Bacillus velezensis strain for preventing and controlling premature bolting of Angelica sinensis, microbial inoculum thereof and application thereof

Abstract

The present invention relates to the isolation of a strain for preventing and controlling premature bolting of Angelica sinensis, the preparation of a microbial inoculum and its application. This strain is isolated, purified and cultured from the rhizosphere soil of Angelica sinensis, and is identified as Bacillus by microbial 16S rDNA sequencing. The strain is deposited in the China Center for Type Culture Collection, address: School of Life Sciences, Wuhan University, Wuhan, Hubei, China; postal code: 430072, and the deposit date is June 24, 2021, with the deposit number: CCTCC NO: M 2021767. The Bacillus velezensis strain XG3 provided by the present invention can promote the germination of Angelica sinensis seeds and delay the flowering of Arabidopsis thaliana by about 2 days. Field trials have verified that this microbial inoculum can increase the root weight, root diameter and the number of lateral roots of Angelica sinensis, can effectively prevent and control premature bolting of Angelica sinensis, can be prepared into a microbial inoculum for preventing and controlling premature bolting of Angelica sinensis that is green, environmentally friendly, highly efficient, low-toxic and cost-effective, can increase the yield of Angelica sinensis, and has important environmental protection significance and economic value, and is worthy of popularization and application.

Description

Technical Field

[0001] The present invention relates to a Bacillus velezensis strain, specifically to a strain that can promote the germination of Angelica sinensis seeds and the growth of plants. The microbial inoculant prepared from this strain can be used for preventing early bolting of Angelica sinensis and increasing the yield of Angelica sinensis, belonging to the field of microbial technology. Background Art

[0002] As a perennial plant with low temperature and long-day requirements, the whole growth and development cycle of Angelica sinensis is generally 3 years. In the first year, sowing and seedling raising are carried out in the mountains from June to July, and the seedlings are harvested in October-November for cellaring. In the second year, the seedlings are transplanted around the Tomb-Sweeping Festival, and the medicinal Angelica sinensis is dug from late October to early November. Some are left for seeding until the third year when they bolt, flower, and set seeds for subsequent planting. However, in the actual production process, the growth of Angelica sinensis is easily disturbed by various ecological factors, resulting in early bolting and flowering in the vegetative growth stage of the second year, lignification of the fleshy roots, reduction of essential oil, decrease in the content of pharmacologically active ingredients, and decline in the quality of the medicinal materials, seriously affecting the yield and daily supply of Angelica sinensis. In the 1980s, a nationwide investigation on the early bolting of Angelica sinensis was carried out. The normal early bolting rate in Min County, Gansu Province was 10%-30%, and it was as high as 80% in severe cases. The early bolting rate in the Baoji area of Shaanxi Province was about 30%, and it was over 90% in severe cases. In 2020, an investigation on the early bolting of Angelica sinensis in 10 townships in four regions of Dingxi, Longnan, Zhangye, and Gannan Tibetan Autonomous Prefecture in Gansu Province was carried out. The early bolting rates in 30 planting areas ranged from 11% to 86%, and the average early bolting rate was 51.62%. In the past 40 years of development, the problem of early bolting of Angelica sinensis still exists and even becomes more serious. How to better reduce the early bolting rate in the production process of Angelica sinensis has become a bottleneck problem restricting the sustainable development of the Angelica sinensis industry.

[0003] Although a large number of studies have been carried out on the early bolting problem of Angelica sinensis, the situation of early bolting of Angelica sinensis is still very serious. Various measures such as controlling seedlings and strengthening field management are taken to avoid it, but the situation is still not optimistic. The formation mechanism of early bolting of Angelica sinensis is complex, including both internal problems such as seeds and seedlings, and external factors such as storage, fertilization, transplanting density, and soil. Although large seedlings prone to early bolting can be removed when selecting seedlings, since early bolting of Angelica sinensis can only be discovered after the seedlings bolt, it is too late to replant at this time. The average bolting rate of about 30% seriously harms the yield of Angelica sinensis medicinal materials and the economic benefits of medicinal farmers. In order to reduce the impact of early bolting on yield and income, some medicinal farmers choose to increase the planting quantity to make up for it, but a higher planting density is likely to cause early bolting of Angelica sinensis. How to discover problems earlier and thus intervene earlier to reduce the adverse impact on the Angelica sinensis medicinal material industry has become a problem worthy of consideration. With the continuous in-depth research on biological bacterial fertilizers in recent years, microbial inoculants have been widely recognized for their characteristics such as green, efficient, and safe. Further developing the rich microbial resources of Angelica sinensis for the prevention and control of early bolting of Angelica sinensis, or replacing traditional chemical fertilizers and pesticides in the planting process to reduce the accumulation of agricultural residues in Angelica sinensis medicinal materials, will better serve the high-quality, high-yield and green planting of Angelica sinensis. Summary of the Invention

