Biopesticide for preventing and treating eggplant phytophthora rot

Abstract

The invention belongs to the technical field of biopesticides, and particularly relates to a biopesticide for preventing and treating eggplant phytophthora rot. The invention relates to a biopesticide. Active ingredients of the biopesticide are formed by binary compounding of lentinan and phenazino-1-carboxylic acid or zhongshengmycin. The biopesticide is prepared by compounding two bioactive components, can effectively restrain the evolution and accumulation of the drug resistance of eggplant phytophthora rot, and is beneficial to prolonging the upgrading cycle of the biopesticide. Besides, the lentinan and the phenazino-1-carboxylic acid or zhongshengmycin in the biopesticide are compounded and combined, so that the biopesticide has a synergistic effect on eggplant phytophthora rot, the control effect is improved, and the control cost is reduced. Secondly, the biopesticide is environment-friendly, green and environment-friendly, and can effectively relieve environmental pressure caused by application of chemical agents.

Description

Technical Field

[0001] This invention belongs to the field of biological pesticide technology, specifically relating to a biological pesticide for controlling eggplant wilt disease. Background Technology

[0002] Eggplant blight is one of the major diseases in eggplant production. It primarily affects nearly ripe eggplant fruits, but the stems, leaves, and flowers of the plant can also be infected by the pathogen. The peak infection period is during the fruiting stage. The pathogens that infect eggplant fruits and cause blight include *Phytophthora parasitica* (…). Phytophthora parasitica ) and Phytophthora capsici ( Phytophthora parasitica Among them, Phytophthora capsici is the main pathogen and has a strong pathogenicity to eggplant.

[0003] In production, the occurrence and spread of eggplant downy mildew can be controlled by spraying chemical agents. However, excessive use of chemical agents leads to environmental pollution, and with the accumulation and development of drug resistance in pathogens and the long-term use of chemical agents, the control effect of chemical agents on the disease gradually decreases. Compared with chemical agents, biopesticides have advantages such as being environmentally friendly, green and environmentally friendly, and less likely to cause drug resistance in diseases. Therefore, the research and development of biopesticides for the control of eggplant downy mildew is of great significance.

[0004] Lentinan, an active ingredient extracted from the fruiting body of shiitake mushrooms, belongs to the fungal polysaccharide family. It possesses disease-inhibiting and disease-resistant activities similar to glucan elicitors, inducing plants or cells to produce accumulated disease-resistant substances such as phytoalexins and chitinases. Existing patent CN103563958B discloses a fungicide composition with lentinan and prochloraz as the main components, which is effective against rice blast fungus (…). pyricularia grisea It exhibits a high synergistic effect; in addition, patent CN117223715A describes a biological pesticide with lentinan combined with osthol, thymol, or hydrated mycin as the active ingredient, which has a synergistic effect on inhibiting the growth of avocado root rot fungus. However, there are currently no reports on the combination of lentinan with shenqinmycin or kasugamycin. Summary of the Invention

[0005] The purpose of this invention is to provide a biological pesticide for controlling eggplant downy mildew, thereby solving the problems existing in the prior art when using chemical agents to control eggplant downy mildew.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A biological pesticide, wherein the active ingredient of the biological pesticide is a binary compound of lentinan and sennamycin or kasugamycin.

[0007] Furthermore, the mass ratio of the lentinan to shenqinmycin is 1-16:16-1.

[0008] Furthermore, the mass ratio of the lentinan to the streptomycin is 1-15:10-1.

[0009] The present invention also provides a pesticide formulation comprising the aforementioned biological pesticide, wherein the active ingredient accounts for 1-85% of the total mass of the pesticide formulation, and the remainder is auxiliary ingredients permitted to be added in pesticide science.

[0010] Furthermore, the active ingredient accounts for 1-45% of the mass of the pesticide formulation.

[0011] The present invention also provides the application of the biological pesticide or the pesticide formulation in the prevention and control of eggplant blight.

[0012] Furthermore, the aforementioned eggplant blight is caused by infection with Phytophthora capsici.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) The biological pesticide of the present invention is composed of two bioactive ingredients, which can effectively inhibit the evolution and accumulation of drug resistance of Phytophthora infestans and help extend the generation cycle of biological pesticides.

[0014] (2) The combination of lentinan and shenqinmycin or kasugamycin in the biological pesticide of the present invention has a synergistic effect on the blight of eggplant, which helps to improve the control effect and reduce the control cost.

[0015] (3) The biological pesticide of the present invention is environmentally friendly and green, and can effectively alleviate the environmental pressure caused by the application of chemical agents. Detailed Implementation

[0016] The technical solution of this invention patent will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0017] 1. Materials and Methods 1.1 Test strains Phytophthora capsici ( Phytophthora parasitica ), isolated from diseased eggplant fruit samples.

[0018] 1.2 Test reagents 99% Lentinan technical grade, 95% Shenqinmycin technical grade, 99% Zhongshengjunxin technical grade.

[0019] The test reagent was dissolved in a solvent and then diluted with a 0.1% Tween-80 aqueous solution to prepare a high-concentration single-agent stock solution. Based on the preliminary test results, multiple ratios were set up. Each single-agent stock solution and the ratio mixture were then diluted with a 0.1% Tween-80 aqueous solution to set up 5 mass concentration gradients for later use.

[0020] 1.3 Culture medium Potato glucose broth (PDA): 200g peeled potatoes, 20g glucose, 17g agar powder, distilled water to a final volume of 1000mL, sterilize at 121℃ for 30min.

[0021] 1.4 Test Methods The mycelial growth rate method was used. The drug solution was added to pre-melted and cooled to 50°C PDA medium at a volume ratio of 1:9. After thorough mixing, 10 mL was placed in each 9 cm diameter sterile Petri dish. After cooling, drug-containing plates were formed. Each treatment was repeated three times, with three plates constituting one replicate. A blank control was provided using sterile water PDA medium.

