Rice seed and fungicide for rice seed

Abstract

The invention discloses a rice seed and a bacterial agent for the rice seed, the surface of the rice seed is covered with bacillus subtilis, the bacillus subtilis is preserved in the China General Microbiological Culture Collection Center, and the preservation number is CGMCC 35166. The bacillus subtilis strain disclosed by the invention has an anti-aflatoxin effect, so that the bacillus subtilis strain has an anti-aflatoxin effect on rice seeds covered with the strain, the quality guarantee period of the seeds can be prolonged, aspergillus flavus pollution can be prevented, and seed germination can be promoted.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural technology, in particular to the field of rice seed protection technology. BACKGROUND

[0002] Aspergillus flavus is a common fungus, and the aflatoxin produced by it has strong carcinogenicity. Rice seeds are easily contaminated by Aspergillus flavus during storage, resulting in a decrease in seed germination rate, deterioration of quality, and even production of toxins, which are harmful to human health. Traditional storage methods, such as drying and low temperature, can inhibit the growth of Aspergillus flavus to some extent, but the effect is limited and it is difficult to completely prevent Aspergillus flavus contamination. SUMMARY

[0003] The present application relates to the field of agricultural technology, in particular to the field of rice seed protection technology.

[0004] The present application provides a rice seed, characterized in that the surface is covered with Bacillus subtilis, which is preserved in the China General Microbiological Culture Collection Center with the preservation number CGMCC 35166.

[0005] Since the Bacillus subtilis strain of the present application has an anti-aflatoxin effect, the rice seeds covered with the strain have an anti-aflatoxin effect, which can prolong the shelf life of the seeds and prevent Aspergillus flavus contamination.

[0006] According to the rice seed of the present application, preferably the surface is covered with 0.1-0.5% solid Bacillus subtilis inoculum by seed mass, wherein the solid Bacillus subtilis inoculum contains a Bacillus subtilis strain and a carrier.

[0007] That is, the strain on the surface of the rice seed of the present application is loaded on a suitable carrier, which can provide nutrients for the strain and protect it from adverse external environments, prolonging the survival time of the strain.

[0008] According to the rice seed of the present application, the carrier is rice bran, corn cob powder, grass carbon, diatomite, starch residue, guar gum, xanthan gum, diatomite, locust bean gum, bentonite, zeolite powder, porous starch, nanocellulose, chitosan, trehalose or a carrier compounded therefrom.

[0009] The carrier is also diatomite and guar gum; nanocellulose and chitosan; diatomite, guar gum, chitosan and trehalose mixed carrier. By using the compound carrier, the adhesion to the rice seeds can be enhanced, so that the strains are not easy to fall off from the seeds, and the protection of the strains to the rice seeds is enhanced.

[0010] According to the rice seed of the present application, 1x10 6 -1x10 8 microbial activity units of Bacillus subtilis.

[0011] By limiting the microbial activity units in a suitable range, the strain concentration can be ensured.

[0012] According to the rice seed of the present application, the Bacillus subtilis can be directly attached to the shell of the rice seed. That is, when the rice seeds are coated with the liquid fungicide, the strains are not loaded on other carriers, but are directly adhered to the gaps on the surface of the rice shell. Compared with the bacterial powder, the liquid bacterial solution is easier to mix uniformly. After the liquid bacterial solution is dried, the solid substances in the liquid can provide appropriate nutrients for the growth of the strains. In addition, since the rice shell is relatively rough, the strains can naturally adhere to the gaps on the shell, inhibit the growth of Aspergillus flavus hidden in the gaps, and occupy the space on the surface of the seeds to inhibit the reproduction of other pathogenic bacteria.

[0013] According to the foregoing rice seed, the rice seed is Longjing 3023, which has the characteristics of anti-lodging and high yield.

[0014] According to the foregoing rice seed, the preferred storage condition of the seed is that the temperature is 4-10℃, the relative humidity is not more than 60%, and direct sunlight is avoided. Under such conditions, the activity of the strains on the surface of the rice can be prolonged, and the production of pathogenic bacteria can be inhibited.

