Application of gentian extract in prevention and treatment of muskmelon fusarium wilt

Abstract

The invention discloses an application of a gentian extract in prevention and treatment of muskmelon fusarium wilt. A preparation method of the gentian extract comprises the steps of gentian raw material treatment, organic solvent extraction and concentration. The gentian extract can significantly inhibit the activity of muskmelon fusarium oxysporum, is a plant extract with good biocontrol effect and no 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 gentian extract in preventing and controlling melon wilt. Background Art

[0002] melon( Cucumismelo L.) is an annual vine herbaceous plant of the Cucurbitaceae family. Its fruit is sweet and has high nutritional value. It is a popular summer fruit for consumers. At present, plant diseases have seriously affected the development of the melon industry, especially melon wilt. Melon wilt is caused by Fusarium oxysporum, melon-specific type ( Fusariumoxysporum f.sp. muskmelonis, Fusarium wilt (FOM) is a worldwide soil-borne fungal disease. This disease has occurred in large areas of melon production areas in my country. Once it occurs, it can spread rapidly in a short period of time and is difficult to prevent and control. As melon wilt disease becomes more serious year by year, it has caused serious economic losses and restricted the development of the melon industry.

[0003] Gentiana Gentianascabra Bunge ) is a perennial herbaceous plant of the Gentianaceae family, also known as gall grass, mountain gentian or bitter gall grass. The rhizome is often used as medicine. It tastes bitter and is cold in nature. It enters the liver and gallbladder meridians and has the effects of clearing away heat and dampness, and purging liver and gallbladder fire. It is a precious Chinese herbal medicine. It is reported that gentian extract has antibacterial activity against animal pathogens such as Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, but has no effect on Fusarium oxysporum melon-specific type ( Fusariumoxysporum f.sp. muskmelonis, There are no reports on the antibacterial effect of FOM on plant 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] Patent application number CN202410163852.6 discloses a soil-specific oxadipazole composition for preventing and controlling diseases and insects and its application, the composition includes an effective component, the effective component includes oxadipazole and modified brown algae polyphenol; the modified brown algae polyphenol is formed by modifying the brown algae polyphenol with ammonium sulfate as a carrier; the modification includes: heating the brown algae polyphenol to 40°C~50°C, performing a first ultrasonic treatment, mixing the ultrasonically treated brown algae polyphenol with ammonium sulfate at a mass ratio of 10:1, and performing a second ultrasonic treatment; the mass ratio of oxadipazole to the modified brown algae polyphenol is (0.1~1):(1~10). The modified brown algae polyphenol and oxadipazole work together to significantly reduce the dosage of oxadipazole and significantly improve its rapid effect and duration against soil-borne diseases and insects, especially against cucumber root-knot nematodes, soybean root rot, leek maggots and melon wilt. Although the composition for inhibiting melon wilt bacteria disclosed in this patent has good antibacterial effect, the component oxazolidinone contained therein is a pesticide. It is safest to use it dry. Wet mixing or soaking the seeds can easily cause pesticide damage, and the amount of pesticide used must be strictly controlled, otherwise it may inhibit crop growth. Therefore, on the one hand, improper use of the composition may bring negative effects. On the other hand, after all, oxazolidinone is a pesticide and will still have an impact on the soil ecological environment.

[0006] Therefore, in view of the problems that the existing use of pesticides for melon wilt disease can easily affect the soil and ecological environment of crops, and the existing antibacterial components are cumbersome to prepare and difficult to promote and apply on a large scale, it is of great significance to study new components that inhibit melon wilt fungi. Summary of the invention

[0007] The purpose of the present invention is to provide an application of a gentian extract in preventing and treating melon wilt, so as to solve the problems that existing pesticides are easy to affect crop soil and ecological environment, and the preparation of existing antibacterial components is cumbersome.

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

[0009] Furthermore, the preparation method of the gentian extract comprises: gentian raw material processing, organic solvent extraction, and concentration. Furthermore, the preparation method of the gentian extract comprises: (1) Gentiana raw material processing: the rhizomes of Gentiana are washed with water, dried, and then crushed, and sieved through a 40-mesh sieve to obtain Gentiana powder; (2) Organic solvent extraction: add organic solvent to gentian powder and immerse it, then filter it; (3) Concentration: The filtrate after filtering in step (2) is evaporated and concentrated to prepare the gentian 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 gentian 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 method is as follows: first impregnation: add 10 times the volume of ethanol to the gentian 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 melon wilt disease comprises contacting melon roots with a gentian extract for prevention and control.

