A Comparison Study in Cadmium Tolerance and Accumulation in Two Cool-Season Turfgrasses and Solanum nigrum L

Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb.), and black nightshade (Solanum nigrum L.) were exposed to cadmium (40, 80 mg Cd kg(-1)) for 9 weeks to compare their cadmium tolerance and accumulation. Results showed that the cadmium inhibited the growth of all plants. The shoot and root biomass of black nightshade was significantly declined under 40 mg Cd kg(-1), while Kentucky bluegrass and tall fescue were tolerant to 40 mg Cd kg(-1) without significant decline of the plant biomass. The total Cd accumulation in Kentucky bluegrass, tall fescue, and black nightshade was 418.6, 383.4, and 9.4 mg m(-2) under 40 mg Cd kg(-1), and 1114.9, 761.5, and 63.7 mg m(-2) under 80 mg Cd kg(-1), respectively. Under 40- and 80-mg Cd kg(-1) treatments, the phytoextraction rate was 2.10 and 4.64 % in Kentucky bluegrass, 0.71 and 1.40 % in tall fescue, and only 0.12 and 0.43 % in black nightshade, respectively. Kentucky bluegrass and tall fescue showed better Cd tolerance and higher Cd accumulation than black nightshade, indicating that Kentucky bluegrass and tall fescue have potential phytostabilization capability in cadmium-contaminated soils.