A soil conditioner which helps to improve the quality of fruit in orchards

Abstract

The application belongs to the technical field of soil conditioners, and particularly relates to a soil conditioner for improving fruit quality in orchards. The soil conditioner is prepared by mixing Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder and Bacillus altitudinis YLB2-1 lyophilized powder. The preservation number of the Bacillus thuringiensis TXB2-5 is CCTCC No: M 2020343, the preservation number of the Bacillus pumilus TXB1-8 is GDMCC No.62525, and the preservation number of the Bacillus altitudinis YLB2-1 is GDMCC No.62524. The soil conditioner is prepared by mixing Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder and Bacillus altitudinis YLB2-1 lyophilized powder, and can improve the control effect on diseases in orchards. In addition, the soil conditioner can improve the sugar content and vitamin C content of fruits in orchards, reduce the titratable acid content, and improve the fruit hardness, so that the fruit quality in orchards can be comprehensively improved, and the problem of single function of the conditioner can be effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of soil conditioner technology, specifically relating to a soil conditioner that helps improve the quality of fruit in orchards. Background Technology

[0002] Orchard soil is the foundation for fruit tree growth and fruit formation. The soil's physical and chemical properties and microbial community structure directly affect nutrient absorption and growth patterns, ultimately determining fruit yield and quality. Currently, the excessive use of chemical fertilizers and pesticides is a widespread problem in my country's orchards, leading to soil compaction, acidification or salinization, frequent soil-borne diseases, and declining fruit quality. This hinders the green and sustainable development of the fruit industry and the improvement of economic benefits. Biological soil conditioners, due to their environmental friendliness and ability to improve agricultural product quality, are gradually replacing traditional chemical conditioners and have become a research hotspot.

[0003] While single-strain Bacillus soil conditioners have been used in orchards, their limited functionality makes it difficult to simultaneously achieve the multiple goals of disease control and fruit quality improvement. Therefore, researching soil conditioners combining multiple microorganisms is of great significance.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a soil conditioner that helps improve the quality of fruit in orchards, thereby solving the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A soil conditioner comprising a mixture of Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder, and Bacillus saltitudinis lyophilized powder; wherein the Bacillus thuringiensis TXB2-5 has the accession number CCTCC No: M 2020343, is classified as Bacillus thuringiensis TXB2-5, and was deposited at the China Center for Type Culture Collection on July 23, 2020; the Bacillus pumilus TXB1-8 has the accession number GDMCC No. 62525, is classified as Bacillus pumilus TXB1-8, and was deposited at the Guangdong Provincial Center for Microbial Culture Collection on June 8, 2022; and the Bacillus saltitudinis TXB2-1 has the accession number GDMCC No. 62524. YLB2-1 was deposited at the Guangdong Provincial Center for Microbial Culture Collection on June 8, 2022.

[0007] Furthermore, the mass ratio of the Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder, and Bacillus hygroscopicus YLB2-1 lyophilized powder is 1:3-7:2-9.

[0008] Furthermore, the mass ratio of the Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder, and Bacillus hygroscopicus YLB2-1 lyophilized powder is 1:3:4.

[0009] Furthermore, the preparation method of the Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder, and Bacillus hygroscopicus YLB2-1 lyophilized powder is as follows: the bacterial strains activated and cultured on LB solid medium are inoculated into LB liquid medium and cultured with shaking until OD... 600 The value is 0.8, and the seed liquid is obtained. The seed liquid is inoculated into the fermentation medium, the fermentation product is dried, crushed and sieved, and the excipients are added to adjust the viable number to the required amount, thus obtaining Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder, and Bacillus hygroscopicus YLB2-1 lyophilized powder.

[0010] Furthermore, the fermentation medium is formulated as follows: 25g corn flour, 20g soybean meal powder, 10g yeast powder, 2g potassium dihydrogen phosphate, 0.5g magnesium sulfate, 3g calcium carbonate, 2g sodium chloride, and 1000mL distilled water, with the pH adjusted to 7.2.

[0011] Furthermore, the fermentation conditions for Bacillus thuringiensis TXB2-5 are: 37℃, stirring speed 180-200 r / min, aeration rate 3-5 L / min, and fermentation time 48-60 h; the fermentation conditions for Bacillus pumilus TXB1-8 are: 37℃, stirring speed 160-180 r / min, aeration rate 2-4 L / min, and fermentation time 36-48 h; and the fermentation conditions for Bacillus hygroscopicus YLB2-1 are: 37℃, stirring speed 200-300 r / min, aeration rate 3-5 L / min, and fermentation time 36-48 h.

[0012] The present invention also provides the application of the soil conditioner in improving the quality of orchard fruits.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) The soil conditioner of the present invention is a mixture of Bacillus thuringiensis TXB2-5 freeze-dried powder, Bacillus pumilus TXB1-8 freeze-dried powder and Bacillus hygroscopicus YLB2-1 freeze-dried powder, and can improve the control effect on orchard diseases.

