Lysinibacillus bacilli Sneb2537 and preparation capable of preventing and treating root knot nematode disease as well as preparation method and application of bacillus bacilli Sneb2537 and preparation capable of preventing and treating root knot nematode disease

Abstract

The invention provides a strain of Lysinibacillus bacilli Sneb2537, a preparation capable of preventing and treating root knot nematode disease as well as a preparation method and application of the preparation, and belongs to the technical field of plant disease prevention and treatment. According to the invention, the Lysinibacillus pakistanensis Sneb2537 with efficient nematode-resistant activity is screened out from soil, and a fermentation broth obtained by fermenting the strain can be directly used in each growth period of plants, and has a promoting effect on prevention and control of root knot nematode diseases and growth of the plants. When being used as a medicament for preventing and treating the root knot nematode disease, the strain and the fermentation liquor have the characteristics of simplicity in operation, high efficiency, safety, environment friendliness and difficulty in generating resistance, and effectively reduce the damage of chemical agents to the environment and the threat of the chemical agents to people.

Description

Technical Field

[0001] The invention belongs to the technical field of plant disease prevention and control, and particularly relates to a Pakistani lysinibacillus Sneb2537 and a preparation capable of preventing and controlling root-knot nematode disease, and a preparation method and application thereof. Background Art

[0002] Meloidogyne spp. is the most serious plant parasitic nematode in the world. It can attack more than 5,500 kinds of plants, including food crops and vegetables. It has a wide distribution range and strong destructive power, causing huge economic losses to agricultural production. According to statistics, there are 105 species of root-knot nematodes reported worldwide, of which four species are the most common: southern root-knot nematode (M. incognita), Java root-knot nematode (M. javanica), northern root-knot nematode (M. hapla) and peanut root-knot nematode (M. arenaria). The occurrence of root-knot nematode disease generally reduces crop yield by 10% to 20%. When the disease is severe, the loss can reach 80%, or even total crop failure. Every year, the garden seedling and vegetable planting industry loses 3 billion yuan due to root-knot nematode damage.

[0003] Root-knot nematodes are fixed endoparasitic nematodes. Under suitable temperature and humidity conditions, they reproduce very quickly and can complete a life cycle in one month. Field cultivation can carry out 6 infection cycles a year. Root-knot nematodes in greenhouse cultivation are more active and can reproduce up to 10 generations a year. After the root-knot nematodes infect the host plant, a large number of root knots are formed on its roots. The root knots are oval and yellow-white in the early stage of the disease, and the color turns brown in the later stage. The roots become rough and even rot. Because the conducting tissue of the root is destroyed, the normal function of the root is affected, resulting in slow plant growth, yellowing of leaves, and even death of the entire plant. In addition to causing direct damage, the wounds caused by the infection of southern root-knot nematodes can also trigger the coordinated invasion of other pathogens, such as Fusarium and Verticillium. The complex infection of multiple pathogens shows multiple symptoms on the host and forms the consequence of 1+1>2, which greatly aggravates the damage.

[0004] At present, the prevention and control of plant parasitic nematodes is still mainly chemical control, but chemical control has the problems of high cost, chemical residues, improper application causing pesticide damage, long-term application causing nematodes to develop drug resistance, and also causing life safety problems for humans and livestock and serious soil pollution. The efficient and environmentally friendly prevention and control methods for root-knot nematode disease are still an issue that needs to be solved urgently. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a strain of Pakistani Lysinibacillus Sneb2537 and a preparation capable of preventing and treating root-knot nematode disease, as well as a preparation method and application thereof. The present invention adopts a biological control method, takes plant root-knot nematodes as targets, and screens out Pakistani Lysinibacillus (Lysinibacillus pakistanensis) Sneb2537 with high anti-nematode activity from soil. The strain has the characteristics of simple operation, high efficiency, safety, environmental protection, and not easy to produce resistance. The fermentation liquid fermented by the Pakistani Lysinibacillus Sneb2537 strain obtained by the present invention can effectively reduce the harm of root-knot nematode disease to plants and promote the growth of plants.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a strain of Pakistani lysinibacillus pakistanensis Sneb2537, wherein the Pakistani lysinibacillus pakistanensis Sneb2537 was deposited in the General Microbiological Center of China National Committee for Microbiological Culture Collection on August 12, 2024, with a deposit number of CGMCC NO.31568.

