Microbial agent and application thereof

Abstract

The invention discloses a microbial agent and application thereof, and belongs to the technical field of biopesticides. The effective components of the microbial agent consist of bacillus velezensis liquid and pseudomonas putida liquid, the concentration of the bacillus velezensis liquid is 1 * 10 < 10 > cfu / mL, and the concentration of the pseudomonas putida liquid is 1 * 10 < 11 > cfu / mL. The volume ratio of bacillus velezensis liquid to pseudomonas putida liquid in the microbial agent is (54-98): (9-20), and the bacillus velezensis liquid and the pseudomonas putida liquid are compounded within the volume ratio range, so that the microbial agent has a better effect of preventing and treating meloidogyne incognita and also has a synergistic interaction effect. When the microbial agent is applied to tomato plants, the growth of tomatoes can be promoted, the stress resistance of the tomatoes is improved, the yield of the tomatoes is increased, and the quality of the tomatoes is improved. The invention provides a biopesticide which is low in cost, environment-friendly and better in prevention and treatment effect for prevention and treatment of root-knot nematodes.

Description

Technical Field

[0001] The invention belongs to the technical field of biological pesticides and relates to a microbial agent and application thereof. Background Art

[0002] Tomato (Solanum lycopersicum L.) is one of the important edible vegetable crops. It is rich in carotene, vitamin C and B vitamins and has high nutritional value. Tomatoes are rich in lycopene, which has antioxidant capacity, can lower blood pressure, and clear away heat and detoxify. Root-knot nematodes (Meloidogyne) are highly specialized omnivorous plant pathogenic nematodes with a wide host range and multiple transmission routes. They are difficult to control and can harm more than 130 crops in 39 families. The vegetable root-knot nematodes in my country mainly include southern root-knot nematodes, peanut root-knot nematodes, northern root-knot nematodes and Javan root-knot nematodes. Southern root-knot nematodes occur more frequently in northern greenhouses. Root-knot nematodes mainly harm the roots of tomatoes, affecting the growth and yield of tomatoes. Therefore, providing a method for controlling root-knot nematodes is of great significance to tomato cultivation.

[0003] At present, the technical means of controlling root-knot nematodes mainly include agricultural control, chemical control and biological control. Soilless seedling cultivation is the main agricultural control method to avoid root-knot nematodes. It can cultivate strong seedlings and avoid early damage by root-knot nematodes. However, soilless seedling cultivation has the problems of high investment cost, high technical requirements and difficult management. Avermectin, avermectin, spinosad, aldicarb and chlorpyrifos are commonly used chemical agents for controlling root-knot nematodes, but chemical nematicides are mostly highly toxic pesticides, which can easily cause poisoning of humans and animals, environmental pollution and ecological damage. Biological control mainly uses biological pesticides or natural enemies to control the number of nematodes. It has the advantages of high safety and no pollution to the environment, and it also helps to improve the soil microecological environment. Therefore, it is of great significance to develop a safe and pollution-free biological pesticide for the control of root-knot nematodes. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a microbial agent and its application. The active ingredients of the microbial agent are composed of Bacillus Velezii liquid and Pseudomonas putida liquid. The concentration of Bacillus Velezii liquid is 1×10 10 cfu / mL, the concentration of Pseudomonas putida was 1×10 11 cfu / mL. The volume ratio of the Bacillus Velezii liquid to the Pseudomonas putida liquid in the microbial agent is 54-98:9-20. The compounding within this volume ratio range has a better effect of preventing and controlling southern root-knot nematodes and also has a synergistic effect. Applying the microbial agent of the present invention to tomato plants can also promote tomato growth, improve tomato stress resistance, increase tomato yield, and improve tomato quality.

