窄冠黑青杨对重金属复合胁迫的生理响应  

Physiological and Ecological Response of Narrow Crown Black-Cathay Poplar to Stress of Mixed Heavy Metals

作　　者：曲木子[1] 谢会成[1] 李际红[1] 

机构地区：[1]山东农业大学林学院,山东泰安271018

出　　处：《西北林学院学报》2013年第5期8-12,共5页Journal of Northwest Forestry University

基　　金：山东农业大学博士基金;山东农业大学青年创新基金(23622)

摘　　要：采用盆栽试验方法研究了不同浓度Pb2+、Cd2+、Hg2+复合胁迫下黑青杨的相关生理生化指标的变化。结果表明:随着重金属复合胁迫浓度的增加,黑青杨的根系活力、光合活性各指标呈下降的趋势;叶片游离脯氨酸含量与丙二醛(MDA)呈逐渐增加趋势;在较低浓度的Pb2+、Cd2+、Hg2+复合胁迫的处理下,黑青杨根系活力稍有增强,说明低浓度的复合胁迫对其有一定的刺激作用;随着土壤复合胁迫浓度增加,黑青杨的净光合速率(Pn)、胞间二氧化碳浓度(Ci)、气孔导度(Gs)和蒸腾速率(Tr)逐渐下降,且均在最高处理浓度时达到谷值。研究发现,高浓度的Pb2+、Cd2+、Hg2+复合胁迫所导致的Pn下降是由气孔限制因素所致。本研究能为环境监测中评价土壤重金属污染程度提供参考,同时也为受污染地区绿化树种的选择提供科学的理论依据。Potted seedlings of Narrow Crown Black-Cathay Poplar were treated by the solutions of mixed heavy metals with different concentrations, including Pb2＋ , Cd2＋ , and Hg2＋ to explore their influences on the physiological and biochemical indices of the poplar. The results showed that the root activity and photosynthetic activity exhibited decreasing tendency while the changes of praline content and the contents of malondialdehyde （MDA） exhibited increasing tendency with the increase of the heavy metal concentrations. Under the low concentration combined stress treatment, the root activity increased slightly, indicating the stimulation effect of the combined stress at low concentrations. With the increase of the concentration, the net photosynthetic rate （P）, intercellular C02 concentration （Ci）, stomatal conductance （Gs） and transpiration rate （Tr） decreased. It was discovered that P,, decline caused by the stress at high con centration was because of stomatal limitation. The results of this research could provide a reference to evaluate the degree of soil heavy metals pollution in environmental monitoring and provide a scientific basis to select the greening tree species in the contaminated areas.

关 键 词：窄冠黑青杨 复合胁迫 丙二醛含量 脯氨酸含量 光合活性 根系活力 

分 类 号：S792.113.01[农业科学—林木遗传育种]