Application of biocontrol strain hzq1601 in prevention and treatment of bacterial blight of rice

Abstract

The invention relates to the technical field of prevention and treatment of plant diseases, in particular to application of a biocontrol strain hzq1601 to prevention and treatment of rice bacterial blight. The biocontrol strain hzq1601 is a bacterial strain hzq1601 of bacillus amyloliquefaciens, the preservation number of the bacterial strain hzq1601 is GDMCC (China General Microbiological Culture Collection Center) NO: 60355, and the biocontrol strain hzq1601 is a bacterial strain hzq1601 of bacillus amyloliquefaciens with the preservation number of GDMCC NO: 60355. The invention further provides a method for preventing and treating the rice bacterial blight, in the rice seedling stage, the biocontrol strain hzq1601 bacterial liquid is sprayed to leaves, so that the morbidity of the rice bacterial blight is remarkably reduced to 1% or below, and losses caused by the bacterial blight are reduced; the bacterial liquid of the biocontrol strain hzq1601 is sprayed to the surface of soil in the tillering stage or booting stage, and the bacterial leaf blight prevention effect and the disease index prevention effect of the biocontrol strain hzq1601 are obviously higher than those of other treatments under the condition that the dosage of the bacterial liquid for seedling treatment is small. The action path of the bacillus amyloliquefaciens is direct and efficient, especially, the strong control effect can be achieved through low-dose spraying in the seedling stage, cost and operation difficulty are reduced, a stable pesticide application window and strategy are formed, and wide popularization prospects are achieved.

Description

Technical Field

[0001] This invention relates to the field of plant disease control technology, specifically to the application of biocontrol strain hzq1601 in the control of rice bacterial blight. Background Technology

[0002] Rice is a staple food crop for humans. Bacterial leaf blight (Xanthomonas oryzae pv. oryae, Xoo) is one of the three major diseases affecting rice. It occurs in rice-growing areas of my country, leading to a decline in rice quality and yield, typically causing a 20%-40% reduction, and in severely affected areas, a 50%-60% reduction, or even total crop failure. It ranks first among bacterial diseases affecting rice worldwide. Chemical fungicides are commonly used for rapid and effective control of rice diseases. While chemical fungicides have some inhibitory effect on rice bacterial leaf blight, their effectiveness is not ideal. In recent years, the ban on straw burning has led to the accumulation of pathogens in the soil, and the use of drones has indirectly exacerbated the disease by damaging rice leaves. Using biocontrol bacteria to control rice bacterial leaf blight, either through seed soaking or direct application to the soil, can be effective, but the consumption is relatively large. Therefore, developing efficient and environmentally friendly methods for using biological fungicides is imperative.

[0003] Patent CN109769535A discloses the application of endophytic fungal strain R5-6-1 in the control of rice bacterial blight. This patent utilizes co-culturing of endophytic fungus R5-6-1 with rice, allowing it to colonize the rice roots and control foliar infection by the bacterial blight pathogen, demonstrating a certain degree of control effect. However, this patent is limited to laboratory research and does not provide field dosage for practical application. Furthermore, the involved fungal strain R5-6-1 is a fungus, and in practical applications, fungal strains may have limitations such as sensitivity to environmental conditions and complex colonization processes. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of this invention is to provide the application of biocontrol strain hzq1601 in the control of rice bacterial blight.

[0005] The present invention is implemented using the following technical solutions: The first aspect of this invention provides the application of biocontrol strain hzq1601 in the control of rice bacterial blight, wherein the biocontrol strain hzq1601 is Bacillus amyloliquefaciens with accession number GDMCC NO:60355. Bacillus amyloliquefaciens Bacterial strain hzq1601.

[0006] The second aspect of this invention provides a method for preventing and controlling bacterial leaf blight in rice, wherein the rice seedlings are treated with a bacterial solution spray, wherein the bacterial solution is a biocontrol strain hzq1601, and the biocontrol strain hzq1601 is Bacillus amyloliquefaciens with accession number GDMCC NO:60355.

[0007] Furthermore, the method includes spraying rice with bacterial solution during the rice seedling stage.

[0008] Furthermore, the seeds were soaked in metalaxyl-mancozeb before the bacterial solution spray treatment.

