A cyperus oleifera root extract and its application as a plant antibacterial

Abstract

The present invention is applicable to the field of biopesticide technology and provides a cyperus root extract and its application as a plant antibacterial agent. The cyperus root extract is a dichloromethane-methanol extract, and the concentration of the dichloromethane-methanol extract when used is 2 to 4 mg / mL. When the dichloromethane-methanol extract is used at a concentration of 4 mg / mL, the inhibition rates of watermelon vine blight, soybean sclerotinia, codonopsis gray mold, and corn leaf spot are 51.39%, 71.50%, 70.00%, and 39.76%, respectively. The cyperus root extract of the present invention is an active ingredient of a plant antibacterial agent and is a plant-derived biopesticide belonging to the category of biopharmaceuticals. 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.

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 its application as a plant antibacterial compound. Background Art

[0002] A variety of diseases that seriously endanger crop quality and yield, such as vine blight, sclerotinia, gray mold and large leaf spot, are not only difficulties that must be addressed in my country's crop production, but also challenges faced by global crop production. In agricultural production, the commonly used prevention and control method is chemical control using chemical pesticides, but chemical control carries the risk of causing resistance in pathogens, residual contamination and resurgence of diseases. Using multiple methods in alternating coordination for comprehensive prevention and control is the development direction for preventing fungal toxin contamination 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 for scientific research. Exploring botanical methods from plants, including developing botanical pesticides, finding lead compounds from botanical 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 phylum Angiosperms, class Monocots, order Cyperales, family Cyperaceae, and genus Cyperus. Cyperus plants are widely distributed worldwide, with more than 5,500 species, of which there are approximately 30 species in my country, of which only Cyperus esculentus is edible. Cyperus esculentus is a grass above ground and a bean below ground. Because it is rich in oil and has a high oil yield, it is considered a potential future oil crop in my country. In addition, Cyperus esculentus 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. Therefore, it has been widely circulated as a new beverage ingredient in many European countries. In addition, the rich sugar content of Cyperus esculentus can also be used for sugar production and winemaking, showing extremely high economic value. In addition to its edible and processing uses, research has shown that its aerial part, Cyperus truncatus, also has antibacterial and antioxidant properties, as well as preventive effects on certain human diseases. While the use of Cyperus truncatus as a therapeutic material has been documented for many years, its application as a biopesticide for disease control has not been reported or studied. Therefore, the present invention provides a Cyperus truncatus root extract and its use as a plant antimicrobial. Summary of the Invention

[0004] The present invention aims 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 is a dichloromethane-methanol extract. The dichloromethane-methanol extract is extracted by the following method: weighing 100 g 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 three times in succession; combining the filtrates obtained each time, concentrating the combined filtrates using a rotary evaporator at 45°C, drying, and storing the extract at 4°C for future 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 during use is 2-4 mg / mL.

[0009] A use of the above-mentioned Cyperus rotundus root extract as a plant antibacterial agent, wherein the Cyperus rotundus root extract, i.e., dichloromethane-methanol extract, has significant antibacterial activity against Citronella citronellosis, Sclerotinia sclerotiorum, Codonopsis pilosula, and Geotrichum maydis.

[0010] Furthermore, when the concentration of the dichloromethane-methanol extract was 2 mg / mL, the inhibition rates against watermelon vine blight, soybean sclerotinia, Codonopsis gray mold 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 against watermelon vine blight, soybean sclerotinia, Codonopsis gray mold 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 involved in the present invention is an active ingredient of a plant antibacterial substance and is a plant-derived biopesticide belonging to the category of biopharmaceuticals. 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, a broad antibacterial spectrum, low resistance to 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 fusarium, soybean sclerotinia, Codonopsis pilosula and corn leaf spot. DETAILED DESCRIPTION

[0014] To provide a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the following detailed description of the technical solution of the present invention is provided. However, this description should not be construed 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 described are commercially available unless otherwise specified.

