不同小麦品种对重金属镉吸收及转运的差异研究

Differences of Cadmium Absorption and Transfer between High-Accumulating and Low-Accumulating Wheat Varities

通过小麦盆栽试验,同时施加不同浓度的镉进行分组试验,研究了不同小麦品种对重金属镉吸收及转运的差异。研究表明,随着镉施加量的增加,土壤中各个形态镉含量均有不同程度的增加,且交换态对外界胁迫响应强度最敏感,而在任一镉胁迫处理下,种植高吸收品种小麦土壤中的交换态均高于低吸收品种;小麦植株各部位的镉转移系数与外源镉的添加浓度呈明显负相关,且高吸收品种对镉的转运能力强于低吸收品种;小麦品种籽粒镉的积累能力与镉在根茎叶中的吸收、转运能力有关,低镉浓度(1 mg·kg-1)时,高吸收品种和低吸收品种对镉的转运能力差别很小,中、高镉浓度(5,15 mg·kg-1)时,高吸收品种对镉的转运能力比低吸收品种强很多。因此,在低度镉污染的土地上,种植小麦时不必过分区别品种;中、高度镉污染的土地上,适合种植低吸收小麦,可以有效抑制土壤中镉的转移,保证小麦籽粒的污染程度不至于过高,保障人们的身体健康。

The present research used the pot experiment to study the differences of Cd absorption and transport between two wheat varieties. The results demonstrated that with the increasing concentration of added Cd, the Cd concentration of each different classes increased, and the exchangeable form increased the most. There was a significant negative correlation between the Cd transfer coefficient and the fortified Cd contents in the soil. The Cd accumulation of seed was influenced by the Cd absorption and transfer of wheat plant. When the Cd concentration was 1 mg·kg-1, there was not significant difference; when the Cd concentration was 5 and 15mg·kg-1, the transfer ability of high-accumulating wheat was stronger than that of low-accumulating wheat. Therefore, selecting the low-accumulating wheat variety was very important for grain production and security.