间作土壤微生物变化对花生青枯病及土壤病原菌的影响

Peanut bacterial wilt is a disastrous soil borne disease. Currently, there’s no effective biological or chemical method to control bacterial wilt. Our project team studied peanut intercropping cultivation theory and found that though the mechanism was not clear, peanut intercropping with gramineae did reduce the incidence of peanut bacterial wilt. This project explores the reasons of reducing peanut bacterial wilt from the angle of soil microbe, which is a key indicator for the health conditions of soil. The incidence of peanut bacterial wilt and dynamic changes of soil pathogen number will be investigated in different intercropping treatments. Changes in the genetic and ecological function of soil microbial species of corn/peanut and sugarcane/peanut intercropping will be observed using plate cultivation method, gradient gel electrophoresis of (DGGE),high-throughput sequencing of 16S rDNA and BOILOG system in order to analyze the correlation between soil microorganisms and bacterial wilt as well as soil microorganisms and soil pathogens, identify major microbial species and micro ecological factors influencing peanut bacterial wilt and reveal the interaction mechanism of microbe-pathogen, micro ecology-pathogen, and microbe-bacterial wilt. In addition, through screening antagonistic bacteria in the rhizosphere soil, the microbial strain inhibiting bacterial wilt will be determined. The completion of the project will provide theoretical references for controlling soil borne diseases by regulating microbial changes under intercropping conditions, and it also will provide microbial materials for biological control technology of peanut bacterial wilt.

花生青枯病是一种毁灭性土传病害，目前仍没有较好的生物、化学防治方法。前期研究发现，花生/禾本科间作可减少花生青枯病害，其机理尚不清楚。本项目拟从衡量土壤健康状况的微生物角度出发，探索间作减轻花生青枯病的原因。通过调查不同间作条件下花生青枯病的发生情况及土壤病原菌数量的动态变化，采用平板培养、16S高通量测序、DGGE、BIOLOG系统等方法研究玉米/花生、甘蔗/花生间作土壤微生物种类、遗传基因及生态功能的变化，分析间作土壤微生物与青枯病、土壤病原菌的相关性，明确影响间作花生青枯病的主要微生物类群及微生态因子，揭示土壤微生物—病原菌、微生态—病原菌、微生物—青枯病的互作机制。另外，在间作根际土壤中筛选青枯病拮抗菌，并通过形态特征和分子鉴定，明确间作土壤中能抑制花生青枯病的有益微生物菌属。项目的完成可为间作土壤微生物变化控制土传病害发生提供理论依据，并为青枯病的生物防治技术提供微生物材料。

花生青枯病是一种毁灭性土传病害，目前仍没有较好的生物、化学防治方法。前期研究发现，花生/禾本科间作可减少花生青枯病害，其机理尚不清楚。本项目通过甘蔗/花生、玉米/花生间作条件下花生青枯病的发生情况及土壤病原菌数量的动态变化，研究间作土壤微生物种类、遗传基因及生态功能的变化，分析间作土壤微生物与青枯病、土壤病原菌的相关性。结果表明，甘蔗/花生、玉米/花生间作可在不同程度上减轻花生青枯病的发生，间作对感病品种的控青枯病效果优于抗病品种，间作花生结荚期对花生青枯病的控病效果优于花生苗期、花针期及饱果期；随着间作年限的延长，土壤中的青枯病原菌数量和青枯病发生逐渐降低。间作土壤微生物杆菌门（Acidobacteria）、芽孢杆菌属（Gemmatirosa）、绿弯菌门（Chloroflexi）的相对丰度增加，并与土壤青枯病原菌呈显著负相关，表明这些微生物门和属是影响土壤青枯病原菌及青枯病发生的主要类群。此外，土壤微生物生态因子中的放线菌、真菌数量及过氧化氢酶、蔗糖酶活性对青枯病原菌影响显著。在间作根际土壤中筛选并鉴定出抑制青枯病原菌生长的拮抗菌株为Pseudomonas和Bacillus。以上研究揭示了土壤微生物—病原菌、微生态—病原菌、拮抗菌—病原菌的互作机制，为间作土壤微生物变化控制土传病害发生提供了理论依据，并为青枯病的生物防治技术提供可供参考的微生物材料。