1. The Effect of Acetic Acid on the Germination of Wheat Seeds Benjamin Cherian Virginia Commonwealth University – BIOZ 151 Introduction Methods Literature Cited Seed germination is an event that is common to all plants that produce seeds. In this process, a seed consumes water from its surroundings until its seed coat bursts and causes roots to emerge (Bewley, 1997). Several factors, such as pH, can affect seed germination (Nandula et al. 2006). The increased prevalence of acidic precipitation has decreased the pH of soils (Krug and Frink, 1983). This occurrence could prove detrimental to agriculture because seeds, such as wheat, may not be able to undergo germination. Therefore, it is beneficial to design an experiment that seeks to understand how reduced pH solutions affect wheat seed germination. Such a study could serve as a model to demonstrate how acid rain impacts seedling development. The purpose of this experiment was to investigate how acetic acid affects wheat seed germination. In a previous study, the researcher concluded that lower pH values negatively impacted seed germination (Lynch 1980). Therefore, it is believed that wheat seeds that are treated with acetic acid will display fewer instances of seed germination than wheat seeds that are treated with deionized water. Two plastic bags were gathered and labeled with the treatment groups. Twenty wheat seeds were collected and randomly assigned to a treatment group. The experimental solution was prepared by adding ten microliters of distilled white vinegar (5% acetic acid) to ten milliliters of deionized water. Two paper towels were gathered and moistened with either ten milliliters of the acetic acid solution or ten milliliters of deionized water (control). The wheat seeds were placed on these paper towels and then transferred into the sandwich bags. Bags were placed in a dark environment at room temperature for one week. Seeds were given one week to germinate. Observations were made daily. Any changes in the seeds were recorded. The experiment was repeated after the testing period ended. There was no noticeable difference in percent seed germination between the experimental and control groups. During the first trial, the seeds in the experimental group had a higher percent germination than the seeds in the control group (Fig. 1). This was contrary to what was expected. Seeds from both groups exhibited a similar percent germination trend during the second trial (Fig. 2). Bewley, J.D. (1997). Seed Germination and Dormancy. The Plant Cell, 9, 1055-1066. Krug, E., & Frink, C. (1983). Acid Rain on Acid Soil: A New Perspective. Science, 221, 520-525. Lynch, J. (1980). Effects of organic acids on the germination of seeds and growth of seedlings. Plant, Cell & Environment, 3(4), 255-259. Mohebbi, S., & Mahler, R. (1989). The effect of soil pH on wheat and lentils grown on an agriculturally acidified northern Idaho soil under greenhouse conditions. Communications in Soil Science and Plant Analysis, 20(3-4), 359-381. Nandula, V., Eubank, T., Poston, D., Koger, C., & Reddy, K. (2006). Factors affecting germination of horseweed (Conyza canadensis). Weed Science, 54, 898-902. Tunes, L., Avelar, S., Barros, A., Pedroso, D., Muniz, M., & Lemos, N. (2012). Critical levels of organic acids on seed germination and seedling growth of wheat. Revista Brasileira De Sementes, 34(4), 366-372. Figure 1. The effect of acetic acid on the germination of wheat seeds (Trial 1) Results Figure 2. The effect of acetic acid on the germination of wheat seeds (Trial 2) Discussion and Conclusion Based on the results of this experiment, the research hypothesis was not supported. The amount of acetic acid used in this experiment may not have been sufficient to cause a marked change in pH. Furthermore, acetic acid is a weak acid that does not readily dissociate in water. Other researchers have conducted research using wheat seeds and acetic acid. Mohebbi and Mahler found that changes in soil pH did not alter wheat seed germination (1989). Furthermore, Tunes et al. concluded that the germination of wheat seeds is not diminished by acetic acid treatment (2012). The results gathered in this study were consistent to the results in both of these studies.