Cyperus esculentus root extract and application thereof as plant antibacterial substance

Abstract

The invention is applicable to the technical field of biopesticides, and provides a cyperus esculentus root extract and application thereof as a plant antibacterial substance, the cyperus esculentus root extract is a dichloromethane-methanol extract, and the concentration of the dichloromethane-methanol extract during use is 2-4 mg / mL. When the use concentration of the dichloromethane-methanol extract is 4 mg / mL, the inhibition ratios of the dichloromethane-methanol extract to watermelon gummy stem blight, soybean sclerotinia sclerotiorum, codonopsis pilosula botrytis cinerea and corn northern leaf blight are 51.39%, 71.50%, 70.00% and 39.76% respectively. The cyperus esculentus root extract is used as an effective component of a plant antibacterial substance, is a plant-derived biopesticide, belongs to the field of biological medicines, not only meets the requirements of modern society on safety and environmental protection of new pesticides, but also has the characteristics of high antibacterial activity, wide antibacterial spectrum, difficulty in generating resistance and no toxicity to human and animals, and has a broad application prospect. Therefore, the safety of crops is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of biological pesticides, and in particular relates to a cyperus oleifera root extract and application thereof as a plant antibacterial substance. Background Art

[0002] A variety of diseases that seriously endanger crop quality and yield, such as vine blight, sclerotinia, gray mold and large spot disease, are not only difficulties that must be solved in my country's crop production, but also a problem faced by global crop production. In agricultural production, the commonly used prevention and control method is chemical control using chemical pesticides, but chemical control has the risk of causing resistance of pathogens, residual pollution and rampant diseases. Using multiple methods alternately to coordinate comprehensive prevention and control is the development direction of preventing fungal toxin pollution and a way to avoid risks. Therefore, finding other ways and methods of non-chemical pesticides is an important task for industrial development and an important topic of scientific research. Exploring plant-based methods from plants, including developing plant-based pesticides, finding lead compounds from plant-based compounds, and directly using plant extracts, is an important part of this development direction.

[0003] Cyperus esculentus L., also known as oil cyperus and tiger fruit, belongs to the angiosperms, monocots, sedges, sedge family, and sedge genus. Cyperus plants are widely distributed around the world, with more than 5,500 species, and there are about 30 species in my country, of which only Cyperus esculentus is edible. Cyperus esculentus is a grass above ground and a bean underground. Because it is rich in oil and has a high oil yield, it is regarded as a reserve plant for future oil crops in my country. In addition, Cyperus esculentus also contains many chemical components that are beneficial to the human body, such as amino acids, peptides, proteins, volatile oils, phenols, organic acids, alkaloids, terpenes, anthraquinones, steroids, coumarins, saponins, cardiac glycosides and flavonoids, etc. Therefore, it has been used as a new beverage raw material and widely circulated in many European countries. Not only that, the rich sugar content of Cyperus esculentus can also be used for sugar making and winemaking, showing extremely high economic value. In addition to its edible and processing functions, studies have shown that the above-ground part of Cyperus oleiferus has antibacterial, antioxidant and preventive effects on some human diseases. Many years ago, there were records of using Cyperus oleiferus as a material for treating diseases, but there were no reports or studies on its application as a biological pesticide in disease prevention and control. For this reason, the present invention provides a Cyperus oleiferus root extract and its application as a plant antibacterial. Summary of the invention

[0004] The object of the present invention is to provide a cyperus oleifera root extract and its application as a plant antibacterial agent, aiming to solve the problems raised in the above background technology.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A cyperus oleifera root extract, the cyperus oleifera root extract is a dichloromethane-methanol extract, and the dichloromethane-methanol extract is extracted by the following method: weighing 100g of plant dry powder, soaking the plant dry powder with 4 times the amount of dichloromethane-methanol, and standing at room temperature for 24 hours; then performing ultrasonic extraction for 0.5 hours; then performing vacuum filtration, and extracting continuously for 3 times; combining the filtrates obtained each time, concentrating the combined filtrates with a rotary evaporator at 45°C, and after drying, storing the extract at 4°C for standby use.

[0007] Furthermore, the dichloromethane-methanol is prepared by mixing dichloromethane and methanol in a volume ratio of 1:1.

[0008] Furthermore, the concentration of the dichloromethane-methanol extract when used is 2-4 mg / mL.

[0009] An application of the Cyperus oleifera root extract as a plant antibacterial agent, wherein the Cyperus oleifera root extract, i.e., dichloromethane-methanol extract, has significant antibacterial activity against Citronella solani, Sclerotinia sclerotiorum, Codonopsis pilosula, and Geotrichum maydis.

[0010] Furthermore, when the concentration of the dichloromethane-methanol extract was 2 mg / mL, the inhibition rates of watermelon vine blight, soybean sclerotinia, Codonopsis pilosula, and corn sclerotinia were 26.14%, 32.94%, 43.04%, and 29.61%, respectively; when the concentration of the dichloromethane-methanol extract was 4 mg / mL, the inhibition rates of watermelon vine blight, soybean sclerotinia, Codonopsis pilosula, and corn sclerotinia were 51.39%, 71.50%, 70.00%, and 39.76%, respectively.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The cyperus oleifera root extract disclosed by the present invention is an effective ingredient of plant antibacterial substances and is a plant-derived biological pesticide belonging to the category of biological medicines. It not only meets the safety and environmental protection requirements of modern society for new pesticides, but also has the characteristics of high antibacterial activity, broad antibacterial spectrum, low resistance and non-toxicity to humans and animals, thereby effectively improving the safety of crops. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The results show the inhibition of dichloromethane-methanol extract at different concentrations against watermelon sclerotinia, soybean sclerotinia, Codonopsis pilosula and corn leaf blight. DETAILED DESCRIPTION

[0014] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of the present invention. The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials can be obtained from commercial sources unless otherwise specified.

