Drought resistance evaluation of three grass species at germination stage from the Northwest Plateau of Sichuan Province

To determine the drought resistance of grass species at germination stage,seeds germination of three grass species(Kengyili rigidula cv.'Aba',Elymus sibiricus cv.'chuancao No.2' and Elymus nutans) which collected at Northwest Plateau of Sichuan Province,were tested under PEG-6000 solution with different concentration of 0,50,100,150,200 g/L.The relative germination rate,relative germination potential,relative germination index,relative vigor index and drought resistance index were synthetically evaluated by applying membership function method.The results showed: 5% concentration of PEG-6000 favored seed germination;relative germination index and drought index were better indicators for drought resistance identification of three kinds of grass species at germination stage;the drought resistance ability for studied species sequenced as K.rigidula E.nutans E.sibiricus cv.'chuancao No.2'.