| Pot experiment was adopted to study the activity change of MDA,SOD,CAT and POD in 8 forage species introduced from USA.The results indicated that MDA content increased greatly under low water stress,but the increase tended to slow when water stress became moderate and high.As to SOD,CAT and POD,with the increasing water stress,enzyme activity increased first and then began to decrease.Under low and moderate stress conditions the activity of SOD had no significant change but sharply decreased when water stress became high.The activity of CAT was comparatively high and changed slightly under all treatments.Although the activity of POD changed significantly,it still maintained a relatively high level even under serious stress conditions.At last,fuzzy subordination method was used for comprehensive evaluation of grass drought resistance and the result of the 8 species was Festuca arundinacea Schreber > Agropyron elongatum > Elymus junceus Fischer > Phleum Pratense L.> Agropyron desertorum > Agropyron trachycaulum > Elymus dahuricus Turcz.ex Griseb.> Bromus Inermis Leyss. |