Fecal sphingobacterium for preventing and controlling root-knot nematode disease and its application

Abstract

The present application discloses a fecal sphingobacillus for preventing and treating root-knot nematodes and its application, which is a fecal sphingobacillus strain PE05 of CCTCC No: M20221104. The strain has a good control effect on root-knot nematodes. The bacterial agent prepared by using the PE05 strain has a control effect of more than 70% on cigar tobacco leaf root-knot nematodes, and has the characteristics of low cost, no residue, and safety for humans and animals. It can be used as a biocontrol microorganism for root-knot nematodes to obtain a good control effect.

Description

Technical Field

[0001] The present application relates to the technical field of microbial pesticides and microbial fertilizers, and in particular to a fecal sphingobacillus for preventing and treating root-knot nematodes and its application. Background Art

[0002] Plant parasitic nematodes are an important class of plant pathogens with a worldwide distribution, causing economic losses of US$157 billion per year worldwide (Abad et al., 2008). Meloidogyne nematodes are one of the most serious pathogens, parasitizing more than 2,000 host species, including tobacco, vegetables, food crops, cash crops, fruit trees, ornamental plants and weeds (Sasser, 1980).

[0003] Javan root-knot nematode (M.javanica) is one of the most serious root-knot nematode species and the dominant species of root-knot nematodes that harm cigar tobacco leaves (Ma Guimei, et al. 2021), which has a great impact on the cultivation of cigar tobacco leaves and the development of the cigar tobacco industry. Using nematode biocontrol bacteria to develop microbial agents to control root-knot nematode disease is one of the most environmentally friendly measures. Nematicides developed using biocontrol microorganisms such as Purpureocillium lilacinum, Pochonia chlamydosporia, Bacillus nematocida, Bacillus firmus, Pasteuriapenetrans, Burkholderia cepacia, and Paenobacillusmacerans have been registered in many countries and used for root-knot nematode disease control (Priyank et al., 2019); however, the types of existing biocontrol microorganisms are limited.

[0004] Sphingobacterium faecale is a new bacterial species published in 2022 (Chen et al., 2022). It functions as a deaminase-producing bacterium and has not been used in the prevention and control of root-knot nematode disease.

[0005] The above literature information: Abad P, Gouzy J, Aury J, et al. Genome sequence of themetazoan plant-parasitic nematode Meloidogyne incognita. Nature Biotechnology, 2008, 26(8): 909-915.

[0006] Sasser J N. Root-knot nematode: a global menace to cropproduction. Plant Disease, 1980, 64:36-41.

[0007] Priyank HM, Chinnannan K, Kadirvelu K, et al., Plant growth promoting rhizobacteria (PGPR): A potential alternative tool for nematodes bio-control. Biocatalysis and Agricultural Biotechnology, 2019,17:119-128.

[0008] Chen M, Li N, Zhang XF, et al. 2022. Sphingobacterium faecalesp.nov., a1-aminocyclopropane-1-carboxylate deaminase producing bacterium isolated from camel faeces. Int.J.Syst.Evol.Microbiol.2022;72:005215.

[0009] Ma Guimei, Tan Tao, Yang Dong, et al. Identification of the pathogen of cigar root knot nematode disease in Jiangcheng, Yunnan and research on the control effect of biogenic ammonia fumigation. Journal of Yunnan University (Natural Science Edition), 2022, 4: 1-7. DOI: 10.7540 / j.ynu.20220171. Summary of the invention

[0010] In view of the problems of existing root-knot nematode control, the present application provides a fecal sphingobacterium for controlling root-knot nematode and its application, wherein the strain is particularly suitable for controlling cigar tobacco leaf root-knot nematodes.

[0011] The present application provides a fecal sphingobacillus for preventing and treating root-knot nematode disease, which is the fecal sphingobacillus strain PE05 with CCTCC No: M20221104.

[0012] Preferably, the control plant is a cigar tobacco plant; preferably, the cigar tobacco plant is a Yunxue No. 2 variety of cigar tobacco.

[0013] Preferably, the root-knot nematode disease is root-knot nematode Javan root-knot nematode; preferably, the mortality rate of strain PE05 against root-knot nematode Javan root-knot nematode J2 reaches 98%.

