A fungicidal composition comprising rhodopseudomonas palustris and anilazine
By combining Rhodopseudomonas palustris with isoprothiolane in a specific ratio, a fungicide composition was prepared for the control of rice blast disease, which solved the problem of rice blast resistance and achieved a highly efficient and low-dose control effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUNAN PLANT PROTECTION INST
- Filing Date
- 2022-08-15
- Publication Date
- 2026-07-24
AI Technical Summary
In the current technology, the control of rice blast mainly relies on isoprothiolane, but long-term use has led to the development of drug resistance in the disease, and there are no reports of combining Rhodopseudomonas palustris with isoprothiolane for control. How to reduce pesticide use and achieve green integrated pest management remains a challenge.
Rhodopseudomonas palustris and isoprothiolane are compounded in a specific ratio to form a fungicide composition, which is then used in an pesticide-acceptable formulation for the control of rice blast. The concentration of Rhodopseudomonas palustris bacterial solution is 1-9×10⁹ cfu/mL, preferably 2-5×10⁹ cfu/mL, and the ratio is 1:50-1:1.
It significantly enhances the control effect against rice blast, reduces the dosage of active ingredients, and slows down the development of pesticide resistance in the disease.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of pesticide compositions, specifically relating to a fungicide composition containing Rhodopseudomonas palustris and isoprothiolane and its application. Background Technology
[0002] my country is a major agricultural country, and rice is a crucial source of food. Therefore, rice quality and disease control have always been key concerns. Rice blast is one of the major diseases affecting rice, and it can occur throughout the entire growth cycle. This disease can occur on leaves, nodes, panicle neck, and grains, with common types including leaf blast, panicle blast, and stem blast. Rice blast is widespread in my country, and severe outbreaks can cause leaf death, shortened nodes, white panicles, and shriveled grains, significantly impacting rice yield. Control measures for rice blast mainly include breeding resistant varieties, chemical control, and strengthening cultivation management. Resistant varieties are often vertically resistant based on the "gene-to-gene" theory. However, the genetic variation of the rice blast pathogen is very frequent, and long-term, large-scale use of a single resistant variety can easily alter its physiological race composition and structure, leading to the loss of resistance.
[0003] Chemical control has advantages such as being economical, effective, convenient, and fast-acting, and has therefore always been an important component of the integrated management system for rice blast. However, due to increased resistance and delayed detection, pesticide application has become extremely unscientific and irrational, with dosages and frequency of application seriously exceeding standards, causing significant problems such as environmental pollution and agricultural product quality and safety. Therefore, how to reduce pesticide use and implement green integrated control of rice blast remains a crucial issue facing rice production in my country.
[0004] The applicant's previous research found that *Rhodopseudomonas palustris* has excellent control effects on rice blast and rice false smut. For example, CN201610333926 discloses the application of *Rhodopseudomonas palustris* fermentation broth in the control of rice blast, characterized in that the fermentation broth is obtained by culturing *Rhodopseudomonas palustris* LY-6. CN201610333888 discloses the application of *Rhodopseudomonas palustris* biocontrol agent in the control of rice blast, characterized in that the biocontrol agent is obtained by culturing *Rhodopseudomonas palustris* LY-6. In addition, the applicant has also studied the good control effects of *Rhodopseudomonas palustris* on various diseases such as potato scab, tomato chlorosis virus, potato late blight, and bacterial leaf streak.
[0005] Isoprothiolane is highly effective against rice blast. After being absorbed by rice plants, it inhibits pathogen invasion, especially by inhibiting phospholipid N-methyltransferase, thereby suppressing pathogen growth and playing a role in prevention and treatment. For the control of rice blast, apply once each at the heading and panicle stages. It can also be used to control large and small leaf spot diseases of corn, and barley stripe and clouding diseases. However, long-term use of isoprothiolane has led to serious resistance development in diseases.
[0006] There are no existing reports on the use of Rhodopseudomonas palustris in combination with isoprothiolane for the control of rice blast disease. Summary of the Invention
[0007] To address the problems existing in the prior art, the present invention provides the following technical solution: A fungicide composition comprising Rhodopseudomonas palustris and isoprothiolane, wherein the mass ratio of Rhodopseudomonas palustris bacterial suspension to isoprothiolane is 1:50-50:1; and the concentration of Rhodopseudomonas palustris bacterial suspension is 1-9×10⁻⁶. 9 cfu / mL. Preferably, the mass ratio of *Rhodopseudomonas palustris* bacterial suspension to isoprothiolane is 1:1-50:1. Preferably, the concentration of the *Rhodopseudomonas palustris* bacterial suspension is 2-5 × 10⁻⁶. 9 cfu / mL.
[0008] The bactericidal composition of this invention also contains pesticide-acceptable excipients, and can be prepared into any acceptable pesticide formulation, such as suspension concentrates or wettable powders. The bactericidal composition of the present invention is used for the prevention and control of rice blast disease.
[0009] Preferably, the Rhodopseudomonas palustris LY-6 used in this application is deposited at the China Center for Type Culture Collection (CCTCC) with accession number CCTCC NO: M 2014525. The depositary address is located at Wuhan University, China, and the deposit date is October 29, 2014. This strain is named Rhodopseudomonas palustris LY-6 (Rhodopseudomonas palustris LY-6 has been patented, patent application number: 201410750073.2).
