The Tolerance and Accumulation of Miscanthus Sacchariflorus (maxim.) Benth., an Energy Plant Species, to Cadmium

摘要

Miscanthus sacchariflorus (Maxim.) Benth. is a metallophyte suitable for the phytoremediation of mine wastes. The tolerance and accumulation of M. sacchariflorus to cadmium was studied by pot experiments. The results showed that O-2(-) generation rate, plasma membrane permeability and MDA content of M. sacchariflorus leaves increased with increasing Cd concentrations in soil, but significant effect was only observed when Cd concentrations were = 50 mg.kg(-1). SOD and POD activities increased initially but decreased later on, whereas CAT activity only increased significantly at higher Cd concentrations, 50-100 mg.kg(-1). The content of photosynthetic pigment and growth of M. sacchariflorus were both not significantly affected when Cd concentration was = 25 mg.kg(-1). In contrast, both parameters were significantly affected when Cd concentration was = 50 mg.kg(-1). M. sacchariflorus could accumulate much Cd, but most of the Cd assimilated was retained in the belowground part, suggesting that M. sacchariflorus has poor ability to translocate Cd to the aboveground part. Our results suggested that although M. sacchariflorus was not a hyper-accumulator, it has a strong capacity to tolerate and stabilize the Cd. Therefore, M. sacchariflorus has a certain potential in the phytostabilization of Cd-contaminated soils.