施用不同有益菌剂对长期连作烤烟根际土壤微生态的影响.

[Objective] The present paper aimed to investigate the impact of different beneficial bacteria on the micro-ecological environment of tobacco rhizosphere soil in long-term continuous cropping of flue-cured tobacco, aiming to provide insights for enhancing continuous cropping soil quality and mitigating obstacles associated with consecutive planting. [Method] The physical and chemical properties, enzyme activities, as well as structure and function of the microbial community in flue-cured tobacco rhizosphere soil were analyzed using pot experiment and high-throughput sequencing technology. The analysis was conducted after long-term continuous cropping of flue-cured tobacco with beneficial bacteria agents including Trichoderma harzianum agent T-22 (T1 treatment), Bacillus subtilis agent (T2 treatment), and a combination of T. harzanum agent T-22 and B. subtilis agent (T3 treatment). [Result] Compared with not applying beneficial bacteria (CK), the application of beneficial bacteria agents could enhance the availability of nutrients and enzyme activities in the rhizosphere soil of long-term continuous cropping flue-cured tobacco. Among the 10 environmental factors examined, available phosphorus (AP) content exhibited the highest contribution (4.97%) to bacterial community distribution in flue-cured tobacco rhizosphere soil. Additionally, Alkali-hydrolyzed nitrogen (AN) content demonstrated the highest contribution (6.91%) to fungal community distribution, while sucrase (SC) activity ranked the second with a contribution of 6.75%; Application of beneficial bacteria agents could increase the diversity index of microbial community structure and the number of unique OTU in long-term continuous cropping tobacco rhizosphere soil; Application of beneficial bacteria agents could increase the abundance, diversity index of microbial community and number of bacteria endemic OTUs in rhizosphere soil of long-term continuous cropping flue-cured tobacco, and change the abundance of indicator species in rhizosphere soil of long-term continuous cropping fluecured tobacco, among them, Pseudomonas and Mortierella were identified as the indicator species for Tl treatment, with Sphingomonas (12. 2%) and Mortierella (25.0%) exhibiting high abundance. The abundance of the main metabolic pathways in the rhizosphere soil of longterm continuous cropping tobacco was decreased by single application of bacteria, but not by single application of fungi. The abundance of bacteria metabolic pathway in rhizosphere soil of flue-cured tobacco could be increased by applying beneficial bacteria agent alone, while beneficial fungal agent along had the opposite effect. The abundance of fungal metabolic pathway in rhizosphere soil of flue-cured tobacco could be increased by applying beneficial fungal agent, beneficial bacteria agent and mixed agents. [Conclusion] The application of beneficial bacteria agents has positive impact on the micro-ecological environment of rhizosphere soil in long-term continuous flue-cured tobacco cultivation. Among them, T. harzianum T-22 demonstrates superior efficacy and can be effectively utilized for the prevention and control of obstacles associated with continuous cropping of flue-cured tobacco. [ABSTRACT FROM AUTHOR]