Application of motherwort herb extract in prevention and treatment of muskmelon gummy stem blight

Abstract

The invention discloses application of a motherwort herb extract in prevention and treatment of muskmelon gummy stem blight. A preparation method of the motherwort herb extract comprises the steps of motherwort herb raw material treatment, organic solvent extraction and concentration. The herba leonuri extract can remarkably inhibit the activity of muskmelon gummy stem blight germs, 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 motherwort extract in preventing and controlling melon vine blight. Background Art

[0002] Melon vine blight is caused by Stagonosporopsiscucurbitacearum Diseases that occur on melons due to infection. Melon vine blight generally harms the main vine and side vines, and sometimes petioles and leaves. In the early stage of leaf damage, yellow-brown "V"-shaped spots with unclear rings appear on the leaf margins, and then the entire leaf dies. In the early stage of petiole damage, yellow-brown oval to stripe-shaped spots appear, and then the diseased part gradually shrinks, and the branches and leaves above the diseased part die. Melon vine blight is a devastating fungal disease that harms the melon industry worldwide. It is highly contagious, develops quickly, and causes serious damage. Once infected, it will have a devastating impact on the melon industry.

[0003] Motherwort (Luffa aegyptiaca Mill.) is an annual climbing vine of the genus Leonurus in the Cucurbitaceae family. It is reported that motherwort has anti-inflammatory, antioxidant, and antibacterial effects. In terms of plant pathogens, motherwort ethanol extract has antibacterial effects on apple anthracnose, Penicillium, apple ring rot fungus, and cotton wilt fungus, but there are no reports on its antibacterial effect on melon pathogens.

[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, for the inhibition of plant pathogens, the application of microbial agents is also a relatively conventional technical means. For example, patent CN202311658214.3 discloses a microbial agent for preventing and controlling melon vine blight and its preparation method, wherein the microbial agent contains 10-15 parts of biological composite bacteria, 20-30 parts of diatomaceous earth, 40-50 parts of seaweed polysaccharides, 3-5 parts of zinc sulfate, 0.5-1 part of copper sulfate, 1-3 parts of sodium molybdate, 0.2-0.5 parts of ferrous sulfate, 1-2 parts of potassium sulfate, and 0.05-0.1 parts of magnesium sulfate; wherein the biological composite bacteria include non-hygroscopic Streptomyces, Bacillus amyloliquefaciens, Trichoderma harzianum, and Pseudomonas fluorescens; the agent has a good effect on preventing and controlling melon vine blight, has a good inhibitory effect on vine blight pathogens, significantly reduces the incidence of melon vine blight, and achieves increased production and income of melons. However, the composition of the microbial agent is complex. On the other hand, during the application process, the microbial agent may be affected by residual pesticides in the field or by the application of pesticides, which may affect the activity of the biological composite bacteria and ultimately greatly reduce the antibacterial effect.

[0006] Therefore, in view of the problems that the use of existing pesticides to prevent and control melon vine blight is likely to affect the crop soil and ecological environment, and the effectiveness of existing microbial agents is easily affected by residual pesticides in the field, it is of great significance to develop new biological pesticides to prevent and control melon vine blight. Summary of the invention

[0007] The purpose of the present invention is to provide an application of a motherwort extract in preventing and treating melon vine blight, so as to solve the problems that existing pesticides are prone to affect crop soil and ecological environment, and microbial agents are easily affected by residual pesticides in the field.

[0008] The purpose of the present invention is achieved through the following technical solutions: Use of motherwort extract in preparing a preparation for preventing and controlling melon vine blight.

[0009] Furthermore, the preparation method of the motherwort extract comprises: processing motherwort raw materials, extracting with organic solvents, and concentrating. Furthermore, the preparation method of the motherwort extract comprises: (1) Processing of motherwort raw materials: Wash the stems and leaves of motherwort with water, dry them, and then grind them into powder, and sieve them through a 40-mesh sieve to obtain motherwort powder; (2) Organic solvent extraction: add organic solvent to Leonurus japonicus 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 motherwort extract.

[0010] Furthermore, the organic solvent used in step (2) is 95% ethanol, wherein the 95% ethanol is a 95% ethanol aqueous solution.

[0011] Furthermore, the soaking method in step (2) is: add 10 times the volume of ethanol to the motherwort powder and fully soak it, oscillate at a constant temperature of 20-30°C for 8-24 hours, and filter to obtain a filtrate and a filter residue.

