印度梨形孢对高丹草生长及Cd吸收与积累的影响

Effects of Piriformospora indica on the growth,Cd uptake and accumulation in Sorghum Hybrid Sudangrass

为探究植物和微生物联合修复对镉(Cd)的作用效应,以一年生草本植物高丹草(Sorghum Hybrid Sudangrass)为试验材料,通过水培试验,研究印度梨形孢(Piriformospora indica)在不同浓度Cd胁迫(0、5、10、30、50、100 mg·L^(-1))下高丹草生长和生理特性,以及重金属Cd在高丹草植物体内转运、富集和分布特征。结果表明:在5 mg·L^(-1)低Cd浓度下,高丹草株高、叶片数、生物量均有一定程度的增加;随着浓度的增加,高丹草株高、叶片数减少,生物量降低,黄叶数增加,生长受到抑制,接菌后能够促进高丹草生物量的积累,缓解叶片发黄现象,改善生长状况。接菌提高了高丹草在Cd胁迫下的抗性生理指标。随着浓度的增加,高丹草未接菌组的可溶性糖、可溶性蛋白、丙二醛、超氧化物歧化酶、过氧化氢酶活性总体上逐渐升高,过氧化物酶活性逐渐降低。接菌提高了可溶性蛋白、可溶性糖含量以及酶活性,降低了丙二醛含量。不同Cd浓度条件下,高丹草体内Cd含量呈根>叶>茎的分布,且含量随着浓度增加而增加,接菌后高丹草地下部Cd含量增加,地上部Cd含量降低,接菌减少了Cd从地下部向地上部的转移,减轻了Cd对高丹草地上部的毒害。研究表明印度梨形孢能有效降低Cd对高丹草生长的抑制作用和毒性损伤。

To explore the effect of plant and microbial joint restoration on cadmium(Cd)content,the annual herb Sorghum Hybrid Sudangrass was used as the experimental material.The effects of Piriformospora indica at different Cd concentrations(0,5,10,30,50,100 mg·L^(-1))on the growth and physiological characteristics of Sorghum Hybrid Sudangrass were investigated along with the transport,enrichment,and distribution characteristics of Cd in Sorghum Hybrid Sudangrass.The results showed that at low Cd concentration of 5 mg·L^(-1),the plant height,number of leaves,and biomass increased to a certain extent.With further increase in concentration,the plant height,number of leaves,and biomass of the plant decreased;number of yellow leaves increased;and the growth was inhibited.After inoculation with Piriformospora indica,accumulation of biomass of Sorghum Hybrid Sudangrass increased,the yellowing of leaves alleviated,and the growth condition improved.Moreover,bacteria inoculation improved the physiological indices of the resistance of Sorghum Hybrid Sudangrass against Cd stress.With concentration increasing,the activities of soluble sugar,soluble protein,malondialdehyde,superoxide dismutase,and catalase in the non-inoculated group of Sorghum Hybrid Sudangrass gradually increased,whereas the peroxidase activity gradually decreased.Inoculation increased the contents of soluble protein,soluble sugar,and malondialdehyde,and reduced enzymatic activity.Under different Cd concentrations,the Cd content in Sorghum Hybrid Sudangrass showed the following distribution:root>leaf>stem.With concentration increasing,the Cd content increased;inoculation reduced the transfer of Cd from underground part to the above ground part,and alleviated the toxicity of Cd in the upper part of the plant.This study shows that Piriformospora indica can effectively reduce the toxic damage and inhibitory effect of Cd on the growth of Sorghum Hybrid Sudangrass.