[0015] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0016] Example 1, preparation of dichloromethane-methanol extract (i.e., Cyperus oleifera root extract);

[0017] The cyperus oleiferus of the present invention is purchased from the cyperus oleiferus cultivation base in Nong'an County, Changchun City, Jilin Province. The reserve material is dried in the sun, crushed, and stored in a ventilated and dry place for standby use. 100 g of the crushed sample is weighed, and the crushed sample is soaked in 4 times the amount of dichloromethane-methanol (dichloromethane and methanol are mixed in a volume ratio of 1:1), and the crushed sample is left standing at room temperature for 24 hours; ultrasonic extraction is performed for 0.5 hours; vacuum filtration is performed, and the extraction is performed continuously for 3 times, and the filtrate obtained each time is combined; the extract is concentrated at 45° C. with a rotary evaporator, and after drying, the extract is stored at 4° C. for standby use.

[0018] Example 2, antibacterial effect of dichloromethane-methanol extract;

[0019] Regarding the antibacterial effect of dichloromethane-methanol extract, the mycelium growth rate method was used to determine the antibacterial activity of dichloromethane-methanol extract against Stagonosporopsis spp., Sclerotiniasclerotiorum, Botrytis cinerea Pers. and Exseiohilum turcicum. The specific experimental steps are as follows:

[0020] First, the frozen bacteria were revived at room temperature, and a small amount of colonies were picked up with an inoculation needle and placed in the center of a culture dish containing PDA culture medium. The culture dish was sealed and inverted in an incubator with a temperature of 25°C and a humidity of 73% without light.

[0021] Next, a certain amount of dichloromethane-methanol extract was weighed and prepared into 40 mg / mL, 30 mg / mL, and 20 mg / mL solutions with sterile water. At the same time, sterile water was set as a blank control, and 40 μg / mL of thiophanate-methyl was set as a positive control. In a sterile clean bench, the prepared solution was mixed with PDA culture medium at a ratio of 1:9, so that the concentration of the drug-containing culture medium reached 4 mg / mL, 3 mg / mL, and 2 mg / mL, respectively, and then the culture medium was poured into a culture dish with a diameter of 60 mm and left to solidify.

[0022] After the strain was activated, a sterile puncher (Φ=5 mm) was used to evenly punch holes in the vigorous mycelial growth area to obtain a bacterial cake, which was inoculated onto the drug-containing culture medium. A bacterial cake was placed in the center of each culture dish. After inverted culture in an incubator at a temperature of 25°C and a humidity of 73% for 3-14 days, the colony diameter was measured by the cross method and the inhibition rate was calculated. Three replicates were set for each treatment.

[0023] The experimental results showed that the root extract of Cyperus oleifera showed different degrees of antibacterial effect on four pathogenic fungi. When the concentration of dichloromethane-methanol extract was 2 mg / mL, the inhibition rates of watermelon vine blight, soybean sclerotinia, Codonopsis pilosula, and corn leaf blight were 26.14%, 32.94%, 43.04%, and 29.61%, respectively. When the concentration of dichloromethane-methanol extract was 4 mg / mL, the inhibition rates of watermelon vine blight, soybean sclerotinia, Codonopsis pilosula, and corn leaf blight were 51.39%, 71.50%, 70.00%, and 39.76%, respectively. The inhibition rates of the positive control (chlorothalonil) on watermelon sclerotinia, soybean sclerotinia, Codonopsis pilosula and corn leaf blight were 31.63%, 24.29%, 74.35% and 30.77%, respectively. Except for Codonopsis pilosula, the methylene chloride-methanol extract had a better inhibitory effect on the other three bacteria (such as Figure 1 shown).

[0024] The above are only preferred embodiments of the present invention. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These should also be regarded as the protection scope of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A Cyperus oleifera root extract, characterized in that The cyperus oleifera root extract is a dichloromethane-methanol extract, and the extraction method of the dichloromethane-methanol extract is as follows: weigh 100g of plant dry powder, soak the plant dry powder with 4 times the amount of dichloromethane-methanol, and stand at room temperature for 24 hours; then perform ultrasonic extraction for 0.5 hours; then perform vacuum filtration, and extract continuously for 3 times; combine the filtrates obtained each time, concentrate the combined filtrates with a rotary evaporator at 45°C, and after drying, store the extract at 4°C for standby use.

2. The Cyperus oleifera root extract according to claim 1, characterized in that The dichloromethane-methanol is prepared by mixing dichloromethane and methanol in a volume ratio of 1:

1.

3. The Cyperus oleifera root extract according to claim 1, characterized in that The concentration of the dichloromethane-methanol extract when used is 2-4 mg / mL.

4. A use of the Cyperus oleifera root extract according to any one of claims 1 to 3 as a plant antibacterial agent, characterized in that: The cyperus oleifera root extract, namely the dichloromethane-methanol extract, has significant antibacterial activity against watermelon spore blight, soybean sclerotinia, codonopsis pilosula and corn leaf blight.

5. The use of the Cyperus oleifera root extract as a plant antibacterial agent according to claim 4, characterized in that: When the concentration of the dichloromethane-methanol extract is 2 mg / mL, the inhibition rates of watermelon vine blight, soybean sclerotinia, Codonopsis pilosula and corn leaf blight are 26.14%, 32.94%, 43.04% and 29.61% respectively; when the concentration of the dichloromethane-methanol extract is 4 mg / mL, the inhibition rates of watermelon vine blight, soybean sclerotinia, Codonopsis pilosula and corn leaf blight are 51.39%, 71.50%, 70.00% and 39.76% respectively.

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