镉在小麦各部位的富集和转运及籽粒镉含量的预测模型

以全国小麦产区的14种土壤为材料,采用盆栽试验方法研究了小麦在对照、Cd处理(0.6 mg·kg-1 p H7.5,1.2 mg·kg-1 p H7.5)条件下,Cd在小麦各部位的含量及其富集和转运。结果表明:对于两组Cd处理而言,Cd在小麦中的分布趋势均为根茎籽粒,而且各部位的Cd含量相互间均显著性相关(Cd处理的籽粒与根除外)。14种土壤种植下,小麦根、茎、籽粒的Cd含量范围分别为:0.11~2.18、0.04~0.75、0.004~0.08 mg·kg-1(对照);3.14~12.04、0.18~0.94、0.09~0.43 mg·kg-1(Cd处理)。14种土壤中根-土的Cd富集系数范围为0.59~13.69(对照)、2.98~14.86(Cd处理);茎-根、籽粒-根的转运系数范围为:0.22~1.60、0.02~0.14(对照);0.04~0.13、0.01~0.06(Cd处理)。小麦籽粒Cd含量与土壤理化性质的相关性分析及预测方程显示,无论土壤是否受Cd污染,籽粒Cd含量与土壤p H均呈极显著性负相关,相关性系数分别为-0.828(对照)、-0.841(Cd处理),p H是影响籽粒吸收Cd的首要土壤因素,有机碳(OC)含量则为第二因素,籽粒Cd含量预测方程拟合效果良好(对照R2=0.84;Cd处理R2=0.93)。

Cadmium Accumulation and Translocation in Wheat and Grain Cd Prediction

Fourteen soil samples, collected from wheat-producing areas across 14 provinces in China, were used in pot experiment to investigate accumulation and translocation of Cd from soil to different parts of wheat with and without Cd addition. Results showed that the Cd content in wheat was in order of rootsb> stems> grains for all tested soils, with Cd content ranges of 0.11~2.18, 0.04~0.75, and 0.004~0.08 mg·kg^-1 in no Cd added soils and 3.14~12.04, 0.18~0.94, and 0.09~0.43 mg·kg^-1 in Cd added soils, respectively. The Cd content in roots, stems, and grains were all significantly correlated with each other(except between grain and root under Cd addition). The bioaccumulation factor of Cd in roots ranged from 0.59 to 13.69 in the control and from 2.98 to 14.86 in Cd addition. The translocation factors of Cd from roots to stems and grains ranged correspondingly from 0.22~1.60 and 0.02~0.14(the control) and 0.04~0.13 and 0.01~0.06(Cd addition). Soil pH was the most important factor influencing wheat grain Cd uptake, with correlation coefficient of r=-0.828 in control and r=-0.841 in Cd addition. A good prediction model of Cd concentrations in wheat grain was established with R²=0.84(in no Cd addition) and R²=0.93(in Cd addition).