0.2MeV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 0.2MeV neutrons to induce micronuclei in the root-tip cells of onion seedlings after irradiation as dry dormant seeds

为更好地了解单能中子照射的相对生物效应(Relativebiologicaleffectiveness,RBE),用加速器产生的0.2MeV单能中子以及Coγ射线照射洋葱种子,观察单位剂量的两种辐射在根尖细胞中的微核诱发率的60差异。0.2MeV中子单位剂量的微核诱发率为5.36±0.30(%Gy?);60Coγ射线单位剂量的微核诱发率为10.031±0.002(%Gy?)。0.2MeV单能中子照射洋葱种子后在根尖细胞诱发微核的RBE值高达173±15,其1中一个十分重要的因素就是,中子照射所致的DNA损伤的修复效率可能不同于由γ射线照射所致的DNA损伤的修复效率。

Dry dormant onion seeds were irradiated by 0.2MeV neutrons from an accelerator, or Co γ-rays, for 60 a better understanding of relative biological effectiveness (RBE) of mono-energy neutrons, and for observing different frequencies of micronuclei in root-tip cells of the onion seedlings induced by unit dose of the neutrons and γ-rays. The frequencies of micronuclei induced by unit dose of the 0.2MeV neutrons and the 60Co γ-rays are 5.36±0.30 and 0.031±0.002 (%Gy-1), respectively. The RBE value for the 0.2MeV neutrons is about 173 ± 15, using the Co γ-rays 60 as reference radiation. The RBE value of the 0.2MeV neutrons to induce micronuclei in the root-tip cells of Allium cepa onion seedlings irradiated as dry dormant seeds is as high as 173 ± 15. Our findings suggested that the repair efficiency of DNA damage induced by mono-energetic neutrons might be different from those by γ-rays.