[0008] The invention provides a preparation capable of preventing and treating root-knot nematode disease. The preparation comprises Pakistani Lysinibacillus Sneb2537 and / or a metabolite of Pakistani Lysinibacillus Sneb2537.

[0009] Preferably, the preparation comprises a fermentation broth containing bacteria or a metabolite extract not containing bacteria.

[0010] Preferably, the live bacterial concentration of Pakistani Lysinibacillus Sneb2537 in the fermentation broth is 1.0×10 8 ~1.0×10 9 CFU / mL.

[0011] The invention provides a preparation method of the preparation, and the strain is activated, and the activated strain is inoculated into a liquid culture medium for fermentation, so as to obtain the preparation capable of preventing and treating root-knot nematode disease.

[0012] Preferably, the fermentation temperature is 25-35° C., and the fermentation time is 1-3 days.

[0013] The present invention also provides the use of the Pakistani lysinibacillus Sneb2537, the preparation or the preparation obtained according to the preparation method in preventing and treating root-knot nematode disease.

[0014] Preferably, the controlling of root-knot nematode disease is killing root-knot nematodes and / or inhibiting the hatching of root-knot nematode eggs.

[0015] The present invention also provides the use of the Pakistani lysinibacillus Sneb2537, the preparation or the preparation obtained according to the preparation method as a seed soaking coating agent in promoting plant growth.

[0016] The present invention also provides the use of the Pakistani lysinibacillus Sneb2537, the preparation or the preparation obtained according to the preparation method as a fertilizer in promoting plant growth.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention obtains a strain by isolating from soil, which is identified as Pakistani Lysinibacillus pakistanensis and named Sneb2537. The fermentation liquid obtained by fermenting the Pakistani Lysinibacillus pakistanensis strain Sneb2537 obtained by the present invention has a certain contact killing activity against the second-instar larvae of root-knot nematodes and can inhibit the hatching of root-knot nematode eggs.

[0019] (2) When the fermentation liquid or fermentation filtrate is used in various growth stages of plants, it can effectively prevent and control root-knot nematode disease and promote plant growth. When the fermentation liquid or fermentation filtrate is used for seed soaking and coating treatment, it can promote seed germination and has no inhibitory effect on plant growth. When the fermentation liquid or fermentation filtrate is used for seedlings, it can resist root-knot nematode disease and promote plant growth.

[0020] (3) The strain, fermentation liquid and fermentation filtrate of the present invention can be used as agents for preventing and treating root-knot nematode disease, and have the characteristics of simple operation, high efficiency, safety, environmental protection, and not easy to produce resistance, and can effectively reduce the damage of chemical agents to the environment and the threat to humans. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 To construct a phylogenetic tree of Pakistani Lysinibacillus Sneb2537 strain based on 16S rDNA sequence.

[0022] Biological Deposit Description

[0023] Pakistani Lysinibacillus Sneb2537, Latin name is Lysinibacillus pakistanensis, the strain is deposited in the General Microbiology Center of China Microorganism Culture Collection Administration, address: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, deposit date: August 12, 2024, deposit number: CGMCC NO.31568. DETAILED DESCRIPTION

[0024] The present invention provides a strain of Pakistani lysinibacillus pakistanensis Sneb2537, wherein the Pakistani lysinibacillus pakistanensis Sneb2537 was deposited in the General Microbiological Center of China National Committee for Microbiological Culture Collection on August 12, 2024, with a deposit number of CGMCC NO.31568.

[0025] The invention provides a preparation capable of preventing and treating root-knot nematode disease. The preparation comprises Pakistani Lysinibacillus Sneb2537 and / or a metabolite of Pakistani Lysinibacillus Sneb2537.

[0026] In the present invention, the preparation comprises a fermentation broth containing bacteria or a metabolite extract without bacteria; the concentration of live bacteria of Pakistani Lysinibacillus Sneb2537 in the fermentation broth is 1.0×10 8 ~1.0×10 9 CFU / mL; the bacterial-free metabolite extract is the fermentation filtrate obtained by centrifuging the fermentation broth of Pakistani Lysinibacillus Sneb2537; the centrifugation speed is 6000-10000r / min, preferably 7000-9000r / min, and more preferably 8000r / min; the centrifugation time is 2-10min, preferably 4-8min, and more preferably 5min.

