耐乙草胺促生菌筛选及其对玉米幼苗的促生效应OA北大核心CSTPCD

Acetochlor-tolerant growth-promoting bacteria were isolated and identified to develop a microbial agent and provide a feasible scheme along with a theoretical basis for this development.Highly acetochlor-tolerant bacteria were isolated from modified media with different acetochlor concentrations.The growth-promoting effect on maize was tested,and the feasibility was verified through germination-promoting and potting experiments.Strains JL7 and JL16 showed a strong ability to induce high acetochlor tolerance and promote growth;moreover,the maximum acetochlor resistance for both strains was achieved at a concentration of 700 mg·L-1.The phosphorus solubilization capacity of JL7 was 223.21 mg·L-1,and the cumulative production of IAA was 82.40 mg·L-1.Strains JL7 and JL16 were identified as Enterbacter sp.and Acetobacter sp.,respectively.The results of the germination promotion test showed that the germination rate increased by 9.42 and 3.84 percent points with the addition of strains JL7 and JL16 after 72 hours,respectively,compared with that of the CK.Furthermore,strain JL16 significantly promoted growth in terms of shoot and root lengths by 52.53%and 23.22%,respectively,compared with those of the CK.In the pot experiment,the addition of both JL7 and JL16 affected morphological indicators such as plant height,stem thickness,root diameter,and root length,all of which were promoted.Strains JL7 and JL16 were still tolerant to ethephon in the soil.Two acetochlor-tolerant strains showed a remarkable effect on promoting plant growth.The study provides a theoretical basis for microbial soil improvements by describing suitable strains and the development of innovative microbial fertilizers for future applications.