纳米炭黑对镉胁迫下黑麦草种子萌发和幼苗生长的影响

采用水培方法,分别进行了镉胁迫、纳米炭黑与镉共同作用下黑麦草种子的萌发实验,并应用电感耦合等离子体质谱(ICP-MS)对黑麦草幼苗体内的镉含量进行测定。镉溶液浓度低于50 mg/L时对发芽率和发芽指数表现为促进作用,而镉溶液浓度高于50 mg/L则为抑制作用。对幼苗的根长、芽长和种子的活力指数表现为典型的Hormesis效应,在溶液镉浓度为5 mg/L时促进作用最为明显。添加定量纳米炭黑后,在较低镉浓度下(≤10 mg/L)可明显提高黑麦草种子的发芽力,其他种子萌发指标均高于未加入纳米炭黑的各项处理组,且趋势相同。ICP-MS测定结果显示,幼苗体内镉含量随镉浓度增加而增加,在溶液镉浓度小于100 mg/L时,添加纳米炭黑的处理组幼苗体内镉含量低于未添加纳米炭黑的处理组,这说明纳米炭黑对镉有一定的钝化作用,可阻碍幼苗对镉的吸收,降低体内镉含量。

Effects of adding nano-carbon black on ryegrass seeds germination and seedling growth under cadmium stress

The hydroponic experiments which included cadmium stress, the observation experiment of ryegrass seed germination and root growth with the combined effects of nano carbon black and cadmium. The determination of cadmium content in three weeks ryegrass seed seedling by applying inductively coupled plasma mass spectrometry (ICP-MS) were carried out to study the impact of cadmium on the germination of ryegrass seed and seedling growth, as well as the recovery effect of nano carbon black on cadmium pollution. The results indicated that the promotion effect of cadmium on ryegrass seed germination rate and germination index is lower with the increasing concentration of cadmium. The concentration of cadmium appears to have typical Hormesis effect on seedling root elongation shoot length and the index of seed vigor. The promotion effect is the most obvious when the concentration of cadmium solution is 5mg/L. The ryegrass seed germination capacity promoted obviously with relatively low cadmium concentration (10mg/L) by adding a fixed amount of nano carbon black. At the same time, the germination rate of other seeds is higher than other treatment groups without nano carbon black. The results of ICP-MS showed that the cadmium content in seed increase as the cadmium concentration is higher. When concentration of cadmium solution is less than 100mg/L, the treatment group with nano black carbon has lower content of cadmium than other treatment groups without cadmium, which means that the nano carbon black has inactivation effect on cadmium and it can reduce the cadmium content in seedling by inhibit seedling to absorb cadmium.