【摘要】 极低温下用³⁰CO—γ射线照射冬小麦风干种子,在确认极低温能减轻M₁代生理损伤的基础上,对M₂代的突变频率进行了研究。实验结果表明:极低温同常温比较,在20—30千伦照射量范围内,大部分性状的突变率有所降低。若分别以其LD₅₀（半致死剂量）为基准进行比较,即在辐射损伤相同的情况下,极低温却导致突变率的显著提高。由此推断,在极低温下照射能够有效地保存射线直接作用对遗传物质所诱发的变异。更多还原

【Abstract】 we studied the mutation frequency of the generation M₂ of winter wheat （T. Vulgare） using air-dried seed radiated by ⁶⁰Co gamma ray at extremely low tem perature based upon the confirmation that extremely low temperatune can decrease the physiological damage of generation M₁. The experiment sh- ows that to compare the radiation at extremely low temperature with ordinary temperatune within20-30 kilo-roentgens, the mutation rate of the most properties has a bit deereased, Let its LD₅₀ as a standard respectively, i. e, at the same radiation damage, while extremely low temperature cause mutat- ion frequency upward significantly. Thus, radiation at extremely temperature can effectively presserve the induced vary of direct action of radiation ray on bereditary substance.更多还原