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.      

有机酸在修复Cd污染土壤中的作用研究

采用盆栽实验研究了有机酸在镉污染土壤修复中的作用.结果表明:土壤采用有机酸处理均能促进试验植物蒲公英的生长.施加有机酸显著的改变了植株各部位镉含量.酒石酸抑制植株各部位对镉的吸收,说明酒石酸可减轻镉对植株的毒害作用.醋酸、EDTA、柠檬酸、乳酸、草酸均能促进植株地上部对镉的吸收作用,其作用次序为醋酸＞EDTA＞柠檬酸＞乳酸＞草酸.施加有机酸增强土壤中重金属的活性,提高植株修复能力.     

Response of photosynthesis, morphology and growth of edysarum mongolicum seedlings to simulated precipitation change in Maowusu sandland

Response patters were investigated for seedlings of Hedysarum mongolicum, a dominant shrub in Maowusu sandland, to the simulated precipitation change by artificially controlling water supply at four levels. Plant growth characters, in terms of branch number and length, leaf number and area, and biomass, increased while water supply increased. However, the effect of water supply on leaf photosynthetic rate was not significant. Root/shoot biomass ratio significantly decreased with the increase of water supply, which was considered adaptive distribution of biomass investments in the different water supply. Water supply obviously affected branching patter. Branch section number,branch number and length of the same section enhanced as water supply increased. Branch number and length were clearly positive correlation with total and aboveground biomass in four water supply treatments. Branch character fully showed plant growth.     

Response of photosynthesis,morphology and growth of Hedysarum mongolicum seedlings to simulated precipitation change in Maowusu sandland

ＩｎｔｒｏｄｕｃｔｉｏｎＭａｏｗｕｓｕｓａｎｄｌａｎｄ ,ａｓｅｍｉ ａｒｉｄａｒｅａｏｆＣｈｉｎａ,ｌｉｅｓｏｎｍｉｄｄｌｅｐａｒｔｏｆＣｈｉｎｅｓｅｎｏｒｔｈｄｅｓｅｒｔ (Ｙａｏ ,1 992 ) .Ａｔｐｒｅｓｅｎｔ,ｄｅｓｅｒｔｉｆｉｃａｔｉｏｎｉｓｂｅｃｏｍｉｎｇｍｏｒｅｓｅｒｉｏｕｓａｎｄｔｈｅｌａｎｄｓｃａｐｅｃｏｍｐｒｉｓｅｓｌａｒｇｅａｒｅａｓｏｆｓａｎｄ ｃｏｖｅｒｅｄｌａｎｄｔｈｅｒｅ(Ｚｈａｎ ,1 994;Ｃｈｉ,1 994) .Ｔｈｅｅｎｖｉｒｏｎｍｅｎｔｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｗａｔｅｒｓ…