Application of scutellaria baicalensis extract in prevention and treatment of sclerotiniose of radish

Abstract

The invention discloses application of a radix scutellariae extract in prevention and treatment of sclerotiniose of radishes. A preparation method of the radix scutellariae extract comprises the steps of radix scutellariae raw material treatment, organic solvent extraction and concentration. The radix scutellariae extract can obviously inhibit the activity of radish sclerotinia sclerotiorum, is a plant extract which is good in biocontrol effect and free of pollution, and has wide development and application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural planting disease prevention and control, and in particular to application of a scutellaria baicalensis extract in preventing and controlling radish sclerotinia rot. Background Art

[0002] Radish (Raphanus sativus L.) is a plant of the genus Raphanus in the family Cruciferae. It is widely grown in my country for its fleshy roots and is an important vegetable in my country. Radish sclerotinia is a fungal disease that harms radish. Its pathogen is Sclerotinia sclerotiorum, which is mainly spread through soil. It develops rapidly and causes serious damage, causing devastating impacts on the radish industry.

[0003] Scutellaria baicalensis, also known as Tujincha root and Camellia root, is a perennial herbaceous plant of the genus Scutellaria in the Lamiaceae family. Scutellaria baicalensis has been used in functional cosmetics such as acne prevention and treatment, sun protection, freckle whitening, anti-skin aging and anti-wrinkle. In addition, there are many studies on the use of Scutellaria baicalensis as an antibacterial and anti-inflammatory Chinese medicine in the clinical field of traditional Chinese medicine. At present, it has been reported that in terms of plant pathogens, Scutellaria baicalensis extract has a good antibacterial effect on strawberry Botrytis cinerea, Alternaria alternata, Rhizopus, kiwifruit bacterial canker, tomato late blight, peach brown rot, and tomato late blight, but there is no report on the antibacterial effect on radish sclerotinia.

[0004] In the prior art, the inhibitory base against plant pathogens is mainly spraying pesticides. Pesticides are highly targeted and will not cause harm to non-target organisms, but they have obvious problems, such as long-term harm to the soil, ecological environment, and human and animal health.

[0005] In addition, the use of antibacterial agents to prevent plants from being infected with Sclerotinia is also a hot topic in research and development. For example, patent CN202311097783.5 discloses an antibacterial agent for inhibiting Sclerotinia and its preparation method. The antibacterial agent is composed of the following substances in mass percentage: peptidoglycan 0.05-0.1%, zeolite imidazole skeleton material 0.05-0.1%, pineol 0.5-1%, thymol 0.5-1%, emulsifier 0.3-0.5%, and water supplement 100%. These substances can inhibit the growth of Sclerotinia and have great application value for the development of antibacterial agents for Sclerotinia. Although the composition for inhibiting Sclerotinia disclosed in this patent has a good antibacterial effect, it needs to be in a specific pH environment to work. If the pH environment of the soil is not within this range, the final antibacterial effect will be greatly reduced.

[0006] Therefore, it is of great significance to study new components that inhibit radish sclerotinia rot, as the use of pesticides for the current radish sclerotinia rot is likely to affect the crop soil and ecological environment, and the existing bacterial agents are sensitive to soil pH, their use areas are limited, and they are difficult to promote and apply on a large scale. Summary of the invention

[0007] The purpose of the present invention is to provide an application of a scutellaria baicalensis extract in preventing and treating radish sclerotinia disease, so as to solve the problems that existing pesticides are prone to affect crop soil and ecological environment, existing bacterial agents are prone to be sensitive to the pH of the use environment, and soils in different regions tend to have different antibacterial effects when used.

[0008] The purpose of the present invention is achieved through the following technical solutions: Use of scutellaria baicalensis extract in preparing a preparation for preventing and treating radish sclerotinia rot.

[0009] Furthermore, the preparation method of the scutellaria baicalensis extract comprises: scutellaria baicalensis raw material processing, organic solvent extraction, and concentration. Furthermore, the preparation method of the scutellaria baicalensis extract comprises: (1) Processing of raw materials of Scutellaria baicalensis: The roots of Scutellaria baicalensis are washed with water, dried, and then crushed, and sieved through a 40-mesh sieve to obtain Scutellaria baicalensis powder; (2) Organic solvent extraction: add organic solvent to Scutellaria baicalensis powder and immerse it in water, then filter it; (3) Concentration: The filtrate after filtering in step (2) is evaporated and concentrated to prepare the Scutellaria baicalensis extract.

