摘要
用放射性同位素￣３Ｈ－胸腺嘧啶核苷渗入法，研究Ｆｅ￣（１＋）注入与￣（６０）Ｃｏγ射线辐照条件下，小麦种子萌发早期种胚内ＤＮＡ的合成动态，以非按期ＤＮＡ合成为标志，比较重离子束与γ射线作用下ＤＮＡ损伤、修复程度的差异。同时采用扫描电镜Ｘ射线能谱分析法（ＳＣＥ－ＥＤＡＸ）对造成这种差异的机制进行了探讨研究。研究结果表明，γ射线辐照后，种胚内存在典型的非按期ＤＮＡ合成，但在重离子注入条件下，这一现象并未表现出来。因此重离子的作用过程和诱变机理与γ射线的作用有所不同。重离子对种子的诱变是一种间接的作用，因为ＳＣＥ－ＥＤＡＸ的结果证明离子注入种子的深度为１４μｍ，并未真正到达小麦种胚内部。
Dry seeds of wheilt were irradiated with 60Co γ-raysand implanted by Fe1+ ions.The un-scheduled DNA synthesis in germination wheat embryos were studied with the method of 3H-TdR incorporation, and the depth of Fe3+ heavy ions implanted were determined by means ofthe scanning electron microscope dispersive analysis of X-ray. The results showed that the γ-rays irradiated seeds induced unscheduled DNA synthesis,However , the seeds implanted byFe1 + ions did not induced unscheduled DNA synthesis clearly during the early stage of germi-nating wheat embryos. It is included that there are differences in mechanism of mutagenesisbetween Fe1+ heavy ions implantation and γ-ray irradiation,Tbe mutagenic action of Fe1+ heavy ions is indirect on wheat embryos,according to the results of SCE-EDAX,whichshowed that the Fe1+ ions implanted stayed in the fruit coat of 14μm and didn’t go into、theembryos.
出处
《核农学报》
CAS
CSCD
1994年第3期135-140,共6页
Journal of Nuclear Agricultural Sciences
基金
国家自然科学基金
关键词
小麦
重离子
DNA合成
电离辐射
Wheat seed, Fe1+ heavy ion, 60Co γ-ray , unscheduled DNA synthesis3H-TdR,SCE-EDAX
