Inquilinus strain and application thereof

Abstract

The invention discloses an Inquilinus strain and application thereof, the Inquilinus strain is # imgabs0 # and is preserved in the China Center for Type Culture Collection (CCTCC) on January 6, 2025, and the preservation number of the Inquilinus strain is CCTCC NO: M 2025044. The Inquilinus strain is subjected to activation and seed culture to obtain the microbial agent. The Inquilinus strain and the microbial agent can be used as biopesticides, can improve the prodenia litura resistance of cotton, and can be used for preventing and controlling tomato late blight and virus diseases, tomato brown wrinkled fruit virus diseases and tomato chlorosis viruses. The method has the advantages of low production cost, good prevention and control effect, high efficiency, no toxicity, environmental protection and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of microbiology, and particularly relates to an Inquilinus strain and its application. Background Art

[0002] Crop pests and diseases are the greatest threats affecting the safe development of the crop industry. Prevention and control still highly rely on chemical pesticides. The use of chemical insecticides has saved a large amount of losses caused by insect pests in agricultural production and greatly promoted the development of modern agricultural production. However, the impact of chemical insecticides on non-target organisms and their residues have caused serious harm to the ecosystem. Microbial inoculants are the current development direction of green prevention and control technologies for crop pests and diseases in the world. Modern microbiomics technologies provide a new technical guarantee for the screening, evaluation of new and highly efficient high-quality microbial strains and the application of secondary metabolites. However, there are currently few highly efficient and excellent microbial strains, and the functional roles of microbial strains are relatively single. Therefore, screening excellent multi-functional strains, developing their highly efficient and low-cost production processes, preparing convenient-to-use inoculants, and applying them rationally are all technical problems that those skilled in the art need to face. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies existing in the prior art and provide an Inquilinus strain and its application. The Inquilinus strain is a photosynthetic bacterial strain that can promote crop growth and activate broad-spectrum resistance of crops, and has advantages such as high efficiency, non-toxicity, and environmental protection. Correspondingly, an application of the Inquilinus strain as a biological pesticide is also provided, which has advantages such as low production cost and no toxic side effects.

[0004] To solve the above technical problems, the present invention provides an Inquilinus strain, and the Inquilinus strain is preserved in the China Center for Type Culture Collection (CCTCC) on January 6, 2025, with the preservation number of CCTCC NO: M 2025044.

[0005] Based on a general technical concept, the present invention also provides a microbial inoculant, and the microbial inoculant is obtained by seed culture and production culture of the above-mentioned Inquilinus strain.

[0006] Based on a general technical concept, the present invention also provides a preparation method of a microbial inoculant, including the following steps: S1. Culture the preserved strain on an LB solid medium plate at 30 °C until single colonies appear; S2. Inoculate the single colony into LB liquid medium, and culture it at 30 °C and 150 rpm for 24 h until OD660 = 0.9 - 1.2 to obtain the microbial inoculum.

[0007] Based on a general inventive concept, the present invention also provides an application of Inquilinus strain or microbial inoculum in enhancing the resistance of cotton to Spodoptera litura.

[0008] Based on a general inventive concept, the present invention also provides an application of Inquilinus strain or microbial inoculum in controlling tomato downy mildew.

[0009] Based on a general inventive concept, the present invention also provides an application of Inquilinus strain or microbial inoculum in controlling tomato brown rugose fruit virus disease.

[0010] Based on a general inventive concept, the present invention also provides an application of Inquilinus strain or microbial inoculum in controlling tomato chlorosis virus disease.

[0011] Compared with the prior art, the advantages of the present invention are as follows: (1) The present invention provides an Inquilinus strain, which can be used to prepare a microbial inoculum that promotes crop growth and activates the broad-spectrum resistance of crops through a simple, fast, and low-cost operation method. The inoculum prepared using the strain of the present invention has the advantages of low production cost, convenient use, good environmental compatibility, etc., and can be effectively used in the production of high-quality grains, fruits, vegetables, etc. in agricultural production. It has the advantages of low production cost, good pesticide removal effect, high efficiency, non-toxicity, environmental protection, etc.

[0012] (2) The present invention provides an application of Inquilinus strain as a biological pesticide. The strain of the present invention can promote crop growth and activate the broad-spectrum resistance of crops under both laboratory conditions and field conditions. It can be used to prevent the occurrence of crop diseases and pests, partially replace chemical pesticides used for controlling crop diseases and pests, and improve crop yield and quality. Moreover, the strain of the present invention itself has various nutrient components and active substances, which can effectively promote crop growth and has the characteristics of safety, non-toxicity, and environmental protection.