[0016] The beneficial effects of the present invention are: 1. The present invention provides an application of a gentian extract in preventing and treating melon wilt. The gentian extract can inhibit the activity of Fusarium oxysporum, a special type of melon pathogen, and effectively prevent and treat melon wilt caused by Fusarium oxysporum, thereby providing a new idea for the subsequent development of preparations using gentian extract to prevent and treat melon wilt.

[0017] 2. The present invention provides an application of a gentian extract in preventing and treating melon wilt disease. The gentian extract is applied to inhibit the activity of melon wilt pathogens. When applied to plants or the environment, it will not cause biological enrichment, environmental pollution, or residue, and will not be affected by the soil environment.

[0018] 3. The present invention provides an application of a gentian extract in preventing and treating melon wilt. The extract is prepared using gentian as raw material. The raw material source is wide, the extraction 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 gentian extract of Example 2 of the present invention on the inhibition of melon wilt bacteria; Figure 2This is a diagram showing the effect of the gentian extract of Example 3 of the present invention on preventing and controlling melon wilt disease. 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.

[0022] The pathogens used in the following examples are described as follows: The pathogen used is Fusarium spp. Fusariumoxysporum.f.sp.cucmrium ", numbered TG-5, the document source is "Identification of Physiological Races of Melon Wilt in Zhejiang Province and Identification of Resistance of Some Melon Varieties", 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. The implementation method is described as follows: Embodiment 1 Preparation of Gentiana extract (1) Wash the rhizome of gentian with water, dry it, and then grind it into powder. Then, sieve it through a 40-mesh sieve to obtain gentian powder.

[0023] (2) The extraction was performed by three immersion methods. Specifically, 50 g of gentian 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; the first filter residue was further immersed in 5 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 filter residue; the second filter 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 to obtain the third filtrate and the third filter residue.

[0024] (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 50° C. to obtain a gentian extract with a concentration of 1 g / mL, wherein the 1 g / mL gentian extract refers to 1 g of gentian sample material contained in 1 ml of gentian extract, and the gentian sample material refers to the rhizome sample of gentian before washing in the above step (1).

[0025] Embodiment 2 Determination of the antibacterial activity of gentian extract against Fusarium oxysporum The growth rate method was used to determine the antibacterial activity of Fusarium oxysporum var.

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

[0027] The prepared gentian extract was sterilized and filtered through a 0.22 μm microporous filter membrane. The PDA culture medium was heated to melt and then cooled to about 50° C. and poured into culture plates, with 15 ml per plate. Different volumes (1500 μL, 1000 μL, 750 μL, 500 μL, 250 μL) of gentian extract solution were added and mixed evenly, so that the final concentrations of gentian extract in each culture dish were 9.09 mg / mL, 6.25 mg / mL, 4.76 mg / mL, 3.23 mg / mL, and 1.64 mg / mL, respectively. After solidification, a 5 mm bacterial block was taken from the edge of the fresh Fusarium oxysporum melon-specific pathogen with a cork hole puncher and inoculated into the center of the culture medium with different concentrations of gentian extract. Each concentration was repeated 3 times, and the Fusarium oxysporum melon-specific pathogen cultured on the culture medium with the corresponding volume (1500 μL, 1000 μL, 750 μL, 500 μL, 250 μL) of sterile distilled water was used as the control.

[0028] The samples were incubated at 25°C, and the colony diameter was measured by the ruler cross method on the 7th day to obtain the inhibition rate of different concentrations of gentian extract against Fusarium oxysporum and melon-specific pathogens. The inhibition rate calculation formula is: inhibition rate (%) = (colony diameter of the control group - colony diameter of the treatment group) / colony diameter of the treatment group × 100%. The specific inhibition effect of gentian extract on Fusarium oxysporum and melon-specific pathogens is as follows: Figure 1 The specific antibacterial rate results 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 gentian extract on Fusarium oxysporum melon-specific pathogen Mass concentration of gentian extract (mg / ml) Colony diameter (cm) Antibacterial rate (%) 9.09 0.53±0.058 99.56±0.75 6.25 4.07±0.31 54.11±4.56 4.76 5.33±0.21 37.64±3.07 3.23 7.77±0.58 6.10±1.46 1.64 8.00±0.25 6.98 0 (CK) 8.53 / According to the results in Table 1, the mass concentration of gentian extract is 9.09 mg / ml, which can achieve an antibacterial effect of 99.56%.

[0030] Embodiment 3 To test the efficacy of gentian extract on melon wilt.

