A seed treatment composition containing paenibacillus polymyxa kn-03 and use thereof

Abstract

The application discloses a seed treatment composition containing paenibacillus polymyxa KN-03, and an effective component of the seed treatment composition is paenibacillus polymyxa KN-03 and tebuconazole, and the mass ratio of the two is 100:1-1:1. The seed treatment composition overcomes the defects of low germination rate, low emergence rate and inhibited root growth of wheat caused by high-concentration tebuconazole seed treatment, can promote the growth of wheat seedling root system, delay the resistance of pathogenic bacteria, and is suitable for preventing and treating wheat sharp eyespot.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pesticides, and particularly relates to a seed treatment composition containing Paenibacillus polymyxa KN-03 and application thereof to control crop diseases. BACKGROUND

[0002] Wheat sharp eyespot is a soil-borne fungal disease caused by Rhizoctonia cerealis, which overwinters in soil as sclerotia, and also overwinters as mycelium and sclerotia on crop residues and weeds, becoming the main primary infection source in the next year. The disease causes wheat to fail to tiller, or to have more barren spikes, and reduces grain weight. In recent years, due to the national promotion of straw returning to the field, which is beneficial to the protection of the environment and the increase of soil organic matter, but also leads to the aggravation of sharp eyespot year by year, and the yield of serious disease plots can be reduced by 50%. The prevention and control of wheat sharp eyespot has become the focus of attention. Conventional spraying cannot grasp the best period of prevention and control of soil-borne diseases, and once the best prevention and control period is missed, it will cause irreparable loss. Seed treatment is the most economical and effective method for the prevention and control of soil-borne diseases. Seed treatment usually includes seed dressing, seed soaking, and seed coating. There are few seed treatment agents for the prevention and control of wheat sharp eyespot, and the conventional thiram, triadimefon, carbendazim, and diniconazole agents have developed resistance to different degrees, and the prevention and control effect is obviously decreased. Tebuconazole is a highly effective, broad-spectrum, and systemic triazole fungicide, which has been widely used in seed treatment agents, and has good prevention and control effect on wheat sharp eyespot. However, there are some problems in the use process, such as the inhibition of wheat seed germination, the delay of emergence time, the reduction of emergence rate, the inhibition of seedling growth, the inhibition of root growth, the increase of the number of abnormal plants, and the drug injury under low temperature stress. With the increase of use frequency and dosage, resistance may be produced.

[0003] Paenibacillus polymyxa KN-03 is isolated and screened from a tomato planting demonstration base in Shandong by Wuhan Konno Biotechnology Co., Ltd., and has been preserved in China Center for Type Culture Collection on March 13, 2012, with a preservation number of CCTCC NO: M2012077. Paenibacillus polymyxa KN-03 is a bacterial biological fungicide, which is a gram-positive bacterium with endogenous spores. By successfully colonizing in the rhizosphere, body surface or body of plants, competing with pathogenic bacteria for nutrients around plants, secreting antibacterial substances to inhibit the growth of pathogenic bacteria, and inducing the plant defense system to resist the invasion of pathogenic bacteria, the biological control purpose is achieved. The drug has a certain prevention and control effect on soil-borne diseases such as wheat scab, strawberry bacterial wilt, and watermelon wilt. The registered use methods of the drug for the prevention and control of soil-borne diseases in China are mainly root irrigation and seed soaking, and seed coating and seed dressing are not registered for use.

[0004] Based on the above problems, the inventors have conducted a large number of formula screening tests, and found that the combination of Paenibacillus polymyxa KN-03 and tebuconazole used as seed coating or seed dressing has a significantly higher control effect on wheat brown leaf spot than the single agent, and has high safety, germination rate and emergence rate, overcomes the disadvantages of low germination rate, low emergence rate and inhibited root growth of wheat caused by high concentration of tebuconazole single agent treatment, and shows obvious root growth promoting effect and yield increasing effect. In the existing seed treatment agents, there is no report on the use of the seed treatment composition of Paenibacillus polymyxa KN-03 and tebuconazole for controlling wheat brown leaf spot. SUMMARY

[0005] The purpose of the present application is to provide a seed treatment composition containing Paenibacillus polymyxa KN-03, which helps to promote wheat root growth, improve wheat germination rate, emergence rate and yield, and improve the control effect on wheat brown leaf spot.

