Influences of CoCl_2 on seed germination and seedling resistance of Lolium multifolorum under acid stress

Seeds of Lolium multiflorum were soaked in different concentrations of CoCl2 solutions for 24 h and then germinated in acid solutions with different pH to study effects of CoCl2 on seed germination and seedling growth under acid stress.With increase of acidity the germination vigor,germination capacity,germination index,vitality index and chlorophyll content of L.multiflorum deceased obviously,while the inhibition index of root,malondialdehyde(MDA) content,production rate of O-2· and H2O2 content and the activities of superoxide dismutase(SOD) increased significantly.The activities peroxydase(POD) increased firstly and then decreased;and membrane stability index also declined.Under the condition of acid stress,seed germination rate,chlorophyll content,shoot length,dry weight of aerial part and the SOD activity of L.multiflorum were obviously elevated by the treatment of 0.1 mmol·L-1 CoCl2,while the MDA content and POD activity were impaired.In general,under the acid stress,the seed germination,seedling growth and the resistance to acid stress of L.multiflorum were prompted obviously by the treatment of 0.1 mmol·L-1 CoCl2.