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。 Hydroxyurea inhibition and flow cytometry analysis showed that DNA synthesis at the initial stage of imbibition of barley seeds was mainly DNA non-intended synthesis. Under a certain dose of 60Co γ radiation, it stimulated the non-predetermined synthesis of DNA in the embryo. Radiation stimulating effect decreased with the prolongation of repair time. Electron beam irradiation at 50-40 Gy also stimulates the non-pre-determined synthesis of barley embryos. There is a peak near the lethal dose and a minimum near the lethal dose.