Bacillus velez YFB3-1 and its separation, screening and identification method and application

Abstract

The present invention belongs to the field of microbial technology, and specifically relates to a Velez subtilis YFB3-1 and its separation, screening and identification method and application. The Velez subtilis YFB3-1 is deposited in the China Center for Type Culture Collection with a deposit number of CCTCC M20221140, and the depository address is No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province. The Bacillus Velez subsp. YFB3-1 of the present invention has a strong antibacterial effect on Fusarium oxysporum, the main pathogenic bacteria of lily wilt, and has a good antagonistic effect on soil-borne pathogenic fungi of lily, such as Fusarium trilineatum, Fusarium solani, Alternaria alternata, Sclerotium solani, Phytophthora, Penicillium and Aspergillus niger, with inhibition rates all above 75%, and has the ability of high efficiency and broad spectrum resistance to soil-borne pathogenic fungi; the method of the present invention can effectively separate, purify, screen and identify Bacillus Velez subsp. YFB3-1 from the intestine of earthworms, the method of the present invention is easy to operate, can quickly separate the contents of the intestine of earthworms, and can accurately and reliably obtain the Bacillus Velez subsp. YFB3-1 through screening and identification.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and specifically relates to Bacillus velez YFB3-1 and a separation, screening and identification method and application thereof. Background Art

[0002] Lily wilt, also known as root rot and stem rot, is the most serious fungal disease in lily production and cultivation, causing the greatest economic losses. It has the characteristics of great harm, wide distribution, and difficulty in prevention and control. It seriously affects the yield and quality of lilies and hinders the development of the lily industry. Lily wilt caused by Fusarium is the most common and serious in its cultivation process. Under any temperature and humidity conditions in the lily cultivation process, Fusarium can effectively survive or grow and reproduce. Therefore, lilies may be infected throughout the growth cycle. The wilt of continuously cropped lilies has the characteristics of widespread occurrence, severe disease, and difficulty in prevention and control, resulting in a sharp decline in yield and quality. It has become the main limiting factor in the development of lily cultivation and related industries. Therefore, the prevention and control of lily wilt has become the main problem faced in its cultivation process.

[0003] Earthworms are the species with the largest biomass among soil animals. They play an important role in the material cycle and energy conversion of soil ecosystems, and play an important regulatory role in maintaining the structure and function of soil ecosystems. Earthworms are "engineers" of soil improvement and have an interactive relationship with microorganisms. Some microorganisms that enter the body with food are killed through their intestines. Microorganisms that exist in mutualistic symbiosis with earthworms will become dominant flora, rapidly expand in the earthworm intestines, and further reproduce and spread in the soil through their digging and excretion, changing the structure and composition of soil microbial communities. The flora isolated from the earthworm intestines is significantly different from that of soil and fresh earthworm castings, and there are four main physiological groups, namely plant growth promoters, free active nitrogen fixers, fungicides, and phosphate solubilizers.

[0004] Earthworms can directly or indirectly affect the composition, richness and activity of microorganisms, thereby effectively regulating the soil microecological system, promoting soil nutrient circulation, improving soil biological fertility, and reducing the occurrence of crop wilt diseases.

[0005] Therefore, using earthworms to regulate soil microecological environment has become a new way to alleviate crop continuous cropping obstacles. Whether there are microorganisms in their intestines that are highly effective in antagonizing Fusarium oxysporum in lilies, as well as their role and application direction have become the main development direction of current research. Summary of the invention

[0006] In view of the above shortcomings, the present invention provides a Velez Bacillus YFB3-1 and its separation, screening and identification method and application. The Velez Bacillus YFB3-1 of the present invention has a strong antibacterial effect on the main pathogenic bacteria of lily wilt-Fusarium oxysporum, and has a good antagonistic effect on the soil-borne pathogenic fungi of lily, Fusarium trilineatum, Fusarium solani, Alternaria alternata, Sclerotium sclerotiorum, Phytophthora, Penicillium and Aspergillus niger, with an inhibition rate of more than 75%, and has the ability of high efficiency and broad spectrum resistance to soil-borne pathogenic fungi; the method of the present invention can effectively separate, purify, screen and identify Velez Bacillus YFB3-1 from the intestine of earthworms, the method of the present invention is easy to operate, can quickly separate the contents of the earthworm intestine, and can accurately and reliably obtain the Velez Bacillus YFB3-1 through screening and identification.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A Bacillus velezensis YFB3-1, characterized in that the deposit number of the Bacillus velezensis YFB3-1 in the China Type Culture Collection is CCTCC M 20221140, the deposit address of the depository institution is No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province, the deposit date is July 21, 2022, and the classification name is Bacillus velezensis YFB3-1.

