| Oil pollution has become one of the global environmental problems,and it is extremely urgent to find effective repair techniques for petroleum hydrocarbon contaminated soil.As a combined repair technology of plants and microorganisms,mycorrhiza repair technology has the advantages of phytoremediation and microbial remediation.The use of Arbuscular Mycorrhizal(AM)to repair petroleum-contaminated soil has become a research hotspot.The mycorrhiza formed by Arbuscular Mycorrhizal Fungi(AMF)and the roots of the host plants can significantly reduce the plant pollution stress and improve the repair and degradation efficiency of the plants.In this paper,a pot experiment was conducted to prepare oil-contaminated soils with concentrations of 3 mg/g and 30 mg/g.The alfalfa was used as a host to repair the plants,and Moxicus mosseae(Gm)was inoculated to study whether AMF was inoculated or not.The effects of various growth indicators on the removal rate of petroleum hydrocarbons in the soil and the effects on rhizosphere microbial communities in the soil.In order to explore the repair potential of AMF-Alfalfa symbiosis on petroleum hydrocarbon contaminated soil.The specific results are as follows:(1)After inoculation of AMF microbial inoculated with different concentrations of petroleum contaminated soil,the mycorrhizal infection rate under the treatment of 30 mg/g concentration was significantly higher than that of 3 mg/g petroleum concentration,and the mycorrhizal infection rate reached 30.21.±4.72%,indicating that G.m and alfalfa formed a good symbiotic relationship.(2)Under the influence of petroleum pollution,the effect of AMF-Alfalfa symbiosis system on plant growth showed that the inoculation of AMF inhibited the plant height of alfalfa,and the inhibition was particularly significant under the treatment of 30 mg/g concentration;alfalfa on the ground.Biomass,underground biomass and total biomass decreased,but at 30 mg/g treatment,root to shoot ratio increased.The increase of oil concentration reduced the root length,root length and root surface area.After inoculation with AMF at 30 mg/g concentration,root length,specific root length and surface area increased significantly,root diameter decreased;oil concentration increased in soil.Total glomalin-related soil protein(T-GRSP)and Easily extracted glomalin-related soil protein(EE-GRSP)were reduced,and AMF was inoculated.The T-GRSP content increased at a concentration of mg/g.This indicates that oil pollution can inhibit alfalfa growth,and AMF-Alfalfa symbiont can improve plant nutrient status and soil environment.(3)Under the influence of petroleum pollution,the influence of AMF-Alfalfa symbiosis system on petroleum hydrocarbon degradation showed that when the petroleum hydrocarbon concentration was 3 mg/g and 30 mg/g,the degradation rate of non-rhizosphere soil was16.05±0.90% and 25.28±5.81%,the petroleum hydrocarbon degradation rate of rhizosphere soil was 23.61±10.92%and 30.02±10.65%,respectively.The petroleum degradation rate in a certain range was positively correlated with the petroleum hydrocarbon concentration.The removal of petroleum hydrocarbons in the rhizosphere soil by AMF was more effective.Significant.In the rhizosphere soil,the degradation rate of petroleum hydrocarbons in the AMF-treated group was2.16 times and 1.33 times that of the sterile plant-free control group and the sterile plant-treated group.Natural degradation of soil is the main way of petroleum hydrocarbon degradation.The contribution rate of natural degradation under the treatment of 3mg/g and 30mg/g petroleum hydrocarbon concentration is 46.74%and 74.95%,and the mycorrhizal contribution rate is 21.13%and 16.33%.The contribution rate of alfalfa It is 32.13%and 8.72%.In the treatment of AMF inoculation,there was a significant positive correlation between mycorrhizal infection rate,T-GRSP and oil degradation rate in soil.(4)Effects of AMF-Alfalfa symbiosis system on soil microbial community under petroleum pollution: Analysis of bacterial species richness in soil showed that 30 mg/g rhizosphere >3 mg/g rhizosphere >30 mg/g Non-rhizosphere>3 mg/g non-rhizosphere,Protepbacteria is the dominant species at the bacterial community level;analysis of fungal diversity showed that 3 mg/g rhizosphere >3 mg/g low Ascomycota is the dominant bacterium in the fungal community with a concentration >30 mg/g non-rhizosphere >30 mg/g rhizosphere.Similar bacterial species diversity and abundance at 3 mg/g oil concentration,inoculation of AMF microbial agents affected the main components of rhizosphere and non-rhizosphere bacteria;30 mg/g oil concentration significantly changed soil microbial community after inoculation with AMF Structure,and there are significant differences between rhizosphere and non-rhizosphere soils. |
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