[0015] The present application also provides a method for preparing the foregoing rice seed, comprising: drying the rice seeds with good maturity and no pests and diseases to a water content of 12%-15%, mixing 1x10 8 -1x10 10 CFU / mL of Bacillus subtilis bacterial solution or equivalent bacterial powder, and then drying to a water content of 10%-12%, wherein the drying condition is preferably a temperature of 25-30℃ and a humidity of 40%-60%, and the drying time is 2-4 hours until the target water content is reached.

[0016] In addition, when the strain of the present application is used for seed aflatoxin prevention, the following advantages are also possessed:

[0017] 1) Good mildew prevention effect: Bacillus subtilis LT-86 can secrete antibacterial substances to inhibit the growth of Aspergillus flavus, and at the same time, through competitive inhibition, it can occupy the survival space on the surface of the seeds, effectively preventing Aspergillus flavus pollution.

[0018] 2) Safe and environmentally friendly: Bacillus subtilis LT-86 is a probiotic bacteria, harmless to humans and animals, and friendly to the environment.

[0019] 3) Promote seed germination: Bacillus subtilis LT-86 can secrete plant growth hormones to promote seed germination and seedling growth.

[0020] 4) Simple operation: The method is simple and easy to operate, and is easy to popularize and apply. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the colony morphology of Bacillus subtilis LT-86 on LB agar medium;

[0022] Figure 2-1 and Figure 2-2 are the microscopic morphology photos of Bacillus subtilis LT-86 after magnification of 400 times and 1000 times;

[0023] Figure 3 is based on the 16S rDNA gene sequence alignment results and phylogenetic tree;

[0024] Figure 4 is the plate antibacterial effect photo of Bacillus subtilis LT-86;

[0025] Figure 5-1 and Figure 5-2 are the inoculation antibacterial experiment effect photos of inoculating bacterial liquid on rice seeds. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only some representative embodiments of the present application, but not all embodiments. All other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0027] Unless otherwise specified, the professional and scientific terms used in this paper have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content can also be applied in the present application.

[0028] Example 1 Bacillus subtilis LT-86 strain

[0029] 1. Source of strain

[0030] The Bacillus subtilis LT-86 involved in the present application is a new strain discovered by the inventors when studying the strain attached to the seeds of rice variety "Longjiang 3023".

[0031] The strain is named LT-86 and is preserved in the China General Microbiological Culture Collection Center, with the preservation number CGMCC35166 and the preservation date July 9, 2025. It was detected to be alive on July 10, 2025.

[0032] 2. Morphology of the strain

[0033] Figure 1 The colony morphology of Bacillus subtilis LT-86 on LB agar medium is shown in the figure. As can be seen from the figure, the strain colony surface is rough and not smooth, with jagged edges; the color is light yellow; the texture is dry, opaque, has certain hardness, and is easy to pick up.

[0034] After the strain was inoculated in LB agar medium and cultured for 24 h to the logarithmic growth phase, the bacterial cells were subjected to Gram staining treatment. Then, an optical microscope (Olympus, TN-B203 biological microscope) was used for observation at 400x and 1000x magnification. As can be clearly seen from the micrograph in FIG. 2, the single strain is rod-shaped, and the bacterial cell thickness is relatively uniform. The cell ends are relatively blunt, and some bacterial cells can be seen to have spores, which are located in the center or slightly offset from one end of the bacterial cell, and are oval-shaped. The spore wall is thick, giving the bacterial cell strong survival ability in adverse environments, and the overall morphological characteristics are typical and clear.

[0035] 3. Identification of the strain

[0036] The 16S rDNA sequence and gyrA gene sequence analysis of Bacillus subtilis LT-86-16S were analyzed and identified. The strain has similarity with Bacillus subtilis, and is identified as Bacillus subtilis.