[0004] Object of the Invention: The object of the present invention is to provide a Bacillus velezensis XG3 for preventing and controlling early bolting of Angelica sinensis, and its isolation, fermentation and culture method and preparation method of microbial inoculant. Another object of the present invention is to provide the application of this strain in the germination of Angelica sinensis seeds and the process of plant growth, and the application of the microbial inoculant of this strain in preventing and controlling early bolting in the production and cultivation process of Angelica sinensis.

[0005] Technical Solution: To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The Bacillus velezensis XG3 for preventing and controlling early bolting of Angelica sinensis provided by the present invention is isolated, purified and cultured from the rhizosphere soil of Angelica sinensis, and is identified as Bacillus spp. by microbial 16S rDNA sequencing. This strain is preserved in the China Center for Type Culture Collection, with the preservation number: CCTCC NO: M 2021767, the preservation date is June 24, 2021, and the taxonomic name is Bacillus velezensis XG3; the 16S rDNA sequence of this strain is as shown in the Sequence listing.

[0007] The isolation, fermentation and culture method of the Bacillus velezensis XG3 strain provided by the present invention includes oscillation, inoculation, separation, culture and preservation, and the specific steps are as follows:

[0008] a) Oscillation: Peel the soil around the Angelica sinensis roots, shake off and collect the rhizosphere soil. Place 5 g of the soil in a triangular flask containing 100 mL of sterile water, and oscillate it at 160 r / min on a constant temperature shaker at 37°C for 2 h. Let it stand for 30 min to obtain 10 -1 soil stock solution. Then, use a pipette to aspirate 1 mL of the supernatant and add it to 9 mL of sterile water, and shake well to obtain 10 -2 soil dilution. By analogy, prepare 10 -1 -10 -6 soil dilutions;

[0009] b) Isolation: Aspirate 0.1 mL of 10 -4 、10 -5 、10 -6 soil dilutions and inoculate them into the prepared LB solid medium. Set 3 replicates for each dilution. Invert the petri dishes, culture them at 37°C and observe the colony growth at any time. Inoculate bacteria with different morphologies on the LB solid medium using an inoculation loop and purify repeatedly until a single colony is obtained.

[0010] c) Culture and preservation: Pick the purified bacteria on the petri dishes into a triangular flask containing LB liquid medium, oscillate it at 160 r / min on a constant temperature shaker at 37°C for 24 h, mix it with 50% glycerol at a volume ratio of 1:1 in a sterilized cryotube, mix well, seal it with a sealing film, and store it in an ultra-low temperature freezer at -80°C.

[0011] A preparation method of a microbial inoculant for preventing and controlling premature bolting of Angelica sinensis includes the following steps: Inoculate Bacillus velezensis XG3 strain into LB liquid medium, activate and culture it on a constant temperature shaker, then take the activated strain into a triangular flask containing LB liquid medium for fermentation, culture it on a shaker, centrifuge the fermentation broth to collect the cell precipitate, add a composite protective agent made of sucrose, trehalose, sodium glutamate, and glucose, and obtain the freeze-dried powder of the microbial inoculant after vacuum freeze-drying.

[0012] As a preferred embodiment, the preparation method of the microbial inoculant of Bacillus velezensis XG3 strain provided by the present invention includes the following steps: Inoculate Bacillus velezensis XG3 strain into LB liquid medium, activate and culture it on a constant temperature shaker at 37°C at 140 r / min. After 24 h, take the overnight-activated strain at a ratio of 1% (v / v) into a new LB liquid medium, culture it at 140 r / min for 24 h, measure its OD value, centrifuge the fermentation broth at 4000 rpm for 5 min, discard the supernatant, and collect the cell precipitate.

