A composite bacterial agent containing Trichoderma aspergillus and its application in tea tree biocontrol

Abstract

The present invention belongs to the field of agricultural microorganisms and discloses a composite bacterial agent containing Trichoderma aculeatus and its application in tea tree biocontrol. Trichoderma rough ) The deposit number of HBTG3306 is: CCTCC NO:M20232116, Taichung Paenibacillus ( Bacillus Taichung )The preservation number of HBTG1666 is: CCTCC NO:M2023678. Compared with a single strain, the composite strain has a synergistic effect on tea cake disease, ring spot disease, gray mold, white star disease, anthracnose, brown star disease and tea sooty disease, and has certain application prospects in tea disease prevention and control.

Description

Technical Field

[0001] The invention belongs to the field of microbial pesticides, and particularly relates to a composite bacterial agent comprising Trichoderma aspergillus and application of the composite bacterial agent in tea tree biocontrol. Background Art

[0002] Tea trees mostly grow in warm and humid tropical and subtropical regions, and the climate in these regions is also conducive to the growth of tea tree diseases. Tea cake disease, ring spot disease, gray mold, white star disease, anthracnose, red star disease, root rot and tea sooty disease all occur in tea-producing areas, especially tea cake disease, which is currently serious in production and causes a large reduction in production. Tea cake disease (Exobasidiumvexans) is an obligate parasite that cannot be cultured in the laboratory, which brings difficulties to its in-depth research. At present, it has been reported that Pseudomonas fluorescens Pf1 has a certain control effect on tea cake disease in the field, but Pseudomonas and other biocontrol bacteria exist in the form of vegetative bodies without spores, resulting in a short shelf life and great difficulties in promotion and application. In addition, Bacillus subtilis B-9 has been reported to have certain antibacterial activity against tea cake disease pathogens. At present, the only registered fungicide variety for tea cake disease is polyoxin, and there is a lack of control agents. Tea wheel spot is mainly caused by Pestalotiopsis spp. Sanjay et al. isolated Trichoderma harzianum, Gliocladium virena and Pseudomonas fluorescens from tea garden soil. The field control effect was less than 40%, which was not ideal. In addition, it was reported that Bacillus velezensis CY30 had a certain control effect on tea wheel spot. Currently, there is no registered agent for tea wheel spot.

[0003] At present, chemical fungicides are mainly used in production to prevent and control tea diseases, which has caused pesticide residues and environmental pollution, and has also become a limiting factor for tea exports. Fertilization is one of the key agricultural measures that affects tea quality and yield and sustainable soil utilization. Fertilizers have a significant effect on improving the quality and efficiency of tea. Traditional tea gardens mainly use quick-acting fertilizers such as urea and compound fertilizers, and the amount of fertilizers used is large, which causes soil acidification and compaction, resulting in a decline in tea quality. The above problems need to be solved urgently in production.

[0004] As a widely used agricultural microbial strain in the field of biological control, Trichoderma has a good inhibitory effect on a variety of plant pathogens. The main manifestations of Trichoderma in controlling plant pathogens are occupying ecological sites, parasitism, secreting antibacterial secondary metabolites, penetrating pathogens and absorbing their nutrients. Due to its good adaptability, strong colonization ability and outstanding biological control effect, it has great potential for biological control application in plant disease control.

[0005] In view of the above problems, the present invention isolates and screens a strain of Trichoderma aspergillus HBTG3306 and a strain of Paenibacillus taichungensis HBTG1666 from the rhizosphere soil of tea trees. The composite bacterial agent has excellent prevention and control effects on tea cake disease, ring spot disease, gray mold, white star disease, anthracnose, brown star disease and tea sooty disease of tea leaves, and also has the ability to colonize tea leaves and rhizosphere, and has the effect of promoting growth and increasing yield of tea trees. Summary of the invention

[0006] The object of the present invention is to provide a composite bacterial agent containing Trichoderma asperellum, wherein the composite bacterial agent contains Trichoderma asperellum HBTG3306 and Bacillus taichungensis HBTG1666, the preservation number of Trichoderma asperellum HBTG3306 is: CCTCC NO: M20232116, and the preservation number of Bacillus taichungensis HBTG1666 is: CCTCC NO: M2023678

[0007] Another object of the present invention is to provide the use of the above-mentioned composite bacterial agent in the preparation of tea tree biocontrol preparations.