[0037] The 16S rDNA sequence and gyrA gene sequence of Bacillus subtilis LT-86-16S are shown below, and the 16S rDNA phylogenetic tree is shown in FIG. 1. Figure 3

[0038] >LT-86-16S

[0039] ​CGTGGTGTGACGGGCGGTGTGTACAAGGCCCGGGAACGTATTCACCGCGGCATGCTGATCCGCGATTACTAGCGATTCCAGCTTCACGCAGTCGAGTTGCAGACTGCGATCCGAACTGAGAACAGATTTATGGGATTGGCTAAACCTTGCGGTCTTGCAGCCCTTTGTTCTGTCCATTGTAGCACGTGTGTAGCCCAGGTCATAAGGGGCATGATGATTTGACGTCATCCCCACCTTCCTCCGGTTTGTCACCGGCAGTCACCTTAGAGTGCCCAACTGAATGCTGGCAACTAAGATCAAGGGTTGCGCTCGTTGCGGGACTTAACCCAACATCTCACGACACGAGCTGACGACAACCATGCACCACCTGTCACTCTGTCCCCGAAGGGAAAGCCCTATCTCTAGGGTTGTCAGAGGATGTCAAGACCTGGTAAGGTTCTTCGCGTTGCTTCGAATTAAACCACATGCTCCACCGCTTGTGCGGGCCCCCGTCAATTCCTTTGAGTTTCAGTCTTGCGACCGTACTCCCCAGGCGGAGTGCTTAATGCGTTAGCTGCAGCACTAAGGGGCGGAAACCC

[0040] The LT-86-gyrA sequence of Bacillus subtilis LT-86-16S is shown below.

[0041] >LT-86-gyrA

[0042] TCACAGTGCAAGCAGGTTGATGCCAAAAGATGTTTGTAGAGCAGTTTGTTTGTACAGATTGTTTAAGATGACATTTGCATTGGCATCGCGTCTTATTTCAATGACAATTCTCATACCTGTACGATCTGACTCATCACGCAGATCTGTGATACCCTCTATCTTTTTGTCCCTTACGAGATCAGCAATTTTCTCAATTAATTTCGCCTTATTTACTTGGTAAGGTAACTCTGTAACGATAATTCTTTCTTTACCCGAAGATGTTTGTTCGATCTCAGCTTTTGCCCGGATCGTGATAGAGCCTCGGCCTGATTCGTATGCTTTCCGGATACCGCTGCGTCCCAAGATTTGACCCGCGGTCGGGAAATCAGGCCCTGGAATGACTTCCATAAGCTCTGGAATGGTAATGTCCGGATTCTCACTGACAGCAAGTACACCGTCAATGATTTCTCCCAGCTGGTGAGGAGGAATGTTTGTTGCCATACCTACCGCAATGCCGGCAGCACCGTTCACGAGCAGATTCGGGAACCTTGAAGGCATAACGACAGGTTCTCTTTCTGACCCGTCATAGTTATCCTGGTAATCGATTGTGTCTTTTGTGATGTCGCGAAGAATCTCCATTGAGATTTTAGACATTCTTGCTTCTGTATAACGCATGGCCGCCGCTGAGTCTCCGTCAACAGAACCGAAGTTTCCATGACCGTCAACGAGCATATAACGGTAGTTGAAATCCTGAGCCATTCTAACCATGGATTCATATACCGCTGAATCACCGTGCGGGTGGTATTTCCCGATAACTTCTCCAACGATACGCGCGGATTTTTTATAAGGCTTGTCACTTGTCATGCCTAAATCATTCATTGCATACAAAATCCGTCTATGAACCGGTTTTAAACCGTCTCGAACATCCGGAAGAGCACGGACACGATACG

[0043] 4. The physiological and biochemical characteristics of Bacillus subtilis LT-86-16S are as follows:

[0044] LT-86

[0045]

[0046] Note: + positive, - negative, W weak positive

[0047] 5. Preservation of the strain

[0048] The short-term preservation of the strain can be placed in a refrigerator at 4°C, which can be preserved for 1-2 weeks. The long-term preservation can be mixed with an equal volume of 50% glycerol and placed in a refrigerator at -20°C or -80°C, which can be preserved for several months to several years. A small amount of recovery can be used.

