Cadmium uptake and speciation changes in the rhizosphere of cadmium accumulator and non-accumulator

• 作 者: SU Dechun XING Jianping JIAO W
• 机 构: College of Resources and Environmental Sciences,China Agricultural University,Beijing 100193,China“,
• 出 处: 环境科学学报(英文版)
• 发表日期: 2009年8期
• 关键词: cadmium oilseed rape rhizosphere uptake kinetics

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 (Vmax) for Cd2+ and Km were significantly different for the two oilseed rape varieties.The value of Vmax for Cd accumulator oilseed rape Zhucang Huazi was two-fold greater than that for oilseed rape Chuangyou II-93.The exchangeable Cd concentration in the rhizosphere was significantly lower than in non-rhizospheric soils supplemented with Cd as 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.