[0009] Preferably, the Bacillus Velezii YFB3-1 colonies are milky white, dull, with wrinkled surfaces, uneven raised edges, and depressions in the middle.

[0010] The present invention also claims a method for separating, screening and identifying the above-mentioned Bacillus Velezii YFB3-1, comprising the following steps:

[0011] (1) Separation: Clean the surface of the earthworms with sterile water, then disinfect the surface of the earthworms with alcohol to kill them, and then dissect and remove the intestinal contents of the earthworms;

[0012] (2) Purification: Add the substance obtained in step (1) into a flask containing sterile water, shake it to make a suspension, and then dilute the suspension with sterile water to 10 -3 Serial dilutions, 10 -4 Serial dilutions and 10 -5 Gradient dilution; the diluted 10 -3 The gradient dilutions were spread on NA medium plates for culture. -4 The gradient dilutions were spread on Bengal red agar plates for culture. -5The gradient dilutions were spread on the plates of modified Gao's medium No. 1 for culture; then single colonies with good growth on the three culture medium plates were selected for streaking and purification of strains;

[0013] (3) Screening: Activate the Fusarium oxysporum of lily on PDA, then use a hole puncher to punch holes at the edge of the activated colony and take out the bacterial cake; transfer the bacterial cake with the mycelium side facing down to the center of a new PDA plate, and then use the cross-cross method to spot isolate and purify the strains for culturing and screening out the antagonistic strain with the strongest antagonistic effect on the lily pathogenic fungus Fusarium oxysporum;

[0014] (4) Identification: The antagonistic strain screened out in step (3) is subjected to morphological identification and then molecular biological identification to identify the Bacillus velezensis YFB3-1.

[0015] Preferably, the volume fraction of the alcohol in step (1) is 75%.

[0016] Preferably, the oscillation time in step (2) is 15-45 min, and the components of the NA medium include: 7.5-15 g of peptone, 2-5 g of beef extract, 3-6 g of NaCl, 18-22 g of agar, and 1000 mL of deionized water; the components of the Bengal rose agar medium include: 3-8 g of peptone, 8-12 g of glucose, 0.25-1.5 g of MgSO4·7H2O, 1.0 g of K2HPO4, 0.015-0.045 g of Bengal rose, 18-22 g of agar, 1000 mL of deionized water, and 2-5 mL of a 1% streptomycin solution; the components of the Gao's No. 1 medium include: 0.5-1.5 g of KNO3, 18-22 g of soluble starch, 0.25-1 g of K2HPO4, 0.25-1 g of MgSO4·7H2O, and 1000 mL of deionized water. 0.25-1.5 g, FeSO4·7H2O 0.005-0.015 g, agar 18-22 g, deionized water 1000 mL; the culture temperature is 25-45°C.

[0017] Preferably, the preparation method of PDA in step (3) is: peel and cut potatoes into pieces and weigh 100-300 g, add water and boil for 25-45 min to make an infusion, then add 18-22 g of glucose and 18-22 g of agar, and add deionized water to make the volume to 1000 mL; the culture temperature is 25-45°C.

[0018] Preferably, the morphological identification method in step (4) is: streaking the antagonistic bacteria onto the NA medium solid plate, culturing in a constant temperature incubator at 25-45°C for 2-5 days, and recording the colony morphology of a single colony, then staining the bacteria with Gram staining, observing the morphological characteristics of the bacteria, and observing the morphology of the bacteria with a scanning electron microscope and measuring the size for morphological identification; the molecular biological identification method is: using universal primers to amplify the bacterial 16S rDNA gene fragment, and then performing gene sequencing for molecular biological identification.

[0019] The present invention also claims to protect an application of the above-mentioned Bacillus Velez subtilis YFB3-1 in preventing and treating lily wilt disease.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The Bacillus Velezii YFB3-1 of the present invention has a strong antibacterial effect on Fusarium oxysporum, the main pathogen of lily wilt, and has a good antagonistic effect on soil-borne pathogenic fungi of lily, including Fusarium trilineatum, Fusarium solani, Alternaria alternata, Sclerotium sclerotiorum, Phytophthora, Penicillium and Aspergillus niger, with inhibition rates of more than 75%, and has the ability to effectively and broadly resist soil-borne pathogenic fungi.