[0049] First, centrifuge the bacterial liquid to collect the bacterial cells, add a protective agent (such as skimmed milk, sucrose, etc.), mix well, and then distribute to ampoule bottles. After pre-freezing, sublimation drying, and analytical drying, the freeze-dried bacterial powder can be obtained, which can be long-term and stable preservation of the strain activity.

[0050] 6. Culture method of the strain

[0051] The commonly used solid or liquid medium can be used for culture. For example, the commonly used LB medium, liquid medium, etc.

[0052] The commonly used liquid medium formula is 1L distilled water containing beef extract 5g, peptone 10g, sodium chloride 5g, pH 7.0-7.2. The optimized formula can add 0.1%-0.2% glucose as a carbon source, or add 0.05% magnesium sulfate, potassium dihydrogen phosphate, etc. Trace elements can better meet the growth needs of the strain and improve the quality of the bacterial liquid.

[0053] Inoculation method: using aseptic operation, a ring of Bacillus subtilis LT-86 bacterial crust is picked up with an inoculation ring and inoculated into the liquid medium; or the bacterial crust is made into a bacterial suspension, and a pipette is used to suck and add the medium according to the inoculation amount of 2%-5%. After shaking well, it is cultured. Cultured at 30-37°C for 24-48 hours, Bacillus subtilis LT-86 bacterial liquid is obtained.

[0054] LB medium (10g of tryptone, 5g of yeast extract, 10g of sodium chloride) can also be used, which is a nutrient-rich medium. Nutrient agar medium can also be used, which has simple ingredients and is suitable for basic culture. Different formulas can be selected according to the experimental purpose and the demand of the strain.

[0055] The conditions such as temperature, pH, and dissolved oxygen can be optimized, such as increasing dissolved oxygen by using a shaking bed; growth factors such as vitamin B can also be added; and stage culture can also be carried out, such as low temperature induction of spore formation in the early stage and promotion of growth in the later stage.

[0056] Example 2: Culture and preservation of Bacillus subtilis LT-86

[0057] Liquid fermentation culture was carried out in the following way:

[0058] Liquid medium formula: 1L distilled water contains beef extract 5g, peptone 10g, sodium chloride 5g, glucose 0.04g, 0.01g magnesium sulfate, pH 7.0-7.2.

[0059] Inoculation method: using aseptic operation, using inoculation ring to pick up Bacillus subtilis LT-86 lichen to cover the inoculation ring, inoculate 100ml liquid medium, shake well and culture. 30℃, 200rpm constant temperature shaker for 24-48 hours, get Bacillus subtilis LT-86 bacteria liquid.

[0060] Bacillus subtilis LT-86 in the above medium growth 2 days after strain morphology as shown in Figure 2.

[0061] Freeze-drying preservation: freeze-drying preservation can be carried out according to the following steps.

[0062] Pre-treatment: centrifugal bacteria liquid, discard supernatant, resuspend bacteria mud with 10% glycerol as protective agent. Dispensed to freeze-drying tube (0.5-1ml per tube), inserted into sterile cotton plug.

[0063] Pre-freezing: placed in-80℃ refrigerator or liquid nitrogen for rapid freezing (1-2 hours), forming solid ice crystals.

[0064] Freeze-drying program: transfer the pre-frozen sample to the freeze dryer, start the program (usually-50℃ to-80℃, vacuum degree <0.1mbar), dry for 24-48 hours.

[0065] Post-processing: after drying, nitrogen sealing, -80℃ or 4℃ storage.

[0066] Example 3: Aspergillus antibacterial effect

[0067] The experiment was carried out on a sterile operation table, the temperature was constant at 28℃, the medium was PDA medium, and the test strains were Bacillus subtilis LT-86 and Aspergillus flavus. Aspergillus flavus was commercially available Aspergillus flavus spores, which were washed with sterile water to prepare spore suspension, and the spore concentration was adjusted to 10 5 CFU / mL, and then mixed with PDA medium and poured into plates. 200μL of Aspergillus flavus spore suspension was added to every 100ml of PDA medium.

