Abstract
Experiments were carried out for the purpose of analysing the mechanism of the development of tillers in rice plants. The results obtained are as follows: 1) The translocation of nitrogen in the control plant suggested the normal life process in the rice plant. The concentration of nitrogen in leaf blades and leaf sheaths decreased gradually during the lifetime while that in stems increased at the tillering or ear forming state and then decreased again. At the harvesting stage, the concentration of nitrogen in the leaf blade, sheath and the stem took almost the same value. The phenomenon indicated that nitrogen in the plant was translocated smoothly from its leaves and stems to its ears. 2) As compared with the control plant, in the potassium deficient plant, the nitrogen decreased very slowly after the ear forming stage. The slow decrease would have brought about the dull regulation of ineffective tillers. At the harvesting stage, the nitrogen concentration in stems was higher, than in leaf blades. 3) In the phosphorus deficient plants, the mode of translocation of nitrogen was remarkably different from that in the control plants or the potassium deficient plants. That is, the concentration of nitrogen in stems was low during the tillering stage and afterwards increased gradually. The low concentration of nitrogen in the stem was connected with the small number of tillers. The fact mentioned above, may indicate the significant relationship between tiller development and the translocation of nitrogen in the stem. 4) When nitrogen was not translocated from the leaves and stems to the ears owing to some conditions, new lateral bud development was induced evidently.
