Biocontrol bacteria strain preventing and curing plant disease

Abstract

The invention provides a biocontrol bacterial strain for preventing and treating plant diseases and its bacterial agent, belonging to the field of biological control. The strains used are Gram-negative bacteria, identified as Lysobacter enzymogenes, and the strain code is OH11. Strain OH11 has no flagella but has slippage, can produce various extracellular hydrolytic enzymes including chitinase, β-1,3-glucanase and protease, and can effectively inhibit the growth of fungi and bacteria. The antibacterial zone diameters of strain OH11 against Sclerotinia sclerotiorum and Phytophthora capsici were both greater than 22.0 mm; the antagonism against potato ring rot was stronger, and the diameter of the inhibition zone reached 50 mm. The OH11 strain was inoculated into the seed tank, cultivated to the logarithmic growth phase, and the seed liquid was connected to the production tank for cultivation. The medium used in the production tank was the same as that of the seed tank. The liquid fermentation adopts aerobic submerged fermentation and fed-batch process, the dissolved oxygen is 15%-20%, the fermentation temperature is 30°C, the fermentation time is 72h, and the initial pH value is 7.5. After the fermentation is completed, the culture solution is taken out of the tank and directly packed into liquid dosage forms with plastic packaging barrels or packaging bottles, or subpackaged into solid dosage forms with peat adsorption packaging bags. The biocontrol strain OH11 can effectively control plant pathogenic fungi, bacteria, nematodes and other diseases, and the overall control effect is 50%-70%. In the greenhouse pot experiment, the control effects of OH11 on pepper blight and tomato bacterial wilt reached 83.6% and 86.4%, respectively. Strain OH11 has the characteristics of broad antibacterial spectrum, high activity, and environmental safety. In today's serious pesticide pollution, zymolysobacterium and its bacterial agent will be a good substitute.

Description

1. Technical field [0001] The invention provides a biocontrol bacterial strain for preventing and treating plant diseases and its bacterial agent, and the obtained biological agent and its method belong to the field of biological control. The biocontrol bacterial strain and its agent provide a new high-efficiency biopesticide for the biological control of plant diseases and are a good substitute for chemical pesticides. 2. Technical Background [0002] Plant diseases have always been a serious threat to agricultural production. The prevention and control of plant diseases by humans can be traced back to thousands of years ago. Most of the agents used in the past were botanical or inorganic chemical pesticides. In the early 1940s, organic synthetic pesticides were widely used. Although they played an important role in ensuring the stability and high yield of crops, due to the shortcomings of chemical pesticides and long-term unreasonable use, some serious problems gradually e...

AI Technical Summary

Problems solved by technology

In the early 1940s, organic synthetic pesticides were widely used. Although they played an important role in ensuring the stability and high yield of crops, due to the shortcomings of chemical pesticides and long-term unreasonable use, some serious problems gradually emerged, such as drug resistance, Pesticide residues and pests and diseases are rampant again, that is, 3R issues (Resistance, Residue, Resurgence)

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