[0027] The invention provides a preparation method of the preparation, and the strain is activated, and the activated strain is inoculated into a liquid culture medium for fermentation, so as to obtain the preparation capable of preventing and treating root-knot nematode disease.

[0028] In the present invention, the activation method is to streak Pakistani Lysinibacillus Sneb2537 on LB solid culture medium, place it in an incubator at 25-30°C, preferably 26-39°C, and more preferably 28°C; culture for 10-14h, preferably 11-13h, and more preferably 12h, until a single colony grows, and an activated strain is obtained. Pick a single colony with good growth and inoculate it into a 250mL triangular flask containing 120-170mL LB liquid culture medium, the amount of LB liquid culture medium is preferably 130-160mL, and more preferably 150mL, at 25-37°C, preferably 27-30°C, and more preferably 28°C, ferment for 1-3d, preferably 2d, to obtain a preparation capable of preventing and treating root-knot nematode disease.

[0029] The present invention also provides the use of the Pakistani lysinibacillus Sneb2537, the preparation or the preparation obtained according to the preparation method in preventing and treating root-knot nematode disease.

[0030] In the present invention, the root-knot nematode disease prevention and control is to kill the root-knot nematodes and / or inhibit the hatching of root-knot nematode eggs; the root-knot nematodes are southern root-knot nematodes.

[0031] The present invention also provides the use of the Pakistani lysinibacillus Sneb2537, the preparation or the preparation obtained according to the preparation method as a seed soaking coating agent in promoting plant growth.

[0032] In the present invention, when used as a seed soaking coating agent, Pakistani lysinic Bacillus Sneb2537 is prepared to contain a bacterial cell concentration of 1×10 8 CFU / mL of fermentation liquid or metabolite extract without bacteria, the immersion time is 1 to 5 minutes, preferably 2 to 4 minutes, and more preferably 3 minutes; the plant is cucumber, and the variety of the cucumber is Zhongnong No. 6.

[0033] The present invention also provides the use of the Pakistani lysinibacillus Sneb2537, the preparation or the preparation obtained according to the preparation method as a fertilizer in promoting plant growth.

[0034] In the present invention, when used as a fertilizer, Pakistani Lysinibacillus Sneb2537 is prepared to have a bacterial cell concentration of 1×10 8 The fermentation liquid with CFU / mL or the metabolite extract without bacteria is used in an amount of 5-15 mL / plant, preferably 7-12 mL / plant, and more preferably 10 mL / plant; the plant is cucumber, and the variety of the cucumber is Zhongnong No. 6.

[0035] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0036] Preparation of LB solid medium: Dissolve 10.0 g peptone, 5.0 g yeast powder, 5.0 g sodium chloride, 1.0 g glucose, and 20 g agar in 1 L distilled water, adjust the pH to 7.0 ± 0.2, and sterilize at 121 °C for 30 min.

[0037] Preparation of LB liquid culture medium: Dissolve 10.0 g peptone, 5.0 g yeast powder, 5.0 g sodium chloride, and 1.0 g glucose in 1 L distilled water, adjust the pH to 7.0 ± 0.2, and sterilize at 121 °C for 30 min.

[0038] Preparation of 30% glycerol: Mix 60 mL of glycerol and 140 mL of deionized water in a 200 mL blue-mouth bottle and sterilize by wet heat at 121°C for 30 min.

[0039] The LB solid culture medium, LB liquid culture medium and 30% glycerol used in the subsequent examples were prepared according to the above method.

[0040] Example 1 Obtaining Pakistani Lysinibacillus Sneb2537 strain

[0041] Soil samples were collected from the cucumber field at No. 15-4, Hushitai South Street, Dadong District, Shenyang City, Liaoning Province (longitude 123°51684, latitude 41°92332). 5 g of soil sample was weighed and added to a 250 mL conical flask containing 45 mL of sterile water. After gradient dilution, the dilution degrees were 10 -2 , 10 -3 , 10 -4 25 μL of each soil suspension was spread on LB solid culture medium and cultured at 37°C for 12 h. The strain was isolated and purified by the plate dilution method, and the strain fermentation liquid was prepared and mixed with 30% glycerol and frozen in a -80°C refrigerator.

