^(60)Co-γ射线辐照玉米种子对基因组DNA分子的影响

The Effect Imposed on DNA Molecule of Maize Seed by ^(60)Co-γ Ray Irradiation

以不同剂量的60Co-γ射线辐照玉米种子,对各处理组分单株,采用CTAB抽提法提取幼叶组织基因组DNA,并对基因组DNA进行酶切,研究辐照对基因组DNA分子的损伤效应。结果表明:辐照剂量不同,得到的基因组DNA分子在各处理组间存在差异,当辐照剂量>200 Gy时,差异更为明显;辐照不仅能引起DNA分子链的断裂,还能改变核苷酸链上的碱基位置和顺序,使酶切位点发生改变。实验还对同一辐照剂量处理下的不同单株幼叶基因组DNA进行了重复实验,结果是一致的。

In this thesis, different doses of ^60Co-γ rays are used to irradiate with maize seed, in the period of threeleaf, making use of CTAB to extract genome DNA of its sprout, from kinds of seedling irradiated by different doses, making restriction enzyme action on genome DNA, which helps to study damage efficiency imposed on DNA molecule by irradiation. It is shown that ： with different doses of irradiation, different genome DNA among various dose would be obtained. The difference is more obvious especially when the dose is more than 200 Gy. Irradiation not only leads to breakage of DNA molecular chain but also can change position and order of bases on DNA nucleolus chain, which also changes position of restriction enzyme. Moreover, genome DNA extracted from kinds of sprouts irradiated by the same doses has been made twice, which give the same result.