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

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

[0017] The cyperus juncea of ​​the present invention was purchased from a cyperus juncea cultivation base in Nong'an County, Changchun City, Jilin Province. The prepared material was sun-dried, crushed, and stored in a ventilated, dry place for future use. 100 g of the crushed sample was weighed and soaked in 4 times the amount of dichloromethane-methanol (dichloromethane and methanol were mixed in a volume ratio of 1:1), and the sample was allowed to stand at room temperature for 24 hours. Ultrasonic extraction was then performed for 0.5 hours. The sample was filtered under reduced pressure for three consecutive extractions, and the filtrates obtained from each extraction were combined. The extract was concentrated using a rotary evaporator at 45° C., dried, and stored at 4° C. for future use.

[0018] Example 2: Antibacterial effect of dichloromethane-methanol extract;

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

[0020] First, revive the frozen bacteria at room temperature, pick a small amount of colonies with an inoculation needle and place them in the center of a culture dish containing PDA culture medium. Seal the culture dish and culture it upside down in an incubator with a temperature of 25°C and a humidity of 73% without light.

[0021] Next, a certain amount of the dichloromethane-methanol extract was weighed and prepared with sterile water to prepare solutions at 40 mg / mL, 30 mg / mL, and 20 mg / mL, respectively. Sterile water was also used as a blank control, and 40 μg / mL of chlorothalonil was used as a positive control. In a sterile clean bench, the prepared solutions were mixed with PDA culture medium at a ratio of 1:9, resulting in concentrations of 4 mg / mL, 3 mg / mL, and 2 mg / mL, respectively. The culture medium was then poured into a 60 mm diameter Petri dish and allowed to solidify.

[0022] After the strain was activated, a sterile punch (Ø = 5 mm) was used to evenly punch holes in areas of vigorous mycelial growth to produce bacterial cakes. These cakes were inoculated onto the drug-coated culture medium, with one cake placed in the center of each culture dish. After inverted culture in an incubator at 25°C and 73% humidity for 3-14 days, the colony diameters were measured using the cross-hatch method, and the inhibition rate was calculated. Three replicates were set up for each treatment.

[0023] The experimental results showed that the root extract of Cyperus oleifera exhibited varying degrees of antifungal activity against four pathogenic fungi. At a concentration of 2 mg / mL, the dichloromethane-methanol extract showed inhibition rates of 26.14% against Citronella citriodora, 32.94% against Soybean Sclerotinia sclerotiorum, 43.04% against Botrytis cinerea, and 29.61% against Urocera zeae. At a concentration of 4 mg / mL, the dichloromethane-methanol extract showed inhibition rates of 51.39% against Citronella citriodora, 71.50% against Soybean Sclerotinia sclerotiorum, 70.00% against Botrytis cinerea, and 39.76% against Soybean Sclerotinia sclerotiorum. The inhibition rates of the positive control (chlorothalonil) on watermelon sclerotinia, soybean sclerotinia, Codonopsis pilosula and corn leaf spot 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 variations and improvements can be made without departing from the concept of the present invention. These should also be regarded as the scope of protection 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. An application of a Cyperus oleifera root extract as a plant antibacterial agent, characterized in that: The cyperus oleifera root extract, i.e., the dichloromethane-methanol extract, has significant antibacterial activity against watermelon sclerotinia, soybean sclerotinia, codonopsis pilosula, and corn leaf mold. The dichloromethane-methanol extraction method comprises the following steps: weighing 100 g of plant dry powder, soaking the plant dry powder with 4 times the amount of dichloromethane-methanol, and allowing the mixture to stand at room temperature for 24 hours; then performing ultrasonic extraction for 0.5 hours; then performing vacuum filtration and extracting three times in succession; combining the filtrates obtained each time, concentrating the combined filtrates using a rotary evaporator at 45° C., drying the extract, and storing it at 4° C. for future use; The dichloromethane-methanol is prepared by mixing dichloromethane and methanol in a volume ratio of 1:

1.

2. The use of the Cyperus oleifera root extract as a plant antibacterial agent according to claim 1, characterized in that: The concentration of the dichloromethane-methanol extract when used is 2-4 mg / mL.

3. The use of the Cyperus oleifera root extract as a plant antibacterial agent according to claim 2, characterized in that: When the concentration of the dichloromethane-methanol extract was 2 mg / mL, the inhibition rates against watermelon wilt, 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 against watermelon wilt, soybean sclerotinia, Codonopsis pilosula, and corn sclerotinia were 51.39%, 71.50%, 70.00%, and 39.76%, respectively.

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