[0010] Furthermore, the organic solvent used in step (2) is ethanol.

[0011] Further, ethanol is 95% ethanol. Here, 95% ethanol refers to 95% ethanol aqueous solution.

[0012] Furthermore, the soaking method in step (2) is: adding 10 times the volume of ethanol to the Scutellaria baicalensis powder and fully soaking it, shaking it at a constant temperature of 30° C. for 8-24 hours, and filtering to obtain a filtrate and a filter residue.

[0013] Furthermore, the number of impregnations is 3 times, and the specific impregnation methods are as follows: first impregnation: add 10 times the volume of ethanol to the Scutellaria baicalensis powder to fully soak it, oscillate at a constant temperature of 30°C for 24 hours, and filter to obtain the first filtrate and the first filter residue; second impregnation: add 5-10 times the volume of ethanol to the first filter residue to fully soak it, oscillate at a constant temperature of 30°C for 12 hours, and filter to obtain the second filtrate and the second filter residue; third impregnation: add 5-10 times the volume of ethanol to the second filter residue to fully soak it, oscillate at a constant temperature of 30°C for 8 hours, and filter to obtain the third filtrate and the third filter residue.

[0014] Furthermore, the temperature of evaporation and concentration in step (3) is 45-55°C.

[0015] A method for preventing and controlling radish sclerotinia disease comprises contacting radish leaves with a scutellaria baicalensis extract for prevention and control.

[0016] The beneficial effects of the present invention are: 1. The present invention provides an application of a scutellaria baicalensis extract in preventing and treating radish sclerotinia rot. The scutellaria baicalensis extract can inhibit the activity of radish sclerotinia rot, effectively prevent and treat radish sclerotinia rot caused by radish sclerotinia rot, and provide a new idea for the subsequent development of a preparation of scutellaria baicalensis extract for preventing and treating radish sclerotinia rot.

[0017] 2. The present invention provides an application of a scutellaria baicalensis extract in preventing and treating radish sclerotinia disease. The scutellaria baicalensis extract is applied to inhibit the activity of radish sclerotinia. The scutellaria baicalensis extract is a plant secondary metabolite and can participate in the natural material and energy metabolism. When applied to plants or the environment, it will not cause biological enrichment, environmental pollution, or residue, and is not affected by the pH of the soil environment.

[0018] 3. The present invention provides an application of a scutellaria baicalensis extract in preventing and treating radish sclerotinia disease. The extract is prepared using scutellaria baicalensis as a raw material. The raw material source is wide, the price is low, the production cost is low, the production process is simple, and it is suitable for production of various scales. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram showing the antibacterial effect of the scutellaria baicalensis extract on Sclerotinia radish in Example 2 of the present invention; Figure 2 This is a diagram showing the effect of the Scutellaria baicalensis extract of Example 3 of the present invention on the prevention and treatment of radish sclerotinia rot. DETAILED DESCRIPTION

[0020] Definitions of terms used in the present invention: Unless otherwise stated, the initial definitions provided for the terms in this document apply to the terms throughout the specification; for terms that are not specifically defined in this document, the meaning that a person skilled in the art would give them should be given based on the disclosure and context.

[0021] The reagents and equipment used in the present invention are all known products or obtained by purchasing commercially available products. The pathogens used in the following embodiments are described as follows: Sclerotiniasclerotiorum ), provided by the Vegetable Institute of Ningbo Academy of Agricultural Sciences. The public can contact the unit to obtain the corresponding pathogens. The biological material is only used to repeat the relevant experiments of the present invention and cannot be used for other purposes.

[0022] In order to more clearly illustrate the technical solution of the present invention, the specific implementation methods are described as follows: Embodiment 1 Preparation of Scutellaria baicalensis Extract (1) Wash the root of Scutellaria baicalensis with water, dry it, and then grind it into powder. Sieve it through a 40-mesh sieve to obtain Scutellaria baicalensis powder.

