Abstract:[Background] Multifaceted factors contribute to the occurrence of root rot, posing challenges to the management of the disease. Bacterial consortia characterized by robust functionality and structural integrity emerge as viable candidates for the sustainable management of root rot. [Objective] To optimize the proportions of strains in the bacterial consortium and elucidate its disease-preventing and plant growth-promoting effects, thus establishing a foundation of the large-scale application of the bacterial consortium in agricultural practice. [Methods] We employed orthogonal design to optimize the structure of the bacterial consortium that had been obtained. The Topsis comprehensive analysis was conducted to evaluate the inhibitory effects on pathogens and the phosphorus-solubilizing, nitrogen-fixing, and potassium-solubilizing capabilities of each treatment, on the basis of which the optimal composition of the bacterial consortium was obtained. Furthermore, indoor pot experiments and field trials were conducted to assess the performance of the optimized consortium in preventing root rot and promoting plant growth, and the changes in nutrient content of rhizosphere soil were measured. [Results] The optimal bacterial consortium, designated as ‘Tuweiwei No. 4’ (SYP006:SYP033:SYP092:SYP202:SYP400=4:2:3:1:4), demonstrated significant control effect on root rot in Solanum lycopersicum and Capsicum annuum, with inhibition rates of 48.9% and 60.9%, respectively. Additionally, greenhouse pot experiments revealed that the plant height, stem diameter, and fresh weight of S.lycopersicum and C.annuum plants treated with the bacterial consortium increased (P<0.05). Meanwhile, the treatment with the bacterial consortium reduced the pH and salt content and increased the available nitrogen, available phosphorus, and available potassium in rhizosphere soil. Moreover, the treatment increased bacteria and actinomycetes and decreased fungi in the rhizosphere soil. The application of the consortium in the field exhibited the control efficacy of 47.94% on root rot and increased the yield of C.annuum by 7.65%. In the cultivation of Lilium davidii var. unicolor, the consortium achieved the control efficacy of 63.43% and increased the plant height (P<0.05). In the cultivation of Lycium barbarum, the consortium inhibited root rot with the efficacy of 56.11% and increased the yield by 119.99%. The optimal dose for application in the field was 10 L/667 m2. [Conclusion] The bacterial consortium ‘Tuweiwei No. 4’ exhibited good performance in controlling root rot, promoting crop growth, improving soil nutrient content, and regulating soil microecology.