[0012] 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 motherwort 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.

[0013] Furthermore, the temperature of evaporation and concentration in step (3) is 45-55°C.

[0014] A method for preventing and controlling melon vine blight comprises contacting melon leaves with a motherwort extract for prevention and control.

[0015] The beneficial effects of the present invention are: 1. The present invention provides an application of a motherwort extract in preventing and controlling melon vine blight. The motherwort extract can inhibit the activity of melon vine blight pathogens, effectively prevent and control melon vine blight caused by melon vine blight pathogens, and provide a new idea for the subsequent development of biological pesticides using motherwort extracts to prevent and control melon vine blight.

[0016] 2. The present invention provides an application of a motherwort extract in preventing and treating melon vine blight. The motherwort extract is applied to inhibit the activity of melon vine blight pathogens. The motherwort extract is a plant secondary metabolite and can participate in natural material and energy metabolism. When applied to plants or the environment, it will not cause biological enrichment, environmental pollution, or residue.

[0017] 3. The present invention provides an application of a Leonurus japonicus extract in preventing and treating melon vine blight. The extract is prepared using Leonurus japonicus as 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

[0018] Figure 1 This is a diagram showing the antibacterial effect of the motherwort extract of Example 2 of the present invention on melon vine blight bacteria; Figure 2 This is a diagram showing the effect of the motherwort extract of Example 3 of the present invention on preventing and controlling melon vine blight. DETAILED DESCRIPTION

[0019] 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.

[0020] 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 examples are described as follows: Stagonosporopsiscucurbitacearum , numbered 14mk020, the document source is "QTL positioning analysis of melon vine blight resistance based on SLAF_seq and BSA technology", which is preserved and 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.

[0021] 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 Leonurus japonicus Extract (1) Wash the stems and leaves of motherwort with water, dry them, and then crush them. Then, sieve them through a 40-mesh sieve to obtain motherwort powder.

[0022] (2) The extraction was performed by three immersion methods. Specifically, 50 g of Leonurus herb 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 residue; the first residue was further immersed in 6 times the volume of 95% ethanol, 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 residue; the second residue was further immersed in 5 times the volume of 95% ethanol, and then oscillated at 30°C and 120 r / min for 8 h, and then filtered under reduced pressure at 50°C to obtain the third filtrate and the third residue.

[0023] (3) The three filtrates obtained by the three immersion methods in step (2), namely the first filtrate, the second filtrate and the third filtrate, are combined by rotary evaporation and concentrated by evaporation at 45° C. to obtain a motherwort extract with a concentration of 1 g / mL. Here, 1 g / mL of motherwort extract means that 1 ml of motherwort extract contains 1 g of motherwort sample material. Here, the motherwort sample material is defined as the stems and leaves of motherwort before washing in the above step (1).

[0024] Embodiment 2 Determination of the antibacterial activity of Leonurus japonicus extract against melon vine blight pathogen The growth rate method was used to determine the antibacterial activity of melon vine blight pathogen.

[0025] Preparation of verification solution of motherwort extract: using distilled water as solvent, dissolve the 1 g / mL motherwort extract prepared in Example 1 to a final concentration of 10% motherwort extract (0.1 g / mL) for testing, where 0.1 g / mL means that 1 ml of motherwort extract contains 1 g of motherwort sample substance.

[0026] The prepared motherwort extract was sterilized and filtered through a 0.22 μm microporous filter membrane, and the PDA medium was heated and melted and then cooled to about 50°C, and poured into a culture plate, with 15 ml per dish. Different volumes (1000 μl, 750 μl, 640 μl, 500 μl, 250 μl) of motherwort extract verification solution were added and mixed evenly, so that the final concentrations of motherwort extract in each culture dish were: 6.25 mg / ml, 4.76 mg / ml, 4.10 mg / ml, 3.23 mg / ml, 1.64 mg / ml, and after solidification, the melon vine blight pathogens expanded and cultured on PDA were cut with a 6 mm diameter puncher and transferred to the center of the culture medium with motherwort extract. Each concentration treatment was repeated for 3 dishes, and the melon vine blight pathogens cultured on the culture medium with sterile distilled water were used as the control.