[0042] Example 2 Identification of Pakistani Lysinibacillus Sneb2537 strain

[0043] The taxonomic status of the strain was determined by morphological, physiological and biochemical characteristics and 16S rDNA sequence analysis.

[0044] Morphological observation: The purified strain in Example 1 was plated on an LB plate using the plate streak method, placed in a 28° C. constant temperature incubator and inverted for 12 h to observe the colony morphology, color, odor, etc.

[0045] Physiological and biochemical characteristics: In the clean bench, the neck of the physiological and biochemical tube (purchased from Qingdao Haibo Biotechnology Co., Ltd.) was broken open, and a fresh single colony was picked up with a sterilized pipette tip and inoculated into the tube. After completion, it was sealed with a sealing film and placed in a 37°C constant temperature incubator. The operation was carried out according to the instructions of the physiological and biochemical kit (purchased from Qingdao Haibo Biotechnology Co., Ltd.), and the corresponding reagents were added as required, and the final results were observed.

[0046] 16S rDNA sequence analysis: Bacterial DNA was extracted according to the DNA extraction method of Sutyak et al. (Sutyak KE, Wirawan RE, Aroutcheva AA and Chikindas M L. 2008. Isolation of the Bacillus subtilis antimicrobial peptide subtilosin from the dairy product-derived Bacillus amyloliquefaciens [J]. Journal of Applied Microbiology, 104, (1067-1074).). Using genomic DNA as a template, bacterial universal primers 27F (5'-AGAGTTTGATCCTGGCTCAG-3', SEQ ID NO.1) and 1492R (5'-ACGGCTACCTTGTTACGACTT-3', SEQID NO.2) were used for 16S rDNA gene amplification. The 25μL PCR amplification system was calculated as follows: 1μL of upstream primer and downstream primer, 2μL of DNA template, 12.5μL of 2×TaqMasterMix (Dye olus), and 8.5μL of ddH2O. The PCR amplification conditions were: 94℃ pre-denaturation for 1.5min, 94℃ denaturation for 0.5min, 58℃ renaturation for 0.5min, 72℃ extension for 1min, 30 cycles, 72℃ extension for 5min, and storage at 4℃. After 1.0% agarose gel electrophoresis, the PCR product was sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing. The sequencing results were compared with the BLAST database in NCBI, and the phylogenetic tree was constructed using the Neighbor-joining method using MEGA7.0 software. The sequence results of the strain were then submitted to the GenBank of NCBI to obtain the accession number. The phylogenetic tree is shown in Figure 1 .

[0047] The results showed that the sequence of the strain was submitted to the GenBank of NCBI and the accession number was PQ157562. The highest homology was with Lysinibacillus pakistanensis, with accession numbers MH934930.1 and PP257351.1. Therefore, the strain was determined to be Lysinibacillus pakistanensis.

[0048] Example 3 Test on the contact killing of root-knot nematodes and the inhibition of root-knot nematode egg hatching by the fermentation liquid of Pakistani lysinibacillus Sneb2537 strain

[0049] Preparation of Pakistani Lysinibacillus Sneb2537 fermentation broth: The Pakistani Lysinibacillus Sneb2537 strain obtained in Example 1 was streaked on LB solid culture medium, placed in a 28°C incubator, and cultured for 12 hours until a single colony grew, thereby obtaining an activated strain. A loop of the activated strain was taken with an inoculation loop and inoculated into a 250mL Erlenmeyer flask containing 150mL LB liquid culture medium, and placed in a shaker for fermentation for 2 days at a temperature of 28°C and a rotation speed of 200r / min to obtain a fermentation broth.

[0050] Metabolite extract without bacteria: The fermentation broth was centrifuged at 8000 r / min for 5 min to obtain a metabolite extract without bacteria (strain fermentation filtrate).

[0051] The egg capsules of the southern root-knot nematode (Meloidogyne incognita) were obtained by propagating cucumber roots. A portion of the egg capsules was made into an egg suspension, and a portion of the egg capsules was hatched into J2 by ​​a shallow tray method to prepare a nematode suspension.

[0052] 400 μL of the fermentation filtrate of Pakistani Lysinibacillus Sneb2537 strain was taken and treated with ddH2O and LB medium as the control group. 100 μL of nematode suspension (about 30 J2 nematodes) was added. The nematode death was observed and the number of nematode deaths was recorded for 12 h and 24 h. The mortality rate and corrected mortality rate were calculated. The results are shown in Table 1.

