摘要
Willows （Salix spp.） have shown high potential for the phytoextraction of heavy metals. This study com- pares variations in copper （Cu） and zinc （Zn） tolerance and accumulation potential among 12 willow clones grown in a nutrient solution treated with 50 pmol/L of Cu or Zn, respectively. The results showed differences in the tolerance and accumulation of Cu and Zn with respect to different species/clones. The biomass variation among clones in response to Cu or Zn exposure ranged from the stimulation of growth to inhibition, and all of the clones tested showed higher tolerance to Cu than to Zn. The clones exhibited less variation in Cu accumulation but larger variation in Zn accumulation. Based on translocation factors, it was found that most of the Cu was retained in the roots and that Zn was more mobile than Cu for all clones. It is concluded that most willow clones are good accumulators of Zn and Cu.
研究目的:柳树(Salix spp.)已广泛用于修复重金属污染,而且修复效率与树种及无性系有关。目前涉及柳树研究主要为铜(Cu)和锌(Zn)的毒性效应,而不是富集能力。本研究以中国常见的柳树无性系评价对Cu和Zn耐性与富集能力。创新要点:目前大多数研究仍集中Cu和Zn对柳树的毒性效应,尤其是Cu,对它们富集能力仍没有评价。中国为柳树的主要分布区。本文以12种优良的常见柳树无性系,通过温室营养液法评价对Cu和Zn耐性及富集潜力差异。利用柳树无性系的耐性与富集变异,旨在选择高耐性与高富集的无性系,提高环境修复效率和加快修复进程。研究方法:选择高生物量12种柳树无性系,采用温室营养液培养法添加Cu或Zn处理,测定生物量参数并计算耐性指数,估计耐性差异;用原子吸收法测定组织中金属浓度并计算金属位移系数,评价富集差异。重要结论:无性系对Cu和Zn耐性显著不同,生物量变化从无影响、抑制到促进生长。无性系对Cu耐性高于对Zn耐性,无性系对Zn富集变异幅度大于对Cu富集变异幅度。Cu主要富集于根部,而Zn较易运输到地上部分。总之测定的大部分柳树无性系为Cu与Zn高富集植物,显示出较高的植物提取能力。
基金
Project supported by the National Natural Science Foundation of China （No. 31100513）, the Key International Cooperative Project of CN-USA from the Ministry of Science and Technology of China （No. 2010DFB 33960）, the Key Project of Ningbo Science and Technology Bureau of Zhejiang Province （No. 2012C10003）, the Key Project of the Ministry of Science and Technology of China （No. 2012BAC17B02）, and the Fundamental Research Funds for the Central Universities, China
