电子束与γ辐射对大麦种胚DNA非预定合成的影响

羟基脲抑制与流式细胞仪检测证明 ,在大麦种子的吸涨初期 ,种胚DNA合成主要是DNA非预定合成 ,一定剂量下6 0 Co γ辐射能刺激增强种胚的DNA非预定合成。辐射刺激效应随修复时间延长呈下降趋势。 50～ 40 0Gy的电子束辐射对大麦种胚的DNA非预定合成也有刺激作用。在半致死剂量附近有一峰值 ,在致死剂量附近出现最小值。

UNSCHEDULED DNA SYNTHESIS INDUCED BY ELECTRON BEAM AND γ IRRADIATION IN BARLEY EMBRYOS

DNA synthesis in barley embryos during the initial imbibition of barley seeds was proved to be unscheduled DNA synthesis (UDS) from the evidence by hydroxyurea treated at 20 mmol/L and flow cytemetric analysis of isolated nuclei. Unscheduled DNA synthesis activity in barley embryos were accelerated by 60 Co|γ ray with its effects decreasing with the repair time. Barley embryos unscheduled DNA synthesis activity were enhanced also by electron beam irradiation in the dosage range from 50 to 400Gy. There was a peak at a dosage lower than LD 50 , and a minimum at the lethal dosage of electron beam irradiation.