[0053] Mortality rate = (number of dead nematodes / total number of nematodes) × 100%.

[0054] Corrected mortality rate = (treated nematode mortality rate - control nematode mortality rate) / (1 - control nematode mortality rate) x 100%.

[0055] Table 1 Contact toxicity of Pakistani Lysinibacillus Sneb2537 to southern root-knot nematodes

[0056]

[0057] Take 400 μL of the fermentation filtrate of Pakistani Lysinibacillus Sneb2537 strain, treat with ddH2O and LB medium as control, add 100 μL of egg suspension (about 300 eggs), culture for 24h and 48h, observe the number of hatched nematodes, calculate the egg hatching rate and relative inhibition rate, and the results are shown in Table 2.

[0058] Egg hatching rate = (number of hatched nematodes / number of hatched nematodes tested) × 100%.

[0059] Relative inhibition rate = [(number of nematodes hatched in the control group - number of nematodes hatched in the treatment group) / number of nematodes hatched in the control group] × 100%.

[0060] Table 2 Effects of Pakistani Lysinibacillus Sneb2537 on the hatching rate of southern root-knot nematode eggs

[0061]

[0062] As shown in Tables 1 and 2, the corrected mortality of the fermentation filtrate of Pakistani Lysinibacillus Sneb2537 strain on the second-instar larvae of southern root-knot nematodes can reach 64.83% in 12 hours and 93.72% in 24 hours; the relative inhibition rate of the fermentation filtrate of Pakistani Lysinibacillus Sneb2537 strain on the hatching of southern root-knot nematodes eggs can reach 87.62% in 24 hours and 89.22% in 48 hours. The results show that Pakistani Lysinibacillus Sneb2537 can effectively kill the second-instar larvae of southern root-knot nematodes and inhibit their egg hatching.

[0063] Example 4 Seed coating germination test of Pakistani lysinibacillus Sneb2537 strain

[0064] The fermentation liquid of Pakistani Lysinibacillus Sneb2537 was prepared in the manner of Example 3 and set aside. The cucumber variety Zhongnong No. 6 was selected; the seeds were sterilized by soaking in warm water at 55° C. for 30 minutes and set aside.

[0065] The seeds were soaked in the fermentation liquid of the strain for 3 minutes, and then placed in a sterile culture dish (d = 90 mm) covered with sterile filter paper. Each treatment was repeated 3 times, with 10 seeds in each repeat, and the control group was treated with equal amounts of sterile water (ddH2O) and LB liquid culture medium. The culture dish was placed in a constant temperature and humidity incubator controlled at 25°C for cultivation. After 24 hours, the number of germinated seeds was counted once a day. After 7 days of cultivation, the germination index and germination rate were calculated, and the bud length and root length were measured, and the vitality index was calculated. The results are shown in Table 3.

[0066] Germination rate = (number of germinated seeds / total number of test seeds) × 100%

[0067] Germination index = Σ(germination number at different time of day / corresponding germination days)

[0068] Seed vigor index = seedling length × germination index.

[0069] Table 3 Effects of Pakistani Lysinibacillus Sneb2537 coating on cucumber seeds germination and growth

[0070]

[0071] Note: The data in the table are mean ± standard deviation. Different letters in the same column indicate significant differences at the P < 0.05 level as tested by Duncan's method.

[0072] As shown in Table 3, after treatment with the fermentation liquid of Pakistani Lysinibacillus Sneb2537, the germination rate and germination index of cucumber seeds increased significantly, and there were no significant differences in root length and seed vigor compared with the control group, indicating that the fermentation liquid of Pakistani Lysinibacillus Sneb2537 was used to soak and coat cucumber seeds, which promoted seed germination and had no inhibitory effect on the growth of cucumber plants.

[0073] Example 5 Experiment on potted plant protection effect of Pakistani Lysinibacillus Sneb2537 fermentation liquid

[0074] The fermentation liquid of Pakistani Lysinibacillus Sneb2537 and the nematode suspension were prepared respectively according to the method of Example 3 and set aside. The cucumber variety Zhongnong No. 6 was selected, and the seeds were sterilized by warm soup soaking method, soaked at 55° C. for 30 minutes, and cultured to the two-leaf and one-heart stage and set aside.

