The Screening And Preliminary Studies On Antiviral Activity Ingredients Of A Bacterium With Antiviral Activity Against TMV

Tobacco mosaic virus (Tobacco mosaic virus, TMV) is one of the common plant diseases in our county, it seriously affects the yield and quality of tobacco.Currently, The control method of chemical pesticides not only control effects was not significant but also endanger the environment and human health. To ensure the sustainability of agricultural production, iocontrol TMV has become the central issue, The features of biological pesticides such as:side variety of sources, high compatibility with the environment, harmless to humans and animals, are favored from the researcher. Therefore, the development of the safely and efficiently biological pesticides is a key factor to achieve the biological control.In this study, TMV as the target, to screen the effective ingredients against the TMV as the purpose, The research of the bacteria isolated and purified, the screen of the activestrains against TMV, classification and identification of the antagonistic strains, the best optimization of fermentation conditions of the strains against TMV, the Separating of the active substance and stability analysis.The results are as follows:(1) With dilution method, were isolated and purified tobacco rhizosphere bacteria64strains obtained.(2) Through the local lesion, screened bacteria has obvious antagonistic activity to TMV,it numbers for Z5.The greenhouse antagonistic test shows:inhibition of strain Z5fermentation liquid on the TMV rate of more than96%, and with the effect of TMV showed the obvious passivation; the field efficacy test showed that:Z5of fermentation liquid on the preventive effect of TMV reached52.01%, East Wang antivirus control effect reached56.79%, compared with the water, a control effect of Z5fermented liquid and Dong Wang antivirus protection, has good.(3)Using morphologic observation, physiological and biochemical characteristics test,16S rDNA fragments amplified by sequencing and phylogenetic analysis, Bio log automatic microbial analysis method for screening, Screening of the strains as Z5was classified and identified. The results showed that, the strain was identified as bacillus, and the NCBI accession number is KC255378recently Bacillus amyloliquefaciens Bacillus amyloliquefaciens relationship,99%homology detection, Biolog the detect of Z5with Bacillus amyloliquefaciens B have the similarity of0.543. Based on the test results, the strain Z5was identified as B. amyloliquefaciens.(4) Culture from the different culture medium, temperature, pH, fermentation time, bottling capacity five factors on the fermentation conditions of strain Z5optimization. Results showed that the most suitable medium, the strain of anti TMV active substances produced by the NB; the optimum culture temperature was32℃; it had the best antiviral effect as its pH; culture time64h; group training for60mL/100mL bottling quantity.(5) Preliminary separated strains it fermented liquid resistance to TMV effective substances and study the material in different temperature, pH, proteinase K, and the stability of trypsin treatment。 The results show that the material for protein in the fermented liquid antagonism, the TMV inhibitory rate of87.21%, far more than to the protein solution This material is sensitive to temperature,100℃after30min, the inhibitory rate was only16.67%, the inhibitory effect is low; in the pH is between5.0-11.0, the inhibition rate fluctuation is not obvious, when the pH is about7of the best inhibitory effect, and the alkaline environment is acidic environment stability; it is not sensitive to proteinase K and trypsin enzyme, after protease treatment, its inhibitory effect changes little.