牧草 研究木地肤幼苗细胞膜透性和酶系统对盐胁迫的适应性研究

通过不同浓度的盐胁迫对木地肤Kochia prostrata幼苗细胞膜透性、丙二醛和3种保护酶活性的测定，获得以下结果：随着盐浓度的增加和胁迫时间的延长，幼苗叶片的细胞膜透性呈递增趋势，且浓度≥150 mmol/L时，细胞膜透性与对照有极显著差异（P＜0.01）。丙二醛含量随胁迫强度和时间的增加而增加，且浓度≥300 mmol/L时,丙二醛（MDA）含量迅速增加（P＜0.05）。幼苗中超氧化物歧化酶（SOD）活性在400 mmol/L处理下呈递减外，其它处理均呈先升后降趋势，且当质量分数≥200 mmol/L时,与对照差异显著（P＜0.05）；过氧化物酶（POD）活性变化比较缓和，仅在第25天与对照呈现极显著差异（P＜0.01），且浓度＜400 mmol/L时,POD活性与对照均无显著性差异（P＞0.05）；过氧化氢酶（CAT）活性变化趋势与SOD酶活性相似，呈先升后降的趋势。

Effects of salt stress on membrane permeability and enzymes system of Kochia prostrata seedling

Membrane permeability,malondialdehyde(MDA) contents and activities of antioxidant enzymes in Kochia prostrata seedlings were studied under different concentrations of salt stress.The result showed that the membrane permeability and MDA contents increased with the increasing of salt concentrations.Compared with CK,a significant(P<0.01) increase in membrane permeability was observed when salt concentration was higher 150 mmol/L;and a remarkable(P<0.05) increase in MDA occurred under 300 mmol/L salt concentration.The activity of SOD decreased at 400 mmol/L salinity concentration,but it showed a single peak curve under other treatments and a significant(P<0.05) difference was observed when salinity stress was more than 200 mmol/L.Compared with SOD,there was slight change of POD in K.prostrata seedling;a remarkable(P<0.01) change was observed 25 days after the treatment.No significant difference was obtained when salt concentration less than 400 mmol/L.CAT showed a similar change with SOD.