[0013] The Inquilinus strain is deposited in the China Center for Type Culture Collection (abbreviated as CCTCC), and the deposit number is CCTCC NO: M 2025044. The address of the depositary institution is located at Wuhan University, Wuhan, Hubei Province, China. The deposit date is January 6, 2025, and the strain is named . Description of the Drawings

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0015] Figure 1 It is the electron micrograph of the Inquilinus strain in Example 1. Detailed implementation manners

[0016] The present invention will be further described below in conjunction with specific and preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0017] The materials, reagents, and instruments used in the following embodiments can all be obtained from commercial channels. The experimental methods in the following embodiments are all conventional methods in the art unless otherwise specified.

[0018] Example 1 An Inquilinus strain: , deposited in the China Center for Type Culture Collection (CCTCC), deposit number CCTCC NO: M 2025044. The depository is the China Center for Type Culture Collection (CCTCC), and the depository address is located at Wuhan University, Wuhan, Hubei, China. The deposit date is January 6, 2025.

[0019] Figure 1 It is the electron micrograph of the Inquilinus strain, and this strain has the following main characteristics: G-, the individual morphology is rod-shaped, V-P reaction negative, MR reaction negative, methyl red reaction negative, can utilize citrate, cannot utilize starch, indole reaction negative, can grow in 3% NaCl, the optimum growth temperature is 30°C - 35°C, the optimum growth pH value is 6.5 - 7.5, the length of the 16S rDNA sequence is 1418 bp, and the accession number in the Genome Sequence Archive (GSA) of the National Genomics Data Center (https: / / ngdc.cncb.ac.cn / ) is C_AA100992.

[0020] The Inquilinus strain in this example was screened by the following method: Mix 2.0 g of rhizosphere soil collected from cotton and tomato and add it to 150 mL of LB liquid medium, and culture at 30°C and 150 rpm for 2 d to obtain a culture solution. Take 50 μL of the culture solution and spread it on the LB solid medium, culture at 30°C for 2 d, pick the bacteria with different morphologies and colors, streak them on the LB solid medium, and culture at 30°C until single colonies appear. Inoculate the single colonies into the LB liquid medium and culture at 30°C and 150 rpm. Select the Inquilinus strain that promotes crop growth most significantly (named )Carry out subsequent research. Inoculate the strain into 150 mL of LB medium and culture it at 30 °C and 150 rpm. Use the gradient dilution plate culture method to measure the biomass of the strain, and adjust the concentration of the bacterial solution to about 2 × 10 9 cfu / mL in subsequent experiments.

[0021] Example 2 A microbial inoculant is prepared by using the method in Example 1, and specifically includes the following steps: (1) Activation: Culture the preserved strain of the strain on an LB solid medium plate at 30 °C until single colonies appear.

[0022] (2) Production culture: Inoculate the single colony into an LB liquid medium and culture it at 30 °C and 150 rpm for 24 h until OD660 = 0.9 - 1.2.

[0023] (3) Bottle out and subpackage to obtain the inoculant.

[0024] The total process culture time of the method in this example is 4 - 5 days. After the culture is completed, the number of bacteria reaches more than 300 million per ml.

[0025] Example 3 Application of the microbial inoculant in Example 2 in enhancing the resistance of cotton to Spodoptera litura.

[0026] Cotton variety Xiangzamian No. 7 is planted in the greenhouse, and cotton seedlings at the 5 - leaf stage are used for the resistance experiment. The microbial inoculant in Example 2 is evenly sprayed on the cotton seedlings at the 5 - leaf stage. One day later, 5 second - instar Spodoptera litura larvae that have been weighed are inoculated. Seven days later, the weight of Spodoptera litura is measured, and the increased value of the weight of Spodoptera litura larvae is calculated. Spraying an equal amount of ddH2O and LB medium is used as a control. All treatments are repeated three times, and the measurement results are shown in Table 1 below.

[0027] Table 1: The microbial inoculant in Example 2 enhances the resistance of potted cotton to Spodoptera litura

[0028] From the results in Table 1, it can be seen that: applying the strain of the present invention significantly inhibits the increased value of the weight of Spodoptera litura, indicating that it significantly enhances the resistance of potted cotton to Spodoptera litura. In Table 1, a and b represent the statistical differences between different groups. The same letter indicates no significant difference, and different letters indicate significant differences.

[0029] Example 4 Application of the microbial inoculant in Example 2 in controlling tomato late blight and virus disease.

[0030] ​80% oxadimethoxine water dispersible granules were selected as the control agent (recommended dosage), and the microbial agent of Example 2 was sprayed on the tomato field at 200 mL / mu and 45 kg of water per mu; the treatment area was 50 m 2 , repeated three times. The disease index of tomato late blight was investigated 15 days after application. The experiment was conducted in accordance with the Guidelines for Field Efficacy Tests of Pesticides (I) Control of Tomato Early Blight and Late Blight with Fungicides (GB / T 17980.13). The control results are listed in Table 2.

[0031] Table 2: Effect of the microbial agent of Example 2 on the prevention and control of tomato downy mildew in the field

[0032] The control effect shown in Table 2 shows that the control effect of the strain of the present invention on tomato late blight is significantly higher than that of the control group, and the control effect is as high as 63.81%. a, b, and c in Table 2 are statistical differences between different groups, the same letters indicate no significant difference, and different letters indicate significant difference.

