中文摘要：

以MG1655（野生型），LE392（recA^-）和DH5a（recA^-）3株E.coli K12菌株为材料，研究了30keV N^＋离子注／k E.coli K12时HRS／IRR效应的诱发情况及recA基因在其诱发中的作用。结果显示：小于10×10^14ions／cm^2低剂量离子注入大肠杆菌可诱发HRS／IRR效应；30keV N^＋离子注入MG1655，LE392菌株都可诱发HRS／IRR效应，而在DH5α菌株中无法诱导IRR效应。recA^-与HRS／IRR效应相斥性表明recA基因在HRS／IRR效应的诱发中发挥了重要作用。

英文摘要：

The HRS/IRR in Escherichia coli had been investigated with E. coli K12 wild strain MG1655 irradiated by the 30 keV N^＋. The curve of the dose-survival effect showed the 30 keV N^＋ ion could induce the HRS/IRR at the dose less than 10×10^14ions/cm^2. Moreover, the effect of recA gene in HRS/IRR inducement had been researched with three E.coli K12 strains, wild strain MG1655, LE392 （recA^＋） and DH5α（recA^-）. The results showed the IRR was disappeared in recA^- DH5α strain, but the HRS/IRR appeared in wild strain MG1655 and recA^＋ LE392, which suggested that recA gene and the DNA damages their repairs including recA gene were essential element in HRS/IRR inducement.