[0013] Dissolve the bacterial cell precipitate with the composite protective agent solution (the composite protective agent solution consists of 15 mg / mL of glucose, 5.37 mg / mL of sucrose, 1.26 mg / mL of trehalose, and 1.87 mg / mL of sodium glutamate) to obtain a bacterial solution. Place the sample in a -80 °C ultra-low temperature refrigerator for pre-freezing. After that, quickly transfer it to a vacuum freeze dryer and dry at -40 °C and 10 Pa. Finally, crush the freeze-dried product to obtain the freeze-dried powder bacterial agent by vacuum freeze drying.

[0014] Bacillus velezensis XG3 isolated in the present invention can be used to promote the germination of Angelica sinensis seeds and plant growth. Obtain the fermentation broth according to the above fermentation method, dilute it into bacterial solutions with different OD concentrations, and co-culture with Angelica sinensis seeds and Arabidopsis thaliana.

[0015] Application of the Bacillus velezensis XG3 microbial agent prepared in the present invention in preventing early bolting during the production and cultivation of Angelica sinensis. The microbial agent obtained according to the above preparation method is dissolved in water to form solutions with different dosages, and then co-cultured with Angelica sinensis plants.

[0016] Beneficial effects: Compared with existing research, the present invention has the following advantages:

[0017] The Bacillus velezensis XG3 strain provided by the present invention can promote the germination of Angelica sinensis seeds and delay the flowering time of Arabidopsis thaliana. The prepared microbial agent can increase the yield of Angelica sinensis and prevent early bolting of Angelica sinensis. Subsequently, it can be used to develop a multi-effect composite biological fertilizer with low cost, no pollution, stable yield increase, and effective prevention of early bolting of Angelica sinensis, and then applied to the green and healthy planting industry of Angelica sinensis, which is beneficial to the green and sustainable development of the Angelica sinensis industry. Description of the Drawings

[0018] Figure 1 It is the front view of the colony of Bacillus velezensis XG3 strain;

[0019] Figure 2 It is the back view of the colony of Bacillus velezensis XG3 strain;

[0020] Figure 3 It is the influence of Bacillus velezensis XG3 on the flowering of Arabidopsis thaliana;

[0021] Figure 4 It is the screening experiment of the protective agent for the preparation of Bacillus velezensis XG3 microbial agent;

[0022] Figure 5 It is the result of the central composite design experiment of the protective agent for Bacillus velezensis XG3 microbial agent;

[0023] Figure 6 It is the Bacillus velezensis XG3 microbial agent;

[0024] Figure 7Results of the effect of Bacillus velezensis XG3 microbial inoculum on the growth of Angelica sinensis. Specific implementation examples

[0025] According to the following examples, the present invention can be better understood. However, those skilled in the art can easily understand that the specific fermentation and culture processes and functional evaluations described in the examples are only used to illustrate the present invention and should not and will not limit the present invention described in detail in the claims.

[0026] The chemical reagents used in the following examples can all be obtained from regular commercial sources.

[0027] Example 1

[0028] A new strain of Bacillus velezensis XG3, which was isolated by the following method:

[0029] (1) Oscillation: The soil around the roots of Angelica sinensis was peeled off, and the rhizosphere soil on the surface was shaken off and collected. 5 g of soil was placed in a triangular flask containing 100 mL of sterile water, and shaken at 140 r / min on a constant temperature shaker at 37 °C for 2 h, then left standing for 30 min to obtain the soil stock solution (10 -1 ). Then, 1 mL of the supernatant was pipetted and added to 9 mL of sterile water, and shaken well to obtain the soil dilution (10 -2 ). By analogy, soil dilutions of 10 -1 -10 -6 were prepared.

[0030] (2) Isolation: 0.1 mL of the 10 -4 , 10 -5 , and 10 -6 soil dilutions were pipetted and inoculated into the prepared LB solid medium (composed of 10 g / L peptone, 5 g / L yeast extract, and 10 g / L NaCl). Three replicates were set for each dilution. The petri dishes were inverted and cultured at 30 °C, and the growth of colonies was observed at any time. Bacteria with different morphologies were inoculated onto the LB solid medium with an inoculation loop and repeatedly purified until a single colony was obtained.

