| With the method of simulating drought stress-water recovery in greenhouse, 8 drought resistant indexes , including the leaf relative water content(RWC), relative electrical conductivity (REC)，free proline accumulation (Pro), soluble sugar content (SSC)，superoxide dismutase(SOD), malondialdehyde (MDA), survival rate (SR), root-shoot ratio (RSR) on the 0 d(CK), 7th d, 14th d, 28th d, 35th d and 42th d under water stress and the 7th d after rewatering, respectively, of 19 Arrhenatherum elatiusm germplasm and materials at the seedling stage were measured and analyzed in order to assess comprehensively the drought resistance. The values of the eight indexes which has been treated under the condition of 42 d of resistant drought stress, which has been analyzed by the Wared's method and Squared Euclidean dis-tance cluster analysis, the results showed that three drought resistant classes including the higher drought resistance (in-
cluding the germplasm of ZXY2005P-1021, ZXY2005P-619, ZXY2005P- 853, ZXY2005P-1160, ZXY2005P-1319，ZXY200SP-901), the medium drought resistance ( including ZXY2005P-706，ZXY2005P-1086, ZXY2005P-1473, ZXY2005P-1296, ZXY2005P-1182, ZXY2005P-1036, ZXY2005P-877, ZXY2005P-837) and the weaker drought resistance (ZXY2005P-1514, ZXY2005P-969，ZXY2005P-1375, ZXY2005P-1362, ZXY2005P-1426) were classified. And the leaf RWC of 19 germplasm decreased, the SSC, Pro and REC increased but the SOD and MDA increased with volatility while the drought stress days were increased. Seven days after rewatering, the RWC and Pro were restored to pristine level, but the SOD and MDA were not restored to the level before stress were exerted al-though they declined in varying degrees. |