花生对土壤镉吸收及镉的亚细胞分布研究

通过土培试验,以鲁花14为材料,采用盆栽方法,设置0.10(CK)、3.24、7.35、8.38、18.80 mg/kg5种土壤镉浓度,研究了鲁花14各器官对土壤镉的富集效应及其镉在各器官亚细胞的分布。结果表明:随着镉浓度的增加,花生根、茎、叶的镉含量也持续增加,不同镉处理间差异显著。土壤镉浓度小于(包含)8.38mg/kg时,镉含量大小顺序为叶>根>茎;土壤镉浓度为18.80 mg/kg时,镉含量大小为根>叶>茎。镉在根、茎、叶中亚细胞组分中的含量及其分布比例在不同镉处理间不同。土壤镉浓度小于(包含)8.38 mg/kg时,镉在根、茎、叶中亚细胞组分的镉含量为细胞壁>细胞器>可溶部分,镉积累在细胞壁是花生忍耐镉的主要机制。但在18.80 mg/kg时,亚细胞组分的镉含量为细胞器>细胞壁>可溶部分,说明在高镉浓度下,花生受到镉的毒害很严重。

Absorption and Subcellular Distribution of Soil Cadmium in Peanut

A pot experiment was conducted with Luhua 14 as material to study the accumulation and subcellular distribution of soil cadmium in peanut.Five levels of cadmium,0.10(CK),3.24,7.35,8.38 and 18.80 mg/kg,was added into soil.The results showed that the cadmium content in leaves,stems and roots of Luhua 14 increased significantly with the increase of cadmium concentration.The cadmium content in different organs in leaves was the highest followed by root and stem,when the cadmium concentration was equal to or less than 8.38 mg/kg;while the cadmium concentration was 18.80 mg/kg,the cadmium content in root was higher than that in leaves,while that in stem was the least.The content and distribution in subcellular fractions of roots,stem and leaves of Luhua 14 were significantly different between different cadmium concentrations.The subcellular distribution of cadmium showed cell wall> organelle>soluble fraction at or more than 8.38 mg/kg,which indicated that cell wall binding cadmium was the main mechanism for peanut to tolerant cadmium.But at 18.80 mg/kg of cadmium,the subcellular distribution presented as organelle>cell wall>soluble fraction,which indicated that the toxicity of cadmium was very serious to peanut in the condition of high cadmium concentration.