[0006] In order to achieve the above-mentioned purpose of the application, the technical scheme adopted by the present application is as follows:

[0007] A seed treatment composition containing Paenibacillus polymyxa KN-03, the effective components of which consist of Paenibacillus polymyxa KN-03 and tebuconazole, and the mass ratio is 100:1 to 1:1.

[0008] Further, the seed treatment composition containing Paenibacillus polymyxa KN-03, the mass ratio of the effective components Paenibacillus polymyxa KN-03 and tebuconazole is 50:1 to 4:1, preferably the mass ratio is 30:1 to 10:1.

[0009] The seed treatment composition containing Paenibacillus polymyxa KN-03 is characterized in that the content of Paenibacillus polymyxa in the composition accounts for 1% to 30% of the total mass percentage of the composition, and the content of tebuconazole accounts for 0.1% to 30% of the total mass percentage of the composition.

[0010] The dosage form of the seed treatment composition is a flowable concentrate or a seed treatment dispersible powder, and the application method is seed coating or seed dressing.

[0011] Further, the seed treatment composition is suitable for preventing and controlling soil-borne diseases such as wheat brown leaf spot, wheat foot rot, potato black scurf, watermelon wilt, and is especially suitable for preventing and controlling wheat brown leaf spot.

[0012] The seed treatment composition of the present application comprises effective components, adjuvants and fillers.

[0013] The effective components consist of Paenibacillus polymyxa KN-03 and tebuconazole, and the adjuvant is selected from one or a combination of two or more of wetting agents, dispersants, film formers, thickeners, antifoaming agents, antifreezing agents, preservatives and warning colors.

[0014] The filler is selected from one or more than two combinations of white carbon black, kaolin, diatomite, bentonite, talc, clay, montmorillonite, clay, deionized water, tap water.

[0015] The above components can be prepared into the suspension seed coating agent and the seed treatment dispersible powder according to the conventional processing method of the pesticide seed treatment agent.

[0016] The application method of the seed treatment composition can be used for but not limited to seed coating or seed dressing, and can also be applied to seed soaking, etc.

[0017] The application range of the seed treatment composition can be used for but not limited to the suspension seed coating agent and the seed treatment dispersible powder, and can also be applied to the wettable powder, the seed treatment suspension concentrate, the water dispersible granule, the seed treatment dry powder, the dry seed dressing agent, the wet seed dressing agent, the seed treatment microcapsule suspension concentrate and other pesticide dosage forms.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] (1) The seed treatment composition overcomes the disadvantages of low germination rate, low emergence rate and inhibited root growth of wheat caused by high concentration of tebuconazole treatment;

[0020] (2) The seed treatment composition has obvious synergistic effect on the control of wheat sharp eyespot;

[0021] (3) The seed treatment composition can significantly promote the growth of wheat seedling roots;

[0022] (4) The seed treatment composition has obvious yield-increasing effect;

[0023] (5) In the seed treatment composition, the action mechanism of Paenibacillus polymyxa KN-03 is special, and the compound with tebuconazole increases the action site and reduces the risk of tebuconazole resistance of the pathogen of sharp eyespot;

[0024] (6) The seed treatment composition greatly reduces the use amount of chemical pesticides, is safe and environmentally friendly. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described below in combination with examples.

[0026] Indoor biological assay test example

[0027] Indoor biological assay test of the compound of Paenibacillus polymyxa KN-03 and tebuconazole on wheat sharp eyespot

[0028] Test object: Rhizoctonia cerealis.

[0029] The test method refers to the Guidelines for Pesticide Indoor Biological Determination Test NY / T 1156.2-2006 of the People's Republic of China Agricultural Industry Standard, and the mycelial growth rate method is adopted. The Bacillus polymyxa KN-03 mother drug and the tebuconazole technical material are respectively dissolved with distilled water and acetone, and then the single agent and each mixed agent are diluted into 5 different mass concentration gradients with 0.1% Tween-80 aqueous solution. The water is blank control, and each treatment is repeated 3 times. The cultured pathogenic bacteria are cut into a bacterial cake with a punch of 5mm in diameter from the edge of the colony under sterile conditions, the bacterial cake is inoculated on the culture medium plate with different concentrations of agents with an inoculation needle, and then placed in a 26℃ constant temperature box for 48h of culture; the colony diameter is checked, the percentage of inhibition of mycelial growth of each agent is calculated, the linear regression analysis between the probability value of inhibition rate and the logarithmic value of the series concentration is carried out, the EC 50 values of each agent are calculated, the co-toxicity coefficient (CTC) of the compound is calculated by Sun Yunpei method to evaluate the activity of the tested agent on the pathogen. The co-toxicity coefficient (CTC) of the compound is greater than or equal to 120, which shows a synergistic effect; the CTC is less than or equal to 80, which shows an antagonistic effect; and 80<CTC<120, which shows an additive effect.