[0008] In order to achieve the above object, the present invention adopts the following technical measures:

[0009] A strain of Trichoderma asperellum isolated from the rhizosphere of tea trees was obtained by screening tea ring spot pathogens, root rot pathogens and gray mold pathogens, and was identified as Trichoderma asperellum (Trichoderma asperellum) by ITS sequence alignment and morphological identification. Figure 1 , 2), the strain was sent to the China Center for Type Culture Collection for preservation on November 2, 2023, with the classification name: Trichoderma asperellum HBTG 3306, and the preservation number: CCTCC NO:M 20232116; Location: Wuhan University, Wuhan, China.

[0010] The bacteria grew well in PDA culture medium, and the colonies were light green ( Figure 1 ).

[0011] A composite bacterial agent comprises Trichoderma asperellum HBTG3306 and Bacillus taichungensis HBTG1666 (CN117305149B), wherein the preservation number of the Trichoderma asperellum is CCTCC NO: M 20232116, and the preservation number of the Bacillus taichungensis is CCTCC NO: M 2023678.

[0012] In the composite bacterial agent described above, preferably, the ratio of the effective bacterial spores of Trichoderma aspergillus and Paenibacillus taichungensis is 1-3:3-1;

[0013] In the composite bacterial agent described above, preferably, the ratio of the effective bacterial spores of Trichoderma aspergillus to Paenibacillus taichungensis is 1:1.

[0014] The protection scope of the present invention also includes:

[0015] Application of the above composite bacterial agent in tea disease prevention and treatment;

[0016] The use of the composite bacterial agent or the fermentation liquid of the composite bacterial agent in the preparation of a microbial preparation for preventing and treating tea diseases; the tea diseases mentioned above include: tea cake disease, ring spot disease, gray mold, white star disease, anthracnose, brown star disease and tea sooty disease. The composite bacterial agent mentioned above is preferably in the form of a powder or liquid preparation containing Trichoderma aculeatus and Paenibacillus taichungensis.

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

[0018] (1) The present invention provides a composite microbial agent, which is reported for the first time to be used for the prevention and treatment of tea cake disease, ring spot disease, gray mold, white star disease, anthracnose, brown star disease and tea sooty disease, and has no cross-resistance with existing fungicides.

[0019] (2) Compared with the currently used chemical synthetic pesticides, since it comes from the natural environment, it has the advantages of high efficiency, low toxicity, no pollution to the environment, and is not easy to produce drug resistance.

[0020] (3) Compared with a single strain, the composite Bacillus obtained in the present invention has a synergistic effect and is particularly suitable for use in tea disease prevention and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the plate colony morphology of strain HBTG3306.

[0022] Figure 2 HBTG3306 spore morphology.

[0023] Figure 3The antibacterial effect of strain HBTG3306 against pathogenic bacteria. DETAILED DESCRIPTION

[0024] In order to better explain the present invention, the main contents of the present invention are further illustrated below in conjunction with specific examples, but the contents of the present invention are not limited to the following examples. The technical solutions of the present invention, if not otherwise specified, are conventional techniques in the art, and the reagents or materials, if not otherwise specified, are all derived from commercial channels.

[0025] Embodiment 1:

[0026] Acquisition and identification of Trichoderma aspergillus HBTG3306:

[0027] Trichoderma asperellum HBTG3306, isolated from tea rhizosphere soil in Yichang, Hubei Province ( Figure 1 ) was screened for antibacterial activity against tea ring spot and gray mold. The strain was further identified by ITS and morphology, and was sent to the China Center for Type Culture Collection for preservation on November 2, 2023. The classification name is Trichoderma asperellum HBTG 3306; the collection number is CCTCC NO: M 20232116; location: Wuhan University, Wuhan, China.

[0028] In the present invention, Trichoderma asperellum HBTG3306 or simply referred to as HBTG3306.

[0029] The bacteria grew well in PDA medium, and the colonies were green ( Figure 1 ).

[0030] Embodiment 2:

[0031] Fermentation of Trichoderma asperellum HBTG3306 (the percentages in the following culture medium formula are all mass fractions):

[0032] Fermentation medium: bran 25%, corn flour 21%, glucose 3%, sodium sulfate 1%, and the rest is water, and the above percentages are all mass fractions.

[0033] The inoculation amount is 6%, the fermentation time is 7 days, the fermentation temperature is 30°C, and the fermentation is completed and dried. The spore count is 10 billion spores / g.

