草莓连作自毒障碍因子的产生机理及其降解菌的筛选

Strawberry is a kind of important economic crop in the city of Yichun, Jiangxi province. Continuous cropping obstacle is a serious constraint to strawberry crop. Strawberry planted in the city of Yichun is used as the research object in this study. In order to reveal the strawberry continuous cropping obstacle factors and the mechanism, some experiment methods are used, such as experiment simulation by means of tissue culture and Continuous cropping test by combining field with plot experiments. We plan to isolate and identify the main phenolic acids allelochemicals secreted by strawberry, then study their interaction and the effect on strawberry red column root rot pathogen infection. At the same time, for strawberry red column root rot pathogen, we study its effect on strawberry secondary metabolic toxin accumulation and secretion during strawberry red column root rot pathogen infect and its response to auto-toxic effect of the continuous cropping strawberry. On this basis, through the domestication of continuous cropping and inducing mutation of toxic phenolic acid, to screen efficient degradation bacteria for strawberry auto-toxic matters, overcome the harm from the continuous cropping obstacles, and provide theoretical and technical basis for bioremediation. It will be a great theoretical significance and practical significance for promoting the sustainable development of the strawberry industry.

连作障碍已成为草莓种植业的重要制约因素。本项目以宜春市区域草莓种植为研究对象，采用组织培养实验模拟、大田露地试验结合盆栽重茬试验的方法，对草莓分泌的主要酚酸类化感物质进行分离鉴定，研究酚酸化感自毒物质及其交互作用对草莓红中柱根腐病病菌侵染的影响，探究草莓红中柱根腐病病菌侵染刺激草莓次生代谢毒素积累、分泌及其对连作草莓自毒的响应机制，揭示草莓连作自毒障碍因子的发生机理。在此基础上，通过连作驯化、酚酸毒物诱导变异的方法，筛选草莓自毒物质的有效降解菌，为克服草莓连作障碍危害和生物修复提供理论和技术依据。这对草莓种植业的可持续发展具有重要的理论和实践意义。

连作障碍已成为制约草莓种植业的关键因素之一。本项目依据酚酸类化感毒物诱发草莓连作障碍的原理，采用实验根际模拟、盆栽重茬结合大田试验方法，① 研究分离鉴定出诱发草莓连作障碍的主要酚酸类化感毒物，包括对羟基苯甲酸、香草酸、丁香酸、4-香豆酸、阿魏酸、肉桂酸6种主要酚酸致毒物在内的10种重茬草莓酚酸化感毒物，并筛选鉴定出能有效降解苯甲酸的枯草芽胞杆菌Bacillus subtilis，丁香酸化感毒物降解菌株降解菌FS3652，香豆酸降解菌株DXDS515在内的50多株酚酸降解菌株，并验证了Bacillus subtilis、FS3652对草莓根腐毁灭性病原的生防功能，为草莓重茬酚酸化感毒物降解及根腐病病害控制打下坚实的菌株资源和基础；② 研究得出酚酸化感毒物积累叠加草莓重茬次生盐渍化致害是诱发草莓连作障碍的关键启动因子，结果导致土壤碳氮代谢相关酶活受抑，重茬草莓土壤呈典型由有利于病害控制的细菌型向不利于病害控制的真菌型转化，微生物种群呈单一化转化趋势明显，结果导致土壤微生态结构失衡，连作病害爆发，草莓枯萎死亡，造成恶性循环；③腐殖质改土及化肥施用的条件下，进一步重施有机肥、生物炭及其配施的处理并没有进一步协同改善重茬草莓根际细菌、真菌微生物结构效应，并进一步加重了酚酸化感毒物积累叠加草莓重茬次生盐渍化的重茬草莓土壤障碍作用。④系统研究表明采用腐殖质改土结合适度化肥施用可以有效消除重茬草莓土壤的盐渍化养分障碍，稳定重茬草莓土壤酶的活性，协调改善土壤细菌微生物结构作用；有机质改土条件下控释肥施用配合诱抗免疫措施既消减盐渍化障碍又降低重茬草莓酚酸积累，并在大田试验示范尺度上达到90%以上的重茬草莓病害免疫，具有消减草莓重茬障碍重要作用。