Abstract:

The mining ecotype Sedum alfredii Hance could tolerate and grow normally in a nutritive solution containing cadmium (Cd) as high as 400 µmol/L. Under such a high Cd concentration, the subcel-lular accumulation of Cd in root, stem and leaf of this plant was found to be the highest in the cell wall, less in the soluble fraction and lowest in the cell organs. The mode of subcellular distribution of Cd in the mining ecotype S. alfredii was similar to other hyper accumulators of heavy metals, in which Cd was distributed more in the aerial part of plant. The results suggest that the mining ecotype S. alfredii is a new species of Cd hyperaccumulator.

镉在东南景天中的亚细胞分配

倪天华 魏幼璋

（浙江大学华家池校区环境资源学院，杭州310029）

摘要：采用差速离心技术,比较研究了Cd在矿山生态型东南景天(Sedum alfredii Hance)根、茎、叶中的亚细胞分布.结果表明:矿山生态型东南景天对Cd具有很好的忍受耐和累积能力,非矿山生态型东南景天则不具有这种能力.Cd在矿山生态型东南景天根、茎、叶各部分的亚细胞分配满足F1(细胞壁部分)>F3(可溶部分)>F2(细胞器及膜)规律,且Cd在细胞壁部分的分配占绝对优势;同时矿山生态型东南景天地上部有很好的Cd累积能力.与众多超累积植物相似的Cd亚细胞分配规律和地上部的良好的Cd累积能力.对此植物的Cd亚细胞分布完全不同于非矿山生态型东南景天的情况作了比较分析,结果显示矿山生态型东南景天很可能是一种新的镉超累积种质资源.

关键词： 镉；东南景天；亚细胞分配

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