SOILS, SEC3 •REMEDIATIONANDMANAGEMENTOFCONTAMINATEDORDEGRADEDLANDS • SHORTORIGINALCOMMUNICATION Root system responses of hyperaccumulator Solanum nigrum

Purpose Though phytoremediation is an important technol-ogy for remedying heavy metal-contaminated soils, hyper-accumulation mechanism, especially in root, is still less known. Materials and methods Pot culture experiment was used to explore the tolerance mechanism of a cadmium (Cd) hyper-accumulator Solanum nigrum L. by determining the main root traits compared to the non-hyperaccumulator Solanum melon-gena L. (cultivar name Liaoqie 3) in the same plant family. Results and discussion The total root lengths, total root surface areas, and total root volumes of S. nigrum were not significantly decreased (p<0.05) compared to their con-trols when Cd spikes were lower than 20 mg kg–1. However, the abovementioned three factors of S. melongena were significantly decreased (p<0.05) when 20 mg kg–1 of Cd was spiked. By contrast, S. nigrum showed stronger toler-ance to Cd. In addition, S. nigrum showed all Cd hyper-accumulator characteristics, i.e., a Cd hyperaccumulator. S. melongena was a non-Cd hyperaccumulator. Conclusions These results indicated that root trait can be a factor of hyperaccumulation because of strong tolerance to Cd