Cadmium uptake and speciation changes in the rhizosphere of cadmium accumulator and non-accumulator oilseed rape varieties.
Characteristics of cadmium (Cd) uptake kinetics and distribution of Cd speciation in the rhizosphere for Cd accumulator and non-accumulator oilseed rape varieties were investigated under nutrient solution and rhizobox soil culture conditions. The results showed that the maximal influx (V(max)) for Cd2+ and Km were significantly different for the two oilseed rape varieties. The value of V(max) for Cd accumulator oilseed rape Zhucang Huazi was two-fold greater than that for oilseed rape Chuan you II-93. The exchangeable Cd concentration in the rhizosphere was significantly lower than in non-rhizospheric soils supplemented with CdSO4 for both the varieties. Carbonate-bound Cd in the rhizosphere of Cd accumulator oilseed rape was significantly higher than that in the rhizosphere of non-accumulator oilseed rape and non-rhizospheric soil. Cd accumulator oilseed rape had a higher Cd2+ affinity and more ability to uptake insoluble Cd in the soil than the non-accumulator oilseed rape.
College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China. dcsu@cau.edu.cn
Dechun
D
Su
Jianping
J
Xing
Weiping
W
Jiao
Woonchung
W
Wong
D001673:Biodegradation, Environmental; D029741:Brassica rapa / Q000378:metabolism*; D002104:Cadmium / Q000378:metabolism*; D007700:Kinetics
D002104:Cadmium