[0034] Embodiment 3:

[0035] In vitro antibacterial activity of HBTG3306 and its application in the prevention and treatment of tea cake disease, ring spot disease, root rot and tea sooty disease:

[0036] 1) In vitro antibacterial activity of Trichoderma aspergillus HBTG3306

[0037] The tested strains were Pestalotiopsis theae, Botrytis cinerea, Fusarium oxysporum, Phytophthora capsici, Sclerotinia sclerotiorum, Rhizoctonia solani, Colletotrichum gloeosporioides and Penicillium italicum.

[0038] The slant strain was transferred to a PDA plate for activation and cultured at 30°C for 6 days. The pathogen and Trichoderma aspergillus HBTG3306 were placed at both ends of the culture medium, 3 cm apart. At the same time, only the pathogen was inoculated as a control. The experiment was repeated three times and cultured in a dark incubator at 25°C for 3 days. The colony radius of the pathogen pointing to Trichoderma was measured. Each setting in the experiment was repeated three times. The colony diameters of each treatment and control were counted, and the inhibition rate was calculated.

[0039] Inhibition rate = [(control colony diameter - treated colony diameter) / (control colony diameter - bacterial cake diameter)] × 100%

[0040] The in vitro antibacterial test showed that HBTG3306 had good antibacterial activity against the above pathogenic fungi. Figure 3 , Table 2).

[0041] Table 1 Antibacterial activity of HBTG3306 against pathogenic bacteria

[0042] Pathogens Antibacterial rate (%) Pestalotiopsis theae 63.89 Botrytis cinerea 64.59 Fusarium oxysporum 55.87 Phytophthora capsici 66.67 Penicillium italicum 84.07 Sclerotinia sclerotiorum 63.79 Rhizoctonia solani 62.96 Colletotrichum gloeosporioides 68.83

[0043] 2) HBTG3306 for the prevention and treatment of tea ring spot

[0044] The tea ring spot test was conducted in Yichang City. Before the disease occurred, the HBTG3306 spore powder prepared in Example 2 was diluted 100 times with clean water (i.e., 1 g of spore powder was diluted with 100 ml of water, the same below). The test was applied once every 7 days for a total of 3 times. The control was sprayed with clean water. The test was repeated 4 times, each with 32 m 2, after the control is fully diseased, the treatment and control disease indexes are statistically analyzed. Five points are taken from each plot, a total of 50 leaves are used to investigate the disease index, and the control effect is calculated. Disease index grading standard: Level 0: no disease spots; Level 1: the disease spot area accounts for less than 1% of the leaf area; Level 3: the disease spot area accounts for 2%-10% of the leaf area; Level 5: the disease spot area accounts for 11%-25% of the leaf area; Level 7: the disease spot area accounts for 26%-50% of the leaf area; Level 9: the disease spot area accounts for more than 50% of the leaf area;

[0045] Disease index = ∑ (number of plants at each level × level) / (total number of plants surveyed × highest representative level) × 100;

[0046] Control effect = (control disease index - treatment disease index) / control disease index × 100%

[0047] The experiment showed that HBTG3306 had good field control effect on tea shift disease, and the control effect of 100 times fermentation liquid reached 64.18% (Table 2).

[0048] Table 2 The control effect of HBTG3306 on tea ring spot

[0049] deal with Disease index Prevention effect (%) HBTG3306 spore powder 100 times diluted 11.29 64.18 Comparison 31.52 -

[0050] 3) HBTG3306 for the prevention and treatment of tea cake disease

[0051] The field efficacy test of tea cake disease was conducted in Yichang City. Before the disease occurred, the HBTG3306 spore powder prepared in Example 2 diluted 100 times with clean water was sprayed once every 7 days for a total of 3 times. The control was sprayed with clean water. The test was repeated 4 times, each with 32 m 2 , after the control is fully diseased, the treatment and control disease indexes are statistically analyzed. Five points are taken from each plot, a total of 50 leaves are used to investigate the disease index, and the control effect is calculated. Disease index grading standard: Level 0: no disease spots; Level 1: the disease spot area accounts for less than 1% of the leaf area; Level 3: the disease spot area accounts for 2%-10% of the leaf area; Level 5: the disease spot area accounts for 11%-25% of the leaf area; Level 7: the disease spot area accounts for 26%-50% of the leaf area; Level 9: the disease spot area accounts for more than 50% of the leaf area;

[0052] Disease index = ∑ (number of plants at each level × level) / (total number of plants surveyed × highest representative level) × 100;

[0053] Control effect = (control disease index - treatment disease index) / control disease index × 100%

[0054] The test showed that HBTG3306 had good field control effect on tea cake disease, and the control effect of 100 times fermentation liquid reached 62.83% (Table 3).