[0023] (2) The extraction was performed by three immersion methods. Specifically, 50 g of Scutellaria baicalensis powder was weighed and placed in a sealed conical flask, and then fully immersed in 10 times the volume of 95% ethanol, and then oscillated at 30°C and 120 r / min for 24 h, and then filtered under reduced pressure to obtain the first filtrate and the first filter residue; 5 times the volume of 95% ethanol was added to the first filter residue and fully immersed, and then oscillated at 30°C and 120 r / min for 12 h, and then filtered under reduced pressure to obtain the second filtrate and the second filter residue; 5 times the volume of 95% ethanol was added to the second filter residue and fully immersed, and then oscillated at 30°C and 120 r / min for 8 h, and then filtered under reduced pressure to obtain the third filtrate and the third filter residue.

[0024] (3) The three filtrates obtained by the three immersion methods in step (2), i.e., the first filtrate, the second filtrate, and the third filtrate, are combined by rotary evaporation and concentrated at 50° C. to obtain a 1 g / mL scutellaria baicalensis extract, wherein the 1 g / mL scutellaria baicalensis extract means that 1 g of the scutellaria baicalensis sample material is contained in 1 ml of the scutellaria baicalensis extract, and the scutellaria baicalensis sample material refers to the scutellaria baicalensis sample before washing in the above step (1).

[0025] Embodiment 2 Determination of antibacterial activity of Scutellaria baicalensis extract against Sclerotinia radish The growth rate method was used to determine the antibacterial activity against radish sclerotinia.

[0026] Preparation of Scutellaria baicalensis extract verification solution: Using distilled water as solvent, dissolve the 1 g / mL Scutellaria baicalensis extract prepared in Example 1 to a final concentration of 10% Scutellaria baicalensis extract (0.1 g / mL) for testing, where 0.1 g / mL means that 1 ml of Scutellaria baicalensis extract contains 1 g of Scutellaria baicalensis sample substance.

[0027] The prepared scutellaria extract was sterilized and filtered through a 0.22 μm microporous filter membrane. The PDA culture medium was heated and melted and then cooled to about 50°C. Culture plates were poured, with 15 ml per plate. Different volumes (1000 μl, 750 μl, 500 μl, 250 μl, 100 μl) of scutellaria extract verification solution were added and mixed evenly, so that the final concentrations of scutellaria extract in each culture dish were 6.25 mg / ml, 4.76 mg / ml, 3.23 mg / ml, 1.64 mg / ml, and 0.66 mg / ml, respectively. After solidification, the radish sclerotinia expanded on PDA was cut with a 6 mm diameter puncher and transferred to the center of the culture medium with scutellaria alcohol extract. Each concentration treatment was repeated for 3 plates, and the radish sclerotinia cultured on the culture medium added with sterile distilled water was used as a control.

[0028] The cells were placed in a constant temperature culture at 25°C. On the third day, the colony diameter was measured by the ruler cross method, and the inhibition rate of different concentrations of Scutellaria baicalensis extract on the growth of Radish Sclerotinia was obtained. The inhibition rate calculation formula is: Inhibition rate (%) = (control group colony diameter - treatment group colony diameter) / treatment group colony diameter × 100%. The specific inhibitory effect of Scutellaria baicalensis extract on Radish Sclerotinia is as follows: Figure 1 The specific results of the inhibition rate of the growth of Radish Sclerotinia are shown in Table 1 below, where Figure 1 CK in Table 1 means the control experimental group.

[0029] Table 1 Inhibition of different concentrations of Scutellaria baicalensis extract on the growth of Sclerotinia radish Scutellaria baicalensis extract mass concentration (mg / ml) Colony diameter (cm) Antibacterial rate (%) 6.25 1.50±0.22 82.52±2.50 4.76 3.00±0.33 65.08±3.87 3.23 4.35±0.35 49.42±4.08 1.64 6.80±0.41 20.93±4.80 0.66 8.00±0.16 7.02±1.80 0 (CK) 8.60 / According to the results in Table 1, the mass concentration of Scutellaria baicalensis extract is 6.25 mg / ml, which can achieve an antibacterial effect of 82.56%.

[0030] Embodiment 3 To test the efficacy of Scutellaria baicalensis extract on radish sclerotinia rot.

