【摘要】 为缓解黄芩的冷害,探讨外源甜菜碱(GB)对低温胁迫下幼苗生理特性的影响,以商洛黄芩为试验材料,在4℃低温胁迫下,研究叶面喷施GB对黄芩幼苗的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、丙二醛(MDA)、可溶性蛋白和叶绿素含量、相对电导率等生理指标的影响。结果表明:施加浓度为0.6g/L外源GB能有效提高黄芩的抗寒性,黄芩幼苗叶片SOD、POD和CAT活性分别为低温蒸馏水对照的1.502倍、2.031倍和2.362倍,且都略低于常温蒸馏水对照;总叶绿素含量相对于低温蒸馏水对照高68%;可溶性蛋白含量较低温蒸馏水对照高178%;随着甜菜碱处理浓度升高,低温胁迫下黄芩的相对电导率和丙二醛含量呈先降后升趋势,且均在GB浓度为0.6g/L时含量达到最低,比低温蒸馏水对照分别下降50%和56%。因此甜菜碱喷洒处理能明显缓解冷害,且在GB浓度为0.6g/L效果最好。更多还原

【Abstract】 The effects of glycine betaine（GB）on leaf SOD,POD and CAT activity,MDA,soluble protein and chlorophyll content and relative conductance rate of Scutellaria Baicalensis seedlings were studied by apot test under 4℃ low temperature stress to discuss the effect of exogenous GB on physiological property of S.Baicalensis seedlings under low temperature stress for relieving cold damage to S.Baicalensis seedlings.Result:Spraying 0.6 g/L GB can effectively improve cold resistance of S.Baicalensis seedlings and the leaf SOD,POD and CAT activity of S.Baicalensis seedlings is 1.502,2.031 and 2.362 times that of CK₂（distilled water+low temperature）,slightly lower than CK1（distilled water+ normal temperature）.Total chlorophyll and soluble protein content in leaves of S.Baicalensis seedlings sprayed with 0.6 g/L GB is 68% and 178% higher than CK₂ respectively.The leaf relative conductance rate and MDA content of S.Baicalensis seedlings both show the rising firstly and then declining trend with increase of GB concentration under low temperature stress.The leaf relative conductance rate and MDA content of S.Baicalensis seedlings both reach the lowest when GB concentration is 0.6 g/L,and are 50% and 56%lower than CK₂ separately.In conclusion,spraying GB can relieve cold damage to S.Baicalensis seedlings and the optimum GB concentration is 0.6 g/L.更多还原