镉胁迫下钝化剂对菠菜镉吸收累积及土壤微生物群落结构的影响

Effects of passivating agents on cadmium uptake and accumulation and soil microbial community structure in Spinacia oleracea L.under cadmium stress

为了探究镉(Cd)胁迫下不同钝化剂对菠菜Cd吸收转运及根际微生物群落结构的影响,设置不施钝化剂(CK)、单施纳米羟基磷灰石(nHAP)、单施巯基生物炭(TMB)、配施纳米羟基磷灰石+巯基生物炭(HPTB)4个处理,比较各处理的土壤微生物群落结构、土壤化学性质与菠菜生物量及Cd含量。结果表明,各钝化剂处理下菠菜生物量均增加,Cd含量均降低;不同钝化剂对土壤主要优势菌群的组成没有显著影响,但会改变细菌和真菌的相对丰度。主成分分析表明,nHAP对细菌群落结构影响较大,对真菌群落结构影响较小。冗余分析发现,pH是影响细菌群落结构的主要因子,全磷含量是影响真菌群落结构的主要因子。综上所述,单施nHAP能够促进菠菜生长,降低Cd含量,且对微生物群落结构的影响较小。

In order to investigate the effects of different passivating agents on cadmium(Cd)uptake and transport and rhizosphere microbial community structure in Spinacia oleracea L.under Cd stress,the Spinacia oleracea L.was selected as the research objects.The four treatments of no passivating agent application(CK),single application of nano-hydroxyapatite(nHAP),single application of thiol biochar(TMB)and combined application of nano-hydroxyapatite+thiol biochar(HPTB)were applied.The microbial community characterization,the chemical properties of soil,and Spinacia oleracea L.biomass and Cd content of each treatment were determined.The results showed that the biomass of Spinacia oleracea L.increased and the Cd content decreased under different passivation treatments.Different passivating agents had no significant effect on the composition of the main dominant flora in the soil,but changed the relative abundance of bacteria and fungi.Principal component analysis showed that nHAP had a greater impact on bacterial community structure and less on fungal community structure.Redundancy analysis found that pH was the main factor affecting bacterial community structure,and total phosphorus was the main factor affecting fungal community structure.In conclusion,single application of nHAP could promote the growth of Spinacia oleracea L.,reduce the Cd content,and have little effect on the microbial community structure.