[0068] LT-86 strain was inoculated into LB liquid medium and cultured at 30℃, 150rpm overnight. The density was 10 8 -10 9The strain suspension (3 μl / plate) of cells / ml was dropped on the filter paper (1 piece / dish) on the PDA medium containing Aspergillus flavus. After 48 h of co-culturing at 30℃, the inhibition zone was observed and measured. The experiment was set in 4 repeats, and the size of the inhibition zone was the average value of 4 repeats on two plates.

[0069] From the plate experiment picture Figure 4 It can be clearly seen from the picture of the plate experiment that on the PDA plate inoculated with Aspergillus flavus, the Aspergillus flavus colonies should have been uniformly outwardly expanded and grown. However, around the filter paper to which the Bacillus subtilis LT-86 strain suspension was dropped, an obvious inhibition zone appeared, the edge of the inhibition zone was neat, and the boundary with the normally grown Aspergillus flavus colonies was clear. The average diameter of the inhibition zone reached a certain value, which directly indicated that the Bacillus subtilis LT-86 had a significant inhibitory effect on Aspergillus flavus and could effectively prevent the growth and diffusion of Aspergillus flavus.

[0070] Example 4: Preparation of the Bacillus subtilis LT-86 bacterial agent

[0071] Under sterile environment operation, 100 ml of the Bacillus subtilis LT-86 bacterial liquid obtained in Example 1 was mixed with 300 g of sterilized bran (water content 20%-30%) to prepare the Bacillus subtilis LT-86 bacterial agent. After testing part of the mixture, the rest was sealed in an aluminum foil bag and stored in a dry, cool, ventilated place, avoiding direct sunlight and high temperature and humidity.

[0072] It was determined that the Bacillus subtilis LT-86 bacterial agent obtained in Example 3 had a viable bacterial count ≥ 108 CFU / g.

[0073] In addition to bran, other known organic or inorganic carriers such as rice bran, corn cob powder, grass carbon, diatomite, starch residue, etc. can also be selected. The corn cob powder is porous and beneficial for bacterial adhesion; the grass carbon has good water retention; the diatomite has strong adsorption; and the starch residue has low cost and can provide certain nutrients, which can be selected according to the actual situation.

[0074] The bacterial agent was stored under different temperature (such as 4℃, 25℃, 37℃) and humidity conditions, and the viable bacterial count was detected regularly to observe the change. The results showed that the bacterial agent of the application could remain stable at 25℃, so the bacterial agent of the application could be stored at room temperature.

[0075] Example 5: Inoculation inhibition experiment

[0076] In two culture dishes, one layer of the same rice seeds was laid respectively, and the bacterial liquid prepared according to the method of Example 3 and the blank culture medium were inoculated into the rice seeds respectively, and the seeds were placed at room temperature. After 10 days, the seed condition was observed.

[0077] Figure 5-1 and Figure 5-2The results of the control group and the inoculated bacteria liquid group are shown in the following figures. As can be seen from the figures, the blank bacteria liquid group produces obvious Aspergillus flavus colonies, and the inoculated bacteria liquid group does not produce Aspergillus flavus. Moreover, from the control group, the Aspergillus flavus colonies are obviously larger than those in the inoculated bacteria liquid group. Figure 5-2 As can be seen, the rice seeds inoculated with the bacteria liquid have obvious signs of germination. Therefore, the strain of the present application also has the effect of promoting the germination of rice.

[0078] Example 6: Rice seeds

[0079] Select 2000 kg of rice seeds with good maturity and no pests and diseases, and air dry until the moisture content is 12.5%. Remove impurities and damaged seeds. Divide the rice seeds into two parts, each weighing 1000 kg. Mix 1.5 kg of Bacillus subtilis LT-86 inoculant prepared according to the method described in Example 3 evenly into one of the seed portions. Package the seed treated with the inoculant in a woven bag, dry in a cool place, and store in a plastic bag in a warehouse with a temperature of 10°C and a relative humidity of 55% (Example).

[0080] Do not treat the other portion of seeds with inoculation, but directly place the seeds in a cool place for a short period of time, then package in a woven bag and store in a warehouse with a temperature of 10°C and a relative humidity of 55% (Comparative Example).

