Introduction
Germination is the biological process in which dormant seeds begin to sprout when they are exposed to favorable conditions for germination. The process normally begins when water sips through to the outer coating of the seed called the seed coat. This process in which the uptake of water is facilitated through the seed is called imbibition. During this process, the seed increases in size due to the imbibition process as water fills up the inner part of the seed. Later the seed bursts the seed coat open, and the seed begins to grow from there. This process is different depending on the time water takes to pass through from the surrounding through the testa all the way up to the inner parts of the cell for germination to begin. It means therefore that those plants with thicker seed coat take a longer time to germinate (Mayer and Poljakoff-Mayber 96).
Seed germination process is affected by various factors. Consequently, seed germination is facilitated by some specific conditions. Therefore the factors that inhibit seed germination have are in one way connected to the factors that promote the process of germination. Seed germination is influenced by some factors. These factors dictate how and when the entire process of seed germination occurs. The first one is the availability of water. This is an essential factor when considering seed germination and without water, many seeds will not germinate. The seed, despite any condition, must go through the imbibition process so that it can become active again and grow. The water activates the enzymes and facilitates the growth of roots that are necessary for the germination process. Besides, temperature is another factor that facilitates the germination process. For instance, there are some plants which only grow in areas with moderate temperature and are destroyed in extreme temperatures. Few other plants can germinate and grow in extreme temperature conditions which make a smaller percentage. The above, temperature and water are the most important factors that inhibit or facilitate the germination process.
Results
During this experiment, pinto bean and grass were used for experiments. A portion of the grass was subjected to sodium chloride treatment, and the other bunch was exempted, and the same case applied to the pinto beans. The results were then recorded. The pinto bean soaked in sodium chloride had a slower growth rate compared to the bean seed with no sodium chloride coating. After seven days, the pinto bean that was soaked in sodium chloride had a shoot with an average length of 14mm and a root with an average length of 108mm. The other seed without a sodium chloride coating on the other side had a shoot with length 39mm after seven days and a root with 143mm in length.
Same measurements were done for grass that was soaked in sodium chloride and that which was not soaked in sodium chloride. For soaked grass, the first three days had no visible germination processes going on. However after five days there was germination in the seeds. Four out of twenty seeds germinated, this is a representation of 20% of the seeds put to the test. The shoot average for the soaked grass was recorded at 17mm and the root average recorded at 8mm. For the grass that was not soaked in sodium chloride, germination process was observed right on the third day where four out of 20 seeds germinated. This represented a 20% of the total and as the days grew the number increased, and so did the percentage. The final shoot average was recorded at 38mm, and the root length average was recorded at 34mm.
Discussion
Many aspects of environmental changes, however, affect germination in this, experiment the main aspect that was being tested was salinity using sodium chloride as a possible hindrance to germination. Soil salinization is a possible cause to soil degradation. The excess salinity in the soil, for instance, has a great effect on the uptake of water by the plant. This is due to differences in osmotic and ionic effects, and this also depends on and varies from plant to plant depending on its adaptive features.
Various plants have different adaptive features that enable them to adapt to different environments. However, not all plants have the same adaptive features. This is the reason why despite the high concentration of sodium chloride in the soil, some of the plants will still be able to germinate in that kind of environment with utmost ease. A high concentration of salt in the plants often acts like a drought to the plant. Therefore, high salt concentration drains water from the seed creating a hostile environment for the seed thereby inhibiting the process of germination (Khan and Darrell 115)
Germination is a crucial step in the growth of a plant. The seed is expected to grow into becoming a seeding and later a fully grown plant. The conditions necessary for the entire process are critical and should be as accurate as possible, and this includes salinity of the soil. The utmost reliable conditions for the ample growth of a seed requires that there is abundant water supply to the seed, there is the right temperature for the process, and also the salinity of the soil also matters. Salinity mainly affects the osmotic component of the seed thereby hindering the ample uptake of water. In the condition where the seed later is provided with an environment in which the salinity is low, and the water is fresh, the seed will still manage to germinate.
This experiment mainly investigated the effects of sodium chloride on the germination of seeds in both grass species and pinto bean. There is a variation in plant tolerance towards salinity of the soil and their survival to complete seed germination. In this experiment, grass proved to be very much intolerant to salinity. This is because the grass specimens that were soaked in sodium chloride were affected so much by the salinity (Deno 256). This is the main reason why for the first three days there was no significant show that there was a change in the germination process for the grass. However, after five days there were only four of the seeds that managed to germinate out of the twenty seeds that were initially under scrutiny. The case was similar for pinto bean seeds. The salinity created by the sodium chloride affected the germination process in pinto seeds as well. This is why only six seeds out of twenty were counted after three days. The saline environment inactivated the other seeds. However when the salinity level reduced, there was a significant increase in the number of seeds germinating. Pinto seeds that were subjected to a normal environment grew together normally.
In conclusion, salinity is a condition that can be created by other potential saline chemicals such as potassium chloride and others. These chemicals also cause the same effects as the one caused by sodium chloride. However, if the experiments were to compare between say a mangrove seed and a pinto bean seed, then the mangrove seed would have grown better and faster as usually compares to the pinto bean seed. This is because the mangrove tree is adapted to live under such conditions. This gives them an upper hand in the process of germinating in such a condition.
- Deno, Norman C. Seed Germination: Theory and Practice. University Park, Pa: Pennsylvania State University, 1994. Print.
- Khan, M A, and Darrell J. Weber. Ecophysiology of High Salinity Tolerant Plants. Dordrecht: Springer, 2006. Internet resource.
- Mayer, A M, and A Poljakoff-Mayber. The Germination of Seeds. Burlington: Elsevier Science, 1982. Internet resource.
