Inquilinus strain and its application

Abstract

The present invention discloses an Inquilinus strain and its application. The Inquilinus strain is Inquilinus sp. PJ-1-11, which was deposited with the China Center for Type Culture Collection (CCTCC) on January 6, 2025, with the accession number CCTCC NO: M 2025044. The Inquilinus strain is activated and seed cultured to obtain a microbial agent. The Inquilinus strain and microbial agent of the present invention can be used as biopesticides to enhance cotton resistance to Spodoptera litura, and can be used to control tomato late blight and viral diseases, tomato brown wrinkled fruit virus disease, and tomato chlorosis virus. They have the advantages of low production cost, good control effect, high efficiency, non-toxicity, and environmental protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of microorganisms, and in particular relates to an Inquilinus strain and an application thereof. Background Art

[0002] Crop diseases and insect pests are the biggest threat to the safe development of the crop industry, and prevention and control still rely heavily on chemical pesticides. The use of chemical pesticides has saved a lot of losses caused by pests in agricultural production and greatly promoted the development of modern agricultural production. However, the impact of chemical pesticides on non-target organisms and their residues have caused serious harm to the ecosystem. Microbial agents are the current development direction of green control technology for crop diseases and insect pests in the world. Modern microbiome technology provides a new technical guarantee for the screening, evaluation and application of secondary metabolites of new, efficient and high-quality microbial strains. However, there are currently few efficient and excellent microbial strains, and the functions of microbial strains are relatively simple. Therefore, screening excellent multifunctional strains, developing efficient and low-cost production processes, preparing easy-to-use microbial agents, and applying them rationally are all technical challenges that those skilled in the art need to face. Summary of the Invention

[0003] The present invention aims to overcome the shortcomings of the prior art by providing an Inquilinus strain and its use. The Inquilinus strain is a photosynthetic bacterial strain that can promote crop growth and activate broad-spectrum crop resistance, offering advantages such as high efficiency, non-toxicity, and environmental friendliness. Furthermore, the present invention also provides the use of the Inquilinus strain as a biopesticide, which offers advantages such as low production costs and no toxic side effects.

[0004] In order to solve the above technical problems, the present invention provides an Inquilinus strain, which is Inquilinus sp. PJ-1-11, deposited in the China Center for Type Culture Collection CCTCC on January 6, 2025, with a preservation number of CCTCC NO: M 2025044.

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

[0006] Based on a general technical concept, the present invention also provides a method for preparing a microbial agent, comprising the following steps:

[0007] S1. Culture the stock of Inquilinus sp. PJ-1-11 on LB solid medium plates at 30°C until single colonies appear.

[0008] S2. The single colony was inoculated into LB liquid culture medium and cultured at 30°C and 150 rpm for 24 h until OD660 = 0.9-1.2 to obtain a microbial agent.

[0009] Based on a general technical concept, the present invention also provides an application of an Inquilinus strain or a microbial agent in improving the resistance of cotton to Spodoptera litura.

[0010] Based on a general technical concept, the present invention also provides an application of an Inquilinus strain or a microbial agent in preventing and controlling tomato brown wrinkled fruit virus disease.

[0011] Based on a general technical concept, the present invention also provides an application of an Inquilinus strain or a microbial agent in preventing and controlling tomato chlorosis virus disease.

[0012] Compared with the prior art, the advantages of the present invention are:

[0013] (1) The present invention provides an Inquilinus strain that can be used to produce a microbial agent that promotes crop growth and activates broad-spectrum crop resistance through a simple, rapid, and low-cost operation method. The agent produced using the strain of the present invention has the advantages of low production cost, ease of use, and good environmental compatibility, and can be effectively used in the production of high-quality grains, fruits, and vegetables in agricultural production. It has the advantages of low production cost, good pesticide removal effect, high efficiency, non-toxicity, and environmental protection.

[0014] (2) The present invention provides an application of an Inquilinus strain as a biopesticide. The strain of the present invention can promote crop growth and activate broad-spectrum crop resistance under both laboratory and field conditions. It can be used to prevent the occurrence of crop diseases and insect pests, and can also partially replace the application of chemical pesticides for crop disease and insect pest control, while also improving crop yield and quality. Moreover, the strain of the present invention itself has a variety of nutrients and active substances, can effectively promote crop growth, and is safe, non-toxic, and environmentally friendly.