[0030] Table 1 Indoor toxicity determination test results of Bacillus polymyxa KN-03 and tebuconazole compound on Rhizoctonia cerealis

[0031]

[0032] The indoor toxicity determination test results show that the Bacillus polymyxa KN-03 and tebuconazole compound in the mass ratio of 100:1-1:1 has good toxicity to Rhizoctonia cerealis, and all show a synergistic effect. The co-toxicity coefficient of the Bacillus polymyxa KN-03 and tebuconazole compound in the ratio of 30:1-10:1 is greater than 180, and the synergistic effect is the most significant.

[0033] Preparation formula example

[0034] Seed treatment dispersible powder

[0035] According to the requirements of the formula, the effective ingredient, wetting agent, dispersing agent, warning color, and filler are uniformly premixed, then crushed, and then uniformly mixed. The indicators are detected at any time, and the product is discharged and packaged after passing the test.

[0036] The following examples 1-3 are prepared according to the above preparation process.

[0037] Example 1: 10.1% Bacillus polymyxa KN-03·tebuconazole seed treatment dispersible powder

[0038]

[0039]

[0040] Example 2: 20.4% Paenibacillus polymyxa KN-03·tebuconazole seed treatment dispersible powder

[0041]

[0042] Example 3: 60% Paenibacillus polymyxa KN-03·tebuconazole seed treatment dispersible powder

[0043]

[0044] Suspension seed coating agent

[0045] According to the requirements of the formula, the effective ingredient, wetting agent, dispersant, film forming agent, thickening agent, antifreezing agent, defoaming agent, preservative, warning color and deionized water are mixed, pre-dispersed by high shear, then added into a sand mill, and grinded to a particle size of less than 5 μm, so that the suspension seed coating agent is prepared.

[0046] The following examples 4-6 are prepared according to the above preparation process.

[0047] Example 4: 4.2% Paenibacillus polymyxa KN-03·tebuconazole suspension seed coating agent

[0048]

[0049] Example 5: 6.2% Paenibacillus polymyxa KN-03·tebuconazole suspension seed coating agent

[0050]

[0051] Example 6: 5% Paenibacillus polymyxa KN-03·tebuconazole suspension seed coating agent

[0052]

[0053] Example 7: 1.1% Paenibacillus polymyxa KN-03·tebuconazole suspension seed coating agent

[0054]

[0055] Indoor germination rate and emergence rate example

[0056] In order to observe the effects of different compound seed treatment compositions on the germination rate and emergence rate of wheat seeds, the germination rate and emergence rate of wheat seeds were determined according to the test standard of GB / T 3543.4-1995, and the soil culture method was used.

[0057] Table 2 Effects of different seed treatment compositions of the present application on the germination rate and emergence rate of wheat

[0058]

[0059] As can be seen from Table 2, after the wheat seeds were treated with the composition of Bacillus polymyxa KN-03 and tebuconazole in different proportions of the present application, the germination rate and emergence rate of the wheat were significantly improved compared with the single-dose tebuconazole control and slightly higher than the water control. It can be seen that the combination of Bacillus polymyxa KN-03 and tebuconazole in a certain proportion can improve the germination rate and emergence rate of wheat seeds and overcome the effects of high-concentration tebuconazole on the germination rate and emergence rate of wheat.

[0060] Field efficacy examples

[0061] The field efficacy test method refers to GB / T 17980.108-2004. Field tests for preventing and treating wheat sharp eyespot by coating wheat seeds with the formulations of Examples 1-7 were carried out in Xizhangru Village, Bo'ai County, Henan Province from October 2018 to June 2019. The control agents were 100 billion CFU / g Bacillus polymyxa KN-03 suspension seed coating agent, 6% tebuconazole suspension seed coating agent, and 15% thiamethoxam·thiuram·diniconazole suspension seed coating agent. The test included 9 treatments, each repeated 4 times, for a total of 36 plots, with a plot area of 20 m 2 , arranged in a randomized block design. The seeds were coated on October 8, 2018, and dried in a cool place for standby, and sown on October 10. No other fungicides were applied between sowing and the investigation results.