[0022] (2) The method of the present invention can effectively separate, purify, screen and identify Bacillus Velez subtilis YFB3-1 from the intestinal tract of earthworms. The method of the present invention is easy to operate, can quickly separate the contents of the intestinal tract of earthworms, and can accurately and reliably obtain the Bacillus Velez subtilis YFB3-1 through screening and identification.

[0023] (3) The Bacillus Velezii YFB3-1 of the present invention has a good preventive and therapeutic effect on Fusarium oxysporum wilt of lily, and has great application value in alleviating the obstacle of crop continuous cropping. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a diagram showing the antagonistic effect of earthworm intestinal microorganisms on Fusarium oxysporum;

[0025] Figure 2 This is a colony morphology diagram of Bacillus Velez YFB3-1 of the present invention;

[0026] Figure 3 This is a biofilm morphology diagram of Bacillus Velez YFB3-1 of the present invention;

[0027] Figure 4 This is an optical microscope image of Bacillus Velez YFB3-1 of the present invention;

[0028] Figure 5 This is a scanning electron microscope image of Bacillus Velez YFB3-1 of the present invention;

[0029] Figure 6 is a phylogenetic tree of the 16S rDNA gene sequence of Bacillus Velez YFB3-1 of the present invention;

[0030] Figure 7 This is a diagram showing the antibacterial effect of the Bacillus Velez YFB3-1 of the present invention on some lily pathogenic fungi. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. 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.

[0032] Unless otherwise specified, the chemical reagents and materials in the present invention are purchased from commercial sources or synthesized from raw materials purchased from commercial sources.

[0033] The Bacillus velezensis YFB3-1 has a deposit number of CCTCC M20221140 in the China Type Culture Collection, a deposit date of July 21, 2022, a classification name of Bacillus velezensis YFB3-1, and an address of the depository institution of No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province.

[0034] The lily variety was Lilium ruthenicum, provided by Hunan Longshan Green Leaf Agricultural Products Co., Ltd. The earthworm variety was Eisenia fetida Daping No. 2, collected from the soil of the Changsha Agricultural and Environmental Monitoring Research Station of the Institute of Subtropical Agricultural Ecology, Chinese Academy of Sciences, where an experiment on inoculating earthworms to alleviate the obstacles of continuous cropping of lilies was carried out.

[0035] The test pathogens: Fusarium oxysportum, Fusarium trilobium and A. alternata were from the College of Plant Protection, Hunan Agricultural University, S. rolfsii, Phytophthora parasitica, F. solani, Penicillium cyclopium, Aspergillus niger and Bacillus subtilis were from the Hunan Institute of Agricultural Environment and Ecology. All of the above pathogenic fungi were isolated from infected lily plants or bulbs.

[0036] The commercially available Bacillus compound preparation is a powder produced by Beijing Zhenyujiang Agricultural Technology Co., Ltd., which contains Bacillus subtilis, Bacillus laterus, Bacillus licheniformis and Bacillus mucilaginosus, with a total number of effective live bacteria ≥ 2×10 8 CFU / g.

[0037] The composition of NA solid medium is as follows: peptone 10.0 g, beef extract 3.0 g, NaCl 5.0 g, agar 20.0 g, deionized water 1000 mL, natural pH, sterilized at 121 °C for 30 min.

[0038] The components of Bengal red agar medium are as follows: peptone 5.0 g, glucose 10.0 g, MgSO4·7H2O 0.5 g, K2HPO4 1.0 g, Bengal red 0.033 g, agar 20.0 g, deionized water 1000 mL, and streptomycin solution 3 mL with a mass concentration of 1%;

[0039] The composition of Gao's medium No. 1 is as follows: KNO3 1.0 g, soluble starch 20.0 g, K2HPO4 0.5 g, MgSO4·7H2O 0.5 g, NaCl 0.5 g, FeSO4·7H2O 0.01 g, agar 20.0 g, deionized water 1000 mL;

[0040] The preparation method of PDA is as follows: peel and cut potatoes into pieces and weigh 200.0 g, add 800 mL of deionized water and boil for 30 minutes to make an infusion, then filter to obtain a filtrate, add 20.0 g of glucose and 20.0 g of agar to the filtrate, and finally add deionized water to make the volume 1000 mL.

