不同牧草在铀胁迫下生长及铀富集的比较研究

Comparative Study on the Growth and Uranium Enrichment in Different Grasses

为考察牧草在铀污染土壤植物修复中的潜在应用价值,对24种牧草进行铀胁迫下的种子萌发分析,再通过盆栽措施考察优势牧草在铀胁迫下的苗期生长及铀富集情况。结果表明,有7种牧草种子在铀胁迫下具有较好的发芽能力,<50 mg·L^(-1)铀对种子萌发具有一定的促进作用,>100 mg·L^(-1)则有明显的抑制作用。不同铀浓度条件下牧草各品种之间的生长差异显著。通过对牧草苗期的铀富集情况分析,发现在150 mg·kg^(-1)和50 mg·kg^(-1)铀胁迫下,单盆铀富集量较大的分别为多花黑麦草(10.36 mg·pot^(-1))和单年生黑麦草(3.58 mg·pot^(-1));多花黑麦草在100 mg·kg^(-1)铀胁迫下的转移系数最高(0.87),而苏丹草在各浓度铀胁迫下的转移系数相对较低。因此,针对不同情况铀污染土壤可选用不同牧草进行生态修复。本研究为铀污染土壤的生物治理提供了新的资源和理论依据。

In order to investigate the potential application of grass seeds in uranium contaminated soil phytoremediation,a set of 24 species were selected to study the grass seeds germination under uranium stress,and pot test was conducted to study the growth and uranium enrichment ability of predominant pastures. The results showed that seven species of grass seeds had a relatively high germination rates under uranium stress condition. The concentration of uranium,less than 50 mg·L^-1,had the promotion effect on seed germination rate,while the concentration of uranium,more than 100mg·L^-1,had an obvious inhibition effect. The growth of different species of grass plant was significantly different under different uranium concentration. The enrichment condition of the grasses to uranium in the seedling stage was studied.And the results also showed that Lolium multiflorum had a high pot accumulation rate（ 10. 36 mg uranium per pot） at uranium concentration of 150 mg·kg^-1,while Lolium perenne had the highest pot accumulation（ 3. 58 mg uranium per pot） at uranium concentration of 50 mg·kg^-1. And L. multiflorum had the highest transfer factor（ 0. 87） at uranium concentration of 100 mg·kg^-1,while Sorghum sudanense had the lowest value in each concentration level. In conclusion,different specie grasses can be selected to remediate uranium-contaminated soil according to the soil conditions. This study provided some new biological resources and a theoretical basis for the bioremediation to uraniumcontaminated soil.