[0031] (3) Cultivation and preservation: The bacteria purified on the petri dishes were picked and transferred to a triangular flask containing LB liquid medium, shaken at 140 r / min on a constant temperature shaker at 37 °C for 24 h, mixed with 50% glycerol at a ratio of 1:1, filled into a sterilized cryopreservation tube, sealed with a sealing film, and stored in a -80 °C ultra-low temperature freezer.

[0032] Example 2

[0033] The new strain of Bacillus velezensis XG3 isolated in the present invention was molecularly identified by the following method:

[0034] The Bacillus velezensis XG3 strain was fermented and cultured according to the method of Example 1, and the bacterial liquid was sent to Sangon Biotech (Shanghai) Co., Ltd. for 16S rDNA sequencing. The upstream primer was 27F (5’-AGTTTGATCMTGGCTCAG-3’), and the downstream primer was 1492R (5’-GGTTACCTTGTTACGACTT-3’). The 16S rDNA sequence was aligned on the Ribosomal Database ( http: / / rdp.cme.msu.edu / index.jsp ). Through Blast sequence alignment analysis, as shown in Table 1, the homology between the XG3 strain and Bacillus velezensis was 100.0%. This strain was identified as Bacillus (Bacillus genus) and was speculated to be Bacillus velezensis.

[0035] The sequence of this bacterium is as follows:

[0036]

[0037] Table 1 Sequence alignment results of XG3 strain

[0038]

[0039] Example 3

[0040] Effect of Bacillus velezensis XG3 strain on the germination of Angelica sinensis seeds. The test was carried out by the following method:

[0041] Select 600 Angelica sinensis seeds with plump grains and uniform quality. Put 150 seeds in each culture bottle. Label the bottles 1 - 4 and disinfect them with 75% ethanol for 1 min, then with mercuric chloride for 9 min, and rinse them with sterile water 5 times. Pour out the sterile water. Obtain the Bacillus velezensis XG3 bacterial liquid according to the fermentation culture method in Example 2, dilute it and measure OD600. Pour 50 mL of the diluted XG3 bacterial liquid with OD600 values of 0.05, 0.5, and 1 into culture bottles 1 - 3 respectively, and pour 50 mL of LB liquid medium into culture bottle 4. Soak the seeds for 24 h. Then transfer the seeds to a petri dish containing two layers of sterile filter paper. Arrange 30 seeds neatly in each petri dish. Repeat each sample 5 times. Pour about 5 mL of sterile water to fully saturate the seeds and the filter paper. Seal the petri dish with a sealing film to prevent contamination. Weigh the petri dish and the seeds together and record. Then place the above petri dishes in a light incubator for cultivation. Weigh the petri dish every 24 h and make up to the original weight and record the number of germinated seeds. Timely remove the infected seeds with sterilized forceps. The results are shown in Table 2. The Bacillus velezensis XG3 bacterial liquid screened in the present invention can promote the germination of Angelica sinensis seeds.

[0042] Table 2 Short - term germination potential of Angelica sinensis seeds treated with different concentrations of XG3 bacterial liquid

[0043]

[0044] Example 4

[0045] Effect of Bacillus velezensis XG3 on the flowering of Arabidopsis thaliana. It was investigated by the following method:

[0046] ]Take an appropriate amount of Col-0 Arabidopsis thaliana seeds, disinfect them with 75% ethanol (v / v) for 5 min, then disinfect them with 5% sodium hypochlorite for 5 min, and then wash them repeatedly with sterile water 4 - 6 times, 1 min each time. Then place the sterilized seeds in a 1 / 2 MS medium, with 15 - 20 seeds in each bottle, ensuring uniform distribution and appropriate density among the seeds for subsequent growth and transplantation. When the Arabidopsis thaliana seedlings grow to the 4 - 6 leaf stage, approximately 2 - 3 weeks after formal cultivation, use tweezers to slowly remove the Arabidopsis thaliana seedlings with relatively consistent growth status from the medium, remove the medium on the roots, and transplant them into the prepared substrate soil. The substrate soil is evenly mixed by peat soil, vermiculite, and perlite in a ratio of 1:1:1, and sterilized at 121 °C for 15 min. After 3 days of adaptive cultivation in the substrate soil, inoculate the XG3 liquid strain by the root irrigation method once a week until full flowering, and observe and record the growth status, flowering time, and number of rosette leaves of Arabidopsis thaliana. The results are as Figure 3 shown: Taking blank water as the control group, the Arabidopsis thaliana treated with XG3 showed a significant late - flowering phenomenon, indicating its potential to be developed into a microbial agent for preventing early bolting of Angelica sinensis.