[0009] Furthermore, the bacterial solution spraying treatment is as follows: using a bacterial solution diluted 300 times, spray 200mL onto each 60cm×25cm seedling tray.

[0010] Furthermore, the bacterial spray treatment is performed twice, with the first treatment occurring when the seedlings have emerged completely, and the second treatment occurring 10 days apart from the first.

[0011] Furthermore, the total amount of bacterial solution used throughout the rice seedling stage is 40 mL per mu.

[0012] This invention discovers that spraying the biocontrol strain hzq1601 onto the leaves during the rice seedling stage significantly reduces the incidence of rice bacterial blight to below 1%, thereby reducing losses caused by bacterial blight.

[0013] Furthermore, the method also includes applying bacterial solution to the soil during the tillering or booting stage of rice.

[0014] Furthermore, the bacterial solution soil application treatment is as follows: 2L of bacterial solution is used per acre to prepare 30L of solution, which is then evenly sprayed onto the soil surface.

[0015] Furthermore, the stock culture density of the bacterial solution is 0.5-1.5 × 10⁻⁶. 10 CFU / mL.

[0016] This invention found that spraying the biocontrol strain hzq1601 onto the leaves during the seedling stage and spraying it onto the soil surface during the tillering or booting stage, with a small amount of bacterial solution used in the seedling stage treatment, resulted in a bacterial blight control efficacy of 94.17% and a disease index control efficacy of 93.49%, both significantly higher than other treatments.

[0017] The present invention has the following beneficial effects: The biological control effect is excellent and stable, achieving both disease control and yield guarantee.

[0018] It requires small amounts and has low costs, making it highly economical for industrial applications.

[0019] It is easy to apply and is compatible with conventional rice planting processes.

[0020] Green and safe, in line with the development needs of green pest control in agriculture.

[0021] It has a wide range of applicable periods and scientific prevention and control strategies, making it suitable for different planting scenarios. Attached Figure Description

[0022] Figure 1 The growth of rice variety Zhongzao 39 was observed after bacterial spray treatment. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments.

[0024] Example 1: Effect of biocontrol strain hzq1601 on seedling stage control of bacterial leaf blight and yield increase in Zhongzao 39 rice. Test strain: Bacillus amyloliquefaciens hzq1601 ( Bacillus amyloliquefaciens The strain has the preservation number GDMCC NO: 60355. This strain is an existing strain. For details on the screening and identification of this strain, please refer to the invention patent with publication number CN 108998395A.

[0025] NA liquid medium: 10 g peptone, 3 g beef extract, 5 g sodium chloride, pH 7.2, sterilized at 121℃ for 15 min; NA solid medium: 15 g agar powder added to the liquid medium.

[0026] Bacterial culture preparation: The bacterial strain, refrigerated at -80℃, was plated onto NA solid medium. After activation, single colonies were picked and incubated in NA liquid medium at 28℃ and 150 rpm for 24 h with shaking. Then, 1 mL of the bacterial culture was transferred to 500 mL of NA liquid medium for further culture, and incubated at 28℃ and 150 rpm with shaking for 3 days. The bacterial density was determined to be 0.5–1.5 × 10⁻⁶. 10 CFU / mL.

[0027] The rice variety tested was Zhongzao 39.

[0028] The efficacy of Bacillus amyloliquefaciens HZQ1601 against bacterial blight in rice variety Zhongzao 39. Seeds were soaked in metalaxyl-mancozeb, and after emergence, they were sprayed with a 300-fold dilution of bacterial solution, 200 mL per seedling tray (60 cm × 25 cm). Ten days later, a second foliar spray of the same 300-fold dilution was applied. Control seedlings were sprayed twice by farmers with 30% metalaxyl-mancozeb aqueous solution for 35 days, with subsequent management identical to the control. Only 20 mL of bacterial solution was needed per acre of rice seedlings per application, with a total of 40 mL applied twice throughout the seedling cycle. Bacterial blight incidence was investigated 10 days before rice harvest. Results showed that the incidence of bacterial blight in the hzq1601 treatment group was <1%, indicating that only 40 mL of bacterial solution at the seedling stage controlled the occurrence of rice bacterial blight, reducing losses caused by the disease. The effects are shown in Table 1. Figure 1 As shown.

