基于东亚金发藓监测土壤镉污染的生物学机理  

Biological Mechanisms of Using Pogonatum Inflexum to Monitor Soil Cd Pollution

作　　者：董萌[1] 赵运林[2] 蒋道松[1] 周小梅[1] 李必才[1] 库文珍[1] DONG Meng ZHAO Yunlin JIANG Daosong ZHOU Xiaomei LI Bicai KU Wenzhen(College of Chemistry and Environment Engineering, Hunan City University, Yiyang, Hunan 413000, China College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410018 China)

机构地区：[1]湖南城市学院化学与环境工程学院,湖南益阳413000 [2]中南林业科技大学环境科学与工程学院,长沙410018

出　　处：《土壤学报》2017年第1期128-137,共10页Acta Pedologica Sinica

基　　金：湖南省自然科学基金项目(2016JJ4015;2015JJ4012);湖南省科技计划重点项目(2010SK2004)资助~~

摘　　要：采用对镉具有高敏感性特征的苔藓植物——东亚金发藓(Pogonatum inflexum)为材料,以不同浓度梯度镉污染基质作为胁迫条件,观测该植物在镉胁迫下的生长发育状况、镉富集能力、叶绿素含量、可溶性蛋白含量及MDA含量,并分析比较了各项指标变化特征与土壤中全镉含量及有效镉含量的相关性。结果显示,供试土壤中有效镉含量约占全镉含量的20%~40%,东亚金发藓对镉的富集能力总体较弱,其最大富集浓度值为1.627 mg kg-1,最高富集系数为63.9%,植株富集浓度与土壤有效镉含量之间的相关性高于全镉;东亚金发藓对镉污染表现出显著反应特征,植株孢子体和配子体受害症状明显,1~2 mg kg-1以上的镉胁迫(土壤有效镉含量大于0.559 mg kg-1时)即可使叶部黄化、褐变,5 mg kg-1的镉处理导致蒴柄弯折、植株枯亡;东亚金发藓叶绿素含量、可溶性蛋白含量、丙二醛(MDA)含量等生理指标变化特征受镉胁迫影响明显,且与有效镉含量呈显著相关性,适合作为东亚金发藓监测土壤镉污染及镉生物有效性的指示指标。【Objective】How to monitor and assess soil Cd pollution and bioavailability is currently an issue of great concern. However, measurements of soil available Cd contents using the conventional chemical methods may only serve as certain reference, because they are not good enough to intuitively and truly reflect the damages soil Cd2＋ does to plants. Bryophyta are simple in structure, free of any cuticle on their surface and quite sensitive to pollutants, so they are usually used in monitoring environmental pollution. In this paper, an effective method was preliminarily studied to monitor and evaluate soil Cd pollution and Cd bioavailability using Pogonatum inflexum, a species of bryophyte highly sensitive to soil Cd. A mature plant of the sporophytic generation of Pogonatum inflexum could be as high as 10 cm. Besides, it is simple in surface structure with no vascular bundle differentiation, but with sporophytes parasitizing on gametophytes. Furthermore, the various organs of Pogonatum inflexum are homogeneous in cell structure and mostly monolayer cells.【Method】In the experiment to validate effectiveness of the method, the tested soil was prepared into media, different in Cd contamination degree （1~5 mg kg-1）, for culture of Pogonatum inflexum. Growth, Cd enrichment, chlorophyll content, soluble protein content and MDA concentration of the bryophyte was observed and/or determined. Soil available Cd contents extracted with acetic acid were cited as indicator parameter for soil Cd bioavailability, and then analysis was done of correlations of the above described indices with content of soil total Cd and content of soil available Cd, separately.【Result】Results show that in the test soil, bioavailable Cd accounted for about 20%~40% of total Cd. All the indexes of Pogonatum inflexummentioned above were closely related to soil Cd stress, especially when soil Cd concentration was higher than 3 mg kg-1. Pogonatum inflexum was low in Cd enrichment and in tolerance to Cd as well. It could enrich as high as C

关 键 词：东亚金发藓 生物监测 土壤镉污染 镉生物有效性 

分 类 号：X171.5[环境科学与工程—环境科学]