Effect of Gravity Variation on the Growth of Wheat and Guinea Corn Seedlings

Abstract

In this study, the impact of gravity on plant growths was studied to determine the orientation of the roots and shoots under simulated microgravity using the clinostat. The experiment was performed with two local seeds-wheat (Triticum aestivum) and guinea corn (Sorghum bicolor). The agar-agar solution prepared was evenly distributed into the petri dishes where nine seeds each of wheat and guinea corn was planted on four petri dishes. The petri dishes containing the seeds were cultivated in the wet chamber for about 20-30 hours. Three petri dishes were selected in the following order, 1g, 90o turned and clinorotated samples respectively. Five readings were taking at thirty minutes interval. Data on plants growth were collected from photographs taken during the course of the experiments and analyzed using Image J software to measure the root curvature and growth rate. The results show that the wheat has the longest root of about 4.2 cm at 90 minutes and Guinea corn 2.58 cm at 120 minutes. The growth rate of clinorotated wheat is 1.88 times that of guinea corn at 90 minutes while that of 1g remained the same. The speed of clinorotation did not affect growth of clinorotated wheat and guinea corn but growth rate of guinea corn was about 23% lower than wheat. The higher value of angle indicates a more pronounced curvature of the root therefore; wheat germinates faster than guinea corn in simulated microgravity.