The Studies On Evolutionary Structures Of Dongdao4under The Salt Stress

This experiment used the methods of slice preparation of plant epidermis and paraffin section to study anatomical structure of Dongdao4, and the changes of structure under stress of different concentration(0、10、20、30、40、50mmol·L-1NaCl). We explored the evolutionary structure of Dongdao4under the stress. The results obtained are as follows:1. Anatomical structure of Dongdao4Leaf of Dongdao4consisted of three parts:epidermis, mesophyll and vein, and there were motor cells between the upper epidermis veins. Stomas existed in upper and lower epidermis. The stoma was made of two guard cell sand subsidiary cells. The guard cell was dumbbell and subsidiary cell was tri angular. The root of Dongdao4consisted of epidermis, cortex, vascular cylind er. The three part structures were basically the same as the other rice root.2. The changes of leaf structure under salt stress:Leaf cuticle thickness increased significantly with the increase of salt concentration. The stomatal stomata density of Dongdao4became larger. There was a positive relationship between the stomata density and concentration of NaCl. The structure of motor cells changed. The number of motor cells in the main vein increased under the20mmol·L-1NaCl stress. The volume of vascular bundle increased, there were three more vascular bundles in the main vein under the20mmol·L-1NaCl stress.3. The changes of root structure under salt stress:The cell wall of scleraenchymatous cell became thicken with the increase of salt concentration.There was a positive relationship between the ratio (metaxyl em diameter of root transverse section/root diameter) and NaCl concentration Horseshoe thickening becomes thicken and widen with the increase of salt co ncentration.Through the study of comparison, we got the first hand data of evolutionary structure of Dongdao4under the stress, and provided technical reference for the identification of salt tolerant rice research.