[0014] The strain provided in the present application is isolated from healthy tobacco leaves of the cigar tobacco Yunxue No. 2 variety in Jiangcheng County, Pu'er City, Yunnan Province, and is a coprolific sphingobacillus PE05 strain. The deposit certificate number of the strain is CCTCC No: M20221104. The strain can be used to prevent and treat root-knot nematodes, especially Javan root-knot nematodes infected on tobacco plants, and Javan root-knot nematodes J2. The control effect of the bacterial agent containing the strain is close to that of the existing commonly used concentration of 10% thiazolyl granules, and the control effect can reach more than 74%.

[0015] Moreover, this bacterial agent will not pollute the environment, is not easy to develop drug resistance, and can be used safely for a long time. It is especially suitable for use in areas with large tobacco planting areas.

[0016] Another aspect of the present application provides a fermentation liquid for preventing and treating Javan root-knot nematode disease, containing the above-mentioned Sphingobacillus sphaerocephalus PE05. The fermentation liquid can be prepared by using LB medium according to the existing microbial fermentation method, and the obtained fermentation liquid also contains the metabolites of the strain, thereby exerting a better control effect on root-knot nematodes.

[0017] Preferably, the method for preparing the fermentation broth comprises the following steps:

[0018] After slant culture, seed liquid culture and fermentation liquid culture, a fermentation liquid containing the bacterial strain and its metabolites is obtained.

[0019] Preferably, the slant culture conditions are: culturing at 32°C to 37°C for 1 to 2 days using LB slant medium;

[0020] Seed solution culture conditions: LB liquid culture medium is used for shaking culture at 32°C to 37°C and 100 to 150 rpm for 2 to 3 days to obtain seed solution;

[0021] Fermentation broth culture conditions: inoculate the seed liquid into LB medium at a volume ratio of 3%-5%, and control the fermentation culture conditions at: temperature 32°C-36°C, stirring speed 120-160rpm, fermentation time 48-72 hours to obtain fermentation broth;

[0022] Preferably, the volume of the fermentation tank used for fermentation broth culture is 500-1000L.

[0023] The fermentation liquid containing the strain can be obtained by culturing and fermenting under the above conditions.

[0024] Another aspect of the present application provides a biocontrol agent for preventing and treating Javan root-knot nematode disease, comprising the above-mentioned Sphingobacillus faecalis PE05;

[0025] Preferably, the preparation method of the biocontrol agent comprises: granulating the fermentation liquid as described above to obtain the biocontrol agent;

[0026] Preferably, the granulation operation is to mix the fermentation liquid with soluble corn starch, and then spray-dry and granulate to obtain the biocontrol agent.

[0027] By granulating the fermentation liquid, a biological control agent with biological activity can be obtained. The agent is easy to transport and can be diluted with water when used, so it is convenient to use. Specifically, the granulation can be carried out by the existing commonly used biological agent preparation method. The specific parameters are set with reference to the existing biological agent preparation parameters. More preferably, the plant seeds are tobacco seeds. The agent can be used in the prevention and control of root-knot nematodes of various plants, for example, tomato seeds, peanut plants, and cucumber plants.

[0028] Preferably, the water content of the biocontrol agent is controlled below 5%; and the effective viable count of the Sphingobacillus faecalis PE05 strain contained in the biocontrol agent is above 1 billion CFU / g.

[0029] Preferably, the method for using the biocontrol agent is as follows: the agent is diluted with water to obtain a bacterial solution, the plant seeds are soaked in the bacterial solution for 2 to 3 hours, and the seeds are taken out for seedling raising and / or transplanting;

[0030] Or, the method for using the biocontrol agent is as follows: the agent is diluted with water to obtain a bacterial solution, and the solution is irrigated through a seedling medium before sowing, seedling raising and transplanting.

[0031] Alternatively, the method for using the biocontrol agent comprises the following steps: diluting the agent with water to obtain a bacterial solution; raising seedlings, and after transplanting the plants, taking the bacterial solution for root irrigation on the second day after transplanting; and taking the bacterial solution for root irrigation on the 30th day after transplanting.

