低温干旱复合胁迫对小黑麦幼苗生理生化性能的影响

Effects of Combined Cold and Drought Stress on the Physiological and Biochemical Characteristics of Triticale wittmack

生长在青藏高原自然环境中的植物常常面临着低温和干旱的双重胁迫,严重影响着植物的生长发育。本研究以两个不同品种的小黑麦(Triticale wittmack)1048和3241为试验材料,通过不同温度和水分条件控制,对低温与干旱复合胁迫对于小黑麦幼苗的生理生化性能的影响进行研究。结果表明:在低温、干旱和复合胁迫下,小黑麦1048和3241幼苗中超氧化物歧化酶(SOD)活性均较对照组下降;干旱胁迫下小黑麦1048中过氧化氢酶(CAT)活性呈上升状态,而3241呈下降趋势;低温胁迫下小黑麦1048中CAT活性的降幅小于3241;在低温或干旱单一胁迫下,小黑麦1048中过氧化物酶(POD)活性的降幅小于3241;复合胁迫下小黑麦1048中CAT和POD活性的降幅大于3241。在低温、干旱和复合胁迫下,小黑麦3241中的丙二醛(MDA)含量较对照组上升的幅度均远大于1048,表明在3种逆境条件下,小黑麦3241幼苗植物细胞的膜脂过氧化程度均大于1048。在低温或干旱单一胁迫下,小黑麦1048中可溶性蛋白质(SPRO)含量的增加幅度小于3241,表明1048自身耐受逆境胁迫的能力较强;而在复合胁迫下,小黑麦1048中SPRO含量的增加幅度大于3241。经综合评价分析,低温胁迫下小黑麦1048的抗寒性强于3241;干旱胁迫下小黑麦1048的耐旱性强于3241;复合胁迫下两品种牧草的抗逆性指标各有高低。牧草抗逆性是复杂的调控过程,今后需从基因调控和生理过程相结合来深入研究。

Plants in the natural environment of the Qinghai-Tibet Plateau often face cold and drought stresses,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 Triticale wittmack 1048 and 3241 seedlings were studied with low temperature and drought conditions control.The results showed that the activity of SOD in 1048 and 3241 seedlings decreased compared with the control group under the cold,drought and combined stresses.Under the drought stress,the activity of CAT in 1048 increased,while the 3241 showed a decreasing trend.Under cold stress,the decrease rate of CAT activity in 1048 was lower than that of 3241.The decrease rate of POD activity in 1048 seedlings was lower than that of 3241 under cold or drought stress.Under combined stress,the decrease rate of POD and CAT activity in1048 was higher than that of 3241.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 in 1048 under these three stress conditions.Under cold or drought stress,the increase rate of SPRO content in 1048 was lower than that in 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 in 3241.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,and the combination between genetic control and physiological processes were demanded to further study.