[0005] In order to achieve the technical purpose of the present invention, on the one hand, the present invention provides a microbial agent, wherein the active ingredients of the microbial agent are composed of a Bacillus Velez bacteria solution and a Pseudomonas putida bacteria solution, and the concentration of the Bacillus Velez bacteria solution is 1×10 10 cfu / mL, the concentration of Pseudomonas putida was 1×10 11 cfu / mL. The volume ratio of the Bacillus Velez subtilis liquid to the Pseudomonas putida liquid in the microbial agent is 54-98:9-20; preferably, the volume ratio of the Bacillus Velez subtilis liquid to the Streptomyces nucleatum liquid in the microbial agent is 62:18 or 70-82:13-16; further preferably, the volume ratio of the Bacillus Velez subtilis liquid to the Streptomyces nucleatum liquid in the microbial agent is 74:15.

[0006] Specifically, the present invention learned through indoor toxicity tests that after the Bacillus Velez bacteria solution and the Pseudomonas putida bacteria solution were compounded in a volume ratio of 54-98:9-20, the toxicity to the southern root-knot nematode was significantly enhanced, and a synergistic effect was shown. After the Bacillus Velez bacteria solution and the Pseudomonas putida bacteria solution were compounded in a volume ratio of 54-98:9-20, the co-toxicity coefficient to the southern root-knot nematode was greater than 120, showing a synergistic effect; after the Bacillus Velez bacteria solution and the Pseudomonas putida bacteria solution were compounded in a volume ratio of 62:18 and 70-82:13-16, the co-toxicity coefficient to the southern root-knot nematode was greater than 130, and the synergistic effect was better; when the compounding volume ratio of Bacillus Velez bacteria solution and the Pseudomonas putida bacteria solution was 74:15, the co-toxicity coefficient to the southern root-knot nematode was 137.83, and the synergistic effect was optimal.

[0007] On the other hand, the present invention seeks to protect the use of the above-mentioned microbial agent in controlling root-knot nematodes, wherein the root-knot nematodes are southern root-knot nematodes.

[0008] On the other hand, the present invention claims the use of the above-mentioned microbial agent in promoting crop growth, wherein the crop is tomato. The said promotion of crop growth includes increasing plant height, stem thickness, fresh weight, and also includes promoting the growth of crop root system.

[0009] Specifically, the present invention has learned through field tests that when microbial agents are applied during tomato seedling cultivation, the plant height, stem thickness, total fresh weight and water content of tomato seedlings applied with microbial agents are significantly increased compared with the control group, with the plant height of tomato seedlings increasing by 21.1%, the root length increasing by 15.0%, the stem thickness increasing by 5.2%, the total fresh weight increasing by 49.7%, and the water content increasing by 1.9%. When microbial agents are applied in the tomato seedling stage, compared with the control group, the plant height, stem thickness, aboveground fresh weight and underground fresh weight of tomatoes are significantly increased, with the plant height increasing by 6.2%, the stem thickness increasing by 4.2%, the aboveground fresh weight increasing by 22.0%, and the underground fresh weight increasing by 33.9%. When microbial agents are applied in the tomato seedling stage, compared with the control group, the plant height, aboveground fresh weight and underground fresh weight of tomato seedlings in the microbial agent group are significantly increased, with the plant height increasing by 9.4%, the aboveground fresh weight increasing by 9.4%, and the underground fresh weight increasing by 10.2%.

[0010] Specifically, the present invention has learned through field experiments that the microbial agent has a promoting effect on the growth of tomato seedlings and can also promote the growth of the root system. Compared with the control group, the root system of the tomato seedlings in the microbial agent group is more developed and luxuriant, and the main root is thicker.

[0011] On the other hand, the present invention requests protection for the use of the above-mentioned microbial agent in improving the stress resistance of crops, wherein the crops are tomatoes, and the improved stress resistance of crops is to improve at least one of superoxide dismutase activity, peroxidase activity, polyphenol oxidase activity and SPAD value.