[0032] The obtained biocontrol agent can obtain better use effect by using the above method, and the control effect on root-knot nematodes can reach more than 74%, and is particularly suitable for controlling root-knot nematodes of tobacco and cigar plants.

[0033] Preferably, the dilution ratio of water is 50 to 500 times of the diluted bacterial agent;

[0034] Preferably, the dilution ratio is 50 to 100 times of the bacterial agent. The dilution ratio can be adjusted within this range as needed.

[0035] The beneficial effects of this application include:

[0036] 1) The fecal sphingobacillus for preventing and controlling root-knot nematodes provided in this application has a good control effect on root-knot nematodes. The bacterial agent prepared by using the PE05 strain has a control effect of more than 70% on cigar tobacco leaf root-knot nematodes, and has the characteristics of low cost, no residue, and safety for humans and animals. It can be used as a microbial microorganism for controlling root-knot nematodes to obtain a good control effect.

[0037] 2) The fecal sphingobacillus strain provided in the present application for preventing and controlling root-knot nematode disease has an indoor biological test showing that the strain has a mortality rate of up to 98% against the second-instar larvae (J2) of the Javan root-knot nematode. The fermentation product of the strain was used in greenhouse tests and field tests, and the results obtained showed that the strain has a good preventive effect on the Javan root-knot nematode that harms cigar tobacco leaves, and can achieve effective prevention and control of the Javan root-knot nematode.

[0038] Biodeposit Information:

[0039] The Sphingobacterium faecale PE05 strain was deposited in the China Center for Type Culture Collection on July 13, 2022; the address of the depository unit is: Wuhan University, Bayi Road, Hongshan District, Wuhan City, Hubei Province; the deposit number is: CCTCC No: M20221104. DETAILED DESCRIPTION

[0040] In order to make the purpose, 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 in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0041] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Example

[0043] The materials, seeds and instruments used in the following examples were obtained from commercial channels unless otherwise specified.

[0044] The LB medium used in the following examples is: 10.0 g of tryptone, 5.0 g of yeast extract, 10.0 g of NaCl, distilled water to 1 000 ml, pH = 7.0-7.5.

[0045] Example 1 Obtaining PE05 strain

[0046] Using the existing method for isolating endophytic bacteria (such as: Feng Yunli, et al. 2011. Screening of biocontrol bacteria antagonistic to tobacco black shank disease in endophytic bacteria of flue-cured tobacco variety NC297 and analysis of population composition. Journal of Yunnan University, 33(4): 488-496), 52 endophytic bacteria were obtained from cigar tobacco leaves, roots and stems of the cigar tobacco variety Yunxue 2 in Jiangcheng County, Pu'er City, Yunnan Province. The 52 endophytic bacteria were cultured in LB liquid culture medium at 37°C and 120rpm in a shaking flask for 48 hours.

[0047] 2 ml of the fermentation liquid of each strain was placed in a culture dish, and about 500 J2 javanica root-knot nematodes were added to the dish. Three parallel treatments were set up.

[0048] LB medium liquid was used as blank control.

[0049] After 24 hours of placement, the average mortality rate of nematodes in each treatment was examined under a microscope. Mortality rate (%) = number of dead nematodes / total number of nematodes examined under a microscope*100%.

[0050] The results calculated according to the above formula based on the microscopic examination results showed that the mortality rate of the PE05 strain to the Javan root-knot nematode J2 was 98%; the mortality rate of the Javan root-knot nematode J2 in the blank control was 0.

[0051] In the research on screening of nematode biocontrol bacteria, 52 endophytic bacteria were isolated from healthy cigar tobacco plants; taking J2, the root-knot nematode infecting cigar tobacco leaves, as the target, the mortality rate of the LB culture medium fermentation broth of each strain to J2 was determined, and it was found that the fecal sphingobacillus PE05 strain isolated from the healthy tobacco leaves of the cigar tobacco Yunxue No. 2 variety in Jiangcheng County, Pu'er City, Yunnan Province, had a mortality rate of up to 98% against J2, which has excellent application prospects and will be further studied.

