Induction of callus from a metal hypertolerant fern, Athyrium yokoscense, and evaluation of its cadmium tolerance and accumulation capacity

The callus of a metal hypertolerant fern, Athyrium yokoscense, was induced from the spores generated on a small sectioned frond in vitro. The callus grew vigorously with the periodical medium change, especially in a liquid culture. When the callus and regenerated tissues were exposed to Cd, every tissue tolerated at least 1 mM Cd for >1 month. These tissues accumulated high levels of Cd (maximum 3.3 mg g^–1 dry weight in roots) in accordance with the Cd concentration of the medium, and the Cd concentrations of all parts, except roots, were at a similar level. The data suggest that the Cd tolerance of this fern is basically independent of the plant parts and the developmental stages, although the accumulation ability is higher in roots than in the other plant parts.     

一种新发现的湿生铬超积累植物——李氏禾(Leersia hexandra Swartz)

通过对广西某电镀厂附近的植物和土壤的野外调查,发现了湿生铬超积累植物--李氏禾（Leersia hexandra Swartz）.结果表明,多年生禾本科李氏禾对铬具有明显的超积累特性,叶片内平均铬含量达1786.9mg/kg,变化范围为1084.2～2977.7mg/kg;叶片内铬含量与根部土壤中铬含量之比最高达56.83,叶片内铬含量与根茎中铬含量之比最高达11.59,叶片内铬含量与水中铬含量之比最高达517.86.李氏禾不仅对铬有很强的富集能力,而且具有生长快、地理分布广、适应性强的特点,因此李氏禾的发现将为植物的铬超积累机理与铬污染环境的植物修复研究提供新的重要物种.