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Sclerotinia sclerotiorum infection caused by Sclerotinia (Sclerotinia Sclerotiorum (Lib) de Bary), is one of the major diseases of rapeseed. Rapeseed after Sclerotinia infection can lead directly to a decrease of 5% -30%, the oil content of 1% to 5% lower. China's annual incidence area of ??about 4.7 million ha, with direct economic losses amounting to several hundred million dollars. Pollution of the environment due to the prevention of chemical pesticides, residues in the food chain, anti-efficiency low pathogen prone to resistance and other problems, and find effective biological pesticides become antagonistic Sclerotinia hotspot. Bacillus velezensis DM09 material and its antifungal physical and chemical properties of the active substance, DM09 colonization of the rape plant induced resistance as well as research on the prevention and control of Sclerotinia sclerotiorum role. Isolated from the deep sea of ??Bacillus velezensis DM09 by MB medium activation, PD liquid medium after fermentation, the fermentation filtrate having a wide range of anti-fungal capability. DM09 produced the antifungal activity of crude extract was stored at 4 ℃ 60 D, 100 ° C for 30 min, and its anti-fungal activity unchanged; not sensitive to proteinase K and trypsin; within the range of pH 7-10, more good activity; not sensitive to ultraviolet. Detached leaf experiments, the Rape, Rape Sclerotinia mycelium growth DM09 ferment filtrate can control, and can effectively reduce the incidence of anti efficiency up to 92.51%; the DM09 live bacteria Rape Sclerotinia's antagonism is not obvious, in less than 25% of the control efficiency; quite effective prevention and fermentation filtrate fermentation bacterial suspension. DM09 by IRRIGATING vaccination in the rapeseed stems and leaves stable colonization. 1 × 105 CFU / mL spore suspension for optimal concentration of vaccination. 20 d after inoculation, the number of bacteria in the body (7.1 ± 0.30) × 103CFU / g fresh plants, 50 d (5.16 ± 0.61) × 103CFU / g fresh plant. DM09 by foliar spray bacteria can in the rapeseed stems and leaf colonization, colonization quantity of with IRRIGATING inoculation method. DM09 very few rape root colonization. DM09 after the colonization of the rape plant, can enhance the Rape Sclerotinia resistance. Specific performance significantly inhibited the mycelial growth of Sclerotinia control efficiency of 54.58%. Rape inoculated DM09 or DM09 fermentation supernatant after treatment, and then inoculated S. sclerotiorum, compared with the blank group, morbidity and plaque area significantly reduced, and the POD (peroxidase), PPO (polyphenol oxidase) enzyme activity of Compared with the control group, have significantly improved. Induced systemic resistance (ISR) is one of the DM09 mechanism to control Sclerotinia Sclerotinia.
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