Impact of high salt stress on Apocynum venetum growth and ionic homeostasis. Effects of NaCl Stress on Ion Absorption and Distribution in Sour Jujube Seedlings Effects of NaCl Stress on Ion Absorption and Distribution in Sour Jujube Seedlings EFFECTS OF DROUGHT ON THE ABSORPTION OF PHOSPHORUS IN MAIZE SEEDLINGS The role of the isotope tracer technique in ecological research of arbuscular mycorrhizal fungi Studies on the Difference of Nitrogen Absorption, Transportation and Distribution in High and Low Protein Wheat Cultivars