[0052] Example 2 Cultivation of PE05 strain and preparation of bacterial agent

[0053] Test tube slant seed culture: Inoculate the PE05 strain onto the LB medium slant and culture at 32°C for 2 days to obtain slant seeds.

[0054] Liquid seed culture of the strain: inoculate the slant seeds into a Erlenmeyer flask filled with LB liquid culture medium and culture in a shaking incubator at 35°C and 120 rpm for 2 days to obtain seed liquid.

[0055] Strain fermentation tank culture: The seed liquid is inoculated into LB medium at a ratio of 3% (V / V), and the fermentation is carried out in a fermentation tank. The volume of the fermentation tank used is 700L, and the fermentation culture conditions are controlled at: temperature 35°C, stirring speed 140rpm, fermentation time 50 hours, and fermentation liquid is obtained. The fermentation liquid contains the bacterial cells of the strain and its metabolites.

[0056] Preparation of the inoculant containing the PE05 strain: The fermentation liquid is mixed with soluble corn starch and then spray-dried to obtain the inoculant. The amount of soluble corn starch added is adjusted according to the requirements of spray-drying granulation.

[0057] The water content of the obtained bacterial agent is controlled below 5%, and the number of effective live bacteria in the PE05 strain in the bacterial agent is above 1 billion CFU / g.

[0058] Example 3: Effect of PE05 bacterial agent on the prevention of root-knot nematode disease in cigar tobacco leaves

[0059] Experimental location: Cigar tobacco planting base in Zhengdong Village, Zhengdong Town, Jiangcheng County, Pu'er City, Yunnan Province.

[0060] Experimental crops: cigar tobacco leaves (variety: Yunxue No. 2).

[0061] Test agent: PE05 bacterial agent prepared according to the method in the above example, with a viable bacterial count of 1 billion CFU / g.

[0062] Pesticide used in the control group: Pesticide used for controlling root-knot nematodes: 10% thiathiazolyl granules (produced by Shandong United Pesticide Industry Co., Ltd.).

[0063] Experimental method: The following three treatments were set up, each with 3 replications, the area of ​​each replication was 0.3 mu, and they were randomly arranged.

[0064] Treatment 1: The bacterial agent obtained in Example 2 was diluted 50 times with water, and tobacco seeds were soaked in the bacterial solution for 2-3 hours, and then the seeds were taken out and seedlings were raised and transplanted according to conventional methods.

[0065] Treatment 2: During land preparation, 10% thiathiazolyl granules (1500 g / mu) were spread on the bed surface and evenly mixed into the tillage layer; conventional tobacco seedlings that had not been treated with the PE05 fungicide were transplanted.

[0066] Treatment 3: blank control without any pesticide application; transplanting conventional tobacco seedlings that were not treated with PE05 fungicide.

[0067] Survey and statistical methods: After the cigar tobacco leaves are harvested, the root nodule disease index of the plants is investigated (level 0: normal roots without nodules; level 1: a small number of root knots on less than one-quarter of the roots; level 3: a small number of root knots on one-quarter to one-third of the roots; level 5: root knots on one-third to one-half of the roots; level 7: more than one-half of the roots have root knots, and a small number of secondary roots have root knots; level 9: all roots (including secondary roots) are covered with root knots, and the disease index and prevention effect are calculated according to the following formula:

[0068] Disease index = (n 1 ×1+n 3 ×3+n 5 ×5+n 7 ×7+n 9 ×9) / (S×9)×100, n 1 -n 9 x and y represent the total number of plants corresponding to the root nodule index level 1-9, and S represents the total number of plants investigated. Control effect (%) = 100 (1-x / y), x and y represent the disease index of the treatment and blank control, respectively.

[0069] The results of the test on the prevention of root-knot nematode disease in cigar tobacco leaves show (Table 1):

[0070] In treatment 1, after the seeds were treated with 50 times the solution of the bacterial agent obtained in Example 2 at 1 billion CFU / g, seedlings were raised and transplanted normally, and the control effect against root-knot nematodes reached 75.37%, which was equivalent to the control effect of the control pesticide 10% thiazolyl granules (80.12%).