[0015] The Inquilinus strain was deposited with the China Center for Type Culture Collection (CCTCC) under the accession number M 2025044. The deposit was made at Wuhan University, Wuhan, Hubei Province, China, on January 6, 2025. The strain was named Inquilinus sp. PJ-1-11. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0017] Figure 1 This is an electron microscope photograph of the Inquilinus strain in Example 1. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with specific preferred embodiments, but the scope of protection of the present invention is not limited thereby.

[0019] The materials, reagents, and instruments used in the following examples can all be purchased from commercial sources. The experimental methods in the following examples, unless otherwise specified, are all conventional methods in the art.

[0020] Example 1

[0021] An Inquilinus strain: Inquilinus sp. PJ-1-11, deposited with the China Center for Type Culture Collection (CCTCCC) with accession number M 2025044. The deposit was made at Wuhan University, Wuhan, Hubei Province, China, on January 6, 2025.

[0022] Figure 1 This is an electron micrograph of the Inquilinus strain, which has the following main characteristics:

[0023] G-, rod-shaped, negative for VP, MR, and methyl red, it can utilize citrate but not starch, has a negative indole reaction, can grow in 3% NaCl, has an optimal growth temperature of 30°C–35°C, and an optimal growth pH of 6.5–7.5. The 16S rDNA sequence is 1418 bp long, and its accession number in the National Genome Science Data Center (GSA) is C_AA100992.

[0024] The Inquilinus strain of this example was screened by the following method: 2.0 g of rhizosphere soil collected from cotton and tomato was mixed and added to 150 mL of LB liquid medium, and cultured at 30°C and 150 rpm for 2 days to obtain a culture solution. 50 μL of the culture solution was spread on LB solid medium and cultured at 30°C for 2 days. Bacteria with different morphology and color were picked and streaked on LB solid medium. The bacteria were cultured at 30°C until a single colony appeared. The single colony was inoculated into LB liquid medium and cultured at 30°C and 150 rpm. The Inquilinus strain that most significantly promoted crop growth (named Inquilinus sp. PJ-1-11) was selected for subsequent research. The strain was inoculated into 150 mL of LB medium and cultured at 30°C and 150 rpm. The biomass of the strain was determined by gradient dilution plate culture. In subsequent experiments, the bacterial solution concentration was adjusted to approximately 2 × 10 9 cfu / mL.

[0025] Example 2

[0026] A microbial agent was prepared using the Inquilinus sp. PJ-1-11 in Example 1, specifically comprising the following steps:

[0027] (1) Activation: Culture the preserved strain of Inquilinus sp. PJ-1-11 on LB solid medium plates at 30°C until single colonies appear.

[0028] (2) Production culture: The single colony was inoculated into LB liquid culture medium and cultured at 30°C and 150 rpm for 24 h until OD660 = 0.9-1.2.

[0029] (3) The microbial agent is bottled and packaged.

[0030] The whole process of the method of this embodiment takes 4 to 5 days to culture. After the culture is completed, the number of bacteria reaches more than 300 million cells / ml.

[0031] Example 3

[0032] A use of the microbial agent of Example 2 in improving cotton resistance to Spodoptera litura.

[0033] Cotton variety Xiangzamian No. 7 was planted in a greenhouse, and five-leaf-stage cotton seedlings were used for resistance testing. The microbial agent from Example 2 was evenly sprayed onto the five-leaf-stage cotton seedlings. One day later, five weighed second-instar Spodoptera litura larvae were inoculated. Seven days later, the weight of the S. litura larvae was measured, and the weight gain was calculated. Equal amounts of ddHO and LB medium were sprayed as controls. All treatments were repeated three times, and the results are shown in Table 1 below.

[0034] Table 1: Microbial agents of Example 2 improve potted cotton resistance to Spodoptera litura

[0035]

[0036] The results in Table 1 show that the strain of the present invention significantly inhibited the weight gain of Spodoptera litura, indicating that it significantly improved the resistance of potted cotton to Spodoptera litura. In Table 1, a and b represent the statistical differences between different groups. The same letters indicate no significant differences, while different letters indicate significant differences.

[0037] Example 4

[0038] A use of the microbial agent of Example 2 in preventing and controlling tomato brown wrinkled fruit virus disease.

