Isolation And Identification Of Cadmium-resistant Microorganisms And Their Effects On Cadmium-absorbing Capacity Of Bermudagrass

With the rapid development of industry and agriculture,the problem of cadmium pollution in soil is increasingly serious.The method of using plants to repair cadmium-contaminated soil is economical and environmentally friendly,but the cycle is long.However,there are few plant species suitable for remediation,and the existing super-enriched plants have problems such as slow growth and small biomass.Remediation of heavy metal contaminated soil by plant-microorganism has great development potential.Through the acquisition of soil heavy metal pollution area,this study deals with the method of dilution coated tablets and crossed the separation of heavy metal pollution in the soil microorganism separation,through ITS sequencing the strains of separation identification,heavy metals in clear ITS patience,biological characteristics,and adsorption characteristics,on the basis of by adding bacteria to under cadmium stress of bermudagrass(Cynodon dactylon)culture in a matrix,add resistance to cadmium fungi of bermudagrass were analyzed,the effects of cadmium,cadmium contaminated soil for plant-microbial joint repair provides resistance to cadmium strains and practice guidance.Here are the results:(1)The microorganism in the heavy metal soil was isolated by diluting coating plate and marking separation method,and Trichoderma harzianum and Penicillium janthinellum were obtained by ITS sequencing identification.(2)The optimum growth p H of T.harzianum and P.janthinellum was 7,the temperature was 30?,and the maximum growth time was 70 h and 66 h,respectively.The adsorption rate of Cd²⁺reached the maximum value of 63.54%and65.87%respectively when Cd²⁺concentration was 100 mg·L^-1.Both fungi can produce IAA,and the yield decreases with the increase of cadmium concentration.(3)The addition of T.harzianum could effectively alleviate the inhibition of cadmium stress on the root length of dog teeth,reduce the content of malondialdehyde and reduce the POD activity.Under the stress of cadmium,the content of Cd²⁺in root leaves and roots of dog teeth was significantly increased and the content of Cd²⁺in rhizosphere soil was significantly decreased.(4)The addition of P.janthinellum could effectively alleviate the inhibition of root length of dog teeth under cadmium stress,and the content of Cd²⁺in the root and root of dog teeth was significantly increased after the addition of Penicillium japonicum.In addition,the content of available cadmium in rhizosphere soil was also significantly increased.The experimental results show that T.harzianum and P.janthinellum are associated with bermudagrass repair of cadmium pollution potential applications.