[0071] The results are shown in the following table:

[0072] Table 1. The results of each treatment on the control of cigar tobacco root knot nematode disease

[0073] deal with Disease index Prevention effect (%) Treatment 1 (PE05 bacterial agent) 9.87b 75.37a Treatment 2 (pesticide treatment) 7.97b 80.12a Treatment 3 (blank control) 40.1a -

[0074] Note: The same letters after the numbers in the same column indicate no significant difference, otherwise the difference is significant.

[0075] Example 4: Effect of PE05 bacterial agent on the prevention of root-knot nematode disease in cigar tobacco leaves

[0076] Experimental location: Cigar tobacco planting base in Zhengdong Village, Zhengdong Town, Jiangcheng County, Pu'er City, Yunnan Province.

[0077] Experimental crops: cigar tobacco leaves (variety: Yunxue No. 2).

[0078] Test agent: PE05 bacterial agent, with a viable bacterial count of 1 billion CFU / g, prepared according to the above method of the present invention; the control pesticide for controlling root-knot nematodes is 10% thiazolyl granules (produced by Shandong United Pesticide Industry Co., Ltd.).

[0079] Experimental method: There are three treatments as follows, each with 3 replicates and each replicate covering 0.3 mu.

[0080] Treatment 1: Place the seedling medium into the seedling tray, take an appropriate amount of the bacterial agent obtained in Example 2, dilute it 100 times with water, and then water the seedling medium thoroughly, and then sow, raise seedlings and transplant according to the conventional method.

[0081] Treatment 2: During land preparation, 10% thiathiazolyl granules (1500 g / mu) were spread on the bed surface and evenly mixed into the tillage layer; conventional tobacco seedlings that had not been treated with the PE05 fungicide were transplanted.

[0082] Treatment 3: Blank control without any pesticide application; transplanting conventional tobacco seedlings without PE05 treatment

[0083] Survey and statistical methods: After the cigar tobacco leaves are harvested, the root nodule disease index of the plants is investigated (level 0: normal roots without nodules; level 1: a small number of root knots on less than one-quarter of the roots; level 3: a small number of root knots on one-quarter to one-third of the roots; level 5: root knots on one-third to one-half of the roots; level 7: more than one-half of the roots have root knots, and a small number of secondary roots have root knots; level 9: all roots (including secondary roots) are covered with root knots, and the disease index and prevention effect are calculated according to the following formula:

[0084] Disease index = (n 1 ×1+n 3 ×3+n 5 ×5+n 7 ×7+n 9 ×9) / (S×9)×100,n 1 -n 9 Respectively represent the total number of plants corresponding to the root nodule index level 1-9, and S represents the total number of plants investigated. Control effect (%) = 100 (1-x / y), x, y represent the disease index of the treatment and blank control, respectively. The results are shown in the following table:

[0085] Table 2. The results of the control effect of each treatment of seedling medium on cigar tobacco leaf root knot nematode disease

[0086] deal with Disease index Prevention effect (%) Treatment 1 (PE05 bacterial agent) 8.14b 78.36a Treatment 2 (pesticide treatment) 7.93b 78.92a Treatment 3 (blank control) 37.62a -

[0087] Note: The same letters after the numbers in the same column indicate no significant difference, otherwise the difference is significant.

[0088] The test results show (Table 2): In treatment 1, the seedling medium was treated with 100 times the dilution of 1 billion CFU / g PE05 fungicide, and then the seedlings were transplanted. The prevention effect against root-knot nematode disease reached 78.36%, which was equivalent to the prevention effect of the control pesticide 10% thiazolyl granules (78.92%).

[0089] Example 5: Effect of PE05 bacterial agent on the prevention of root knot nematode disease in cigar tobacco leaves

[0090] Experimental location: Cigar tobacco planting base in Zhengdong Village, Zhengdong Town, Jiangcheng County, Pu'er City, Yunnan Province.

[0091] Experimental crops: cigar tobacco leaves (variety: Yunxue No. 2).