[0033] Example 5 An application of the microbial agent of Example 2 in preventing and controlling tomato brown wrinkled fruit virus disease.

[0034] The half-leaf method was used to determine the effect of the microbial agent in Example 2 on the prevention and treatment of tomato brown wrinkled fruit virus disease. A total of 4 treatment groups were set up: (1) the microbial agent in Example 2; (2) commercially available 5% morpholinoguanidine hydrochloride soluble powder; (3) culture medium control treatment; (4) clear water as a blank control; 10 plants were treated in each group, and the test was repeated 3 times.

[0035] Taking the main vein as the interval, the left part of the leaf was the control group and the right part of the leaf was the treatment group. The number of necrosis spots for prevention and treatment effects was the mean of the total number of necrosis spots of heartleaf tobacco in each group (10 plants) after three experimental repetitions.

[0036] Prevention test: Heartleaf tobacco was cultivated in a greenhouse until the 5-leaf stage, and covered with hard plastic boards. The left part of the leaves was sprayed with ddH2O as a blank control, and the right part was sprayed with fungal agents, chemical agents or culture media. After an interval of 1 day, the virus was inoculated by friction inoculation method. The disease condition of the leaves was observed after 3 days, and the number of leaf spots after 3 repetitions was counted to calculate the prevention effect.

[0037] Treatment test: The virus was inoculated by friction inoculation method at the 5-leaf stage. The spraying was carried out at intervals of 6 hours. The leaves were shielded with hard plastic boards. ddH2O blank control was sprayed on the left side of the leaves, and fungal agents, chemical agents or culture media were sprayed on the right side. The disease condition of the leaves was observed and photographed after 3 days. The number of leaf spots was counted for 3 repetitions, and the treatment effect was calculated. The treatment results are listed in Table 3.

[0038] Table 3: Prevention and control effects of the microbial inoculum in Example 2 against tomato brown rugose fruit virus disease

[0039] The results in Table 3 show that when the strains of the present invention are applied, the control effect against tomato brown rugose fruit virus disease is comparable to that of the control medicament, 5% moroxydine hydrochloride soluble powder; and the preventive effect is higher than the treatment effect. In Table 3, a and b represent the statistical differences between different groups. The same letters indicate no significant difference, and different letters indicate a significant difference.

[0040] Example 6 Application of the microbial inoculum in Example 2 in the prevention and control of tomato chlorosis virus disease

[0041] Select 5% moroxydine hydrochloride soluble powder as the control medicament (recommended dosage). The microbial inoculum in Example 2 is sprayed at 200 mL / mu, calculated according to a water volume of 45 kg per mu for spraying; the treatment plot area is 50 m 2 , and repeated three times. The number of diseased tomato plants with tomato chlorosis virus disease was investigated 15 days after spraying. The experiment was carried out in accordance with the Guidelines for the Field Efficacy Trials of Pesticides - Part 8: Fungicides for Controlling Tomato Virus Diseases (NY / T 1464.8). The experimental results are listed in Table 4.

[0042] Table 4: Field prevention and control effects of the microbial inoculum in Example 2 against tomato chlorosis virus disease

[0043] The prevention and control effects in Table 4 show that when the strains of the present invention are applied, the control effect against tomato chlorosis virus disease is comparable to that of the control medicament, 5% moroxydine hydrochloride soluble powder. In Table 4, a and b represent the statistical differences between different groups. The same letters indicate no significant difference, and different letters indicate a significant difference.

[0044] The above are only preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above, or modify it into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An Inquilinus strain, characterized in that, The Inquilinus strain is , and was deposited at the China Center for Type Culture Collection (CCTCC) on January 6, 2025, with the deposit number CCTCC NO: M 2025044.

2. The Inquilinus strain according to claim 1, wherein The Inquilinus strain is activated and subjected to production culture to obtain a microbial inoculum.

3. The Inquilinus strain according to claim 2, characterized in that, The preparation method of the microbial inoculum includes the following steps: S1. Inoculate the preserved strain on an LB solid medium plate and incubate at 30 °C until single colonies appear; Inoculate the preserved strain on an LB solid medium plate and incubate at 30 °C until single colonies appear; S2. Inoculate the single colony into an LB liquid medium and culture it at 30 °C and 150 rpm for 24 h until OD660 = 0.9 - 1.2 to obtain a microbial inoculum.

4. Application of the Inquilinus strain according to any one of claims 1 to 3 in enhancing the resistance of cotton to Spodoptera litura.

5. Application of the Inquilinus strain according to any one of claims 1 to 3 in controlling tomato downy mildew.

6. Application of the Inquilinus strain according to any one of claims 1 to 3 in controlling tomato brown rugose fruit virus disease.

7. Application of the Inquilinus strain according to any one of claims 1 to 3 in controlling tomato chlorosis virus disease.

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