Response of the Osmotic Stress on the Wheat Seedlings Drought Resistance Under the Different time Betaine Pretreatment

Effects of root-applied exogenous betaine(2.0 g/L) at different time(48 h,72 h,96 h) on the drought-tolerance of wheat(Changwu 134) seedlings under PEG-6000(-0.1 MPa) osmotic stress was examined,including the water status,Proline content,soluble sugars content,soluble protein content,chlorophyll content and the activities of antioxidant enzymes.The results showed that the exogenous betaine could promote the activities of membrane protecive enzymes,increase the content of the osmotically adjustive things,decrease the drought-stress-induced injuries of wheat seedlings and protect the cell structure,and pretreating 72 h provided the better effect.