重金属镉胁迫对小麦生长的影响及小麦镉污染预测的研究

Study on Influence of Cadmium on Growth of Triticum Aestivum and Forecast of Contamination to Wheat

采用盆栽试验的方法,研究了土壤中不同镉浓度对小麦生长、结实及重金属镉富集的影响。研究表明,低浓度的镉对小麦生长稍有促进作用,而高浓度镉对小麦生长有明显抑制作用。当土壤中镉的质量比大于5 mg/kg时,小麦的生长和结实状况开始急剧下降,当镉的质量比达50 mg/kg时,小麦的穗长、单株产量、百粒重都较对照显著降低。镉在小麦植株中总的分布趋势为根>茎、叶>子粒。试验进一步研究了小麦子粒(可食部位)对镉的富集量与土壤中镉总量和有效态镉含量的关系,结果表明用4种有效态提取剂(0.1 mol/L CaCl2、DTPA、0.05 mol/L EDTA和1 mol/L NH4OAc)浸提出的有效态镉的含量比土壤中镉总量更能准确地预测出小麦子粒受镉污染的程度。

Influence of different contents of Cd in soil on the growth and yield of triticum aestivum as well as the accumulation of Cd under a potted experiment has been studied. Low contents of Cd has promotion effect on the growth of triticum aestivum, but high contents of Cd has obvious restrain on it. When the concentration of Cd in soil was greater than 5 mg·kg^-1, the growth and yield of triticum aestivum began to go worse rapidly,and when the concentration reached 50 mg·kg^-1, the length of ear, yield of per pot and weight of per hundred grains were notably lower than CK. The total trend of distribution of Cd in triticum aestivum is root〉stem, leaves〉seeds. The relation between Cd contents in seeds and total Cd in soil as well as availability Cd in soil has been investigated. The result showed that the availability Cd could forecast the contamination of Cd to grain more exactly than total Cd in soil.