外源钙盐对盐胁迫下沙拐枣渗透调节和膜脂过氧化的影响

为了解外源钙对缓解沙拐枣（Calligonum mongolicum）盐胁迫的主要生理机制，采用盆栽法探究在0、100、200 mmol/L的NaCl胁迫下，分别添加5、10、15和20 mmol/L的Ca（NO₃）₂对沙拐枣同化枝中w（脯氨酸）、丙二醛含量、w（可溶性蛋白）、w（可溶性糖）的影响.结果表明，单独添加Ca（NO₃）₂使沙拐枣同化枝内w（脯氨酸）、丙二醛含量、w（可溶性蛋白）以及w（可溶性糖）增加，即Ca（NO₃）₂对沙拐枣的生长造成了胁迫.对w（脯氨酸）、丙二醛含量、w（可溶性蛋白）、w（可溶性糖）来说，NaCl和Ca（NO₃）₂之间均存在极显著的交互作用，与对照相比，在c（NaCl）分别为100、200 mmol/L，添加c[Ca（NO₃）₂]为10、20 mmol/L时，w（脯氨酸）显著增加，分别达到最大值（736.7、1 086.3 μg/g）；丙二醛含量分别降低了37.8%和40.5%，w（可溶性蛋白）以及w（可溶性糖）均增加.总之，适宜浓度的钙盐通过增加渗透物质w（脯氨酸）、w（可溶性蛋白）及w（可溶性糖），降低丙二醛的含量来有效缓解盐胁迫对沙拐枣幼苗产生的伤害，当c（NaCl）/c[Ca（NO₃）₂]为10:1时，缓解作用最佳，并且钙盐对沙拐枣盐胁迫的缓解属于抗性诱导的调节作用. 

Effects of Exogenous Calcium on Osmotic Adjustment and Peroxidation of Calligonum mongolicum Membrane Under Salt Stress

The aim of this study was to explore the regulating mechanism of exogenous calcium in Calligonum mongolicum under salt stress. The effects of calcium (5, 10, 15 and 20 mmol/L concentrations) on osmotic adjustment and peroxidation of C.mongolicum membrane under NaCl stress (0, 100, 200 mmol/L) were studied, including the contents of proline, malondialdehyde, soluble proteins and soluble sugars in assimilating shoots of C.mongolicum. The results showed that the contents of proline, malondialdehyde, soluble proteins and soluble sugars were increased after Ca(NO₃)₂ treatment, which indicates that Ca(NO₃)₂ addition alone is harmful to C.mongolicum. There was a highly significant interaction between calcium and salt on the content of proline, malondialdehyde, soluble protein and soluble sugar in assimilating shoots. Compared with the control, when NaCl concentration was 100 and 200 mmol/L, and Ca(NO₃)₂ was 10 mmol/L and 20 mmol/L; the content of proline was significantly increased to 736.7 μg/g and 1086.3 μg/g; the content of malondialdehyde decreased by 37.8% and 40.5%; and the contents of soluble proteins and soluble sugars were increased. As a whole, it could be noticed that suitable concentrations of calcium improved the salt tolerance of C. mongolicum by increasing the osmoregulation substances such as proline, soluble protein and soluble sugar content, and decreasing malondialdehyde content. The optimal proportion was c(NaCl)/c(Ca(NO₃)₂) of 10:1. The alleviation mechanism of exogenous calcium under salt stress was the regulation of resistance induction.