本文采用80MeV/u的12C6+辐照番茄干种子,研究处于不同离子贯穿深度番茄干种子的辐照生物学效应,检测其生理生化指标.结果表明:辐照后不同贯穿深度上番茄种子的发芽势与物理剂量对应,第8层样品(对应于碳离子在水中的贯穿深度为15mm)出现峰值76.7%,发芽率随离子入射深度的变化不明显;不同贯穿深度辐照样品的根尖细胞微核率也与物理剂量相对应,在第6、7层样品中出现峰值0.257%;另外,辐照样品幼苗茎叶的一氧化氮合酶(NOS)活性、谷胱甘肽(GSH)含量及总抗氧化力在第9层出现峰值,谷胱甘肽过氧化物酶(GSH-PX)活性在第7-8层出现峰值,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性的变化与重离子贯穿深度没有明显的相关性.总而言之,本工作发现辐照样品的多个生理生化指标均与入射离子的微剂量分布相对应,即存在生物效应峰.

The radiobiological effects with regard to physiological an biochemical characters of dry tomato seeds which were located in different penetration depths of a 80MeV/u12C6+ ion beam were studied in this paper. Experimental results show that the germination potential of the irradiated has relationship with dose distribution of the ions, a peak value of 76.7% appears in the sample of layer 8, corresponding to the depth of 15mm in water. But their germination fraction does not have any relationship with dose. Secondly, frequency of micronucleus of the samples also changed with dose and a peak value of 0.257% comes out in 1214mm depths. Thirdly, when the irradiated seeds sprouted, protective enzymes of their leaves were extracted and analyzed with biochemical kits. It was found that the activities of nitric oxide synthetase, glutathione peroxidase, the content of glutathione and total antioxygenate ability have their peak values in the sample of layer 9, but the activities of superoxide dismutase and catala