Effect Of Water Stress Simulated By PEG6000 On Physiological Indices In Agropyron Mongolioum Keng,Agropyron Cristatum(L.) Gaertn And Leymus Mollis Seedings

Studies on germination and physiological indices in seedings of Agropyron mongolioum keng,Agropyron cristatum(L.) Gaertn and Leymus mollis under PEG6000 water stress.The correlativity of some drought resistance indexes of 3 plants under water stress was analyzed.The drought resistance of 3 plants was evaluated by using subordination function method.The results are followings:1,The germination rate,germination vigor and seed germination drought resistance index decreased obviously under the water stress.Agropyron mongolioum keng was more strong drought resistance than the others in the germination stage.2,Under water stress conditions simulated by different concentration of polyethylene glycol 6000(PEG6000),physiological indices of drought resistance in Agropyron mongolioum keng,Agropyron cristatum(L.) Gaertn and Leymus mollis seeding were studied.The results showed that:the relative water contents in leaves,chlorophyl contents decreased,the proline content and soluble sugar increased;SOD and POD activity increased in the light stress,they were decreased or hold on in the medium or severe stress,the membrane permeability increased obviously,MDA increased too.3,The result of correlation analysis showed that there are positive or negative correlations between some physiology indexes of Agropyron mongolioum keng,Agropyron cristatum(L.) Gaertn and Leymus mollis under 24h water stress.The positive correlations are followings:between cell membrane permeability and MDA content (R=0.81,P=0.01);cell membrane permeability and SOD activity(R=0.75,P=0.01); chlorophyll content and SOD activity(R=0.66,P=0.05);MDA content and SOD activity (R=0.63,P=0.05);MDA content and POD activity(R=0.61,P=0.05).The negative correlations are followings:between relative water contents and cell membrane permeability(R=-0.76,P=0.01);relative water of leaves content and MDA content(R=-0.73,P=0.01);relative water of leaves content and SOD activity(R= -0.57,P=0.05);proline content and chlorophyll content(R=-0.55,P=0.05);MDA content and SOD activity(R=0.63,P=0.05);MDA content and SOD activity(R= 0.61,P=0.05).4,The result of correlation analysis showed that there are positive or negative correlations between some physiology indexes of Agropyron mongolioum keng,Agropyron cristatum(L.) Gaertn and Leymus mollis under 48h water stress.The positive correlations are followings:between cell membrane permeability and MDA content(R=0.61,P=0.05);cell membrane permeability and SOD activity(R=0.87, P=0.01);soluble sugar and MDA content(R= 0.63,P=0.05);chlorophyll content and SOD activity(R=0.60,P=0.05).The negative correlations are followings:between relative water contents and cell membrane permeability(R=-0.62,P=0.05);relative water contents and proline content(R=-0.55,P=0.05);relative water contents and soluble sugar(R=-0.62,P=0.05);relative water contents and MDA content(R=-0.73, P=0.01);proline content and chlorophyll content(R=-0.68,P=0.05).5,The result of correlation analysis showed that there are positive or negative correlations between some physiology indexes of Agropyron mongolioum keng,Agropyron cristatum(L.) Gaertn and Leymus mollis under 72h water stress.The positive correlations are followings:cell membrane permeability and MDA content(R =-0.66,P=0.05);cell membrane permeability and SOD activity(R=0.61,P=0.05); proline content and MDA content(R= 0.62,P=0.05);proline content and POD activity(R= 0.80,P=0.01).The negative correlations are followings:between relative water contents and cell membrane permeability(R=-0.66,P=0.05);relative water contents and MDA content(R=-0.76,P=0.01);proline content and chlorophyll content (R=-0.76,P=0.01);chlorophyll content and MDA content(R=0.80,P=0.01); chlorophyll content and POD activity(R=-0.79,P=0.01);MDA content and POD activity(R=0.56,P=0.05).6,The results of subordination function method of drought resistance for Agropyron mongolioum keng,Agropyron cristatum(L.) Gaertn and Leymus mollis in water stress 24h,48h,72h showed their resistance ability as following:Leymus mollis＞Agropyron mongolioum keng＞Agropyron cristatum(L.) Gaertn...