[0012] Specifically, the present invention has learned through field tests that when microbial agents are applied during tomato seedling cultivation, the superoxide dismutase activity in the tomato seedlings applied with microbial agents is significantly increased compared with the control group, with superoxide dismutase activity increasing by 11.6% and polyphenol oxidase activity increasing by 1.9%. When microbial agents are applied during the tomato seedling stage, the peroxidase activity is significantly increased compared with the control group, with peroxidase activity increasing by 60.8%, superoxide dismutase activity increasing by 4.3%, and SPAD value increasing by 10.9%. Improve the resistance of tomato seedlings to environmental stress. When microbial agents are applied during the tomato seedling stage, the peroxidase activity in the tomato seedlings in the microbial agent group increases by 1.8% and the polyphenol oxidase activity increases by 20.8% compared with the control group.

[0013] In addition, the present invention requests protection for the use of the above-mentioned microbial agent in improving crop quality, wherein the crop is tomato, and the improvement of crop quality includes increasing soluble sugar content, sugar content, lycopene content and soluble solids content, and also includes reducing acidity.

[0014] Specifically, the present invention has learned through field trials that the quality of tomato fruit significantly increased after the application of microbial agents, among which the soluble sugar content, sugar content, lycopene content and soluble solid content all increased significantly, and the acidity decreased significantly. Compared with the control, the soluble sugar content of tomatoes in the microbial agent group was 24.3%, the sugar content increased by 13.2%, the vitamin C content increased by 8.7%, the lycopene content increased by 6.7%, the hardness increased by 1.2%, the soluble solids increased by 4.3%, and the acidity decreased by 4.0%.

[0015] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0016] After the Bacillus Velez and Pseudomonas putida in the microbial agent of the present invention are compounded in a volume ratio of 54-98:9-20, the toxicity to southern root-knot nematodes is significantly enhanced, and a synergistic effect is shown. After the Bacillus Velez and Pseudomonas putida are compounded in a volume ratio of 54-98:9-20, the co-toxicity coefficient to southern root-knot nematodes is greater than 120, showing a synergistic effect; after the Bacillus Velez and Pseudomonas putida are compounded in a volume ratio of 62:18 and 70-82:13-16, the co-toxicity coefficient to southern root-knot nematodes is greater than 130, and the synergistic effect is better; when the compounding volume ratio of Bacillus Velez and Pseudomonas putida is 74:15, the co-toxicity coefficient to southern root-knot nematodes is 137.83, and the synergistic effect is optimal. When the composite volume ratio of Bacillus velezensis liquid and Pseudomonas putida liquid exceeds 54-98:9-20, the co-toxicity coefficient to southern root-knot nematode is lower than 120, showing an additive effect, indicating that when the ratio range provided by the present invention is exceeded, the microbial agent does not have a synergistic effect on the prevention and control of southern root-knot nematode.

[0017] Applying the microbial agent of the present invention to crops can promote crop growth. The present invention learned through field tests that when microbial agents were applied during tomato seedling cultivation, compared with the control group, the plant height, stem thickness, total fresh weight and water content of the tomato seedlings applied with microbial agents were significantly increased, and the plant height of the tomato seedlings increased by 21.1%, the root length increased by 15.0%, the stem thickness increased by 5.2%, the total fresh weight increased by 49.7%, and the water content increased by 1.9%. When microbial agents were applied in the tomato seedling stage, compared with the control group, the plant height, stem thickness, aboveground fresh weight and underground fresh weight of the tomatoes increased significantly, with a plant height increase of 6.2%, a stem thickness increase of 4.2%, an aboveground fresh weight increase of 22.0%, and an underground fresh weight increase of 33.9%. When microbial agents were applied in the tomato seedling stage, compared with the control group, the plant height, aboveground fresh weight and underground fresh weight of the tomato seedlings in the microbial agent group increased significantly, with a plant height increase of 9.4%, an aboveground fresh weight increase of 9.4%, and an underground fresh weight increase of 10.2%. Microbial agents can also promote root growth. Compared with the control group, the root system of tomato seedlings in the microbial agent group is more developed and lush, and the taproot is thicker.

