硬叶空气凤梨对铅的富集特征研究

空气凤梨是一类生长在空气中、不需要土壤的特殊植物,是有效的监测环境变化的指示植物。文章以硬叶空凤为材料,以环境中最典型的污染物—铅对其进行胁迫处理后,发现硬叶空凤对铅具有很强的耐性,而且可对铅进行有效的富集,是一种合适的指示铅污染的植物。扫描电镜和能谱分析表明,不论何种铅浓度处理植物体,硬叶空凤叶表鳞片中都可检测到铅元素的存在,进一步表明叶表鳞片很可能是铅等重金属元素的主要富集结构。另外,硬叶空凤叶表鳞片的3类细胞在富集铅时所起的作用是不同的,最内部的碟状细胞中铅的含量要大于中间的环状细胞,更大于最外部的翼状细胞,暗示铅的迁移是一种代谢性主动吸收过程。

Accumulation of Pb with Epiphytic Plant Tillandsia stricata

Epiphytic Tillandsia species are special plants growing in the air and don't need soil.It receives water and nutrients directly from the air through specialized leaves.For this reason they can been selected to carry out monitoring environmental pollution.We selected T.stricata as the materials and cultivate them with Pb,typical pollutant in the environment.The results showed that T.stricata was able to survive relative high Pb stress concentrations.With the increase of Pb concentration,the total concentration of Pb in plants increased significantly,which suggested the plants could accumulate Cs quickly and effectively.Therefore,they had high potential for monitoring in Pb polluted environment.In addition,scanning electron microscopy(SEM) and energy dispersive spectrometer(EDS) analysis showed Pb was detected on each type of cells in foliar trichomes,and the ratio of Pb in the internal disc cell was higher than those in ring cell and wing cell,which indicated foliar trichomes were main structure in enriching heavy metals,including Pb,and the mechanism of adsorbing Cs in Tillandsia had an active component.