Stress Resistance Of Rye, Triticale And Elymus Nutans Seedlings Under Low Temperature And Drought Stress

Plants in the natural environment of the Qinghai-Tibet Plateau often face many stresses,such cold and drought,which seriously affects the growth and development of plants.In this study,the effects of cold and drought stress on the physiological and biochemical properties of Secale cereale,Aokelong(AKL)and Dongmu 70(DM70),Triticale wittmack 1048 and 3241,and Elymus Breviaristatus seedlings were studied with low temperature and drought conditions,comparing with the control.The study is aming at exploring the physiological features of cold and drought tolerance,in order to provide scientific basis for further cultivation and breeding of artificial grass in Tibet.The main research results as follows:1.From the three indicators of SOD,POD and CAT,the protection ability of antioxidant enzyme system in AKL was stronger than DM70's.2.Under cold,drought and combined stress,DM70's malondialdehyde(MDA)content of increase rate was higher than that of AKL's,which indicated the membrane lipid peroxidation of DM70 was greater than AKL and the AKL's resistance was strong.3.Compared with the DM70,the increase rate of the soluble protein(SPRO)content in AKL was lower under cold,drought and combined stress,which indicated that the AKL's resistance was strong.The above results showed that the resistance to stress of Secale cereale AKL was stronger than that of DM70 under cold,drought and combined stress.4.From the three indicators of SOD,POD and CAT,the cold resistance of 1048 was stronger than 3241 under cold stress;the drought resistance of 1048 was stronger than 3241 under drought stress;under combined stress,3241 had stronger resistance to stress than that of 1048.5.Compared with the control group,the increase rate of MDA content in 3241 was much higher than that in 1048 under cold,drought and combined stress,which indicated that the membrane lipid peroxidation of the plant cells in 3241 were more seriously than that of 1048 under the three stress conditions.6.Under cold or drought stress,the increase rate of SPRO content in 1048 was lower than that of 3241,which indicated that 1048 had strong ability to tolerate stress;while under combined stress,the increase rate of SPRO content in 1048 was higher than that of 3241,indicating that 3241 has stronger ability to control combined stress.7.The effect of cold or drought stress on 3241 was higher than that under combined stress,indicating that the effect of combined stress on plants could not be considered a simple superposition effect,because the combined stress could have synergistic effect or antagonistic effect on plants.The above results showed that the cold resistance of 1048 was lower than that of 3241 under cold stress;the drought tolerance of 1048 was stronger than that of 3241 under drought stress;under combined stress,the resistance to stress of 1048 and 3241 were nearly equal.Plants' resistance is a complex regulatory process,the next step needs to combine genetic control and physiological processes to further study.8.The SOD and CAT activities reached the minimum value under cold and drought combined stress,which indicated that the combined stress made a larger damagement to Elymus breviaristatus' s antioxidant enzyme system,its antioxidase system had a limited ability to protect themselves.