[0018] Applying the microbial agent of the present invention to crops can improve the resistance of crops to environmental stress and improve the activity of crop defense enzymes. The present invention learned through field tests that when microbial agents were applied during tomato seedling cultivation, the superoxide dismutase activity in the tomato seedlings applied with the microbial agent increased significantly compared with the control group, with an increase of 11.6% in superoxide dismutase activity and 1.9% in polyphenol oxidase activity. When microbial agents were applied during the tomato seedling stage, the peroxidase activity increased significantly compared with the control group, with an increase of 60.8% in peroxidase activity, 4.3% in superoxide dismutase activity, and 10.9% in SPAD value. Improve the resistance of tomato seedlings to environmental stress. When microbial agents were applied during the tomato seedling stage, the peroxidase activity in the tomato seedlings in the microbial agent group increased by 1.8% and the polyphenol oxidase activity increased by 20.8% compared with the control group.

[0019] Applying the microbial agent of the present invention to crops can improve the quality of the crops. The present invention learned through field trials that the quality of tomato fruits increased significantly after the application of the microbial agent, wherein the soluble sugar content, sugar content, lycopene content and soluble solid content all increased significantly, and the acidity decreased significantly. Compared with the control, the soluble sugar content of tomatoes in the microbial agent group was 24.3%, the sugar content increased by 13.2%, the vitamin C content increased by 8.7%, the lycopene content increased by 6.7%, the hardness increased by 1.2%, the soluble solids increased by 4.3%, and the acidity decreased by 4.0%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a graph showing the effect of microbial agents on promoting the growth of tomato seedlings. Figure 1 A in the figure is the front view of tomato seedlings in the control group and the microbial agent group; Figure 1B in the figure is a top view of tomato seedlings in the control group and the microbial agent group; Figure 1 Figure C is a comparison chart of tomato seedling sampling in the control group and the microbial agent group.

[0021] Figure 2 This is a diagram showing the effects of microbial agents on the root system of tomato seedlings.

[0022] Figure 3 This is a graph showing the effect of microbial agents on the growth of tomato seedlings.

[0023] Figure 4 This is a diagram showing the effect of microbial agents on the root system of tomato seedlings.

[0024] Figure 5 This is a graph showing the effect of microbial agents on tomato yield. DETAILED DESCRIPTION

[0025] The technical scheme of the present invention is described in conjunction with the embodiments, but the present invention is not limited to the following embodiments. The experimental methods and detection methods described in each embodiment are conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0026] The deposit number of Bacillus Velez is CGMCC No.14384.

[0027] The deposit number of Pseudomonas putida is CGMCC No.10729.

[0028] NA solid culture medium: peptone 10.0 g / L, beef extract powder 3.0 g / L, sodium chloride 5.0 g / L, agar 15.0 g / L, pH 7.2.

[0029] NB liquid culture medium: peptone 10.0 g / L, beef extract powder 3.0 g / L, sodium chloride 5.0 g / L, pH 7.2.

[0030] Beef extract peptone medium: beef extract 3g / L, yeast extract 1g / L, peptone 10g / L, sucrose 10g / L, agar 17g / L.

[0031] Liquid culture medium: beef extract 3g / L, yeast extract 1g / L, peptone 5g / L, sucrose 1g / L, pH 6.8-7.0.

[0032] Example 1

[0033] This example provides an indoor toxicity test of a microbial agent against southern root-knot nematodes.

[0034] Preparation of Bacillus Velez bacteria suspension: Bacillus Velez with the deposit number of CGMCC No.14384 was activated on NA solid medium for 24 h, and a single colony was picked and inoculated into NB liquid medium, and cultured on a shaker at 28°C and 180 rpm until the bacterial suspension concentration was 1×10 10 cfu / mL, stop fermentation and keep aside.

[0035] Preparation of Pseudomonas putida liquid: Pseudomonas putida with the deposit number of CGMCC No.10729 was activated on beef extract peptone medium for 3 days, and a single colony was picked and inoculated into liquid medium, and cultured on a shaker at 28°C and 150 rpm until the concentration of the bacterial suspension was 1×10 11 cfu / mL, stop fermentation and keep aside.

