农用无机纤维对镉胁迫下黑麦草生长的影响及其机理

Effect of agricultural inorganic fibers on the growth of ryegrass under cadmium stress and its mechanism

研究农用无机纤维(IF)对镉(Cd)胁迫下黑麦草生长的影响及其机理。采用盆栽试验,研究了IF和污染土壤体积比分别为1∶19(IF1)、1∶9(IF2)和3∶17(IF3)的IF对Cd污染土壤(ω(Cd)=50 mg/kg)上黑麦草生长、生理生化特性、土壤理化性质和Cd质量分数的影响。结果表明:Cd胁迫显著抑制了黑麦草的生长,IF1处理能有效促进黑麦草的生长,降低黑麦草根系与叶片丙二醛(MDA)含量和超氧阴离子(O2·-)产生速率,提高可溶性蛋白质量分数和抗氧化酶活性,增加土壤中有效硅的质量分数,增加黑麦草根和叶的Cd质量分数和地上部Cd积累量。IF2和IF3处理对Cd胁迫下黑麦草的促生作用不明显,但也能改善黑麦草根和叶的上述生理生化指标,且与IF1处理差异不显著;IF2和IF3处理能显著增加土壤中有效硅质量分数,降低土壤有效Cd质量分数,降低黑麦草叶片与根系中Cd质量分数与Cd积累量。本研究可为开辟外源物质提高植物耐Cd性,强化植物修复Cd污染土壤的绿色新途径提供依据。

The study was to analyze the effect and mechanism of agricultural inorganic fibers(IF)on ryegrass growth under cadmium(Cd)stress.The effects of IF with volume ratios of 1∶19(IF1),1∶9(IF2)and 3∶17(IF3)on the growth,physiological and biochemical characteristics,soil physicochemical properties and Cd mass fraction of ryegrass on Cd contaminated soil(ω(Cd)=50 mg/kg)were studied by pot experiments.The results showed that:Cd stress significantly inhibited the growth of ryegrass,and the treatment of IF1 could effectively promote the growth of ryegrass,reduce the content of malondialdehyde(MDA)and the production rate of superoxide anion(O·-2)in roots and leaves of ryegrass,improve the mass fraction of soluble protein and antioxidant enzyme activity,increase the mass fraction of available silicon in soil,and increase the Cd mass fraction of ryegrass roots and leaves and the accumulation of Cd in the aboveground part.The growth promotion effect of the treatment of IF2 and IF3 on ryegrass under Cd stress was not obvious,but it can also improve the above physiological and biochemical indexes of ryegrass roots and leaves,and the difference with the treatment of IF1 was not significant;The treatment of IF2 and IF3 could significantly increase the available silicon mass fraction in soil,reduce the soil effective Cd mass fraction,and reduce the Cd mass fraction and Cd accumulation in leaves and roots of ryegrass.This study can provide a basis for opening up a new green way for exogenous substances to improve plant Cd tolerance and strengthen phytoremediation of Cd contaminated soil.