[0039] The half-leaf method was used to determine the efficacy of the microbial agent in Example 2 in preventing and treating tomato brown wrinkle fruit virus disease. Four treatment groups were set up: (1) the microbial agent in Example 2; (2) a commercially available 5% morpholinoguanidine hydrochloride soluble powder; (3) a culture medium control treatment; and (4) a water blank control. Ten plants were treated in each treatment group, and the experiment was repeated three times.

[0040] 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 in the prevention and treatment effects was the mean of the total number of necrosis spots in each group (10 plants) of heartleaf tobacco after three repeated experiments.

[0041] Prevention test: Heartleaf tobacco was cultivated in a greenhouse until the 5-leaf stage, and then covered with hard plastic boards. The left side of the leaves was sprayed with ddH2O as a blank control, and the right side was sprayed with fungal agents, chemical agents or culture medium. After an interval of 1 day, the virus was inoculated using the 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.

[0042] Treatment trials: 5-leaf tobacco leaves were inoculated with the virus using the friction inoculation method. Treatments were repeated 6 hours apart, shielded by a hard plastic sheet. The left side of the leaves was sprayed with a blank control of ddH2O, while the right side was sprayed with a fungicide, chemical agent, or culture medium. Three days later, the leaves were observed for disease development, photographed, and the number of lesions on the leaves was counted across three replicates to calculate treatment efficacy. Treatment results are listed in Table 2.

[0043] Table 2: The preventive and control effects of the microbial agent of Example 2 on tomato brown wrinkled fruit virus disease

[0044]

[0045] The results in Table 2 show that the strain of the present invention is as effective in preventing tomato brown wrinkle fruit virus as the control agent, 5% morpholinoguanidine hydrochloride soluble powder; the preventive effect is greater than the therapeutic effect. In Table 2, a and b represent statistical differences between different groups; identical letters indicate insignificant differences, while different letters indicate significant differences.

[0046] Example 5

[0047] An application of the microbial agent of Example 2 in preventing and controlling tomato chlorosis virus disease.

[0048] 5% morpholinoguanidine hydrochloride soluble powder was selected as the control agent (recommended dosage). The microbial agent of Example 2 was sprayed at 200 mL / mu and 45 kg of water per mu. The treatment area was 50 m 2 , with three replicates. Fifteen days after application, the number of plants infected with tomato chlorosis virus was measured. The experiment was conducted in accordance with the Guidelines for Field Efficacy of Pesticides, Part 8: Control of Tomato Viruses with Fungicides (NY / T 1464.8). The results are listed in Table 3.

[0049] Table 3: Field control effect of the microbial agent of Example 2 on tomato chlorosis virus disease

[0050]

[0051] The control efficacy shown in Table 3 demonstrates that the strains of the present invention are comparable in effectiveness against tomato chlorosis virus as the control agent, 5% morpholinoguanidine hydrochloride soluble powder. In Table 3, a and b represent statistical differences between groups; identical letters indicate insignificant differences, while different letters indicate significant differences.

[0052] The above description is only a preferred embodiment of the present invention and does not constitute any formal limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the spirit and technical solution of the present invention, use the methods and technical contents disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment of 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 content of 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 Inquilinus sp. PJ-1-11, which was deposited in the China Center for Type Culture Collection (CCTCC) on January 6, 2025, with the deposit number being CCTCC NO: M2025044.

2. A microbial agent, characterized in that: The microbial agent is obtained by activating and cultivating the Inquilinus strain according to claim 1.

3. A method for preparing the microbial agent according to claim 2, characterized in that: The preparation method of the microbial agent comprises the following steps: S1. Culture the stock of Inquilinus sp. PJ-1-11 on LB solid medium plates at 30°C until single colonies appear. S2. The single colony was inoculated into LB liquid culture medium and cultured at 30°C and 150 rpm for 24 h until OD660 = 0.9-1.2 to obtain a microbial agent.

4. Use of the Inquilinus strain according to claim 1 or the microbial agent according to claim 2 in improving cotton resistance to Spodoptera litura.

5. Use of the Inquilinus strain according to claim 1 or the microbial agent according to claim 2 in preventing and controlling tomato brown wrinkled fruit virus disease.

6. Use of the Inquilinus strain according to claim 1 or the microbial agent according to claim 2 in preventing and controlling tomato chlorosis virus disease.

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