分蘖洋葱套作增强番茄根际微生物抑病力的植物种间化学信息交流途径及作用机理

连作障碍严重制约了设施蔬菜产业可持续发展，合理的多样性种植模式能缓解连作障碍。前期我们发现分蘖洋葱套作能通过增强番茄根际微生物抑病力而抑制番茄黄萎病，但机理不明。本项目拟在已有基础上，(1)通过不同间隔处理实验，从根系分泌物、CMNs和VOCs角度探明分蘖洋葱套作增强番茄根际微生物抑病力、促进根系招募PGPR的信息交流途径；(2)利用LC-MS和GC-MS等技术，鉴定分蘖洋葱根系分泌物和VOCs中的活性物质；(3)通过qPCR和高通量测序，探明不同信息交流途径及活性物质对番茄根际微生物菌群的影响；(4)利用LC-MS技术、体外趋化性试验等，明确不同信息交流途径及活性物质对番茄根系分泌物的作用及其对PGPR根际定殖能力的影响，揭示番茄根系代谢塑性与招募PGPR间的关系，从而阐明分蘖洋葱套作增强番茄根际微生物抑病力的植物种间化学信息交流途径及作用机理，为通过植物多样性缓解连作障碍提供理论依据。

Soil sickness has severally constrained the sustainable development of facility vegetable industry, and suitable diversified cropping systems can alleviate soil sickness. Previously, we found that intercropping Potato onion (Allium cepa var. agrogatum Don.) can suppress Verticillium wilt of tomato (Solanum lycopersicum) through enhancing the disease suppressiveness of tomato rhizosphere microbiota. However, the mechanism involved is still unclear. This study will further (1) elucidate the roles of root exudates, CMNs and VOCs-mediated interspecific communications in enhancing the disease suppressiveness of tomato rhizosphere microbiota and promoting the recruitment of PGPR; (2) isolate and identify active compounds in the root exudates and VOCs of Potato onion; (3) clarify the effects of different interspecific communication pathways and active compounds on tomato rhizosphere microbial communities with quantitative PCR and high throughput sequencing; (4) evaluate the effects of different interspecific communication pathways and active compounds on tomato root exudates and their effects on the root colonization ability of PGPR, and thus decipher the relationship between the metabolic plasticity of tomato root and recruitment of PGPR. This project is expected to reveal the plant interspecific chemical communication pathways and their function mechanisms of intercropping potato onion enhances the disease suppressiveness of tomato rhizosphere microbiota. This study could also provide theoretical foundation for alleviating soil sickness through increasing plant diversity.