连作番茄青枯病发生的动态过程及土壤生态学机制

番茄青枯病是由土壤中青枯病菌逐渐积累而引起的一种严重的典型性土传病害。目前病害发生的土壤生态过程尚未明确。本项目拟跟踪研究连作番茄青枯病发生的整个过程并解析其土壤生态学机制。首先，通过盆栽和小区试验研究番茄青枯病从低到高的连续变化过程，验证连作青枯病的自然消退现象，探明此过程中青枯菌的累积规律、致病力变化情况和发病阈值。其次，通过高通量测序研究番茄根部微生物多样性、种类和功能随连作时间的变化规律，查明各阶段起主导作用的微生物及其潜在功能，厘清病原菌与其它微生物的互作关系。再次，通过宏蛋白组学研究根际土壤中微生物功能蛋白随连作时间的变化规律，结合微生物群落结构变化特征系统性阐述土壤微生物结构和蛋白功能之间的“构效”联系。最终，联合“地上-地下”的耦合关系，揭示连作青枯病发生的动态过程及土壤生态学机制。该研究有望以番茄青枯病为例，发现土传病害一种新的发生模式，并可为青枯病的防治提供理论指导。

Bacterial wilt in tomato is a serious and typical soil-borne disease caused by the gradual accumulation of Ralstonia solanacearum in soil. However, the soil ecological processes correlating to the pathogenesis has not been elucidated yet. The present project aims to clarify the occurrence of continuous bacterial wilt process and its soil ecological mechanism through the tracking of the entire course of the disease. Firstly, the continuous change of disease severity of tomato bacterial wilt from low to high and its natural decline will be identified through pot experiment，and the accumulation process and virulence changes of pathogen in soil and its threshold to cause bacterial wilt will be verified. Secondly, the variation of tomato root microbial diversity, species and function with continuous cropping time will be studied by high-throughput sequencing technology to clarify the interaction between pathogen and other microorganisms, as further to identify the dominant microorganisms at each stage and their potential function. Thirdly, the variation of microbial functional proteins in rhizosphere soils with the time of continuous cropping will be verified through the macro-proteomics, and the relationship between soil microbial structure and protein function was systematically described in combination with microbial community structure. Finally, the dynamic process and soil ecological mechanism of continuous cropping bacterial wilt will be revealed by integration the coupling relationship of "aboveground and underground". This study is expected to take tomato bacterial wilt as an example, and find a new pattern of soil-borne diseases. It will provide theoretical guidance for the prevention and control of bacterial wilt.