| Abstract: | 1. By means of cell separation method, we studied the differentiation of the leaf cells of wheat, Nongda 183 and the development of the chloroplasts in the mesophyll. cells. 2. The differentiation of the cells of the first leaf can be divided into 3 stages. Beginning from the leaf primordium to the fully expanded leaf, the cells are in the stage of division and expansion. When the fully expanded leaf becomes deep green in color, the leaf cells are in the prime of life. When the leaf begins to show yellowish colored spots to its complete withering, the cells are in the stage of senescence. Accompanying these stages, the external form and the internal structure of the cells change also. 3. In the early stage of cell division and expansion, one can observe many 0.5μ × 3.4μ mitochondria-like protoplastids which go through various morphological changes to become chloroplasts. 4. The mesophyll cells of the leaf begin to show the signs of senescence sooner than the epidermal cells and the cells of the vascular bundle. The latter last the longest in the life span of the leaf. |
