0.5MeV单能中子照射洋葱干种子后在根尖细胞内诱发微核的相对生物效应  

The Relative Biological Effectiveness of 0.5?MeV Neutrons to Induce Micronuclei in the Root-tip Cells of Onion Seedlings After Irradiation as Dry Dormant Seeds.

作　　者：张文艺[1] 焦玲[1] 星正治[2] 

机构地区：[1]中国医学科学院中国协和医科大学放射医学研究所,天津300192 [2]日本广岛大学原爆放射线医科学研究所

出　　处：《中国辐射卫生》2005年第4期255-256,共2页Chinese Journal of Radiological Health

摘　　要：目的了解0.5 MeV单能中子照射洋葱干种子后在根尖细胞中诱发微核的相对生物效应(RBE)。方法通过由加速器产生的0.5 MeV单能中子和60Coγ射线照射洋葱干种子,观察这两种辐射在根尖细胞中微核诱发率的差异。结果单位剂量0.5 MeV中子和60Coγ射线的微核诱发率分别为4.36±0.17和0.031±0.002(%Gy-1)。因此,0.5 MeV单能中子照射洋葱干种子后在根尖细胞中诱发微核的RBE值为141±11。结论0.5 MeV单能中子照射洋葱干种子后在根尖细胞中诱发微核的RBE值高达141±11,一方面是由于低氧效应,另一方面就是中子照射所致DNA损伤的修复效率可能远远低于?射线照射所致的DNA损伤的修复效率。Objective To best understand the relative biological effectiveness （RBE） of 0.5 MeV neutrons to induce mieronuclei in the mot-tip cells after irradiation as dry dormant seeds. Methods To observe the difference of the frequencies of micronuclei induced in the mot-tip cells of onion seedlings after irradiation as dry dormant seeds by 0.5 MeV neutrons from an accelerator and by γ rays from a ^60Co source. Results The frequencies of micronuclei induced by unit dose of 0.5 MeV mono-energetic neutrons from an accelerator and γrays from a ^60Co source are 4.36 ± 0.17 and 0.031±0.002 （% Gy^-1 ）, respectively. Thus, the RBE value for 0.5 MeV mono-energetic neutrons to induce micronuclei in the mot-tip cells of onion seedlings irradiated as dry dormant seeds is about 141 ±11. Conclusion The RBE value of 0.5 MeV mono-energetic neutrons to induce micronuclei in the mot-tip cells of Allium cepa onion seedlings irradiated as dry dormant seeds is as high as 141 ±11. Our findings suggested that the repair efficiency of DNA damage induced by mono-energetic neutrons may be lower than that by γrays.

关 键 词：中子 微核 洋葱种子 相对生物效应 

分 类 号：Q691.5[生物学—生物物理学]