Cd污染土壤景观修复植物筛选研究

在温室条件下,研究了香樟、圆柏、侧柏、夹竹桃、珊瑚树、四季桂、红花檵木、金边黄杨、金叶女贞和海栀子10种常见景观植物对污染土壤中Cd的耐受能力和富集特征。试验设置的三个处理分别为不添加外源Cd的CK处理(土壤中Cd本底值为3.6mg·kg~(-1))和添加外源Cd的T_1、T_2处理(土壤中Cd含量分别为9.6、24.6 mg·kg~(-1))。结果表明,在T_1和T_2处理下,圆柏、侧柏和四季桂的根、茎、叶和整株生物量与CK处理无显著差异(P0.05)。当土壤中Cd含量范围为3.6~24.6 mg·kg~(-1)时,侧柏、珊瑚树、四季桂和金边黄杨光合作用正常;T1和T2处理下香樟、侧柏、珊瑚树、四季桂、红花檵木、金边黄杨和金叶女贞叶片中丙二醛含量与CK处理无显著差异(P0.05)。珊瑚树对土壤中Cd有一定的富集能力,而香樟对Cd具有较强的转运能力。供试植物Cd富集系数的聚类分析表明,圆柏、夹竹桃和珊瑚树可用于Cd污染土壤修复与景观美化,红花檵木、金边黄杨、香樟、四季桂、侧柏和金叶女贞可用于Cd重污染土壤中Cd的稳定。

Potential of ornamental plants for remediating soil polluted with cadmium

Under greenhouse condition, the tolerance and accumulation characteristics for ornamental plants of 10 species grown on Cd contaminated soil, including Cinnamomum camphora, Sabina chinensis, Platycladus orientalis, Nerium indicum, Viburnum odoratissimum, Osmanthus fragrans, Loropetalum chinense, Euonymus japonicus, Ligustrum vicaryi and Gardenia Ellis, were studied. Three levels of Cd in polluted soil were designed, which is the background level of 3.6 mg·kg^-1(CK), the content of 9.6 mg·kg^-1(T₁) and 24.6 mg·kg^-1(T₂) with addition of external cadmium, respectively. The results showed that the biomass of roots, stems, leaves and total plant among Sabina chinensis, Platycladus orientalis and Osmanthus fragrans was slightly significant difference(P>0.05) compared with CK treatment under T₁ and T₂ treatment. When the content of Cd in soils were from 3.6 to 24.6 mg·kg^-1, Platycladus orientalis, Viburnum odoratissimum, Osmanthus fragrans and Euonymus japonicus could photosynthesize regularly, and the content of malondialdehyde in leaves of Cinnamomum camphora, Platycladus orientalis, Viburnum odoratissimum, Osmanthus fragrans, Loropetalum chinense, Euonymus japonicus and Ligustrum vicaryi were slightly changed. The accumulation capacity of Cd in Viburnum odoratissimum and the transferring coefficient of Cd to aboveground of Cinnamomum camphora was relatively higher compared with the other tested plants. According to the hierarchical cluster analysis based on Cd bioaccumulation factors of tested plants, Sabina chinensis, Nerium indicum and Viburnum odoratissimum can serve for phytoremediation and ameliorate the landscape of Cd contaminated soil. Loropetalum chinense, Euonymus japonicas, Cinnamomum camphora, Osmanthus fragrans, Platycladus orientalis and Ligustrum vicaryi is helpful for stabilization of Cd in contaminated soil.