[0092] Test agent: PE05 bacterial agent, with a viable bacterial count of 1 billion CFU / g, prepared according to the above method of the present invention; the control pesticide for controlling root-knot nematodes is 10% thiazolyl granules (produced by Shandong United Pesticide Industry Co., Ltd.).

[0093] Experimental method: There are three treatments as follows, each with 3 replicates and each replicate covering 0.3 mu.

[0094] Treatment 1: conventional seedling raising and transplanting were carried out. On the second day after transplanting, the bacterial agent obtained in Example 2 was diluted 500 times with water and irrigated the roots, 200 ml / plant; and the roots were irrigated again on the 30th day after transplanting.

[0095] Treatment 2: During land preparation, 10% thiazolyl granules (1500 g / mu) were spread on the bed surface and evenly mixed into the tillage layer.

[0096] Treatment 3: blank control without any pesticide application.

[0097] Survey and statistical methods: After the cigar tobacco leaves are harvested, the root nodule disease index of the plants is investigated (level 0: normal roots without nodules; level 1: a small number of root knots on less than a quarter of the roots; level 3: a small number of root knots on a quarter to a third of the roots; level 5: a third to a half of the roots; level 7: more than half of the roots have root knots, and a small number of secondary roots have root knots; level 9: all roots (including secondary roots), and the disease index and prevention effect are calculated according to the following formula:

[0098] Disease index = (n 1 ×1+n 3 ×3+n 5 ×5+n 7 ×7+n 9 ×9) / (S×9)×100,n 1 -n 9 Respectively represent the total number of plants corresponding to the root nodule index level 1-9, and S represents the total number of plants investigated. Control effect (%) = 100 (1-x / y), x, y represent the disease index of the treatment and blank control, respectively. The results are shown in the following table:

[0099] Table 3. The efficacy of PE05 inoculant in root irrigation against root knot nematode disease in cigar tobacco leaves

[0100] deal with Disease index Prevention effect (%) Treatment 1 (PE05 bacterial agent) 11.02b 74.02a Treatment 2 (chemical treatment) 10.33b 75.64a Treatment 3 (blank control) 42.41a -

[0101] Note: The same letters after the numbers in the same column indicate no significant difference, otherwise the difference is significant.

[0102] Judging from the number of nodules on the root system, the treatment (blank control)

[0103] The test results show (Table 3): In treatment 1, 500 times dilution of 1 billion CFU / g PE05 fungicide was used to irrigate the roots twice after transplanting, and the control effect against root-knot nematode disease reached 74.02%, which was equivalent to the control effect of 10% thiazolyl granules (75.64%).

[0104] It can be seen from the above that the strain provided in the present application has a good control effect on root-knot nematodes and can be used as a biocontrol agent to achieve the control of root-knot nematodes.

[0105] Example 6

[0106] The difference from Example 2 is: Test tube slant seed culture: the PE05 strain was inoculated onto the LB medium slant and cultured at 30° C. for 1 day to obtain slant seeds.

[0107] Liquid seed culture of the strain: inoculate the slant seeds into a Erlenmeyer flask filled with LB liquid culture medium and culture in a shaking incubator at 30°C and 100 rpm for 2 days to obtain seed liquid.

[0108] Strain fermentation tank culture: The seed liquid is inoculated into LB medium at a ratio of 3% (V / V), and the fermentation is carried out in a fermentation tank. The volume of the fermentation tank used is 1000L, and the fermentation culture conditions are controlled at: temperature 37°C, stirring speed 160rpm, fermentation time 72 hours, and fermentation liquid is obtained. The fermentation liquid contains the bacterial cells of the strain and its metabolites.

[0109] Example 7

[0110] The difference from Example 2 is:

[0111] Test tube slant seed culture: Inoculate the PE05 strain onto the LB medium slant and culture at 37°C for 2 days to obtain slant seeds.

[0112] Liquid seed culture of the strain: inoculate the slant seeds into a Erlenmeyer flask filled with LB liquid culture medium and culture in a shaking incubator at 37°C and 150 rpm for 3 days to obtain seed liquid.

