Molecular study of the mechanisms of plant genetic mutation by space environment

Plant seeds traveling in space can be mutated. A variety of mutants have been obtained from green pepper, rice, and tomato after boarded a recoverable satellite. One feature of mutants is change in the heading time in several species of plant, but the mechanism of these mutations is not understood.For studying the mechanism of genetic mutations in space, We used dry seeds of rice which are sensitive to space environment in heading time, and put them both on board recoverable satellite and in high energy particle accelerator with several LET (13 kev/um, 80 kev/um, 450kev/um) to study the following: identify, collect, and classify the mutations; identify the factor or factors that cause the mutations; and identify the nature of DNA modifications caused by space environments