[0055] Table 3 Effect of HBTG3306 fermentation liquid on tea cake disease prevention and control

[0056] deal with Disease index Prevention effect (%) HBTG3306 spore powder 100 times diluted 20.33 62.83 Comparison 54.62 -

[0057] 4) HBTG3306 for the prevention and treatment of tea sooty disease

[0058] The field efficacy test of tea sooty disease was conducted in Yichang City. Before the disease occurred, the HBTG3306 spore powder prepared in Example 2 diluted 100 times with clean water was sprayed once every 7 days for a total of 3 times. The control was sprayed with clean water. The test was repeated 4 times, each with 32 m 2 , after the control is fully diseased, the treatment and control disease indexes are statistically analyzed. Five points are taken from each plot, a total of 50 leaves are used to investigate the disease index, and the control effect is calculated. Disease index grading standard: Level 0: no disease spots; Level 1: the disease spot area accounts for less than 1% of the leaf area; Level 3: the disease spot area accounts for 2%-10% of the leaf area; Level 5: the disease spot area accounts for 11%-25% of the leaf area; Level 7: the disease spot area accounts for 26%-50% of the leaf area; Level 9: the disease spot area accounts for more than 50% of the leaf area;

[0059] Disease index = ∑ (number of plants at each level × level) / (total number of plants surveyed × highest representative level) × 100;

[0060] Control effect = (control disease index - treatment disease index) / control disease index × 100%

[0061] The test showed that HBTG3306 had good field control effect on tea cake disease, and the control effect of 100 times fermentation liquid reached 54.81% (Table 4).

[0062] Table 4 Effect of HBTG3306 fermentation liquid on tea sooty disease prevention and treatment

[0063] deal with Disease index Prevention effect (%) HBTG3306 spore powder 100 times diluted 10.33 54.81 Comparison 22.86 -

[0064] Embodiment 4:

[0065] Effect of HBTG3306 on tea plant growth and yield

[0066] The experimental field is located in Yichang City. The tea variety is Zhongcha 108. The HBTG3306 spore powder was diluted 100 times with clean water. On January 20, the tea trees were irrigated with roots, and the liquid volume per mu was 250L. The control was irrigated with clean water. The application was once every 7 days, and a total of three applications. After 20 days, the germination density was counted at the one bud and two leaves stage, and the germination density (within a 33.3cm×33.3cm box) was investigated, and the weight of 100 buds was measured.

[0067] The experiment showed that HBTG3306 could significantly increase the germination density and 100 bud weight of tea trees, and had a significant yield-increasing effect (Table 5).

[0068] Table 5 Effect of HBTG3306 on tea plant growth and yield

[0069] deal with Germination density (pieces) 100 bud weight(g) HBTG3306 spore powder 100 times diluted 133.88 45.33 CK 112.19 42.75

[0070] Embodiment 5:

[0071] Colonization ability of HBTG3306 in tea tree roots:

[0072] The resistance of Trichoderma HBTG3306 was screened in different carbendazim-containing media, and the carbendazim-resistant strain 5 μg·mL was obtained. -1 The mutant strain (except for resistance to carbendazim, the other physiological and biochemical characteristics of the strain were not significantly different from those of the native strain) can be grown in the presence of 5 μg mL -1 The carbendazim grew normally in PDA.

[0073] The resistant mutant HBTG3306 was fermented according to Example 2, and the spore count was adjusted to 100 million cfu / mL with clean water, and sprayed on the roots of tea trees at an application rate of 5L / plant. The roots were collected 30 days later, the surface was disinfected with 75% and rinsed with sterile water three times. After drying, 1g of tea tree roots and walnut roots were weighed, and then 1mL of sterile water was added and ground in a mortar. After standing, the supernatant was aspirated, diluted by gradient dilution method, and applied to a 5μg·mL -1 The colonization ability of HBTG3306 on tea tree and walnut roots was determined by counting the number of colonies on PDA plates with carbendazim and cultured at 30℃ for 24h.

[0074] The experiment showed that HBTG3306 had a stronger colonization ability in tea tree roots, with a colonization rate of 8.2×10 4 cfu / g, while in walnut root it was 3.6×10 3 cfu / g, this colonization ability is more conducive to its growth-promoting, yield-increasing and biological control effects on tea trees.