[0036] Preparation of southern root-knot nematode suspension: Collect southern root-knot nematode (Meloidogyne incognito) egg masses from the roots of diseased tomatoes, place the egg masses on a gauze in a small culture dish (3.5 cm in diameter), add a small amount of distilled water to the culture dish, and culture in a constant temperature incubator at 28°C. Collect the second-instar larvae (J2) after 24 hours, collect once a day for a total of 3 days, prepare a larval suspension, and then dilute the larval suspension to 200 larvae / mL for use.

[0037] The bacterial solutions of Bacillus Velez and Pseudomonas putida were diluted 50 times with water to prepare single-dose mother solutions, which were compounded according to the volume ratio shown in Table 1 to obtain mixed mother solutions. Five volume concentration gradients were set for each single agent and mixture in an equal ratio. Each single agent and mixture was added to a 24-well plate, 0.5 mL was added to each well, 3 wells were added for each concentration, and sterile water was added as a control. The root-knot nematode larvae suspension was added to each of the above treatment wells, 0.5 mL was added to each well, and the 24-well plate was placed in a constant temperature incubator at 25°C. After 24 hours, the activity inhibition rate was examined under a microscope, and the corrected mortality rate was calculated. The activity was inhibited when the nematode body was stiff and crescent-shaped, and the inhibition rate of the control group did not exceed 10%. The toxicity regression equation and LC were calculated by regression analysis. 50 The Sun-Johnson method was used to calculate the co-toxicity coefficient (CTC value) of each compound mixture. The Bacillus velezii liquid was used as the standard agent, and its toxicity index (TI) was 100. The calculation results are shown in Table 1.

[0038] Corrected mortality rate (%) = (mortality rate of treatment group - mortality rate of control group) × 100 / (1-mortality rate of control group);

[0039]

[0040] TTI = TI of agent A × the percentage of agent A in the mixture + TI of agent B × the percentage of agent B in the mixture;

[0041]

[0042] In the formula, TI is the toxicity index of the measured single agent, ATI is the toxicity index of the measured mixture, TTI is the toxicity index of the theoretical mixture, CTC is the co-toxicity coefficient of the compound, A is the standard agent Bacillus Velez bacteria solution, and B is the Pseudomonas putida bacteria solution. The synergistic effect of the mixture is judged by the CTC value, CTC value ≥ 120 is synergistic effect, CTC value ≤ 80 is antagonistic effect, and 80 < CTC value < 120 is additive effect.

[0043] Table 1: Toxicity of microbial agents to southern root-knot nematodes

[0044]

[0045]

[0046] As shown in Table 1, after the Bacillus Velez and Pseudomonas putida were mixed in a volume ratio of 54-98:9-20, the toxicity to southern root-knot nematodes was significantly enhanced, and a synergistic effect was shown. After the Bacillus Velez and Pseudomonas putida were mixed in a volume ratio of 54-98:9-20, the co-toxicity coefficients to southern root-knot nematodes were greater than 120, showing a synergistic effect; after the Bacillus Velez and Pseudomonas putida were mixed in a volume ratio of 62:18 and 70-82:13-16, the co-toxicity coefficients to southern root-knot nematodes were greater than 130, and the synergistic effect was better; when the volume ratio of Bacillus Velez and Pseudomonas putida was 74:15, the co-toxicity coefficient to southern root-knot nematodes was 137.83, and the synergistic effect was optimal. When the composite volume ratio of Bacillus velezensis liquid and Pseudomonas putida liquid exceeds 54-98:9-20, the co-toxicity coefficient to southern root-knot nematode is lower than 120, showing an additive effect, indicating that when the ratio range provided by the present invention is exceeded, the microbial agent does not have a synergistic effect on the prevention and control of southern root-knot nematode.

[0047] Example 2

[0048] This example provides the effect of applying microbial agents to tomatoes on tomato yield and quality.

