CLINOSTAT MICROGRAVITY IMPACT ON ROOT MORPHOLOGY OF SELECTED NUTRITIONAL AND ECONOMIC CROPS

The use of the microgravity simulators such as Clinostat has enhanced microgravity research on Earth as engaging in real space flight microgravity experiments are expensive and unusual. The reduction of gravity causes significant changes on biological organisms, macromolecules, fluids and materials. Some of these changes that occur have led to discoveries that have been found to be of social-economic benefits. The use of Clinostat as a source of simulated microgravity impact for the growth of plants has produced several positive implications especially for the agriculture sector. It is also predicted that space explorers in distant future will have improved breeds of crops that will adapt and survive well in the harsh environment of space from microgravity simulations experiments from Earth. In this research, 10 essential plants: peanut, cowpea, watermelon, okra, cotton, cucumber, wheat, sorghum, rice and corn were selected because of their nutritional and economical values. They were separately grown under normal Earth gravity (control) and under simulated-microgravity (clinorotation) using Clinostat. The experimental variables on the Clinostat were rotation-speed, rotational-axis angle and rotation-direction. Observations were made for hours during the experiment on the roots morphological developments range from the physical characterization of the roots to the growth-rate and root-curvature using ImageJ software. Results revealed that there were mostly improved growth-rates and reduced response to gravity per-hour on the microgravity simulated samples than the control plants. The clinorotated-samples root-curvatures ranged from 1.33°/hr to 28.25°/hr for the ten plants; while the 90°-turned sample ranged from 3.99°/hr to 33.13°/hr. The clinorotated-samples of eight plants showed increased growth-rate per hour than their 1 g-control and ranged from 2 mm/hr to 10.75 mm/hr while cotton and sorghum had 2.13 mm/hr and 6.08 mm/hr respectively as decrease in growth-rates. The growth-rate for 1 g-control of the ten plants ranged from 0.69 mm/hr to 8.01 mm/hr.