[0113] Strain fermentation tank culture: The seed liquid is inoculated into LB medium at a ratio of 5% (V / V), and the fermentation is carried out in a fermentation tank. The volume of the fermentation tank used is 500L, and the fermentation culture conditions are controlled at: temperature 30°C, stirring speed 120rpm, fermentation time 48 hours, and fermentation liquid is obtained. The fermentation liquid contains the bacterial cells of the strain and its metabolites.

[0114] The results of the bacterial agents obtained in Examples 7 to 8 are similar to those of Example 2, and are not described here.

[0115] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fecal sphingobacterium for preventing and treating Javan root-knot nematode J2 disease ( Sphingobacterium faecale ) strain PE05, characterized in that The deposit number of Sphingobacillus faecalis strain PE05 is CCTCC No: M20221104.

2. The strain PE05 according to claim 1, characterized in that The plant to be controlled is the cigar tobacco plant.

3. The strain PE05 according to claim 2, characterized in that The cigar strain used is the Yunxue No. 2 variety.

4. A fermentation liquid for preventing and treating Javan root-knot nematode J2 disease, characterized in that: Containing the fecal sphingobacterium for preventing and treating Javan root-knot nematode J2 disease as described in any one of claims 1 to 3 ( Sphingobacterium faecale ) strain PE05.

5. The fermentation broth according to claim 4, characterized in that The method for preparing the fermentation broth comprises the following steps: After slant culture, seed liquid culture and fermentation liquid culture, the fecal sphingobacillus ( Sphingobacterium faecale )'s strain PE05 and its metabolites fermentation broth.

6. The fermentation broth according to claim 5, characterized in that Slant culture conditions: Use LB slant medium and culture at 30℃~37℃ for 1~2 days; Seed solution culture conditions: Use LB liquid medium to culture in a shaking incubator at 30°C~37°C and 100~150 rpm for 2~3 days to obtain seed solution; Fermentation broth culture conditions: The seed liquid is inoculated into LB culture medium at a volume ratio of 3%-5%, and the fermentation culture conditions are controlled at: temperature 30°C~37°C, stirring speed 120~160 rpm, fermentation time 48~72 hours to obtain fermentation broth.

7. The fermentation broth according to claim 6, characterized in that The volume of the fermentation tank used for fermentation broth culture is 500-1000L.

8. A biocontrol agent for controlling Javan root-knot nematode J2 disease, characterized in that: Containing the fecal sphingobacterium for preventing and treating Javan root-knot nematode J2 disease as described in any one of claims 1 to 3 ( Sphingobacterium faecale ) strain PE05.

9. The biocontrol agent according to claim 8, characterized in that The preparation method of the biocontrol agent comprises: granulating the fermentation liquid according to any one of claims 4 to 7 to obtain the biocontrol agent.

10. The biocontrol agent according to claim 9, characterized in that The granulation operation is to mix the fermentation liquid with soluble corn starch, and then spray-dry and granulate to obtain the biocontrol agent.

11. The biocontrol agent according to claim 9, characterized in that The water content of the biocontrol agent is controlled below 5%; the effective live bacteria count of the fecal sphingobacterium strain PE05 contained in the biocontrol agent is above 1 billion CFU / g.

12. The biocontrol agent according to claim 8, characterized in that The method for using the biocontrol agent is as follows: the agent is diluted with water to obtain a bacterial solution, the plant seeds are soaked in the bacterial solution for 2 to 3 hours, and the seeds are taken out for seedling raising and / or transplanting; Or, the method of using the biocontrol agent is as follows: the agent is diluted with water to obtain a bacterial solution, and the solution is poured through the seedling medium for sowing, seedling raising and transplanting; Alternatively, the method for using the biocontrol agent comprises the following steps: diluting the agent with water to obtain a bacterial solution; raising seedlings, and after transplanting the plants, taking the bacterial solution for root irrigation on the second day after transplanting; and taking the bacterial solution for root irrigation on the 30th day after transplanting.

13. The biocontrol agent according to claim 12, characterized in that: The dilution ratio with water is 50~500 times of the diluted bacterial agent.

14. The biocontrol agent according to claim 12, characterized in that: The dilution ratio with water is 50~100 times of the diluted bacterial agent.