[0049] The tomato variety is Provence, and the cultivation method of one ridge and two rows is adopted. 14 plants are planted in each row, and 4 ridges are planted in each treatment, totaling 112 plants. The ridge width is set to 50 cm, the ridge spacing is 80 cm, the row spacing is 40 cm, and the plant spacing is 38 cm. Tomato fertilization adopts the method of base fertilizer + topdressing. The amount of fertilizer is estimated based on the nutrient requirements of tomatoes during the whole growth period recommended by the crop nutrition team of Northwest Agriculture and Forestry University and the measured values ​​of soil nutrients. The basic properties of field soil are: alkaline nitrogen 9.08 mg / kg, available phosphorus 12.97 mg / kg, and available potassium 121.03 mg / kg. The fertilization plan is shown in Table 2. Bacillus Velez and Pseudomonas putida were fermented to a bacterial suspension concentration of 1×10 10 cfu / mL and 1×10 11 cfu / mL, and after diluting them 50 times respectively, the Bacillus Velez bacteria solution and the Pseudomonas putida bacteria solution were compounded in a volume ratio of 74:15 to obtain the microbial agent. The microbial agent was watered on the day of transplanting tomato seedlings. After transplanting, the second application was made 20 days later, and the third application was made after an interval of 30 days.

[0050] Table 2: Fertilization plan

[0051] type Organic Fertilizer fertilizer base fertilizer 1000kg / mu Urea 21kg / mu, superphosphate 21kg / mu Topdressing 1 0 Balanced fertilizer (20-20-20) 10kg / mu Topdressing 2 0 Balanced fertilizer (20-20-20) 10kg / mu Topdressing 3 0 Balanced fertilizer (20-20-20) 4kg / mu, potassium dihydrogen phosphate 2kg / mu

[0052] Note: Organic fertilizer was purchased from Luochuan Yuangu Ecological Agriculture Co., Ltd., with organic matter ≥40%. Balanced fertilizer is a nitrogen, phosphorus and potassium nutrient element fertilizer, 20-20-20 means N 20%, P2O5 20%, K2O 20%.

[0053] 1. Effect of microbial agents on tomato seedling cultivation

[0054] The bacterial agent was applied during tomato seedling cultivation, and the bacterial concentration was controlled at 0.2×10 9 cfu / g substrate, and record the growth status when the tomato seedlings grow to four leaves and one heart ( Figure 1 ), sampling was performed to detect biological indicators (plant height, root length, stem diameter, total fresh weight, water content) and defense enzyme activity indicators of tomato seedlings. The defense enzyme activity indicators included superoxide dismutase (SOD) activity (colorimetric method), peroxidase (POD) activity (guaiacol colorimetric method), and polyphenol oxidase (PPO) activity (catechol colorimetric method). The test results are shown in Tables 3 and 4.

[0055] Table 3: Effects of microbial agents on biological indicators of tomato seedlings

[0056] deal with Plant height(cm) Root length (cm) Stem diameter (mm) Total fresh weight (g) Water content (%) Control group 22.67±1.53d 8.84±0.78b 3.24±0.20d 3.92±0.41c 89.40±0.73a Microbial Agent Group 27.45±1.17b 10.17±1.01ab 3.41±0.06c 5.87±0.14ab 91.11±0.27c

[0057] Table 4: Effects of microbial agents on defense enzyme activity indicators in tomato seedlings

[0058]

[0059] Depend on Figure 1 It can be seen that the application of microbial agents during the matrix seedling cultivation process can significantly promote the growth of tomato seedlings, and the growth of tomato seedlings in the microbial agent treatment group is significantly better than that in the control group. As shown in Table 3, compared with the control group, the plant height, stem thickness, total fresh weight and water content of tomato seedlings treated with microbial agents increased significantly, with the plant height of tomato seedlings increasing by 21.1%, the root length increasing by 15.0%, the stem thickness increasing by 5.2%, the total fresh weight increasing by 49.7%, and the water content increasing by 1.9%. As shown in Table 4, compared with the control group, the superoxide dismutase activity in tomato seedlings treated with microbial agents increased significantly, with the superoxide dismutase activity increasing by 11.6% and the polyphenol oxidase activity increasing by 1.9%. It can be seen that the application of the microbial agent of the present invention can significantly improve the biological indicators of tomato matrix seedling cultivation, and can also improve the defense enzyme activity indicators of tomato matrix seedling cultivation, and enhance the stress resistance of tomatoes.