[0010] Preparation of Rhodopseudomonas palustris LY-6 was performed according to (Patent Application No.: 201410750073.2): (1) Activation: The preserved strain of Rhodopseudomonas palustris was cultured using the double-layer plate culture method until red single colonies appeared; (2) Seed culture: The red single colonies cultured in step (1) were inoculated into serum bottles and cultured in photosynthetic bacteria liquid culture medium at a temperature of 30℃~32℃, a light condition of 2500Lx~4000Lx, and a pH of 7.0 until the logarithmic growth phase to obtain bacterial solution. (3) Production culture: The bacterial solution obtained after seed culture in step (2) is inoculated into the production bottle and cultured in the photosynthetic bacteria production medium. The inoculation amount of the bacterial solution is 5% of the total volume of the photosynthetic bacteria production medium. The culture is carried out in the logarithmic growth phase under the conditions of temperature of 30℃~32℃, light conditions of 2500Lx~4000Lx and pH=7.0. The concentration of Rhodopseudomonas palustris bacterial suspension is 1-9 × 10⁻⁶. 9 cfu / mL.
[0011] By adopting the above technical solution, the present invention has the following beneficial effects: The combination of Rhodopseudomonas palustris and isoprothiolane has a significant synergistic effect on rice blast pathogens, which can reduce the dosage of active ingredients and slow down the development of drug resistance in the disease. Detailed Implementation
[0012] The present invention will be further explained below with reference to specific embodiments.
[0013] Example 1: Indoor toxicity test of compound agent against rice blast disease Test strain: Magnaphalthe oryzae, the pathogen causing rice blast; collected, isolated and purified at the experimental site.
[0014] Test reagents: Rhodopseudomonas palustris bacterial suspension (A): concentration 5×10 9 cfu / mL; Rice Blast (B): Raw material, commercially available.
[0015] Test method: The mycelial growth rate inhibition method was employed. Based on preliminary experiments, each test agent was prepared into a series of dilutions at varying concentrations under aseptic conditions. These were then added aseptically to melted PDA medium at specific ratios, mixed, and poured into sterile Petri dishes to create a series of drug-containing medium plates with varying concentrations. The tested rice blast fungus strains were first incubated on PDA medium at 25°C for 5-7 days. When the colonies reached the edge of the Petri dish, mycelial cakes were collected from the edge of the colonies using a 5mm diameter punch and then transferred to the center of the drug-containing medium plates. Plates without added drugs served as a control. One plate was inoculated per plate, with each agent constituting one treatment, and each treatment was replicated four times.
[0016] The growth of pathogenic mycelia was investigated based on the growth of bacteria in the blank control culture dishes. The diameter of the colonies was measured with calipers. Each colony was measured twice using the cross-sectional method, and the average value was used to represent the size of the colony. The inhibition rate and virulence index were calculated using the following formula: Inhibition rate = (Coronary diameter of control group - Colony diameter of treatment group) / Colony diameter of control group × 100%.
[0017] The toxicity index and co-toxicity coefficient (CTC) of the drug were calculated according to Sun Yunpei's method.
[0018] Actual toxicity index (ATI) = (EC50 of standard reagent / EC50 of test reagent) × 100; Theoretical toxicity index (TTI) = Toxicity index of agent A × Percentage content of A in the mixture + Toxicity index of agent B × Percentage content of B in the mixture; Co-toxicity coefficient (CTC) = [Actual toxicity index (ATI) of mixture / Theoretical toxicity index (TTI) of mixture] × 100; When CTC≤80, the composition exhibits antagonistic effects; when 80<CTC<120, the composition exhibits additive effects; when CTC≥120, the composition exhibits synergistic effects.
[0019] Test results: The combination of Rhodopseudomonas palustris and isoprothiolane showed different synergistic effects on rice blast pathogens. When the ratio of Rhodopseudomonas palustris to isoprothiolane was 1:1-50:1, it had a significant synergistic effect, which could reduce the dosage of active ingredients and slow down the development of drug resistance in the disease.
[0020] Table 1: Indoor toxicity test of compound pesticides against rice blast disease Example 2: Field control efficacy of compound pesticide against rice blast. Test location: Chunhua Test Base Experimental crop disease: Rice blast Experimental Methods: A pesticide treatment and a blank control were set up, with each treatment replicated three times. The plot area was 50 m², with a protection row and randomized block design. At the rice heading stage, a manual sprayer was used to spray the pesticide-treated leaves and panicles with an equal volume of water in the blank control area. No other fungicides were applied during the experiment, and field management was carried out as usual.
[0021] Thirty days after application, the incidence of rice blast was investigated using parallel skip sampling. Twenty holes were investigated in each plot, and the disease index and control effect were calculated (the disease index is based on GBT17980.19-2000, Field Efficacy Trial Guidelines - Fungicide Control of Rice Leaf Diseases).
[0022] Test results: Compared with the use of Rhodopseudomonas palustris alone, the combination of Rhodopseudomonas palustris and isoprothiolane significantly improved the control effect of the agent on rice blast.
[0023] Table 2: Field control efficacy of compound pesticides against rice blast Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.
Claims
1. A fungicide composition comprising Rhodopseudomonas palustris and blast fungicide, characterized in that, The mass ratio of Rhodopseudomonas sphagnum moss inoculum to rice blast fungicide is 1:1-50:1; The concentration of *Rhodopseudomonas palustris* bacterial suspension was 5 × 10⁻⁶. 9 cfu / mL; The Rhodopseudomonas palustris LY-6 is deposited at the China Center for Type Culture Collection (CCTCC) with accession number CCTCC NO: M 2014525.
2. The bactericidal composition according to claim 1, characterized in that, It also contains pesticide-acceptable excipients.
3. The bactericidal composition according to claim 2, characterized in that, The bactericidal composition is formulated as a suspension or wettable powder.
4. Use of the bactericidal composition according to any one of claims 1-3 for the prevention and control of rice blast disease.