How the Space Environment Affects Seed Germination and Growth

Alexander Souvall, Utah State University
Gareema Dhiman, Logan High School
Andre Nguyen, Logan High School
Michelle Jung, Logan High School
Astrid Ji, Logan High School
Takayuki Sakai, University of Tsukuba
Takahiro Shimizu, University of Tsukuba
Midori Morikawa, University of Tsukuba
Shusuke Okita, University of Tsukuba
Akihiro Nagata, University of Tsukuba
Shaunda Wenger, Utah State University
Toshihiro Kameda, University of Tsukuba
JR Dennison, Utah State Univesity


Understanding observed space environment effects on biological organisms such seeds are important in design of long duration space missions, such as to those planned for Mars, where appropriate storage and growth of food resources is essential. Evaluation of the effects of the real and simulated space environment on seed germination and growth in space is the purpose of this research. Preliminary tests of germination rate and growth of radish seeds in a controlled environment have identified statistically significant differences between control samples and seeds flown for 30 days in low earth orbit on the Bion M-1 launch capsule Russian research flight in 2013. Most significantly, average germination of space exposed radish seeds was 2 days less than the 6 days observed for the control seed group. Seed coats of the control group, space-exposed, and vibration-exposed seed were also inspected by LHS and USU students for physical changes. Observed changes in both the space-exposed and vibration-exposed seeds coats included the production of proteins presumably related to defense of the embryo from soil pathogens during seed germination. Previous research by others has shown production of anti-fungal proteins in radish seed coats is initiated by disturbance. Effects to germination rate from ionizing radiation up to 1 kGy were studied. Radiation exposure occurred with a custom biological exposure test chamber designed by Tsukuba students for the USU Materials Physics Group Space Survivability Test (SST) chamber, which is designed to mimic low-earth and geosynchronous orbital environments.

* USU STARS! GEAR UP partnership

# Partially funded by Japan Student Services Organization (JASSO), and University of Tsukuba