[0031] The in vitro leaf method was used to detect the preventive and therapeutic effect of Scutellaria baicalensis extract on radish sclerotinia disease. The radish variety was the Sichuan local variety Liushi Zao radish, and the seeds were purchased from Sichuan Guanghan Longsheng Seed Co., Ltd. Place absorbent paper in a rectangular plastic dish and spray water to soak it. Select radish leaves in the mature stage and place them on the absorbent paper. Inoculate a 6mm Sclerotinia mycelium block in the center of the leaf. Use a pipette to draw 300μl of the Scutellaria baicalensis extract verification solution prepared in Example 2 (that is, 10% Scutellaria baicalensis extract) and drop it on the mycelium block. Add clean water as a control. Each treatment was repeated 3 times. Cover the treated plastic dish with plastic wrap to keep it moist, and place it in an incubator at 20°C. After 72 hours, the diameter of the sclerotinia disease spots was counted. The specific preventive and therapeutic effect of Scutellaria baicalensis extract on radish sclerotinia disease is shown in the figure below. Figure 2 The specific results of the sclerotinia lesion diameter are shown in Table 2 below. Figure 2 CK in Table 2 means control group.

[0032] Table 2 The effect of Scutellaria baicalensis extract on the control of radish sclerotinia Processing Name Diameter of lesion (cm) 10% Scutellaria baicalensis extract 0 CK 3.33±0.29 According to the results in Table 2, after treatment with 10% Scutellaria baicalensis extract, the diameter of radish sclerotinia lesions was 0 cm, showing a good antibacterial effect.

Claims

1. Use of a scutellaria baicalensis extract in preparing a preparation for preventing and treating radish sclerotinia rot.

2. Use of the scutellaria baicalensis extract according to claim 1 in preparing a preparation for preventing and treating radish sclerotinia rot, characterized in that: The preparation method of the scutellaria baicalensis extract comprises: scutellaria baicalensis raw material processing, organic solvent extraction and concentration.

3. Use of the scutellaria baicalensis extract according to claim 2 in preparing a preparation for preventing and treating radish sclerotinia rot, characterized in that: The preparation method of the scutellaria baicalensis extract comprises: (1) Processing of raw materials of Scutellaria baicalensis: The roots of Scutellaria baicalensis are washed with water, dried, and then crushed and sieved through a 40-mesh sieve to obtain Scutellaria baicalensis powder; (2) Organic solvent extraction: add organic solvent to Scutellaria baicalensis powder and immerse it in water, then filter it; (3) Concentration: The filtrate after filtering in step (2) is evaporated and concentrated to prepare the Scutellaria baicalensis extract.

4. Use of the scutellaria baicalensis extract according to claim 3 in preparing a preparation for preventing and treating radish sclerotinia rot, characterized in that: The organic solvent used in step (2) is ethanol.

5. Use of the scutellaria baicalensis extract according to claim 4 in preparing a preparation for preventing and treating radish sclerotinia rot, characterized in that: The ethanol is 95% ethanol.

6. Use of the scutellaria baicalensis extract according to claim 3 in preparing a preparation for preventing and treating radish sclerotinia rot, characterized in that: The soaking method in step (2) is as follows: add 10 times the volume of ethanol to the scutellaria powder to fully soak it, oscillate at a constant temperature of 30° C. for 8-24 hours, and filter to obtain a filtrate and a filter residue.

7. Use of the scutellaria baicalensis extract according to claim 3 in preparing a preparation for preventing and treating radish sclerotinia rot, characterized in that: The number of immersions is 3 times; The specific impregnation method is as follows: first impregnation: add 10 times the volume of ethanol to the Scutellaria baicalensis powder to fully soak it, oscillate at a constant temperature of 30°C for 24 hours, and filter to obtain the first filtrate and the first filter residue; second impregnation: add 5-10 times the volume of ethanol to the first filter residue to fully soak it, oscillate at a constant temperature of 30°C for 12 hours, and filter to obtain the second filtrate and the second filter residue; third impregnation: add 5-10 times the volume of ethanol to the second filter residue to fully soak it, oscillate at a constant temperature of 30°C for 8 hours, and filter to obtain the third filtrate and the third filter residue.

8. Use of the scutellaria baicalensis extract according to claim 3 in preparing a preparation for preventing and treating radish sclerotinia rot, characterized in that: The temperature of evaporation and concentration in step (3) is 45-55°C.

9. A method for preventing and treating radish sclerotinia disease, characterized in that: It includes contacting radish leaves with Scutellaria baicalensis extract for prevention and control.

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