加速重离子辐射对玉米的诱变效应

用不同剂量的3种高传能线密度的加速重离子氖—20、氩—40及铁—56,与低传能线密度的钴—60γ射线分别照射具标志基因(Lw_1/Iw_1)的玉米干种子,以当代植株叶片黄白条纹产生频率为指标,比较其诱发效应。结果表明:在所用剂量范围内,此4种辐射的剂量—效应关系曲线为直线。氖—20、氩—40及铁—56重离子束对应于钴—60γ射线的相对生物学效应分别为2.02、8.31和12.45。叶片具黄白条纹的植株自交,后代仍有黄白条纹。光学显微镜及透射电子显微镜观察发现黄白条纹部位的叶肉细胞及其内的叶绿体形态结构明显不同于正常绿叶。

MUTAGENIC EFFECTS OF ACCELERATED HEAVY ION IRRADIATION ON ZEA MAYS

The frequency of occurence of white - yellow stripes on plant leaves,developed from irradiated maize seeds containing lemon - white gene (Lw1/lw1), was used as a criterion in comparing the mutagenic effects of high LET heavy ion beam and low LET radiation. Dose - response curves for 20Ne,40Ar,56Fe ion beam, and 60Co gamma rays were linear. The RBE for neon, argon and iron beam, when compared with 60Co gamma rays, were 2. 02, 8. 31 , and 12. 45, respectively. Lemon -white gene nmtalion was observed in inbred plants in the second generation. Electron microscope observation showed that both the structure and the number of chloroplasts in mesophy Is of white -yellow stripes were significantly altered.