[0014] (2) The soil conditioner of the present invention can increase the sugar content and vitamin C content of orchard fruits, reduce the titratable acid content and increase the firmness of fruits, and can comprehensively improve the quality of orchard fruits, effectively solving the problem of the single function of conditioners. Detailed Implementation

[0015] The technical solution of this invention patent will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0016] 1. Indoor testing 1.1 Test culture medium LB solid medium: 10g peptone, 5g yeast extract, 10g sodium chloride, 15g agar, 1L distilled water, adjust pH to 7.2.

[0017] LB liquid medium: 10g peptone, 5g yeast extract, 10g sodium chloride, 1L distilled water, adjust pH to 7.2.

[0018] Fermentation medium: 25g corn flour, 20g soybean meal, 10g yeast powder, 2g potassium dihydrogen phosphate, 0.5g magnesium sulfate, 3g calcium carbonate, 2g sodium chloride, 1000mL distilled water, adjust the pH to 7.2.

[0019] PDA medium: 200g peeled potato, 20g glucose, 15g agar, 1L distilled water, natural pH.

[0020] 1.2 Test bacterial powder The preparation methods for Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder, and Bacillus glomeratus YLB2-1 lyophilized powder are as follows: the corresponding bacterial strains are inoculated into LB solid medium and activated at 37℃ for 12 h, then inoculated into LB liquid medium and cultured with shaking until OD... 600 The concentration was 0.8, and the seed culture was obtained. The seed culture was inoculated into fermentation medium at an 8% inoculum volume and fermented for 48 hours. The culture was then centrifuged at 5000 rpm for 30 minutes, and the cells were collected. The cells were mixed with a protectant (by mass percentage: 12% skim milk powder, 8% trehalose, 2% lactose, 0.5% Tween-80, and distilled water to 100%) at a 2:1 volume ratio. The mixture was freeze-dried, pulverized, and passed through a 100-mesh sieve. Soluble starch was added to adjust the viable count to 1.0 × 10⁻⁶. 9 cfu / g is the corresponding freeze-dried powder.

[0021] The fermentation conditions for Bacillus thuringiensis TXB2-5 were: 37℃, stirring speed 2000r / min, and aeration rate 4L / min; the fermentation conditions for Bacillus pumilus TXB1-8 were: 37℃, stirring speed 180r / min, and aeration rate 3L / min; and the fermentation conditions for Bacillus hygroscopicus YLB2-1 were: 37℃, stirring speed 200r / min, and aeration rate 4L / min.

[0022] The freeze-drying conditions are as follows: maintain at -35℃ for 4 hours, increase by 5℃ every 2 hours, and keep the temperature constant at 30℃ until the moisture content in the material is less than 4%.

[0023] 1.3 Test strains Fusarium oxysporum Cuban transformation ( Fusarium oxysporum f.sp. from Cuba The sample was isolated from banana wilt disease specimens and preserved on PDA medium.

[0024] 1.4 Test Methods The toxicity of the mycelial growth rate method to the tested strains was determined. The specific method was as follows: sterile water was added to the mycelial powder (100% by mass) to dilute it into a single-agent stock solution. Multiple formulations were set up, and each single-agent stock solution and each formulation mixture were then diluted with sterile water to form 5 mass concentration gradients. All the above solutions were prepared and used immediately.

[0025] Mix 40 mL of pre-melted and cooled PDA medium to about 50°C with 4 mL of the prepared drug solution. Then pour the mixture into four 9 cm diameter petri dishes. After cooling, form drug-containing plates. Each treatment is repeated three times, with four plates per repetition. The sterile water treatment is set as a blank control.

[0026] The tested strains were inoculated onto PDA medium and cultured at 25°C for 4 days. Using a punch, 6 mm diameter mycelial discs were cut along the edge of the colony and inoculated into the center of the plate, one disc per plate, with the mycelial side facing down. The plates were then capped and transferred to 25°C for further culture. After 4 days, the colony diameter was measured using the cross-hatching method, and the inhibition rate of mycelial growth by different treatments was calculated.

[0027]

[0028] 1.5 Data Analysis Linear regression was performed with the logarithm of the fungicide concentration as x and the corresponding probability of mycelial growth inhibition as y to derive the virulence regression equation and the EC50 of the fungicide against the target pathogen. 50 The co-toxicity coefficient (CTC value) of the mixture was calculated using the Sun Yunpei method. The synergistic effect of the drug was evaluated based on the calculated CTC value. The results are shown in Table 1.

[0029] Table 1. Virulence of different fungal powders and their combinations against the pathogen of banana wilt.