[0041] Example 1

[0042] A method for separating, screening and identifying the above-mentioned Bacillus Velezii YFB3-1 comprises the following steps:

[0043] (1) Separation: First, clean the surface of the earthworms with sterile water, then disinfect the surface of the earthworms with 75% alcohol to kill them, and then dissect and remove the intestinal contents of the earthworms;

[0044] (2) Purification: The substance obtained in step (1) was added to a flask containing sterile water, and the suspension was prepared by shaking for 30 min. The suspension was then diluted with sterile water to 10 -3 Serial dilutions, 10 -4 Serial dilutions and 10 -5 Gradient dilution; the diluted 10 -3 The gradient dilutions were spread on NA medium plates for culture. -4The gradient dilutions were spread on Bengal red agar plates for culture. -5 The gradient dilutions were spread on plates of modified Gao's medium No. 1 for culture; cultured at 30°C, and when the colonies grew to a certain extent, single colonies with good growth on the three culture medium plates were picked for streaking and purification of strains (colonies with the same morphology were grouped as one strain) and stored for later use.

[0045] (3) Screening: Activate the lily oxysporum Fusarium on PDA, then use a 0.6 cm diameter puncher to punch holes at the edge of the activated colony and take the bacterial cake; transfer the bacterial cake with the mycelium side facing down to the center of a new PDA plate, and then use the cross method to spot the isolated and purified strain 2.5 cm away from the center of the plate, and use no inoculation as a control. Incubate at 30°C until the control pathogens grow all over the plate, measure the diameter of each pathogen, the inhibition bandwidth and other indicators, calculate the inhibition rate, and screen out the antagonistic strain with the strongest antagonism to the lily pathogen Fusarium oxysporum based on the inhibition rate. Calculate the inhibition rate according to the following formula:

[0046] Inhibition rate = [(control pathogen radius - 0.3) - (treated pathogen radius - 0.3)] / (control pathogen radius - 0.3) × 100%.

[0047] (4) Identification: The antagonistic strain screened out in step (3) is subjected to morphological identification and then molecular biological identification to identify the Bacillus velezensis YFB3-1.

[0048] Morphological identification: streak the selected earthworm intestinal antagonistic bacteria onto a solid NA medium plate, culture it in a constant temperature incubator at 30°C for 3 days, record the colony morphology of single colonies, stain the bacteria with Gram staining, observe the morphological characteristics of the bacteria, and observe the bacterial morphology and measure the size using a scanning electron microscope.

[0049] Molecular biological identification: The strain to be tested was inoculated into sterilized NB medium and cultured at 30°C for 48 hours. The fermented bacterial liquid was centrifuged at 10,000 r / min for 10 minutes, the precipitate was collected, mixed with sterile physiological saline and centrifuged again, the bacterial precipitate was collected, and quickly frozen at -80°C. It was then delivered to Changsha Aoki Biotechnology Co., Ltd. by ice pack express. The universal primers (27F and 1492R) of the bacterial 16S rDNA gene fragment were used for amplification and gene sequencing.

[0050] 146 strains (including bacteria, fungi and actinomycetes) were isolated and purified from the intestines of earthworms inoculated with earthworms to alleviate continuous lily cropping. Using the plate confrontation method and taking Fusarium oxysporum as the target, the isolated and purified strains were preliminarily screened for antibacterial tests. A total of 33 strains (including 18 bacteria, 3 fungi and 12 actinomycetes) with obvious antibacterial effects on Fusarium oxysporum were screened, and 11 strains had an inhibition rate of more than 76% on Fusarium oxysporum on lilies, as shown in Table 1:

[0051] Table 1 Antagonistic effect of earthworm intestinal microorganisms on Fusarium oxysporum

[0052]

[0053] Note: Data are the average of four replicates. Lowercase letters indicate significant differences among different treatments (P<0.05)

[0054] As shown in Table 1, the bacterial strain YFB3-1 has the best antibacterial effect on Fusarium oxysporum, and its inhibition rate is significantly higher than that of other strains, which is 80.03%. Figure 1 This is a diagram of the antagonistic effect of earthworm intestinal microorganisms on Fusarium oxysporum. In the figure, A is the negative control, B is the positive control (Bacillus subtilis), C is YFB1-4, D is YFB3-1, and E is YFB6-2.

