野茼蒿对镉的富集及其镉耐性

Cadmium Tolerance and Accumulation Characteristics of Crassocephalum crepidioides

通过盆栽试验研究了不同镉(Cd)浓度(0、30、60、90、120、150、180mg.kg-1)胁迫下野茼蒿(Crassocephalum crepidioides(Benth.)S.Moore)的生长及其对Cd的富集特征。结果表明,随着Cd添加水平的增大,处理组野茼蒿的主根长、株高、叶绿素含量、根和地上部生物量均呈降低趋势,且主根长、株高、根和地上部生物量均显著低于对照植株;当Cd添加水平不断提高,处理组野茼蒿根和地上部Cd浓度呈显著增加趋势,而累积总量呈先增加后下降的趋势,但仍显著高于对照植株。处理Cd浓度为180mg.kg-1时,野茼蒿地上部Cd浓度最高,为1288.12mg.kg-1;处理Cd浓度为60mg.kg-1时,野茼蒿地上部Cd累积量最高,为每盆4.28mg。当Cd浓度≤90mg.kg-1时,野茼蒿生长正常,未出现Cd中毒症状。野茼蒿地上部Cd富集系数和转移系数分别为3.48～21.71和1.12～2.31。因此,野茼蒿对Cd具有较强的耐受性和转运能力以及其地上部对Cd的累积能力,适合于Cd污染土壤的植物修复。

Phytoremediation of soil heavy metals is generally considered as a clean and economical method of bioremediation. In this study, a pot experiment was used to investigate growth responses and cd accumulation of Crassocephalum crepidioides, under treatments of Cd con- centration gradient at 0 -180 mg.kg^-1. With the increasing of Cd-spiked level, main root length, plant height, chlorophyll content and root- shoot biomass of C. crepidioides decreased, and compared to the control treatment, main root length, plant height and root ＆ shoot biomass decreased significantly. When the Cd-spiked level increased, Cd concentration in the root and shoot of C. crepidioides increased remarkably, while the total amount of Cd accumulation in the root and shoot at first increased and then decreased, but still much higher than the control. In the shoot of C crepidioides, Cd concentration was highest（ 1 288.12 mg.kg^-1） at the Cd-spiked level of 180 mg.kg^-1, and Cd accumulation reached the biggest amount（4.28 mg.kg^-1） when Cd was spiked at 60 mg.kg^-1. C. crepidioides could grow normally without visible symptoms of Cd toxicity under treatments of Cd-spiked concentrations ≤ 90 mg.kg^-1. The bioconcentration factor and transloeation factor in the shoot were 3.48-21.71 and 1.12-2.31, respectively. These results indicated that C. c repidioides showed strong capability in tolerance, accumula- tion and transport of Cd, and it could be used for Cd-phytoremediation.