[0062] Crop health survey: On November 27, the growth of wheat in each treatment area was recorded, with 5 points investigated in each treatment area, and 200 plants in each point, including root length, root number, and other indicators.

[0063] Efficacy survey: On March 3, the occurrence of sharp eyespot in each treatment area was investigated, with 5 points investigated in each treatment area, and 200 plants in each point, the incidence index of sharp eyespot in each plot was investigated, and the control effect was calculated.

[0064] Yield survey: On June 5, the yield of wheat in each treatment was investigated, with 5 points investigated in each treatment area, the effective ear number per mu (the effective ear number per square meter was counted in each point), the ear grain number (30 ears were taken in each point, and the ear grain number per ear was counted), and the thousand-grain weight were investigated, and the yield per mu of each treatment was calculated.

[0065] Table 3 Effects of different seed treatment compositions on the root system of wheat seedlings

[0066]

[0067]

[0068] As shown in Table 3, after the wheat seeds were treated with the different proportion compositions of Bacillus polymyxa KN-03 and tebuconazole according to the present application, the number of roots and the length of roots of the wheat were obviously increased compared with the single agent control and the water control. It can be seen that the combination of Bacillus polymyxa KN-03 and tebuconazole in a certain proportion not only overcomes the inhibitory effect of high concentration tebuconazole on the root system of the wheat seeds, but also shows a significant root growth promoting effect.

[0069] Table 4 Control effect of different seed treatment compositions on wheat sharp eyespot

[0070]

[0071]

[0072] As shown in Table 4, after the wheat seeds were treated with the different proportion compositions of Bacillus polymyxa KN-03 and tebuconazole according to the present application, the control effect on wheat sharp eyespot was all above 86%, which was obviously higher than that of the single agent control and the conventional pesticide control. It can be seen that the combination of Bacillus polymyxa KN-03 and tebuconazole in a certain proportion has a good synergistic effect on wheat sharp eyespot.

[0073] Table 5 Influence of different seed coating agent compositions on the yield of wheat

[0074]

[0075] As shown in Table 5, after the wheat seeds were treated with the different proportion compositions of Bacillus polymyxa KN-03 and tebuconazole according to the present application, the yield per mu of the wheat was obviously affected. The yield per mu of the wheat treated with the different proportion compositions according to the present application was obviously higher than that of the single agent control, the conventional pesticide control and the water control. The yield per mu of the wheat treated with the different proportion compositions according to the present application was obviously higher than that of the single agent control and the conventional pesticide control, and was as high as 39%. It can be seen that the combination of Bacillus polymyxa KN-03 and tebuconazole in a certain proportion can obviously increase the yield per mu of the wheat.

[0076] As shown in Table 2, Table 3, Table 4 and Table 5, the use of the seed treatment agent prepared by the combination of Bacillus polymyxa KN-03 and tebuconazole for controlling wheat sharp eyespot can reduce the amount of chemical pesticides used and reduce environmental pollution.

[0077] The above describes the present application by way of examples in connection with the embodiments. Obviously, the implementation of the present application is not limited to the above embodiments, and various improvements made by using the method concept and technical solution of the present application, or direct application of the concept and technical solution of the present application to other occasions without improvement, are all within the protection scope of the present application.

Claims

1. A seed treatment composition comprising Paenibacillus polymyxa KN-03, characterized in that, The seed treatment composition is a seed treatment composition for controlling wheat sharp eyespot, and the effective components of the seed treatment composition are Paenibacillus polymyxa KN-03 and tebuconazole, the mass ratio of which is 30:1-10:1, the spore content of the Paenibacillus polymyxa KN-03 is 30 billion viable spores per gram, and the preservation number of the Paenibacillus polymyxa KN-03 is CCTCC NO: M2012077.

2. The seed treatment composition according to claim 1, characterized in that, The Paenibacillus polymyxa KN-03 accounts for 1%-30% of the total mass percentage of the seed treatment composition, and the tebuconazole accounts for 0.1%-30% of the total mass percentage of the seed treatment composition.

3. The seed treatment composition according to claim 2, characterized in that, The dosage form of the seed treatment composition is flowable concentrate or seed treatment dispersible powder.

4. Use of the seed treatment composition according to any one of claims 1-3 for controlling wheat sharp eyespot.

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