[0055] The antagonistic bacteria YFB3-1 was identified by morphology. The antagonistic bacteria YFB3-1 was grown on NA medium. Figure 2 As shown in the figure, the pure culture formed by growing at 28°C for 3 days has the following characteristics: the colonies are milky white, dull, with wrinkled surfaces, uneven raised edges, and concave in the middle; Figure 3 As shown, a milky white bacterial film is formed during static liquid culture; Figure 4 As shown in the figure, after Gram staining, it was found that YFB3-1 bacteria were blue-purple under a microscope, and were Gram-positive bacteria. Most of them were oval, and a small part was rod-shaped, straight or slightly curved, and arranged alone or in short chains; Figure 5 As shown, the spores are oval, central, 1.4-1.8 μm long, and 0.7 μm wide. Based on the morphological characteristics of the colonies and bacteria, it was preliminarily determined that YFB3-1 belongs to the Bacillus family.

[0056] The antagonistic bacteria YFB3-1 was identified by molecular biology. The genomic DNA of the strain YFB3-1 to be tested was used as a template and the bacterial universal primers 27F / 1492R were used to amplify YFB3-1 by PCR to obtain a DNA fragment of 1417 bp in length. The 16SrDNA gene sequence of the strain YFB3-1 was input into the NCBI database for Blast similarity comparison analysis. Based on the homology of the 16SrDNA gene sequence, 12 representative strains were selected from the results and the phylogenetic tree of the strain was constructed using MEGA 7.0 software, as shown in Figure 1. Figure 6 As shown, the genetic evolutionary distance of strain YFB3-1 is closest to Bacillus, and it is in the smallest branch with the known strain B. velezensis Wh-1 (MK522153.1S), with a homology of 99%. It can be determined that strain YFB3-1 is Bacillus velezensis.

[0057] The antimicrobial spectrum of Bacillus Velezii YFB3-1 was determined, and different lily pathogenic fungi required for the test were activated on PDA medium. Pathogenic fungi that do not produce or produce poor spores, such as Fusarium oxysporum, Fusarium solani, Phytophthora, Fusarium trilineatum, Sclerotium truncatum, and Alternaria alternata, were punched at the edge of the pathogen with a 0.6 cm diameter puncher to take out the bacterial cake, and the side with hyphae on the bacterial cake was transferred to the center of a new PDA plate facing down. Lily pathogenic fungi that produce good spores, such as Aspergillus niger and Penicillium, were inoculated to the center of the PDA plate by spotting.

[0058] The antibacterial test method and the inhibition rate calculation formula using the bacterial cake transfer method are as follows: Use the cross method to spot the isolated and purified strains at 2.5 cm from the center of the plate, and use no inoculation as a control. Incubate at 30°C until the control bacteria grow all over the plate, measure the diameter of each pathogen, the inhibition bandwidth and other indicators, and calculate the inhibition rate. The inhibition rate calculation formula is as follows:

[0059] Inhibition rate = [(control pathogen radius - 0.3) - (treated pathogen radius - 0.3)] / (control pathogen radius - 0.3) × 100%.

[0060] The inhibition rate calculation formula using the disease spore spotting method is as follows:

[0061] Inhibition rate = (control pathogen radius - treated pathogen radius) / control pathogen radius × 100%.

[0062] The results are shown in Table 2:

[0063] Table 2 Antibacterial spectrum results of YFB3-1

[0064]

[0065] Note: Data are the average of four replicates. Lowercase letters indicate significant differences among different treatments (P<0.05)

[0066] As shown in Table 2, Bacillus Velezii YFB3-1 has good antibacterial effect on eight pathogenic fungi including Fusarium oxysporum, Fusarium trilineatum, Fusarium solani, Alternaria alternata, Sclerotium sclerotiorum, Phytophthora, Penicillium and Aspergillus niger. Figure 7 As shown in the figure, A is Fusarium oxysporum; B is Fusarium solani; C is Fusarium trilineatum; D is Alternaria alternata; E is Sclerotium solani; and F is Aspergillus niger.

[0067] A potted plant prevention and control experiment was conducted. Round flower pots (upper inner diameter 0.25m × lower inner diameter 0.16m × inner height 0.16m) were selected. Three lily bulbs were planted in each pot. After planting around September 25 of the first year, they were placed in a net house for wintering and germination management. Around April 3 of the second year, when the lilies emerged, the lily pots with a seedling height of 0.15m were transferred to a room with a certain light intensity for standby use.

