Abstract
The growth of embryo of Triticu, m monococcum L. was analyzed in detail. The caryopses were collected every two hours. At each time, the growth rate of embryo was calculated for the length and thickness, which showed an undulatory variation. Then the correlogram analysis was applied to the stationary growth rate. It also showed the apparent periodicity. In the next place, the correlation coefficient between the autocorrelogram and the cosine function was calculated as a periodogram. The periodogram showed two significant peaks in the thickness. Though only one peak was significant in the length, the second highest peak in the length existed at the same position as the significant one in the thickness. Furthermore, the other peaks near the significant one in the periodogram are considered to be of no biological meaning, resulted from the finiteness of the number of samples. Therefore, it is concluded that the growth rate of embryo both in the thickness and length are represented by the summation of two cosine functions with periods of 6.06 and 7.72 hr in thickness and 6.00 and 7. 74 hr in length. But the variation of the growth rate at the very early stage did not agree well with the two rhythms. Embryo starts the dual rhythmic growth at the 100-cell stage. This suggests that at the 100-cell stage cells in embryo begin synchronous divisions at two regions which eventually develop into two apical meristems.
