1964 Volume 77 Issue 909 Pages 77-80
The duration of mitotic cycle and its three subperiods were measured by means of autoradiographic technique in root tip cells of Luzula purpurea (n=3). Thymidine-H3 (0.5-2.0μc/ml) was used for the labeling of DNA and was supplied to the roots for 1/2hr. After labeling, roots of the seedling were allowed to grow in the absence of labeled thymidine for periods up to 26hrs. The average time of mitotic cycle was determined to be 17.0hrs. in duration, the time of DNA synthesis 6.5hrs., presynthetic interphase 6hrs., postsynthetic interphase 4.5hrs.