Seed germination is a complex phenomenon involving many physiological and biochemical changes and leading to the activation of embryo (Bewley & Black, 1985). Seeds vary in their rate of germination. In normal conditions, soybean seeds should germinate in one to two days.
It first reduces imbibition of water because of the lowered osmotic potential of the medium (Bliss et al., 1985). Second, it causes toxicity; that is, it changes enzymatic activity, hampers protein metabolism, upsets plant growth regulators balance, and reduces the utilization of seed reserves. It may elicit changes at ultrastructural, cellular and tissue, or even at organ levels (Dell'Aquila & Spada, 1993). Salinity interacts with certain plant and environmental factors during germination. Among these plant factors are seed coat, dormancy, seed age, seed polymorphism, and seedling vigor. Environmental factors include temperature, light, availability of water, and oxygen (Pessarakli, 1999).
In this experiment, it will be determined if salt will interfere with the rate of germination of soybean seeds. To assure that all other factors are held constant, a standard germination test will be undertaken under optimum conditions for seed germination.
2. Five rectangular plates (12"x5") will be lined with paper towels pre-moistened by different solutions. Plate A is the control and it will be moistened with distilled water. Plate B will be moistened by the 0.5M NaCl solution, Plate C will be moistened with 1M NaCl solution, Plate D will be moistened with 2M NaCl solution and Plate E is moistened with 3M NaCl solution.