Analysis of mutation spectrum induced by carbon ions and -rays in higher plant

Yoshihara, Ryohei; Hase, Yoshihiro; Takimoto, Koichi*; Narumi, Issei

Mutation spectrum induced by 220 MeV Carbon ion beam (220 MeV C), -rays and Carbon ion near the Bragg peak in seed was determined. Mutant frequency was increased by 220 MeV C and -rays irradiation. 220 MeV C and -rays induced G:C to A:T transition and deletion efficiently. 220 MeV C induced higher incidence of complex type of mutation. Frameshift mutation in -rays irradiated seed was frequent, but it was background level in 220 MeV C irradiated seed. These difference of mutation spectrum might be caused by the difference of DNA damage formed by 220 MeV C and -rays irradiation. Mutant frequency in seed exposed to carbon ion near the Bragg peak was not increased. The fluence of carbon ion near the Bragg peak was lower because it has higher cell killing effect. The fluence of carbon ion might be too low to detect mutation in target gene.