Germination of Medicago truncatula for Enclosed Environments.

摘要

Plant and microbes co- exist together naturally in nature. Each depends upon each other for survival for food and nutrition. The purpose of this study is to find a method of successfully sterilizing and scarifing Medicago truncatula seeds prior to planting for a space flight experiment on-board the space shuttle Atlantis on mission STS-13 5. Medicago truncatula and Sinorhizbium meliloti have been chosen for this study as they are able to form a symbiotic relationship together. Medicago truncatula is the model species for the legume and Sinorhizbium meliloti is the model species for nitrogen fixing bacteria. Cellular and morphological data from tissue specimens grown and fixed in orbit on board the International Space Station (ISS) will be compared with tissue grown in ground controls at Kennedy Space Center (KSC) Space Life Science Lab (SLSL). The process of scarification and sterilization will play a role in the study to avoid infection and premature germination before launch into orbit. In this study a variety of different methods for scarification and sterilization will be tested to see which gives the most uniform and reproducible results with the highest percentage germination. A comparison of chemical and mechanical methods of scarification is done to fmd a suitable method that is safe but still effective. Sterilization techniques used are both dry and wet, in the case of long term storage a dry sterilization procedure would be required to prevent premature germination.