Method for screening and identifying melon fusarium wilt resisting activity product in Fosmid library

Abstract

The invention belongs to the technical field of prevention and treatment of melon fusarium wilt and discloses a method for screening and identifying a melon fusarium wilt resisting activity product in a Fosmid library. The method comprises steps as follows: soil microorganism genome DNA is extracted with an ectopic pyrolysis method; metagenome Fosmid library construction and quality detection are performed; a metagenome Fosmid expression library is screened, and Fosmid activity clone is obtained; a fermentation broth is extracted, and a relatively pure activity layer is obtained; purified melon fusarium wilt resisting activity substances are obtained; an atlas is analyzed, an activity substance structure is determined, and the melon fusarium wilt resisting activity of a compound is verified; endogenous strains of plants are screened and modified, genes are transferred to the modified endogenous strains, and an efficient expression system of melon fusarium wilt resisting drug genes is established by selecting different promoters, different media and fermentation conditions. The bottleneck that conventional biocontrol fungus cannot be subjected to field planting is broken through, and the research, development and commercialization process of new drugs for resisting melon fusarium wilt is greatly accelerated.

Description

technical field [0001] The invention belongs to the technical field of melon wilt prevention and control, and in particular relates to a screening and identification method for anti-cucurbit fusarium wilt active products of a Fosmid library. Background technique [0002] Fusarium wilt of melon, also known as vine cutting disease and wilt disease, is one of the main soil-borne diseases in melon production, especially the most serious damage to watermelon, cucumber and muskmelon. The disease has spread to dozens of countries and regions such as China, the United States, Italy, Israel, Japan, and India, and occurs to varying degrees in the watermelon growing areas in the north and south of my country. Especially in the southern tropical and subtropical regions, the rainfall is abundant, the climate is mild, and the pathogenic bacteria do not overwinter, resulting in a large accumulation of spores of the pathogenic bacteria in the soil, and the incidence of diseases is extremely...

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Problems solved by technology

[0003] In summary, the problem in the prior art is that the fungi (Trichoderma fungus), bacteria (Pseudomonas, etc.) On the basis of purification and culture, the vast majority of non-cultivable microorganisms are ignored, especially those in extreme environments such as tropical rainforests. The more extreme the environment, the more likely it is to obtain enzymes and other active substances with special properties, and the corresponding Microbes are harder to grow

Greatly limited the breadth and depth of development, ignoring the development and utilization of new non-culture sources of microbial active substances; in addition, the screened live bacteria are based on laboratory confrontation culture, once used in greenhouses and fields , due to the influence of complex environmental conditions, the control effect is not obvious, or even has no effect, so it cannot be developed into a commercial biological control agent and applied to the actual production in the field

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