[0030] Table 1 shows that Bacillus thuringiensis TXB2-5 freeze-dried powder, Bacillus pumilus TXB1-8 freeze-dried powder, and Bacillus hygroscopicus YLB2-1 freeze-dried powder can all inhibit the mycelial growth of the pathogen of banana wilt, with toxicities of 46.8318 mg / L, 23.3968 mg / L, and 72.0420 mg / L, respectively. When the three agents are used in pairs, their co-toxicity coefficients against banana wilt are 122.2267-130.2629, which is greater than 120, indicating a synergistic effect. When the three agents are used together, the co-toxicity coefficients are 185.0104 and 342.6923 at mass ratios of 1:1:1 and 1:3:4, respectively, which are significantly higher than when used in pairs. The synergistic effect is most significant when the three agents are used in a mass ratio of 1:3:4. This indicates that the present invention can improve the control effect against banana wilt by using a mixture of Bacillus thuringiensis TXB2-5 freeze-dried powder, Bacillus pumilus TXB1-8 freeze-dried powder, and Bacillus hygroscopicus YLB2-1 freeze-dried powder.

[0031] 2. Field trials 2.1 Different treatments See Table 2.

[0032] Table 2 Soil conditioners for different treatments

[0033] 2.2 Test Methods In the same Wogan mandarin orchard, the trees were 5 years old and of uniform growth. They were randomly divided into multiple groups, with 10 trees in each group, and the distance between trees in each group was maintained at 3.5m × 4.0m. The soil conditioner (Table 1) was applied once each during the budding and fruit enlargement stages, at a dosage of 50g per tree each time. The soil conditioner was diluted 300 times with water and applied to the base of the trees.

[0034] After the fruits were harvested, 20 fruits were randomly selected from each group, and the sugar content, vitamin C content, titratable acid content, and weight of a single fruit were measured using a fruit firmness tester. The results are shown in Table 3.

[0035] Table 3. Effects of different soil conditioners on the fruit quality of Wogan mandarins.

[0036] As shown in Table 3, the soil conditioner of this invention can increase the sugar content and vitamin C content of orchard fruits, reduce the titratable acid content and increase fruit firmness, thus comprehensively improving the quality of orchard fruits.

[0037] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A soil conditioner, characterized in that, The soil conditioner is a mixture of Bacillus thuringiensis TXB2-5 freeze-dried powder, Bacillus pumilus TXB1-8 freeze-dried powder, and Bacillus hygroscopicus YLB2-1 freeze-dried powder; wherein... The Bacillus thuringiensis TXB2-5 has the accession number CCTCC No: M 2020343; The Bacillus pumilus TXB1-8 has the accession number GDMCC No. 62525; The preservation number of the Bacillus hygroscopicus YLB2-1 is GDMCC No. 62524.

2. The soil conditioner according to claim 1, characterized in that, The mass ratio of Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder, and Bacillus hygroscopicus YLB2-1 lyophilized powder is 1:3-7:2-9.

3. The soil conditioner according to claim 2, characterized in that, The mass ratio of Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder, and Bacillus hygroscopicus YLB2-1 lyophilized powder is 1:3:

4.

4. The soil conditioner according to claim 1, characterized in that, The preparation methods for the Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder, and Bacillus glomeratus YLB2-1 lyophilized powder are as follows: The activated bacterial strains, cultured on LB solid medium, are inoculated into LB liquid medium and cultured with shaking until OD... 600 A value of 0.8 indicates the seed culture has been obtained. The seed culture was inoculated into the fermentation medium, the fermentation product was dried, pulverized and sieved, and excipients were added to adjust the viable cell count to the required amount, thus obtaining Bacillus thuringiensis TXB2-5 lyophilized powder, Bacillus pumilus TXB1-8 lyophilized powder, and Bacillus hygroscopicus YLB2-1 lyophilized powder.

5. The soil conditioner according to claim 4, characterized in that, The fermentation medium is formulated as follows: 25g corn flour, 20g soybean meal powder, 10g yeast powder, 2g potassium dihydrogen phosphate, 0.5g magnesium sulfate, 3g calcium carbonate, 2g sodium chloride, and 1000mL distilled water, with the pH adjusted to 7.

2.

6. The soil conditioner according to claim 4, characterized in that, The fermentation conditions for Bacillus thuringiensis TXB2-5 were: 37℃, stirring speed 180-200r / min, aeration rate 3-5L / min, and fermentation time 48-60h. The fermentation conditions for Bacillus pumilus TXB1-8 are: 37℃, stirring speed 160-180r / min, aeration rate 2-4L / min, and fermentation time 36-48h. The fermentation conditions for Bacillus oryzae YLB2-1 were: 37℃, stirring speed 200-300r / min, aeration rate 3-5L / min, and fermentation time 36-48h.

7. The application of the soil conditioner according to any one of claims 1-6 in improving the quality of fruit in orchards.

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