[0060] 2. Effects of microbial agents on the growth of tomato seedlings

[0061] Basal fertilizer and microbial agents were applied at a rate of 50 mL / plant. On December 1, 2021, Provence tomato seedlings with four leaves and one heart were transplanted according to the planting plan. 30 days after planting tomatoes (January 1, 2022), destructive sampling was performed on the tomato plants. The root system scan of the tomato seedlings is shown in the figure below: Figure 2 As shown, biological indices (plant height, stem diameter, aboveground fresh weight, underground fresh weight) and defense enzyme activity indices were measured. The defense enzyme activity indices included peroxidase activity, superoxide dismutase activity, and SPAD value (SPAD clamp measurement method). The measurement results are shown in Tables 5 and 6.

[0062] Table 5: Effects of microbial agents on biological indicators of tomato seedlings

[0063] deal with Plant height / cm Stem diameter / mm Fresh weight above ground / g Underground fresh weight / g Control group 42.75±1.57c 9.86±0.68b 74.33±12.93b 8.90±1.89bc Microbial Agent Group 45.39±2.04b 10.27±0.57a 90.69±6.81a 11.92±1.27a

[0064] Table 6: Effects of microbial agents on defense enzyme activity indicators of tomato seedlings

[0065]

[0066] Depend on Figure 2It can be seen that after the application of microbial agents in the seedling stage, the growth of tomatoes is better. Compared with the control group, the root system of tomato seedlings in the microbial agent group is more developed and luxuriant, and the taproot is thicker. As shown in Table 5, after the application of microbial agents in the seedling stage, compared with the control group, the height, stem thickness, aboveground fresh weight and underground fresh weight of tomatoes increased significantly, with a plant height increase of 6.2%, a stem thickness increase of 4.2%, an aboveground fresh weight increase of 22.0%, and an underground fresh weight increase of 33.9%. As shown in Table 6, after the application of microbial agents in the seedling stage, compared with the control group, the peroxidase activity increased significantly, the superoxide dismutase activity and SPAD value increased insignificantly, the peroxidase activity increased by 60.8%, the superoxide dismutase activity increased by 4.3%, and the SPAD value increased by 10.9%. It can be seen that the application of the microbial agent of the present invention can significantly improve the biological indicators of tomato seedlings, and can also improve the resistance of tomato seedlings to environmental stress.

[0067] 3. Effects of microbial agents on tomato seedling growth

[0068] After planting tomatoes, topdressing is carried out according to the fertilization plan. The growth status of tomatoes 150 days after planting (May 2, 2022) is as follows Figure 3 As shown, the tomato plants were destructively sampled for the second time 150 days after planting (fruiting period). The root system of the tomato seedlings is shown in Figure 4 As shown, biological indicators (plant height, stem diameter, aboveground fresh weight, underground fresh weight) and defense enzyme activity indicators were measured. The defense enzyme activity indicators included superoxide dismutase activity, peroxidase activity, polyphenol oxidase activity and SPAD value. The measurement results are shown in Tables 7 and 8.

[0069] Table 7: Effects of microbial agents on biological parameters of tomato seedlings

[0070] deal with Plant height / m Stem diameter / mm Fresh weight above ground / kg Underground fresh weight / g Control group 2.03±0.07b 13.695±0.635b 1.038±0.221c 33.88±7.85b Microbial Agent Group 2.22±0.17a 13.777±1.454b 1.136±0.157b 37.33±9.53a

[0071] Table 8: Effects of microbial agents on the activity of defense enzymes in tomato seedlings

[0072]

