【摘要】 1.酵母菌 Saccharomyces cerevisiae Я在对数生长期对X射线最为敏感,延迟期次之,停滞期抗性最大。 2.其存活菌数与剂量间关系近似S形曲线,半致死剂量(LD₅₀是16.5kr,平均致死剂量(LD₆₃)是20.65kr。 3.X射线能延迟每个酵母细胞开始分裂的时间。 4.在所用剂量范围内（0—150 kr）,X射线剂量对酵母菌的对数期生长曲线式 n==neoekt中的K值无影响,各种剂量处理后酵母菌的生长曲线主要取决于存活的细胞数和延迟期的长短。更多还原

【Abstract】 (1) The logarithmic phase in the life span of Saccharomyces cerevisiae Я is themost sensitive, the lag phase, the less, and the stationary phase, the least, to X-ray radia-tion. （2） The relation between the number of survival cells and radiation dose is some-what sigmoid. Both the medial lethal dose (LD₅₀) and the mean lethal dose (LD₆₃)have been determined to be 16.5Kr and 20.65Kr, respectively. （3） One of the effect of X-ray treatment is the delay of the starting time of yeastcell divisions. （4） Within the range of doses （0-150Kr） used in the experiments, X-irradiationhas no significant effect on the constant K of the equation N=N（e0）e^kt. The differencesfound among the post-irradiation growth curves are mainly determined by the numberof survival cells and the length of lag phase.更多还原