[0081] Both samples are turned over every two months. After 3 days of storage, 1000 seeds are randomly selected from each group. In the general storage group, 125 seeds are found to be infected with Aspergillus flavus, with an infection rate of 12.5%. In the inoculant storage group, only 20 seeds are infected, with an infection rate of 2%. It can be seen that the use of the strain of the present application for inoculation significantly reduces the infection rate of Aspergillus flavus.

[0082] Example 7: Optimization of Bacillus subtilis LT-86 inoculant carrier

[0083] According to the method for preparing the inoculant in Example 4, replace the bran with rice bran, corn cob powder, grass carbon, diatomite, starch residue, guar gum, xanthan gum, diatomite, locust bean gum, bentonite, zeolite powder, porous starch, nano cellulose (all commercially available) and compound carrier. Replace the ordinary rice seeds with commercially available Longjing 3023 rice seeds. Analyze the strain storage stability and the adhesion of the carrier to the rice seeds when the strain is loaded on different carriers.

[0084] Among them, the strain storage stability is tested under the following conditions: the prepared inoculant is divided into sealed light-proof containers and placed in an environment of 40°C±2°C. Samples are taken at 0, 30, 60, 90 days, and the viable cell count is determined by the TSA plate count method (GB4789.2). The survival rate is calculated based on the initial viable cell count.

[0085] The adhesion of rice seeds is tested under the following conditions:

[0086] Take 200 g of rice seeds in a beaker, add 0.4 g of the prepared microbial agent, and mix evenly in the beaker. After mixing, shake on a 100 mesh sieve for 2 minutes, collect the sieved microbial agent powder, and weigh it. The more microbial agent sieved out, the weaker the adhesion, the easier it is to fall off during storage and sowing; on the contrary, the less microbial agent sieved out, the stronger the adhesion, the more difficult it is to fall off during storage and sowing.

[0087] The adhesion is evaluated according to the proportion of the remaining microbial agent on the seeds (total microbial agent - sieved microbial agent):

[0088] Remaining microbial agent 80-99% excellent adhesion

[0089] Remaining microbial agent 60-79% good adhesion

[0090] Remaining microbial agent 0-60% general adhesion

[0091] On the other hand, considering the possibility of microbial agent on the surface of rice being washed away or dissolved due to rainwater, moisture, etc. after rice is sown. To evaluate the effect of rainwater, the aforementioned mixed microbial agent seeds are soaked in water for 10 minutes, then taken out and dried until there is no obvious moisture on the surface, and the surface adhered microbial agent particles are observed under a microscope. The adhesion before and after soaking is measured to evaluate the effect of moisture.

[0092] The adhesion is evaluated according to the proportion of the remaining microbial agent after soaking:

[0093] Remaining microbial agent 80-99% excellent adhesion

[0094] Remaining microbial agent 60-79% good adhesion

[0095] Remaining microbial agent 0-60% general adhesion

[0096] Table 1

[0097]

[0098]

[0099] As can be seen from the table, the strain of the present application has good adaptability, and can maintain a survival rate of more than 60% at 40°C±2°C for 90 days on a conventional carrier.

[0100] In a single carrier, the survival rate of the strain in guar gum is the best, followed by rice bran, xanthan gum, locust bean gum, and nanocellulose. At the same time, guar gum also shows excellent water resistance. It is speculated that because guar gum has high viscosity and film-forming property, it forms a porous network structure after drying, providing a good protective environment for the strain and reducing the loss of activity during storage.

[0101] The survival rate of the strain is high and the adhesion performance to the rice seed is good when diatomaceous earth: guar gum: chitosan: trehalose 6:3:0.8:0.2 is used as the carrier. The survival rate and water resistance of the strain when four carriers are compounded is slightly higher than when two carriers are compounded.

[0102] Therefore, in order to improve the adhesion and water resistance, it is preferred to use a compounded carrier, for example, a diatomaceous earth: guar gum compounded carrier. The diatomaceous earth: guar gum compounded carrier has high viscosity and film forming property, is not easily dissolved by water, and is difficult to be washed away in water. Therefore, the fungicide can still be firmly attached to the surface of the rice seed during the rice seeding process, ensuring the sustained effectiveness of the fungicide after seeding.