[0073] Depend on Figure 3 and Figure 4 It can be seen that the tomato root system is more vigorous after the application of the microbial agent. Compared with the control group, the root system of the tomato seedlings in the microbial agent group is more developed and dense. As shown in Table 7, compared with the control group, the plant height, aboveground fresh weight and underground fresh weight of the tomato seedlings in the microbial agent group increased significantly, with a plant height increase of 9.4%, an aboveground fresh weight increase of 9.4%, and an underground fresh weight increase of 10.2%. As shown in Table 8, compared with the control group, the peroxidase activity in the tomato seedlings in the microbial agent group increased by 1.8% and the polyphenol oxidase activity increased by 20.8%. It can be seen that the application of the microbial agent of the present invention can significantly improve the biological indicators of tomato seedlings.

[0074] 4. Effect of microbial agents on tomato yield

[0075] During the tomato fruiting period, ripe tomato fruits were collected and the tomato yield ( Figure 5 ), and the fruit quality was measured and evaluated at the same time. The fruit quality related indicators include soluble sugar content, vitamin C content, sugar content, acidity, lycopene, soluble protein, soluble solids content, and hardness. The measurement results are shown in Table 9.

[0076] Table 9: Effects of microbial agents on tomato quality

[0077]

[0078] As shown in Table 9, the quality of tomato fruit increased significantly after the application of microbial agents, including a significant increase in soluble sugar content, sugar content, lycopene content and soluble solids content, and a significant decrease in acidity. Compared with the control, the soluble sugar content of tomatoes in the microbial agent group increased by 24.3%, sugar content increased by 13.2%, vitamin C content increased by 8.7%, lycopene content increased by 6.7%, hardness increased by 1.2%, soluble solids increased by 4.3%, and acidity decreased by 4.0%. Figure 5 It can be seen that the tomato fruit yield was significantly increased after the application of microbial agents.

[0079] The embodiments described above are part of the embodiments of the present invention, but not all of them. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but only represents selected embodiments of the present invention. All other embodiments obtained without creative work and related deductions and substitutions made by ordinary technicians in the field under the conditions of the concept of the present invention belong to the scope of protection of the present invention.

Claims

1. A microbial agent, characterized in that: The active ingredients of the microbial agent are composed of Bacillus Velez bacteria liquid and Pseudomonas putida bacteria liquid; The volume ratio of the Bacillus Velez bacteria liquid to the Pseudomonas putida bacteria liquid in the microbial inoculant is 54-98:9-20.

2. The microbial agent according to claim 1, characterized in that The concentration of the Bacillus Velez bacteria solution is 1×10 10 cfu / mL, the concentration of the Pseudomonas putida bacterial solution is 1×10 11 cfu / mL.

3. The microbial agent according to claim 1, characterized in that: The volume ratio of the Bacillus Velez bacteria liquid to the Pseudomonas putida bacteria liquid in the microbial inoculant is 62:18 or 70-82:13-16.

4. The microbial agent according to claim 1, characterized in that The volume ratio of the Bacillus Velez bacteria liquid to the Pseudomonas putida bacteria liquid in the microbial inoculant is 74:

15.

5. Use of the microbial agent according to any one of claims 1 to 4 in controlling root-knot nematodes, characterized in that: The root-knot nematode is the southern root-knot nematode.

6. Use of the microbial agent according to any one of claims 1 to 4 in promoting crop growth, characterized in that: The crop is tomato.

7. The use according to claim 6, characterized in that: The promoting of crop growth includes increasing plant height, stem thickness, fresh weight, and promoting the growth of crop root system.

8. Use of the microbial agent according to any one of claims 1 to 4 in improving crop stress resistance, characterized in that: The crop is tomato; The method of improving crop stress resistance is to improve at least one of superoxide dismutase activity, peroxidase activity, polyphenol oxidase activity and SPAD value.

9. Use of the microbial agent according to any one of claims 1 to 4 in improving crop quality, characterized in that: The crop is tomato; The improving of crop quality includes increasing soluble sugar content, sugar content, lycopene content and soluble solid content, and also includes reducing acidity.

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