[0031] The melon variety was Fresh and Crunchy No. 1, a variety selected and bred by Ningbo Academy of Agricultural Sciences. The root injury inoculation method was used to test the control effect of gentian extract on melon wilt. When the melon seedlings had 2 leaves and 1 heart, 25 seedlings were grouped into one group, with 3 replicates in each group. This experiment set up 3 treatments. In the early stage, the seedlings of the three treatments were taken out of the plug tray, the roots were slightly damaged, and the roots were washed. (1) FOM group: The roots of the seedlings were immersed in 50 mL of wilt fungus spore solution for 20 minutes. The spore solution concentration was 4×10 6 / mL, the root system was completely invaded, and then transplanted to the nutrient soil. (2) Gentian extract + FOM group: The seedlings were soaked in 25 mL of 4×106 / mL wilt fungus spores + 25 mL10% gentian extract for 20 minutes, and then transplanted to the nutrient soil. (3) Gentian extract + H2O group (CK): The seedlings were soaked in 25 mL10% gentian extract + 25 mL clean water for 20 minutes, and then transplanted to the nutrient soil. Shade the seedlings for the first 3 days after inoculation, and keep the temperature at 25 ℃. After 3 days of acclimatization, remove the shade net, manage the greenhouse normally, and investigate the disease situation after 15 days. Identification standards: if the whole plant is free of symptoms, it is level 0; if the cotyledons wilt or some cotyledons and true leaves slightly wilt at noon on a sunny day, it is level 1; if one true leaf wilts or the cotyledons wilt severely, it is level 2; if the cotyledons and true leaves wilt and their development is hindered, it is level 3; if the whole plant wilts and more than 60% of the leaves die, and the heart leaves survive, it is level 4; if the whole plant severely wilts and dies, it is level 5.

[0032] Disease index = ∑ (level × number of plants in that level) / (total number of plants × highest level) × 100 Relative control effect / %=(control disease index-treatment disease index) / control disease index×100 The specific effect of gentian extract on melon wilt is shown in the figure below: Figure 2 The relative control effect of the specific gentian extract on melon wilt is shown in Table 2. Figure 2 CK in Table 2 means control group.

[0033] Table 2 Relative control effect of gentian extract on melon wilt deal with Disease index Relative control effect% Gentiana extract + FOM 45.6 53.28 FOM 97.6 / <![CDATA[CK (Gentiana scabra Bunge extract + H2O group)]]> 0 / The higher the disease index, the more serious the plant disease is, and the greater the impact on plant growth and yield. According to the results in Table 2, after the roots of melon seedlings were treated with 10% gentian extract and an equal volume of water, the disease index was basically zero, and melon wilt was effectively controlled.

Claims

1. Use of gentian extract in preparing a preparation for preventing and treating melon wilt.

2. Use of the gentian extract according to claim 1 in preparing a preparation for preventing and treating melon wilt disease, characterized in that: The preparation method of the gentian extract comprises: gentian raw material treatment, organic solvent extraction and concentration.

3. Use of the gentian extract according to claim 2 in preparing a preparation for preventing and treating melon wilt disease, characterized in that: The preparation method of the gentian extract comprises: (1) Gentiana raw material processing: the rhizomes of Gentiana are washed with water, dried, and then crushed, and sieved through a 40-mesh sieve to obtain Gentiana powder; (2) Organic solvent extraction: add organic solvent to gentian powder and immerse it, then filter it; (3) Concentration: The filtrate after filtering in step (2) is evaporated and concentrated to prepare the gentian extract.

4. Use of the gentian extract according to claim 3 in preparing a preparation for preventing and treating melon wilt disease, characterized in that: The organic solvent used in step (2) is ethanol.

5. Use of the gentian extract according to claim 4 in preparing a preparation for preventing and treating melon wilt disease, characterized in that: The ethanol is 95% ethanol.

6. Use of the gentian extract according to claim 3 in preparing a preparation for inhibiting melon wilt pathogenic bacteria, characterized in that: The soaking method in step (2) is: add 10 times the volume of ethanol to the gentian powder and fully soak it, shake it 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 gentian extract according to claim 3 in preparing a preparation for preventing and treating melon wilt disease, 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 gentian 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 gentian extract according to claim 3 in preparing a preparation for preventing and treating melon wilt disease, characterized in that: The temperature of evaporation and concentration in step (3) is 45-55°C.

9. A method for preventing and treating melon wilt pathogen, characterized in that: This involves contacting the melon roots with a gentian extract.

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