盐碱胁迫对寸草苔渗透调节物质含量和抗氧化酶活性的影响

Effects of saline-alkali stress on the contents of osmotic adjustment and activityof antioxidant enzymes of Carex duriuscula

以分布于科尔沁沙地的粉煤灰草地,盐碱地和荒地3种不同生境的野生寸草苔为材料,通过蛭石营养液培养,进行混合盐碱胁迫处理,检测其生理生化变化。结果表明:3种生境寸草苔的相对电导率和丙二醛(MDA)含量随着盐碱胁迫处理浓度的增大而增加;盐碱地寸草苔的超氧化物岐化酶(SOD)和过氧化物酶(POD)活性在300mmol/L高浓度盐碱胁迫增加明显,荒地寸草苔和粉煤灰草地寸草苔则变化不明显,过氧化氢酶(CAT)活性则随着盐碱胁迫浓度增大呈现先升高后降低的变化趋势,3种抗氧化酶的活性均以盐碱地寸草苔最强;可溶性糖和脯氨酸两种渗透调节物质的含量,随着盐碱胁迫浓度的增大而增加,尤以高浓度处理增加显著。

Selected Carex duriuscula living in three habitats, including grassland with coal-ash, saline-alkali land,and wildland to test its physiological and biochemical characteristics in vermiculite nutritive medium under mixed saline-alkali stress. The results showed that the relative electric conductivity and MDA content of Carex duriuscula in three habitants increased as saline-alkali concentrations increase. The activities of SOD,POD of Carex duriuscula in alkali-saline land increased obviously in alkali-saline concentrations of 300 mmol/L,there was no significant changes of Carex duriuscula in grassland with coal-ash and wildland. The activity of CAT firstly increased and then declined as alkali-saline concentrations increase. The activity of antioxidant enzymes for Carex duriuscula in alkali-saline land was the highest, the contents of osmotic adjustment,including soluble sugar and proline increased as alkali-saline concentrations increase,in particular the treatments under high con- centration of stress.