[0075] Embodiment 6:

[0076] Acid resistance test of HBTG3306 strain

[0077] The HBTG3306 bacterial disc was inoculated on PDA plates with pH values ​​of 3, 4, 5 and 6, and the growth status was observed. The pH 7 PDA plate was used as a control.

[0078] The HBTG3306 bacterial disc was inoculated on a PDA plate and placed at 0℃, 2℃, 4℃, 6℃, 8℃ and 10℃, with 30℃ as the control, and the growth was observed after 7 days.

[0079] The test results showed that under acidic medium conditions, HBT3306 can grow normally under pH 4, 5, 6 and 7 conditions. This acid resistance is more conducive to its colonization and reproduction in the acidic soil of tea trees. HBTG3306 has good low temperature resistance and grows at a low temperature of 4°C (Table 6). This low temperature resistance helps it reproduce in the soil under low temperature conditions during spring tea picking and better exert its performance.

[0080] Table 6 Low temperature resistance of HBTG3306 strain

[0081] temperature Growth 0℃ — 2℃ — 4℃ + 6℃ + 8℃ + 10℃ + 30℃ +

[0082] Example 7: Effect of composite bacterial agent on tea ring spot control

[0083] In this embodiment, the composite bacterial agent is a mixed bacterial agent of Trichoderma asperellum HBTG3306 and Bacillus taichungensis HBTG1666, the deposit number of Trichoderma asperellum HBTG3306 is: CCTCC NO: M20232116, the deposit number of Bacillus taichungensis HBTG1666 is: CCTCC NO: M2023678; the ratio of effective bacterial spores of Trichoderma asperellum and Bacillus taichungensis is 1: 1. The properties of Bacillus taichungensis have been disclosed in CN117305149B.

[0084] The experiment was divided into three groups: a composite bacterial agent group, a single-agent group of Trichoderma aspergillus HBTG3306, and a single-agent group of Paenibacillus taichungensis. After the three groups of bacterial agents were diluted 100 times, the concentrations were all 100 million spores / ml.

[0085] The tea ring spot test was conducted in Yichang City. Before the disease occurred, 100-fold diluted HBTG3306, HBTG1666 and composite bacterial agents were sprayed once every 7 days for a total of 3 times. The control was sprayed with water. The test was repeated 4 times, each with 32 m 2 , after the control is fully diseased, the treatment and control disease indexes are statistically analyzed. Five points are taken from each plot, a total of 50 leaves are used to investigate the disease index, and the control effect is calculated. Disease index grading standard: Level 0: no disease spots; Level 1: the disease spot area accounts for less than 1% of the leaf area; Level 3: the disease spot area accounts for 2%-10% of the leaf area; Level 5: the disease spot area accounts for 11%-25% of the leaf area; Level 7: the disease spot area accounts for 26%-50% of the leaf area; Level 9: the disease spot area accounts for more than 50% of the leaf area;

[0086] Disease index = ∑ (number of plants at each level × level) / (total number of plants surveyed × highest representative level) × 100;

[0087] Control effect = (control disease index - treatment disease index) / control disease index × 100%

[0088] The experiment showed that the composite bacterial agent had good field control effect on tea shift disease, and the control effect was better than that of a single bacterial agent. The control effect of 100 times the fermentation liquid reached 73.60% (Table 7).

[0089] Table 7 Control effect of composite bacterial agent on tea ring spot

[0090] deal with Disease index Prevention effect (%) HBTG3306 diluted 100 times 15.36 62.74 HBTG1666 diluted 100 times 12.93 68.63 Compound bacterial agent diluted 100 times 10.88 73.60 Comparison 41.22 -

[0091] Example 8: Effect of compound bacterial agent on tea cake disease prevention and control

[0092] The experimental grouping and bacterial agent concentration in this example are the same as those in Example 7.