[0075] The control group was irrigated with ddH2O and inoculated with southern root-knot nematode J2, LB liquid medium and J2, and the drug (1.8% avermectin emulsion, purchased from Yantai Obeisi Biochemical Co., Ltd.) was irrigated with J2 as the root control group, and the Pakistani Lysinibacillus Sneb2537 fermentation liquid was irrigated with J2 as the treatment group. 2 mL of the second-instar larvae suspension (about 1000 J2) was added to each seedling, and 10 mL of Pakistani Lysinibacillus Sneb2537 fermentation liquid (concentration of about 1×10 8 CFU / mL), and the control group was irrigated with an equal amount of ddH2O or LB liquid culture medium or agent (1.8% avermectin emulsion) per seedling. Each treatment was repeated 5 times, with 1 seedling per repeat, and they were placed completely randomly. After 30 days of cultivation, the number of root knots was investigated and the root knot reduction rate was calculated. The root knot reduction rate was used to represent the relative control effect. The results are shown in Table 4.

[0076] Root knot reduction rate = [(number of control root knots - number of treated root knots) / number of control root knots] × 100%.

[0077] Table 4 The effect of Pakistani Lysinibacillus Sneb2537 fermentation liquid on root irrigation of cucumber root knot nematode disease

[0078]

[0079] Note: The data in the table are mean ± standard deviation. Different letters in the same column indicate significant differences at the P < 0.05 level as tested by Duncan's method.

[0080] As shown in Table 4, in the pot test under room temperature, after the cucumber seedlings were treated with the fermentation liquid of Pakistani Lysinibacillus Sneb2537, the number of root knots in the cucumber roots was significantly lower than that in the LB liquid medium control group, and there was no significant difference with the control group treated with avermectin, and the root knot reduction rate was 66.17%. Therefore, in the pot test, Pakistani Lysinibacillus Sneb2537 can effectively prevent and control cucumber root knot nematode disease.

[0081] Example 6 Effect of Pakistani Lysinibacillus Sneb2537 Fermentation Broth on Cucumber Plant Growth

[0082] The fermentation liquid of Pakistani Lysinibacillus Sneb2537 was prepared in the manner of Example 3 and set aside. The cucumber variety Zhongnong No. 6 was selected, and the seeds were sterilized by warm water soaking method, soaked at 55° C. for 30 minutes, and cultured to the two-leaf and one-heart stage and set aside.

[0083] The control group was irrigated with ddH2O or LB liquid medium, and each seedling was irrigated with 10 mL of ddH2O or LB liquid medium. The Pakistani Lysinibacillus Sneb2537 strain was irrigated with 10 mL of Pakistani Lysinibacillus Sneb2537 fermentation liquid (concentration of about 1×10 8 CFU / mL). Each treatment was repeated 3 times, and each repeat had 3 seedlings, which were placed completely randomly. After 30 days of cultivation, the height, root length, root fresh weight, and plant fresh weight of cucumber plants were investigated.

[0084] Table 5 Effects of Pakistani Lysinibacillus Sneb2537 fermentation liquid root irrigation on cucumber plant growth

[0085]

[0086] Note: The data in the table are mean ± standard deviation. Different letters in the same column indicate significant differences at the P < 0.05 level as tested by Duncan's method.

[0087] As shown in Table 5, in the pot experiment under room temperature, after the cucumber seedlings were treated with the fermentation liquid of Pakistani Lysinibacillus Sneb2537, the plant height, plant fresh weight and root fresh weight were significantly increased compared with the LB liquid medium control group, and the root length was not significantly different from the LB liquid medium control group. Therefore, in the pot experiment, Pakistani Lysinibacillus Sneb2537 can effectively promote the growth of cucumber plants.

[0088] Example 7 Field control effect experiment of Pakistani Lysinibacillus Sneb2537 strain

[0089] The fermentation liquid of Pakistani Lysinibacillus Sneb2537 was prepared according to Example 3 and set aside. The cucumber variety Zhongnong No. 6 was selected, and the seeds were sterilized by warm soup soaking method, soaked at 55°C for 30 minutes, cultured to the two-leaf and one-heart stage, and transplanted to a large field with root-knot nematode disease.

