氚水对蚕豆根尖的诱变效应

Micronuclei induced by HTO in Vicia faba

通过蚕豆根尖细胞微核率的变化来研究氚水β射线的对蚕豆根尖的诱变效应,探索微核率作为测定氚水引起细胞损伤指标的可能性.将蚕豆根尖置于不同活度的氚水中培养24 h后,收获蚕豆根尖细胞得到与氚水作用后细胞微核率并将实验结果进行回归方程拟合,得到HTOβ射线的最佳回归方程是Y=0.90+4.64x,细胞微核剂量-效应关系符合线性拟合方程.得到相对60Coγ射线,氚水(HTO)β射线诱发微核的相对生物效应(Relative biological effectiveness RBE)值在0.57—1.43之间.在所研究的较低剂量范围0—2 Gy以内,HTOβ射线对生物体的作用更加明显;微核的产生主要是由于在低剂量情况下HTOβ射线在一个电离辐射径迹上使两个染色单体各产生一个损伤的效率更高.

To explore the possibility of determining the rate of cell damage caused by HTO,through the change of micronucleus rate in the root tip cells of Vicia faba,the mutagenic effect of HTO βrays on the root tip of Vicia faba was studied. The root tip cells of Vicia faba were cultured for 24 hours in the HTO with different activity. The root tip cells were obtained from the root tip cells of the Vicia faba and the cell micronucleus rate after the action of HTO was obtained,and the results were fitted by regression equation. The best regression equation of HTO β rays was y = 0.90＋4.64 x and the dose effect relationship of the cells fits the linear eqution. The relative biological effectiveness of HTOβ rays was between 0.57 and 1.43. In the lower dose range 0—2 Gy studied,the effect of HTO βrays on the organism is more obvious. Micronucleus was produced mainly due to the increased rate of two chromosome damage by low dose HTO β rays on an ionization radiation track.