The pot culture experiment was conducted in a greenhouse atthe South China Botanical Garden, Chinese Academy of Sciences(2380 N, 113170E). Top soil (0e20 cm) was collected froma local abandoned kaleyard, and soil properties were as follows:soil texture of 70.5% sand, 12.2% silt, and 17.3% clay, soilpH of 6.09, organic matter of 3.9%, cation exchange capacity(CEC) of 79.7 mmol kg1, total Cd concentration of1.35 mg kg1, and available Cd concentration of 0.17 mgkg1.Six treatments (0, 8, 15, 30, 60 and 100 mg kg1 Cd) with 4replicates were set up and designated as CK, Cd8, Cd15, Cd30,Cd60 and Cd100, respectively. Dried soil (12.5 kg) sievedthrough 1 cm mesh was put into each plastic pot (30 cm indiameter and 25 cm in height), and then saturated with aheavy metal solution containing the required amount ofCdCl2$2$5H2O. One month later, 3 uniform-sized plants wereplanted into each plot. The plants were obtained by cuttingstem nodes of king grass from a king grass plantation in theSouth China Botanical garden, Chinese Academy of Sciencesin 2009 March, and then were rooted in soil. Ten days later,when the cuttings had grown to 10e12 cm height and wereused for transplanting. All pots were watered each day inorder to keep the soil moisture at 70e85%. After 90 days ofcultivation, the growth indicators, chlorophyll content andphotosynthetic rate were determined. After that, the shootwas cut and weighed immediately, and then washed with tapwater, followed by deionized water. Meanwhile, the rootswere dug up, washed thoroughly, and then the root lengthswere measured. Then all the samples were dried at 75 C untilcompletely dry, weighed, ground to <0.5 mm, and sealed intoplastic bags for analyses.2.2. Growth
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