[0090] During transplanting, the control group was irrigated with ddH2O, LB liquid medium, or agent, and each seedling was irrigated with 10 mL of ddH2O or LB liquid medium or agent (1.8% avermectin emulsion). The Pakistani Lysinibacillus Sneb2537 was irrigated with 10 mL of fermentation liquid (concentration of about 1×10 8 CFU / mL). After 30 days of cultivation, the physiological indices of cucumber plants, such as plant height, root length, root fresh weight, and plant fresh weight, were measured, the root knot index was investigated, and the control effect was calculated.

[0091] The root knot index grading standard is as follows: level 0, no root knots; level 1, some small root knots on the fibrous roots; level 2, some obvious small root knots on the fibrous roots, and no root knots on the taproot; level 3, some obvious large root knots on the fibrous roots, and no root knots on the taproot; level 4, most of the fibrous roots are large root knots, and there are no root knots on the taproot; level 5, half of the root system has root knots, and there are also root knots on the taproot; level 6, a large number of root knots appear on the taproot; level 7, most of the taproots have root knots; level 8, all taproots have root knots; level 9, all roots have root knots; level 10, severe root knots, and no fibrous roots.

[0092] Root knot index = Σ[(number of diseased plants at each level × representative value of each level) / (total number of plants surveyed × highest representative value)] × 100%

[0093] Control effect = [(control root knot index - treatment root knot index) / control root knot index] × 100%.

[0094] Table 6 The efficacy of Pakistani Lysinibacillus Sneb2537 in root irrigation of cucumber against cucumber root-knot nematode disease

[0095]

[0096]

[0097] Note: The data in the table are mean ± standard deviation. Different letters in the same column indicate significant differences at the P < 0.05 level as tested by Duncan's method.

[0098] As shown in Table 6, in the field test, the Pakistani Lysinibacillus Sneb2537 fermentation liquid was used to treat cucumber seedlings, and the control effect was 55.64%, which was significantly higher than that of the LB medium control group and the avermectin treatment control group; compared with the LB medium control group and the avermectin treatment control group, the root length, root fresh weight, plant fresh weight, and plant height were significantly increased. Therefore, in the field test, Pakistani Lysinibacillus Sneb2537 can effectively prevent and control cucumber root knot nematode disease and promote plant growth.

[0099] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A strain of Pakistani Lysinibacillus pakistanensis Sneb2537, characterized in that: The Pakistani Lysinibacillus Sneb2537 was deposited in the General Microbiology Center of China Microorganism Culture Collection Administration on August 12, 2024, with the deposit number CGMCC NO.31568.

2. A preparation capable of preventing and treating root-knot nematode disease, characterized in that: The preparation comprises the Pakistani Lysinibacillus Sneb2537 and / or a metabolite of the Pakistani Lysinibacillus Sneb2537 according to claim 1.

3. The preparation according to claim 2, characterized in that The preparation includes a fermentation liquid containing bacteria or a metabolite extract liquid not containing bacteria.

4. The preparation according to claim 3, characterized in that The live bacterial concentration of Pakistani Lysinibacillus Sneb2537 in the fermentation broth was 1.0×10 8 ~1.0×10 9 CFU / mL.

5. The method for preparing the preparation according to any one of claims 2 to 4, characterized in that: The strain described in claim 1 is activated, and the activated strain is inoculated into a liquid culture medium for fermentation, so as to obtain a preparation capable of preventing and treating root-knot nematode disease.

6. The preparation method according to claim 5, characterized in that: The fermentation temperature is 25-35° C., and the fermentation time is 1-3 days.

7. Use of Pakistani Lysinibacillus Sneb2537 according to claim 1, the preparation according to any one of claims 2 to 4, or the preparation obtained according to the preparation method according to any one of claims 5 to 6 in preventing and controlling root-knot nematode disease.

8. The use according to claim 7, characterized in that: The method for preventing and controlling the root-knot nematode disease is to kill the root-knot nematodes and / or inhibit the hatching of root-knot nematode eggs.

9. Use of the Pakistani Lysinibacillus Sneb2537 according to claim 1, the preparation according to any one of claims 2 to 4, or the preparation obtained by the preparation method according to any one of claims 5 to 6 as a seed soaking coating agent in promoting plant growth.

10. Use of the Pakistani Lysinibacillus Sneb2537 according to claim 1, the preparation according to any one of claims 2 to 4, or the preparation obtained by the preparation method according to any one of claims 5 to 6 as a fertilizer in promoting plant growth.

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