广谱拮抗菌暹罗芽孢杆菌N-1抑制几种热带水果采后病害的生理与分子机制

热带果蔬产区气温高湿度大，果实采后病害严重。虽然拮抗菌是采后病害生物防治中最重要的方法之一，但其抑菌谱窄、防效低成为限制生防菌应用和推广的瓶颈。项目组前期从海南莲雾果园土壤中分离得到一株暹罗芽孢杆菌（N-1），发现其对多种热带水果采后病害具有高效的抑制作用。目前国内外对于广谱拮抗菌抑病的机制还缺乏深入的研究。因此，本项目选择几种代表性的热带水果--芒果、荔枝和莲雾，以其主要采后病害芒果炭疽病、荔枝褐斑病和莲雾软腐病为研究对象，研究离体和活体条件下拮抗菌N-1对几种病原菌生长的抑制作用，探讨拮抗菌N-1对果实贮藏品质的影响及其对寄主的诱导抗病能力，进而研究确定其广谱抑菌的关键基因及表达水平的变化，以期全面揭示拮抗菌N-1广谱抑病的生理与分子机制。研究结果不仅能为高效控制热带水果采后病害提供理论依据，也能为推广应用广谱拮抗菌、促进热带果品产业的健康发展提供技术支撑。

Because of the high temperature and humidity in tropical fruits producing areas, the postharvest diseases of fruits are very serious. Although the use of antagonistic strain is one of the most important biological control methods, narrow antibacterial spectrum and low control effect of antagonistic strain are becoming bottlenecks of application and promotion of biocontrol technology. Previously, we screened and obtained a strain of Bacillus siamese N-1 from the soil of wax apple garden, and the higher inhibitory effects of N-1 on pathogens of a variety of tropical fruits were found. At present, the mechanism of broad-spectrum antagonists inhibiting pathogens is still lack of in-depth study. Therefore, in this project, the representative postharvest diseases of tropical fruits were selected as the research objects, including mango anthracnose, litchi brown spot and wax apple soft rot, the inhibition of antagonistic N-1 on the growth of several pathogens will be studied in vitro and in vivo, and the effects of antagonistic N-1 on the storage quality of fruit and the induced resistance of host to disease will be explored. Moreover, the key genes and it’s changes in expression level of antagonistic N-1 inhibiting pathogens with broad-spectrum will be confirmed. Subsequently, the physiological and molecular mechanisms of broad-spectrum antagonistic N-1 inhibiting postharvest diseases will be systematically elucidated. The findings of this project will not only provide a theoretical foundation for controlling effectively and safely the postharvest diseases of tropical fruits, but also provide a strong technical support for the application of broad-spectrum antagonistic strain, and for accelerating development of tropical fruit industry.