[0093] The field efficacy test of tea cake disease was conducted in Yingshan County, Huanggang City. Before the disease occurred, 100-fold diluted HBTG3306, HBTG1666 and compound bacterial agents were sprayed once every 7 days for a total of 3 times. The control was sprayed with water. The test was repeated 4 times, each with 32 m 2 , after the control is fully diseased, the treatment and control disease indexes are statistically analyzed. Five points are taken from each plot, a total of 50 leaves are used to investigate the disease index, and the control effect is calculated. Disease index grading standard: Level 0: no disease spots; Level 1: the disease spot area accounts for less than 1% of the leaf area; Level 3: the disease spot area accounts for 2%-10% of the leaf area; Level 5: the disease spot area accounts for 11%-25% of the leaf area; Level 7: the disease spot area accounts for 26%-50% of the leaf area; Level 9: the disease spot area accounts for more than 50% of the leaf area;

[0094] Disease index = ∑ (number of plants at each level × level) / (total number of plants surveyed × highest representative level) × 100;

[0095] Control effect = (control disease index - treatment disease index) / control disease index × 100%

[0096] The experiment showed that the composite bacterial agent had good field control effect on tea cake disease, and the control effect was better than that of a single bacterial agent. The control effect of 100 times the fermentation liquid reached 70.37% (Table 8).

[0097] Table 8 Control effect of composite bacterial agent on tea cake disease

[0098] deal with Disease index Prevention effect (%) HBTG3306 diluted 100 times 18.77 60.81 HBTG1666 diluted 100 times 17.64 63.17 Compound bacterial agent diluted 100 times 14.19 70.37 Comparison 47.89 -

[0099] Example 9: Effect of composite bacterial agent on tea sooty mold prevention and control

[0100] The experimental grouping and bacterial agent concentration in this example are the same as those in Example 7.

[0101] The field efficacy test of tea coal disease was conducted in Yichang City. Before the disease occurred, 100-fold diluted HBTG3306, HBTG1666 and compound bacterial agents were sprayed every 7 days for a total of 3 times. The control was sprayed with water. The test was repeated 4 times, each with 32 m 2 , after the control is fully diseased, the treatment and control disease indexes are statistically analyzed. Five points are taken from each plot, a total of 50 leaves are used to investigate the disease index, and the control effect is calculated. Disease index grading standard: Level 0: no disease spots; Level 1: the disease spot area accounts for less than 1% of the leaf area; Level 3: the disease spot area accounts for 2%-10% of the leaf area; Level 5: the disease spot area accounts for 11%-25% of the leaf area; Level 7: the disease spot area accounts for 26%-50% of the leaf area; Level 9: the disease spot area accounts for more than 50% of the leaf area;

[0102] Disease index = ∑ (number of plants at each level × level) / (total number of plants surveyed × highest representative level) × 100;

[0103] Control effect = (control disease index - treatment disease index) / control disease index × 100%

[0104] The experiment showed that the composite bacterial agent had good field control effect on tea sooty mold, which was better than that of a single bacterial agent. The control effect of 100 times the fermentation liquid reached 63.71% (Table 9).

[0105] Table 9 Effect of HBTG3306 fermentation liquid on tea sooty disease prevention and treatment

[0106] deal with Disease index Prevention effect (%) HBTG3306 diluted 100 times 11.45 52.51 HBTG1666 diluted 100 times 10.21 57.65 Compound bacterial agent diluted 100 times 8.75 63.71 Comparison 24.11 -

Claims

1. A composite bacterial agent, comprising: Trichoderma acanthosporum Trichoderma asperellum ) HBTG3306 and Paenibacillus taichungensis ( Bacillus taichungensis ) HBTG1666, the Trichoderma spinulosa ( Trichoderma asperellum ) The deposit number of HBTG3306 is: CCTCC NO: M20232116, and the Taichung Paenibacillus ( Bacillus taichungensis ) The deposit number of HBTG1666 is: CCTCC NO: M2023678.

2. The composite bacterial agent according to claim 1, characterized in that: The ratio of the effective bacterial concentration of Trichoderma aculeatus to that of Paenibacillus taichungensis is 1-3:3-1.

3. The composite bacterial agent according to claim 2, characterized in that: The ratio of the effective bacterial concentration of Trichoderma aculeatus to that of Paenibacillus taichungensis is 1:

1.

4. Use of the composite bacterial agent according to claim 1 in the prevention and treatment of tea diseases, wherein the tea diseases are tea cake disease, ring spot disease, gray mold, white star disease, anthracnose, brown star disease and tea sooty disease.

5. Use of the composite bacterial agent according to claim 1 in the preparation of a microbial preparation for preventing and treating tea diseases, wherein the tea diseases are tea cake disease, ring spot disease, gray mold, white star disease, anthracnose, brown star disease and tea sooty disease. The composite bacterial agent according to claim 1, wherein the formulation of the bacterial agent is a powder or liquid preparation containing Trichoderma aspergillus HBTG3306 and Paenibacillus taichungensis HBTG1666.

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