鸭跖草的铀富集与耐性特征研究

Bioconcentration and tolerance characteristics of Commelina communis on uranium

为了研究鸭跖草在铀胁迫下的富集和耐性特征,探究其用于铀污染土壤修复的可行性,通过设置不同铀处理浓度(25、75、125、175、275、375、485 mg/kg)进行盆栽试验。结果表明,铀浓度为25~375mg/kg时,鸭跖草地上、地下部铀含量随着铀浓度的提高而增加,分别达到最高值541.733、776.497 mg/kg。鸭跖草的铀转移系数、地上部和地下部生物富集系数分别为0.035~0.698、0.08~1.444、1.674~2.56。选取最大光化学量子产量、地上部生物量、株高、根长4个生物性状值,分别计算其耐性指数,单因素方差分析(α=0.05)结果表明各处理间的耐性指数均没有显著差异。鸭跖草是铀的根际富集植物,而且对浓度介于25~485 mg/kg的铀污染具有良好的耐受性。对根际富集植物在土壤修复方面的应用,认为植物提取的本质是利用植物将污染物聚集到体内,然后对污染物浓度高的植物进行灰化或消解等集中处理;鸭跖草根部体积小,且易于收割,而且其根系不发达,收割后对水土流失影响小,在其地下部分生物富集系数>1时,可以考虑将其地下部分进行收割用于植物提取修复重金属污染。

In order to study bioconcentration and tolerance characteristics of Commelina communis,and explore its feasibility in phytoremediation of U contaminated soil.A pot experiment was conducted with different concentrations of uranium(U)i.e.25,75,125,175,275,375 and 485 mg/kg.The U-concentrations in shoots and roots of Commelina communis’s gradually increased with the increase of U-concentration in soil(25-375 mg/kg),and the maximum value of 541.73 and 776.497 mg/kg was recorded in soil added with 375 mg/kg.Transfer factor,shoots and roots bioconcentration factor of Commelina communis were in the range of 0.035-0.0698,0.08-1.444,and 1.674-2.56,respectively.The tolerance indexes of maximum quantum yield(Fv/Fm)among chlorophyll fluorescence parameters,the shoots biomasses,plant heights and root lengths,in different treatments wereanalyzed(α=0.05),it was indicated that there were no significant differences between different treatments.The results showed that Commelina communis was a kind of rhizosphere bioconcentration plant,and had a high tolerance to U-concentration with from 25 to 485 mg/kg.As for application of rhizosphere bioconcentration in soil phytoremediation,the essence of phytoremediation is to use plants to gather pollution into the body,then the plants with high concentration of pollution were treated with ash or digestion and so on.Commelina communis’s roots were small in volume and convenient to crop,which had little soil erosion after cropping,when the roots bioconcentration coefficient was greater than 1,its’roots could be reaped for remediation of heavy metal pollution.