喜盐鸢尾铅（Pb）胁迫耐性生理研究

采用溶液培养方法，以喜盐鸢尾（Irishalophila Pall．）为材料，对不同铅（Pb）浓度和时间胁迫下植物叶片叶绿素、丙二醛（MDA）和脯氨酸（Pro）的含量以及超氧化物歧化酶（SOD）的活性变化进行了研究。结果表明：在Pb胁迫下，喜盐鸢尾叶片的叶绿素含量随Pb处理浓度的增加而降低；在相同Pb浓度胁迫下，叶绿素含量随时间的延长而降低，虽然在8mmol／L和10mmol／L胁迫28d后，随着植物生长稍有恢复，叶绿素a含量有一定的提高，但仍处于较低水平。喜盐鸢尾在4mmol／L以下低浓度Pb胁迫下，叶片的MDA含量在不同胁迫时间内与对照均无显著差别，表明喜盐鸢尾对相对低浓度Pb胁迫具有一定的耐性能力。SOD活性和脯氨酸含量在Pb胁迫下均有不同程度增加，特别是在高浓度胁迫下增加显著，表明喜盐鸢尾具有一定的胁迫诱导抗性能力。

Effects of Pb on physiological response ofIris halophila

The seedlings of Iris halophila Pall. were subjected in 0 - 10 mmol/L Pb and then determined its physiochemical parameters in different period. The results showed that the contents of chlorophylls decreased as Pb concentrations raised and exposed time prolonged. The contents of chlorophyll a were little increased as the seedlings exposed to 8- 10 mmol/L Pb in 28 days as the seedlings got little better, while the contents were still lower than that of other treatments. The contents of MDA in the leaves of I. halophila were not significantly different from those of control below 4 mmol/L Pb treatments in the period of 7-28 days. The contents of proline and the activities of SOD in the leaves of I. halophila increased as the Pb concentrations raised. The results indicated that I. halophila was a tolerant species in the physiological characters.