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作 者 ：郑桂灵1,2,王思维1,李 鹏1,2*

期 刊 ：西北植物学报 2013年 3期 页码：564~569

关键词：空气植物；生物监测；叶表鳞片；重金属污染；

Keywords:air plant, bio-monitoring, foliar trichome, heavy metal pollution,

摘 要 ：以贝可利空气凤梨为材料,用不同浓度的硝酸铅溶液（0～100 mg/L）对其进行胁迫处理,探讨空气凤梨对重金属污染物铅的吸收积累特征。结果发现,胁迫处理15 d后,所有贝可利空气凤梨植株都没有明显的死亡症状；随着铅浓度的提高,贝可利空气凤梨植株中的铅含量随之显著增加。扫描电镜结合能谱分析表明,不论何种铅浓度处理植物体,贝可利空气凤梨叶表鳞片中的3类细胞上都可检测到铅元素的存在；但3类细胞在富集铅时所起的作用不同,并以最内部的碟状细胞中铅的含量最高。结果表明,贝可利空气凤梨对铅胁迫具有很强的耐性,并且可对铅进行有效的积累,是一种合适的指示铅污染的植物；其叶表鳞片则可能是铅等重金属元素的主要富集结构,而且铅在从外部细胞进入内部细胞的迁移过程中存在主动运输的成分。

Abstract:Epiphytic Tillandsia species receive water and nutrients directly from the air through foliar trichomes.For this reason,they can be selected to carry out monitoring environmental pollution.Tillandsia brachycaulos was selected as the materials and cultivated with different Pb(NO₃)₂ solutions (0～100 mg/L).All T.brachycaulos remained alive after 15 days,and the total concentration of Pb in plants increased significantly with the increase of Pb concentration.Scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) analysis showed Pb was detected on each type of cells in foliar trichomes,but the ratio of Pb in the internal disc cells was higher than those in ring cells and wing cells.The results suggested that the plants of T.brachycaulos were able to survive under relatively high Pb stress,and accumulated Pb quickly and effectively.Therefore,they had high potential for monitoring in Pb polluted environment.Foliar trichomes of T.brachycaulos were probably the main structure in enriching heavy metals,while the mechanism of adsorbing heavy metals in Tillandsia had an active component.

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