四种重金属胁迫下朝天委陵菜的生长特性及富集能力

The Growth Characters and Enrichment Capacity of Potentilla supina Stressed by Four Kinds of Heavy Metals

通过砂基培养，研究了朝天委陵菜（Potentilla supina）在不同浓度Cd^2＋、Cu^2＋、Pb^2＋、Zn^2＋胁迫下的生长特性及富集能力。结果表明，朝天委陵菜对Cu^2＋、Zn^2＋、Pb^2＋、Cd^2＋的耐受性较强，在≤130mg／L的胁迫下未出现死亡，仅随浓度增大而植株生长减慢；Cu^2＋的富集量及富集系数为50mg／L组最大，分别达1422．91mg／kg和28．46；Pb^2＋的富集量及富集系数为70mg／L组最大，分别达1148．92mg／kg和16．41；Zn^2＋的富集能力较弱，富集系数在1．48～6．33之间；Cd^2＋的富集量最少，各浓度组富集系数均小于0．1。在砂培条件下，朝天委陵菜对四种重金属的富集能力，各浓度组均为Cu^2＋〉Pb^2＋〉Zn^2＋〉Cd^2＋；当Cu^2＋、Pb^2＋污染物浓度≤90mg／L时，朝天委陵菜对Pb^2＋和Cu^2＋的富集达到超富集植物的富集水平，可选作Cu^2＋、Pb^2＋污染土壤的修复植物；Cu^2＋、Pb^2＋污染土壤上生长的朝天委陵菜，因Cu^2＋、Pb^2＋含量超标不宜采食或药用。

Using sand cuhure, the growth characters and accumulation capacity of Potentilla supina L. stressed by different concentrations of Cd^2＋ , Cu^2＋ , Ph^2 ＋ or Zn^2＋ were studied. The results showed that P. supina had a good tolerance to Cd^2＋ ,Cu^2＋ ,Pb^2＋ or Zn^2＋. It could grow even when the heavy metals were up to 130 mg/L, but grew slowly as the concentration raised. It was also found that P. supina had great capacity of accumulating Cu^2＋. When the concentration of Cu^2＋ was 50 mg/L, the accumulation and enrichment coefficient both reached to the maximum 1 422. 91 mg/kg and 28.46, respectively. As for Pb^2＋ , both the accumulating and enrichment coefficient reached to the maximum as the concentration was 70 mg/L. But the accumulating Zn^2＋ capacity of Potentilla supina L. was lower, the enrichment coefficients were between 1.48 and 6.33. The quantity of enriching Cd^2＋ was the least, and all the enrichment coefficients were below 0. 1. Using sand culture, the abilities that P. supina enriched the four heavy metals were： Cu^2＋ 〉 Pb^2＋ 〉 Zn^2＋ 〉 Cd^2＋. The enriching Cu^2 ＋ or Pb^2 ＋ capacity of P. supina L. could reach to the hyperaccumulator standard when the concentration was less than 90 mg/L, so P. supina L. may be selected to purify the soil polluted by Cu^2＋ or Pb^2＋. It was also suggested that P. supina growing in the soil polluted by Cu^2＋ or Pb^2 ＋ could not be used as vegetable or herbal medicine.