[0029] Table 1. Control efficacy of Bacillus amyloliquefaciens hzq1601 against bacterial blight in rice variety Zhongzao 39. Processing group Incidence rate (%) Rice yield (kg / mu) hzq1601 <1 553.8 CK 37 480.0 Example 2: Control efficacy of biocontrol strain hzq1601 at different growth stages against bacterial blight in Shunda 135 rice. The test strains, culture media, and bacterial solutions were prepared in the same manner as in Example 1.

[0030] The rice variety tested was Shunda 135.

[0031] The efficacy of Bacillus amyloliquefaciens HZQ1601 against bacterial blight in rice Shunda 135 Treatment a: Seedling stage treatment (treatment method is the same as in Example 1), no treatment during the mature stage; Treatment b: No treatment during the seedling stage, but treatment during the tillering stage. Use 2L of bacterial solution per acre to make 30L of solution and spread it evenly on the soil surface. Treatment c: No treatment during the seedling stage, but treatment during the booting stage. Use 2L of bacterial solution per acre to make 30L of solution and spread it evenly on the soil surface. Treatment d: CK, no bacterial inoculum used, treated according to standard farmer practices. None of these treatments control bacterial blight. Ten days before rice harvest, bacterial blight incidence was assessed using a 5-point sampling method, and the incidence rate, disease index, and control efficacy were calculated.

[0032] The formulas for calculating the disease index and prevention and control effectiveness are as follows:

[0033] The results showed that the seedling stage treatment used the least amount of bacterial solution, and its control efficacy against bacterial blight reached 94.17% and the disease index control efficacy reached 93.49%, both significantly higher than other treatment groups, significantly reducing the incidence and disease index. The effects of each treatment group are shown in Table 2.

[0034] Table 1. Control efficacy of Bacillus amyloliquefaciens hzq1601 against bacterial blight in rice Shunda 135. Processing group Incidence rate (%) Preventive efficacy (%) Disease index Preventive efficacy (%) a Seedling stage 2.80D 94.17A 1.64D 93.49A b Tillering stage 12.40C 63.44B 10.31C 59.19B c. Booting stage 18.80B 47.04C 14.93B 40.90C d CK 28.20A ―― 25.27A ―― Note: Different capital letters after data in the same column indicate that... P The difference was statistically significant at the <0.05 level.

Claims

1. The application of biocontrol strain hzq1601 in the control of rice bacterial leaf blight, characterized in that, The biocontrol strain hzq1601 is *Bacillus amyloliquefaciens* with accession number GDMCC NO:60355. Bacillus amyloliquefaciens Bacterial strain hzq1601.

2. A method for controlling bacterial leaf blight in rice, characterized in that, Rice seedlings were treated with a bacterial solution spray. The bacterial solution was a biocontrol strain hzq1601, which is a Bacillus amyloliquefaciens with accession number GDMCC NO:60355.

3. The method as described in claim 2, characterized in that, The seeds were soaked in metalaxyl-mancozeb before the bacterial solution was sprayed.

4. The method as described in claim 2, characterized in that, The bacterial solution spraying treatment is as follows: use a bacterial solution diluted 300 times, and spray 200mL onto each 60cm×25cm seedling tray.

5. The method according to claim 3, characterized in that, The bacterial spray treatment is performed twice, with the first treatment occurring when the seedlings have emerged completely, and the second treatment occurring 10 days apart from the first.

6. The method as described in claim 3, characterized in that, The total amount of bacterial solution used throughout the rice seedling stage is 40 mL per mu.

7. The method as described in claim 1, characterized in that, This also includes applying bacterial solution to the soil during the tillering or booting stage of rice.

8. The method as described in claim 5, characterized in that, The bacterial solution soil application treatment is as follows: 2L of bacterial solution is used per acre to prepare 30L of solution, which is then evenly sprinkled on the soil surface.

9. The method as described in claim 4 or 8, characterized in that, The stock culture density of the bacterial solution is 0.5-1.5 × 10⁻⁶. 10 CFU / mL.

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