[0027] The samples were cultured at 25°C and the colony diameter was measured by the ruler cross method on the 6th day to obtain the inhibition rate of different concentrations of motherwort extract on the growth of melon vine blight pathogen. The inhibition rate calculation formula is: inhibition rate (%) = (colony diameter of control group - colony diameter of treatment group) / colony diameter of treatment group × 100%. The specific inhibition effect of motherwort extract on melon vine blight pathogen is as follows: Figure 1 The specific results of the inhibition rate of melon vine blight pathogen growth are shown in Table 1 below, where Figure 1 CK in Table 1 means the control experimental group.

[0028] Table 1 Inhibition of different concentrations of Leonurus japonicus extract on the growth of melon vine blight pathogen Motherwort extract mass concentration (mg / ml) Colony diameter (cm) Antibacterial rate (%) 6.25 2.42±0.31 71.90±3.55 4.76 3.12±0.27 63.72±3.08 4.10 5.61±0.34 34.73±3.91 3.23 6.34±0.50 26.28±5.81 1.64 7.22±0.10 16.05±1.16 0 (CK) 8.60 / According to the results in Table 1, the antibacterial effect of Leonurus japonicus extract can reach 71.86% when the mass concentration reaches 6.25 mg / ml.

[0029] Embodiment 3 To test the efficacy of Leonurus japonicus extract on melon vine blight.

[0030] The in vitro leaf method was used to detect the control effect of motherwort extract on melon vine blight. The melon variety was Oriental Honey No. 1, which is a common melon variety on the market. Place absorbent paper in a disposable culture dish and spray water to soak it. Pick the second true leaf when the melon has three leaves and one heart, and place the true leaf on the absorbent paper in the culture dish. Inoculate a 6mm mycelium block of vine blight fungi in the center of the leaf. Use a pipette to draw 300μl of the motherwort extract verification solution prepared in Example 2 (that is, 10% motherwort extract) and drop it on the mycelium block. Add clean water as a control. Each treatment was repeated 3 times. Cover the treated culture dish with a lid and seal it with a sealing film to keep it moist. Place it in an incubator at 25°C. After 72 hours, the diameter of the vine blight lesions is counted. The specific control effect of motherwort extract on melon vine blight is shown in the figure below. Figure 2 The specific results of the lesion diameter of the vine blight are shown in Table 2. Figure 2 CK in Table 2 means control group.

[0031] Table 2 Control effect of motherwort extract on melon vine blight Processing Name Diameter of lesion (cm) 10% Motherwort Extract 0.50±0.10 CK 4.47±0.21 According to Table 2 and Figure 2 The results showed that 10% motherwort extract had a significant preventive and therapeutic effect on melon vine blight.

Claims

1. Use of motherwort extract in preparing a preparation for preventing and treating melon vine blight.

2. Use of the motherwort extract according to claim 1 in the preparation of a biological pesticide for preventing and controlling melon vine blight, characterized in that: The preparation method of the motherwort extract comprises: processing the motherwort raw material, extracting with an organic solvent, and concentrating.

3. Use of the motherwort extract according to claim 2 in the preparation of a biological pesticide for preventing and controlling melon vine blight, characterized in that: The preparation method of the motherwort extract comprises: (1) Processing of motherwort raw materials: Wash the motherwort with water, dry it, and then grind it into powder, and sieve it through a 40-mesh sieve to obtain motherwort powder; (2) Organic solvent extraction: add organic solvent to Leonurus japonicus 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 motherwort extract.

4. Use of the motherwort extract according to claim 3 in the preparation of a biological pesticide for preventing and controlling melon vine blight, characterized in that: The organic solvent used in step (2) is 95% ethanol.

5. Use of the motherwort extract according to claim 3 in the preparation of a biological pesticide for preventing and controlling melon vine blight, characterized in that: The soaking method in step (2) is as follows: add ethanol to the motherwort powder and fully soak it, oscillate at a constant temperature of 20-30° C. for 8-24 hours, and filter to obtain a filtrate and a filter residue.

6. Use of the motherwort extract according to claim 5 in the preparation of a biological pesticide for preventing and controlling melon vine blight, 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 motherwort 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.

7. Use of the motherwort extract according to claim 5 in the preparation of a biological pesticide for preventing and controlling melon vine blight, characterized in that: The temperature of evaporation and concentration in step (3) is 45-55°C.

8. A method for preventing and treating melon vine blight, characterized in that: This involves contacting the leaves of melon with an extract of motherwort for control.

Images