[0047] Example 5 Screening Experiment of Compound Protectants

[0048] The present invention optimizes the compound protectant of the best XG3 microbial agent through single - factor experiments and central composite design experimental methods.

[0049] (1) In the single - factor experiment, trehalose (mus, 0.5, 1, 2 mg / mL), sucrose (suc, 2.5, 5, 10 mg / mL), sodium glutamate (msg, 0.5, 1, 2 mg / mL), and glucose (glu, 5, 10, 15 mg / mL) were selected as protectants, and three concentrations were set for each. Using sterile water as the control, with the survival rate of freeze - dried Bacillus velezensis as the index, the protectant concentrations with better protection effects were screened out. According to the screening results of the single - factor experiment, the response surface central composite design was used to optimize the ratio of trehalose, sucrose, sodium glutamate, and glucose, and the best formula was determined with the survival rate of freeze - dried Bacillus velezensis as the index.

[0050] (2) To increase the viable count in the freeze - dried powder of the microbial agent, various protectants are usually added before the freezing of the bacteria to maintain the activity and stability of the strain. From Figure 4 it can be seen that without adding any protectant and using sterile water to freeze - dry the bacteria, the survival rate is 20.12%. After adding different protectants, the survival rate of the bacteria increased to varying degrees. According to the results of the single - factor experiment, the Design - Expert 11.0 software was used for quadratic regression fitting, and the fitting equation for the survival rate Y = 88.74 + 5.10A - 3.82B + 0.2176C + 3.22D - 2.48A 2 - 8.17B 2-7.57C 2 -1.94D 2 According to the analysis of variance (Table 3), the fitted regression equation conforms to the above test principle and has good adaptability. Through the prediction analysis of the regression model, the optimal formula of the XG3 cryoprotectant Figure 5 ) is glucose 15 mg / mL, sucrose 5.37 mg / mL, trehalose 1.26 mg / mL and sodium glutamate 1.87 mg / mL, and the predicted survival rate is 87.96%. Under the conditions of this formula, a verification test was carried out, and the survival rate of XG3 was 82.45%. The measured value is not much different from the predicted value, indicating that this formula is feasible. From Figure 6 It can be seen that the color of the microbial inoculant powder prepared from the blank water after freeze-drying is yellowish, and the color of the microbial inoculant powder prepared from the cryoprotectant after freeze-drying is grayish-white. The volume of the cryoprotectant after freeze-drying is not much different from the volume before freeze-drying, slightly shrinking, and the volume reduction of the blank water after freeze-drying is more obvious.

[0051] Table 3 Analysis of variance of the response surface model

[0052]

[0053]

[0054] Example 6

[0055] A method for preparing a microbial inoculant of Bacillus velezensis XG3 strain, comprising the following steps:

[0056] (1) Inoculate Bacillus velezensis XG3 into LB liquid medium and activate it in a constant temperature shaker at 37°C at 140 r / min. After 24 h, take the overnight-activated strain at a ratio of 1% (v / v) and transfer it to a new LB liquid medium. After culturing at 140 r / min for 24 h, measure its OD value. Centrifuge the fermentation broth at 4000 rpm for 5 min, discard the supernatant, and collect the cell precipitate.

[0057] (2) Add 1 mL of a composite cryoprotectant (glucose 15 mg / mL, sucrose 5.37 mg / mL, trehalose 1.26 mg / mL and sodium glutamate 1.87 mg / mL) solution to the cell precipitate obtained by centrifuging every 100 mL of the bacterial solution. Put the sample into a -80°C ultra-low temperature refrigerator for pre-freezing. After completion, quickly transfer it to a vacuum freeze dryer and dry it at -40°C and 10 Pa. Finally, crush the freeze-dried product to obtain the freeze-dried XG3 powder inoculant by vacuum freeze-drying.

