The Bacteriostasis Of Secondary Metabolites Of Pathogenic Bacteria Xenorhabdus Bovienii SN84 On Three Kinds Of Plant Pathogenic Fungus

With the continuous development of human society and people's quality of life,the living environment of the requirements are also increasing,although the various requirements of mankind to promote the development of science and technology,but it also brings a lot of environmental problems.In agricultural production,chemical pesticide is the most effective pest control methods,due to the deterioration of the environment and the people's increasing awareness of environmental protection,instead of looking for alternatives to chemical pesticides has become a hot topic.Because of its low residue,low toxicity,not easy to produce drug resistance,strong selectivity and other advantages,bio pesticide has become the focus of research in the world.Agricultural antibiotics mainly refers to the microbial pesticides in biological pesticides,currently in the field of insecticidal and bactericidal has achieved remarkable control effect,has become the focus of today's research.In this experiment,isolated strains of entomopathogenic nematode symbiotic bacteria Xenorhabdus bovienii SN84 in soil,the growth of the secondary metabolites of the strain can effectively inhibit Botrytis cinerea,Phytophthora capsici and Phytophthora sojae.Determination of inhibition effect of 7 kinds of pure compounds and separation of pathogenic bacteria Xenorhabdus bovienii SN84 fermentation,crude extract of Botrytis cinerea,Phytophthora sojae and three kinds of plant pathogenic fungi by experiment,and on Tomato Seedling bioassay was carried out using Xenorhabdus bovienii SN84 fermentation liquid of pathogenic bacteria,in order to get a strains can inhibit plant pathogenic fungi of new agricultural antibiotics or its leading active product strains,so as to solve the possible target of three strains with antibiotics varieties of safe and efficient production in short.The main research results are as follows:Determination of inhibitory effect of fermentation liquid of Xenorhabdus bovienii SN84 coli pathogenic strain of some three plant pathogenic fungi showed that the inhibitory effect of Xenorhabdus bovienii SN84 strain sterile fermentation broth was three kinds of target pathogens were.When the concentration of Xenorhabdus bovienii SN84 fermentation filtrate reached 2%,inhibition of Botrytis cinerea mycelial growth can reach nearly 50%;when the concentration of Xenorhabdus bovienii SN84 fermentation filtrate reached 0.6%,inhibition of Phytophthora capsici and Phytophthora sojae mycelial growth can reach nearly 50%.Determination of Xenorhabdus bovienii SN84 coli pathogenic strain fermentation crude extracts of some three plant pathogenic fungi showed that the inhibitory effects of A,B,C and D four components,only B component has a bacteriostatic effect,and the inhibitory effect of Botrytis cinerea in addition to the best inhibitory effect of two kinds of plant pathogens fungi are poor,solid to Botrytis cinerea as the key research test next,and to explore the causes of antibacterial effect was decreased in the fermentation liquid.Determination of fermentation products from Xenorhabdus bovienii SN84 coli pathogenic strains were isolated from 7 kinds of pure compounds have inhibitory effect on Botrytis cinerea spore germination,the results showed that only the strongest inhibitory effect of C2-2 on Botrytis cinerea spore germination,and the duration of the most lasting,if it were more in-depth research,is expected to be a strain on the tomato Botrytis cinerea inhibited the biological pesticide active or lead compounds.The inhibitory effect of fermentation broth of Bacillus sp.Xenorhabdus bovienii SN84 on tomato gray mold was determined,and the protective effect of fermentation broth of this strain on tomato seedlings was detected.The results showed that with the increase of the amount of fermented liquid,the incidence of Botrytis cinerea decreased gradually.When the concentration of Xenorhabdus bovienii SN84 was 8%,it was effective to prevent tomato gray mold.The results showed that the further study of Xenorhabdus bovienii SN84 strain as a biological pesticide or its leading compounds.