[0022] The tested strains were inoculated onto PDA medium and cultured at 25°C for 5 days. Using a punch, 6 mm diameter mycelial cakes were taken from the edge of the colony and inoculated into the center of the drug-containing plate and the blank control plate, one mycelial cake per plate. The plates were covered and placed in a constant temperature incubator at 25°C for incubation and observation. When the diameter of the blank control colony reached 6-7 cm, the colony diameter was measured using the cross-cross method, and the inhibition rate of mycelial growth by different treatments was calculated.

[0023]

[0024] 1.5 Data Analysis Linear regression analysis was performed using the logarithm of fungicide concentration as x and the probability of mycelial growth inhibition rate as y to derive the toxicity regression equation and EC50 of the fungicide on the tested strains. 50 The cotoxicity coefficient (CTC) was calculated using the Sun Yunpei method.

[0025]

[0026] In the above formula: ATI --The measured toxicity index of the mixture; S --EC of standard reagents 50 The unit is mg / L; M --EC mixture 50 The unit is mg / L.

[0027]

[0028] In the above formula: TTI --Theoretical toxicological index of the mixture; TI A--Toxicity index of drug A; P A --Percentage content of drug A in the mixture, expressed as percentage (%). TI B --Toxicity index of drug B; P B --The percentage content of drug B in the mixture, expressed as a percentage (%).

[0029]

[0030] In the above formula: CTC --Cotoxicity coefficient; ATI --Measured toxicity index of the mixture; TTI --Theoretical toxicity index of mixed formulations.

[0031] 1.6 Measurement Results The synergistic effect of the drug was evaluated based on the calculated co-toxicity coefficient (CTC). CTC ≤ 80 indicates antagonistic effect, 80 < CTC < 120 indicates additive effect, and CTC ≥ 120 indicates synergistic effect. The results are shown in Table 1-2.

[0032] Table 1. Indoor bioactivity assay of lentinan combined with shenqinmycin against *Phytophthora indicum*, the causal agent of *Phytophthora indicum*. Drug Name and Proportion <![CDATA[EC 50 (mg / L)]]> ATI TTI CTC Lentinan 13.1947 100.0000 -- -- Shenqinmycin 7.2512 181.9657 -- -- Lentinan 1: Shenqinmycin 16 4.6199 285.6057 177.1442 161.2278 Lentinan 1: Shenqinmycin 8 5.8639 225.0158 172.8584 130.1734 Lentinan 1: Shenqinmycin 4 6.2567 210.8891 165.5726 127.3696 Lentinan 1: Shenqinmycin 1 7.5974 173.6739 140.9829 123.1879 Lentinan 4: Shenqinmycin 1 5.0252 262.5706 116.3931 225.5894 Lentinan 8: Shenqinmycin 1 3.4459 382.9101 109.1073 350.9482 Lentinan 16: Shenqinmycin 1 7.9864 165.2146 104.8215 157.6152 As shown in Table 1, the co-toxicity coefficients of lentinan and shenqinmycin against *Phytophthora indicum* in eggplant were all greater than 120 within a mass ratio range of 1-16:16-1, indicating a synergistic effect.

[0033] Table 2. Indoor bioactivity determination of lentinan combined with streptomycin against Phytophthora solani. Drug Name and Proportion <![CDATA[EC 50 (mg / L)]]> ATI TTI CTC Lentinan 13.1947 100.0000 -- -- Bismuth subsalicylate 4.5603 289.3384 -- -- Lentin 1: Gefitin 10 3.8434 343.3080 272.1258 126.1578 Lentinan 1: Gefitin 5 3.6725 359.2839 257.7820 139.3751 Lentinan 1: Gefitin 3 4.1221 320.0966 242.0038 132.2692 Lentin 1: Gefitin 1 5.4025 244.2332 194.6692 125.4606 Lentin-3: Gelatin-1 6.4691 203.9650 147.3346 138.4366 Lentinan 5: Gefitin 1 8.1548 161.8029 131.5564 122.9912 Lentinan 10: Gefitin 1 9.1283 144.5472 117.2126 123.3205 Lentinan 15: Gefitin 1 9.7762 134.9676 111.8337 120.6860 As shown in Table 2, the co-toxicity coefficients of lentinan and streptomycin against Phytophthora solani in eggplant were all greater than 120 in the mass ratio range of 1-15:10-1, indicating a synergistic effect.

[0034] In summary, the combination of lentinan and sennamycin or streptomycin in the biological pesticide of this invention has a synergistic effect on the blight pathogen of eggplant, which helps to improve the control effect of blight pathogen of eggplant and reduce the control cost.

Claims

1. A biological pesticide, characterized in that, The active ingredient of the biological pesticide is a binary compound of lentinan and sennamycin or kasugamycin.

2. The biological pesticide according to claim 1, characterized in that, The mass ratio of the compound lentinan to shenqinmycin is 1-16:16-1.

3. The biological pesticide according to claim 1, characterized in that, The mass ratio of the compound lentinan to kasugamycin is 1-15:10-1.

4. A pesticide formulation comprising the biological pesticide of claim 1, characterized in that, The active ingredient accounts for 1-85% of the total mass of the pesticide formulation, with the remainder being auxiliary ingredients permitted for addition in pesticide science.

5. The pesticide formulation according to claim 4, characterized in that, The active ingredient accounts for 1-45% of the mass of the pesticide formulation.

6. The use of the biological pesticide according to any one of claims 1-3 or the pesticide formulation according to any one of claims 4-5 in the prevention and control of eggplant blight.

7. The application according to claim 6, characterized in that, The eggplant blight is caused by infection with Phytophthora capsici.