锶及柴油胁迫下3种杨树对土壤锶的富集特征

Comparison of Strontium Accumulation Among Three Poplar Species Under Soil Strontium and Diesel Contamination

为探究杨树对土壤锶污染的修复能力,以白杨、俄罗斯杨和青杨为试材,在100 mg·kg^(-1)Sr^(2+),15mg·kg^(-1)柴油,15 mg·kg^(-1)柴油+100 mg·kg^(-1)Sr^(2+)条件下处理60 d,通过测定杨树的生长指标及各器官Sr^(2+)富集浓度,探讨比较不同种的杨树对土壤Sr^(2+)的富集特征和富集能力差异。结果表明,单一Sr^(2+)胁迫能够促进俄罗斯杨和青杨幼苗的生长,对白杨的生长表现出一定抑制效应;而柴油污染胁迫对杨树的生长均具有明显的抑制作用,其中白杨对柴油胁迫的耐受性优于俄罗斯杨和青杨。单独Sr^(2+)胁迫下3种杨树幼苗各器官Sr^(2+)富集为叶>根>茎,其中白杨的总富集浓度最高,达到2.369 mg·g^(-1)DW,青杨最低,为1.203 mg·g^(-1)DW。在柴油和Sr^(2+)的复合胁迫下,白杨、俄罗斯杨和青杨对Sr^(2+)的富集浓度明显减小,分别为1.344、1.145和0.604 mg·g^(-1)DW;但白杨和俄罗斯杨富集特征变化不大,青杨Sr^(2+)富集浓度最大的器官由叶变为根。此外,柴油的施加对3种杨树转运能力的影响具有显著差异,其中白杨的转运能力增强了15.76%,青杨显著降低了61.83%,说明杨树对土壤Sr^(2+)及其与柴油复合污染胁迫都有较好的耐受及Sr^(2+)富集能力,其中白杨更适合作为污染治理树种。本研究结果为锶及柴油污染土壤的植物修复提供了参考依据。

In order to understand the potential of poplar trees to remediate strontium polluted soil,investigate the strontium accumulation among three poplar species under soil strontium and diesel contamination,Populus alba,P.russkii and P. cathayana seedlings were treated at different stress（ 100 mg·kg（-1）Sr（2＋）,15 mg·kg（-1）diesel,15 mg·kg（-1）diesel ＋ 100 mg·kg（-1）Sr（2＋）） for 60 d. The growth index and Sr（2＋） accumulation in different parts of plants were measured to evaluate the accumulation potential and characteristics of three poplar species. The results indicated that Sr（2＋）stress could improve growth of P. russkii and P. cathayana seedlings,while the growth of P. alba was inhibited.Diesel could obviously inhibit growth of three poplar species,especially for P. alba. The significant difference was found in enrichment ability among different organs of the poplars under Sr（2＋）stress alone,with the order as followed root stem leaf,as well as the order of enrichment ability was P. alba（ 2. 369 mg·g（-1）DW） P. russkii P. cathayana（ 1. 203 mg·g（-1）DW）. The Sr（2＋）accumulation of three poplars under strontium-diesel combination stress were decreased obviously,and the Sr（2＋）content of P. alba was 1. 344 ± 0. 039 mg·g（-1）DW,P. russkii was 1. 145mg·g（-1）DW and P.cathayana was 0. 604 mg·g-1DW. However,the organ with maximum accumulation index of P. cathayana was changed from leaf to root. Furthermore,diesel could impact Sr（2＋）transport capacity of three poplars,and the difference was significant. The combined stress could increase the Sr（2＋）transport capacity of P. alba by 15. 76% and decrease that of P. cathayana＇s by 61. 83%. Our results demonstrated that the poplars were adapted to the stress of Sr and diesel stress and the P. alba was proved to be more suitable for the combined pollution remediation. The results might helpful to support the evidence of phytoremediation of Sr and diesel polluted soil.