[0068] Preventive test: First, the Velez Bacillus YFB3-1 was fermented in sterilized NB medium and then diluted to a bacterial concentration of 10 7 CFU / mL of bacterial solution, sterile water was used as negative control, and commercial Bacillus was dissolved in sterile water to make a bacterial concentration of 10 7 CFU / mL of bacterial solution was used as the positive control. After irrigating the roots of each lily with 50mL of bacterial solution or sterile water for 3 days, a 1cm diameter bacterial cake of lily pathogenic fungus Fusarium oxysporum was inoculated at a distance of 3cm from each lily. Five pots were cultivated for each treatment, and three lily bulbs were planted in each pot. This was repeated three times, for a total of 45 pots. The indoor temperature was controlled at 28℃, and the relative humidity was maintained at about 90%. The disease condition of the lily was observed 20 days after root irrigation.

[0069] Treatment test: First, a 1cm diameter bacterial cake of lily pathogenic fungus Fusarium oxysporum was inoculated at a distance of 3cm from each lily, and then treated with the prepared bacterial solution of Bacillus Velez YFB3-1, with sterile water as the negative control and the bacterial solution of commercially available Bacillus compound preparation as the positive control. Each lily was irrigated with 50mL bacterial solution or sterile water. Five pots were cultivated for each treatment, and three lily bulbs were planted in each pot. The results were repeated three times, for a total of 45 pots. The indoor temperature was controlled at 28℃, and the relative humidity was maintained at about 90%. The disease of lilies was observed after irrigating the roots for 20 days. The investigation was carried out in units of plants, and the relevant graded investigation was carried out according to the degree of lily wilt disease, and the total number of plants and the number of diseased plants at each level were counted. The survey grading standards are as follows: Level 0 means the plant stems are normal and there are no diseased leaves on the whole plant; Level 1 means the number of yellow or purple leaves on the bottom of the diseased plant does not exceed 25% of the total number of leaves on the whole plant, the top of the stem turns light purple, and the heart leaves are slightly bent to one side; Level 2 means the leaves on the bottom of the diseased plant are withered or the number of withered leaves accounts for 25% to 50% of the whole plant, and the upper part of the stem turns purple and is obviously bent; Level 3 means more than 50% of the leaves on the diseased plant are withered, the upper and middle parts of the stem turn purple, and are severely bent; Level 4 means all the leaves on the plant are withered or the whole plant is dead, and the vascular bundles at the base of the stem turn brown. Among them:

[0070] Incidence rate = number of diseased plants / total number of plants × 100%

[0071] Disease index = Σ(number of diseased plants at each level × relative level value) / (total number of plants × highest level value) × 100

[0072] Relative control effect = (disease index of control - disease index of treatment) / disease index of control × 100%

[0073] The results are shown in Table 3:

[0074] Table 3 Control effect of Bacillus Velezii YFB3-1 on lily wilt

[0075]

[0076] As shown in Table 3, under the prevention condition, the root irrigation Bacillus Velez YFB3-1 bacterial solution has the lowest incidence and disease index of lily wilt caused by Fusarium oxysporum, which are 35.56% and 13.33 respectively, which are significantly lower than the sterile water and commercial biocontrol agent controls, and its control effect relative to sterile water is 64.18%, which is 34.38% higher than the control effect of commercial Bacillus compound preparations. Under the treatment condition, the root irrigation Bacillus Velez YFB3-1 bacterial solution has the lowest incidence and disease index of lily wilt caused by Fusarium oxysporum, which are 62.22% and 25.56 respectively, which are significantly lower than the clear water control, and its control effect relative to clear water is 30.3%, which is 33.3% higher than the control effect of commercial Bacillus compound preparations. Therefore, Bacillus Velez YFB3-1 has a good prevention and treatment effect on lily Fusarium oxysporum wilt under root irrigation conditions.

[0077] The above contents are further detailed descriptions of the present invention in combination with specific implementation examples. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention.

[0078] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A Bacillus velezensis YFB3-1, characterized in that: The deposit number of the Bacillus velezensis YFB3-1 in the China Center for Type Culture Collection is CCTCC M 20221140, and the address of the depository institution is No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province.

2. An application of the Bacillus Velez subtilis YFB3-1 described in claim 1 in preventing and treating lily wilt disease.

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