[0058] Example 7 Experiment on the effect of Bacillus velezensis XG3 microbial inoculant on the growth of Angelica sinensis and the prevention and control of early bolting, which was verified through the samples of the experimental field:

[0059] Preferably, Angelica sinensis seedlings without root irrigation treatment were used, with blank water as the control group (Control), 500 mL per ridge. The low dose of XG3 microbial inoculant (XG3L) prepared according to the method of Example 6 was 0.8 g per ridge, the medium dose of XG3 microbial inoculant (XG3M) was 2.4 g per ridge, and the high dose of XG3 microbial inoculant (XG3H) was 7.2 g per ridge. Intervention was carried out one week after the Angelica sinensis seedlings turned green, once every two weeks for a total of three times. The first time was by root irrigation treatment, 5 mL per plant, and then by spraying method. The effects on the bolting and flowering of Angelica sinensis and the formation of its quality were monitored. The early bolting rate of Angelica sinensis in the blank control group was 32.03%, and the early bolting rates of XG3 low, medium, and high doses were 18.75%, 22.27%, and 11.72% respectively, indicating that the XG3 microbial inoculant prepared by the present invention can effectively prevent the early bolting of Angelica sinensis. In addition, as Figure 7 shown, the microbial inoculant prepared by the present invention can also significantly increase the yield of Angelica sinensis, increase the diameter of the main root, and increase the number of lateral roots.

[0060] The above results show that a new rhizosphere bacterium of Angelica sinensis - Bacillus velezensis XG3 was screened and obtained in the present invention, and a method for its isolation, culture, preservation, analysis of growth-promoting function and preparation of its microbial inoculant was established. Bacillus velezensis XG3 has good functions of promoting the germination of Angelica sinensis seeds, the growth of Angelica sinensis plants and delaying the flowering of Arabidopsis thaliana. The developed microbial inoculant can effectively prevent the early bolting of Angelica sinensis and increase the yield of Angelica sinensis, having important practical application value.

[0061] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A Bacillus velezensis for preventing and controlling premature bolting of Angelica sinensis, which is preserved in the China Center for Type Culture Collection (CCTCC) with the preservation number of CCTCC NO: M 2021767 and the taxonomic name of Bacillus velezensis XG3.

2. A preparation method of a microbial inoculum for preventing and controlling premature bolting of Angelica sinensis, characterized in that, including the following steps: the Bacillus velezensis XG3 strain is inoculated into an LB liquid medium and activated by culturing in a constant temperature shaking incubator. Then, the activated strain is taken into an Erlenmeyer flask containing the LB liquid medium for fermentation, and cultured on a shaking incubator. After centrifuging the fermentation broth, the cell precipitate is collected, and a composite protective agent made of sucrose, trehalose, sodium glutamate, and glucose is added. After vacuum freeze-drying, a freeze-dried powder of the microbial inoculant is obtained.

3. The preparation method of a microbial inoculant for preventing and controlling premature bolting of Angelica sinensis according to claim 2, characterized in that, comprises the following steps: Inoculate Bacillus velezensis the XG3 strain into LB liquid medium, and activate and culture it in a constant temperature shaker at 37°C at 140 r / min. After 24 h, take 1% (by volume) of the overnight-activated strain and transfer it to a new LB liquid medium. After culturing at 140 r / min for 24 h, measure its OD value. Centrifuge the fermentation broth at 4000 rpm for 5 min, discard the supernatant, and collect the cell precipitate; Dissolve the cell precipitate with a composite protective agent solution to obtain a cell suspension. The composite protective agent solution consists of glucose at 15 mg / mL, sucrose at 5.37 mg / mL, trehalose at 1.26 mg / mL, and sodium glutamate at 1.87 mg / mL. Then, place the cell suspension sample in a -80 °C ultra-low temperature freezer for pre-freezing. After that, quickly transfer it to a vacuum freeze dryer and dry at -40 °C and 10 Pa. Finally, crush the freeze-dried product to obtain the freeze-dried powder bacterial agent by vacuum freeze drying.

4. Use of the Bacillus velezensis according to claim 1 in the preparation of a microbial bacterial agent for promoting the germination of Angelica sinensis seeds.

5. Use of the Bacillus velezensis according to claim 1 in the preparation of a microbial bacterial agent for preventing and controlling premature bolting of Angelica sinensis.

6. Use of the Bacillus velezensis according to claim 1 in the preparation of a microbial bacterial agent for increasing the yield of Angelica sinensis.

7. A microbial inoculant for preventing and controlling premature bolting of Angelica sinensis, characterized in that, It includes that in claim 1 Bacillus velezensis XG3.

Images