Effects Of Salt Stress On Morphological Structure In Vegetative Organs Of Atriplex Centralasiatica Iljin And Study On The Development Of Salt Bladder

The mechanism of plant adapting to environment is complex, and differentenvironment leads to different structures. The salinity is responsible for the differentstructural characteristics of halophytes. The morphological structure in vegetativeorgans of Atriplex centralasiatica Iljin was studied under light microscopy andscanning electron microscope, and the development of salt bladders was emphasized atdifferent NaCl concentration. The results showed the countermeasures against saltstress as follows:1. The root diameter of Atriplex centralasiatica Iljin was remarkably decreased with theincrease of NaCl concentrations, so was the vessel diameter of xylem in the root. Thenumber of vessels increased with the stimulation of NaCl. There were crystalliferouscells and anomalous secondary structure in the root, which were important for Atriplexcentralasiatica Iljin to adapt to salinity and drought.2. Under salt stress, the stem diameter of the plant was decreased as the root, so was thevessel diameter of xylem in it. Up the gradient of NaCl concentration, layer number ofcortical cells in stem wasn't changed evidently, however, the ratio between corticalthickness and stem increased as the ratio between vascular cylinder and stem.3. Growth of palisade tissue increased with the stimulation of NaCl, just as the vessel ofthe mid rib. Leaves became smaller with the increase of NaCl concentrations. In thesame process, the cuticle become thicker while stoma become less in number andsmaller in area. There were crystalliferous cells in mesophyllous tissue too.4. The structure and development about salt bladders were studied. The results showedthat a salt bladder was composed of one or two stalk cell and one bladder cell with...