the high concentration samples was higher than in the samples with lower concentration. It also proved the prediction that the concentration of KCL would inhibit growth. These varying germination percentages show that the mung bean seeds can comfortably survive in soils with similar concentration. In normal circumstance, the concentration levels between zero M KCL and 0.25M KCL would be ideal for the mung bean seeds as they can grow well.
In the early stages of germination, salt concentration also has effects. In saline concentrated environment, the seeds are unable to absorb water and thus inhibiting germination (Othman et al. 37). This process was observed in the experiment as the seeds on saline soil had stunted growth.
Other researchers could use the results of this experiment in the future in determining the favorable environment for growing mung beans. The contribution of this research and the procedures can be applied in other tests and comparisons. The knowledge of the behavior of mung bean seeds in this situation will help soil scientists in deciding the best soils to grow these seeds and the expected germination rates.
Discussion
The retarded growth of the mung bean seeds was attributed to the presence of high concentrations of KCL solution in the filters. These results showed that mung seeds growing in environments with high presence of KCL had a harder time surviving than the plants growing in KCL free environments. This experiment also proved that the presence of salts in the soil had a harmful impact on the plants. Salty environments are not favorable for plant growth; the plants have to adapt in order to survive, and this can be seen in the experiment (Zahedi et al. 45).
This experiment also proved that the osmosis process in plants is affected by the different concentration levels. It, therefore, indicates that the concentration of the plant should be lesser than the concentration of the soil to ensure the efficiency of this process. The reason is that the water cannot cross the membranes of the plants and thus the plants were denied this crucial essential component of growth. Furthermore, these data support the hypothesis that high concentration of KCL decreases the germination rate of mung bean seeds.
Field and full-scale laboratory trials to determine the salinity tolerance of plants at the germination and early seedling growth stages take a considerable amount of time and require large labor and resource inputs (Fidalgo et al.185). Therefore, laboratory experiments save time and resources that could have been used in the fields. This idea necessitates a small experiment, which gave the desired direction of the test and whose results can be implemented in a large project and yield similar results. In light of this, a laboratory experiment with small sample was sufficient to give a direction on the results that were to be received in a large-scale project. These data could be used for improvement and development in agriculture systems.
Works Cited
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