[0103] The diatomaceous earth: guar gum compounded carrier is easily degraded by soil microorganisms, and the degradation produces nutrients such as N, P, and K required for plant production, and does not pollute the environment, meeting the development requirements of green agriculture.

[0104] As described above, the Bacillus subtilis LT-86 of the present application has aspergillus flavus resistance and can promote seed germination. Therefore, it can be developed as a green pesticide to prevent and treat aspergillus flavus on seeds and promote seed germination. In particular, the Bacillus subtilis of the present application is found on rice seeds and has no toxic side effects on rice, and is a pure natural fungicide. It provides a new solution to the current problem of moldy rice seeds. In the examples, rice seeds are used as examples, but the fungicide of the present application can also be applied to other crop seeds, such as soybean, corn, wheat, and other common crop seeds. In addition, rice bran was used in the preparation of the fungicide in the examples, but those skilled in the art will understand that other suitable carriers can be used.

[0105] In addition, in the seed dressing examples, the fungicide is used for seed dressing, and those skilled in the art will understand that the same effect can be achieved by using the fungicide solution directly for seed dressing and then drying.

[0106] Although specific embodiments of the present application have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the general scope of the present disclosure, and the examples can also be combined. Therefore, all changes, modifications, and combinations that do not depart from the scope of the technical idea of the present application are within the scope of the present application.

[0107] In addition, although the application of the strain-containing strain to agricultural seed mold prevention treatment is illustrated in the specification, those skilled in the art will understand that as long as the strain is used to prevent aspergillus flavus and promote seed germination, it can also be applied to other fields, such as being sprayed as a liquid preparation on crops.

[0108] In addition, although the example of producing the live bacterial preparation by liquid fermentation of Bacillus subtilis LT-86 is illustrated in the specification, it is understood by those skilled in the art that the live bacterial preparation can also be produced by solid fermentation. However, the liquid fermentation is a more efficient and low-cost method.

Claims

1. A type of rice seed, characterized in that, The surface is covered with Bacillus subtilis, which is preserved at the China General Microbiological Culture Collection Center with accession number CGMCC 35166.

2. The rice seed according to claim 1, wherein the surface is covered with 0.1%-0.5% solid Bacillus subtilis inoculant by weight of the seed.

3. The rice seed according to claim 2, wherein, The solid Bacillus subtilis inoculant contains Bacillus subtilis strains and a carrier.

4. The rice seed according to claim 2, wherein, The carrier is rice bran, corn cob powder, peat moss, diatomaceous earth, starch residue, guar gum, xanthan gum, diatomaceous earth, locust bean gum, bentonite, zeolite powder, porous starch, nanocellulose, chitosan, trehalose, or a combination thereof.

5. The rice seed according to claim 2, wherein, The carrier is composed of diatomaceous earth and guar gum; nanocellulose and chitosan; or a carrier composed of a mixture of diatomaceous earth, guar gum, chitosan and trehalose.

6. The rice seed according to claim 1, wherein each gram of seed contains 1×10 6 -1×10 8 Bacillus subtilis, a microbial active unit.

7. The rice seed according to claim 1, characterized in that, The Bacillus subtilis directly attaches to the outer shell of the rice seed.

8. The rice seed according to any one of claims 1 to 7, characterized in that, The rice seeds mentioned are Longjing 3023.

9. The rice seed according to claim 1, wherein the seed storage conditions are: temperature 4℃-10℃, relative humidity not exceeding 60%, and avoidance of direct sunlight.

10. A method for preparing the rice seeds of claim 1, comprising: Dry mature, disease-free rice seeds to a moisture content of 12%-15%, then mix them with a solution containing 1×10⁻⁶ ppm. 8 -1×10 10 The bacterial solution or equivalent powder of Bacillus subtilis at CFU / mL is then dried until the moisture content is 10%-12%. The preferred drying conditions are a temperature of 25℃-30℃, a humidity of 40%-60%, and a drying time of 2-4 hours until the target moisture content is reached.

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