Biocontrol inoculant for preventing and treating root rot of xanthoceras sorbifolia bunge and application of biocontrol inoculant

Abstract

The invention discloses a biocontrol inoculant for preventing and treating root rot of xanthoceras sorbifolia bunge and application, and belongs to the technical field of microbial prevention and treatment. Streptococcus thermophilus and common desulfurization vibrio are used as a biocontrol bacterium combination and are fermented respectively to prepare a mixed bacterium solution, and straw biomass charcoal is added as a carrier and an auxiliary material to prepare the biocontrol bacterium agent. Field planting experiments show that the biocontrol inoculant can obviously control the occurrence and progress of the root rot of the xanthoceras sorbifolia bunge and reduce the occurrence rate and disease index of the root rot of the xanthoceras sorbifolia bunge, and the prevention and treatment effect is superior to that of a common bactericide hymexazol; streptococcus thermophilus and common desulfurized vibrio have an obvious synergistic effect in the aspect of preventing and treating shiny-leaved yellowhorn root rot, and straw biomass charcoal also enhances the prevention and treatment effect of biocontrol bacteria. The invention provides a brand-new biocontrol microbial inoculum for preventing and treating the root rot of the xanthoceras sorbifolia bunge, and the biocontrol microbial inoculum is wide in source, simple to prepare and wide in application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of microbial control, and in particular to a biocontrol agent for controlling Xanthoceras sorbifolia root rot and an application thereof. Background Art

[0002] Xanthoceras sorbifoiium is a unique medicinal plant and precious woody oil plant in my country, with high comprehensive economic value for medicine, food and ornamental purposes. The fruit of Xanthoceras sorbifoiium has a sweet and unique taste. The plant likes light, is drought-resistant, barren-resistant, and salt-alkali-resistant, has good adaptability, is not strict with soil requirements, is not tolerant to waterlogging, and is afraid of wind. It has deep roots, a well-developed taproot, and strong sprouting ability. At the same time, because Xanthoceras sorbifoiium has obvious taproots, underdeveloped lateral roots, and a fleshy root system, it is easy to cause root damage. After damage, the root healing ability is poor, and it is easy to be infected by strains of Fusarium and Rhizoctonia in the soil, causing root rot, destroying the absorption of water and nutrients, and then causing the plant to die, which is root rot. Due to the characteristics of being susceptible to root rot, the survival rate of Xanthoceras sorbifoiium is low, and the scope of promotion and planting is limited by the survival rate. In some areas, the survival rate of transplantation is even less than 30%, which limits the large-scale development of this tree species.

[0003] At present, the main methods for preventing and controlling Xanthoceras sorbifolia root rot are to breed varieties with strong disease resistance, strengthen field management, maintain good soil drainage and ventilation, and use chemical agents such as metalaxyl mancozeb and oxazolidinone for prevention and control when the disease occurs. Overall, the prevention and control effects of the above methods are not ideal. Therefore, how to effectively prevent and control Xanthoceras sorbifolia root rot has become a difficult problem to be solved by technicians in this field. Biocontrol agents are a type of method that uses beneficial microorganisms to kill or reduce the number of pathogens to control the occurrence and development of plant diseases. Biocontrol bacteria have the characteristics of many types, high fertility, complex metabolic activities and many products, diverse modes of action on pathogens, short life cycles, and easy artificial cultivation. They play an important role in the application of biological control. However, how to specifically select biocontrol agents with better prevention and control effects on Xanthoceras sorbifolia root rot still requires further research. Summary of the invention

[0004] The purpose of the present invention is to provide a biocontrol agent for preventing and treating root rot of Xanthoceras sorbifolia and its application, so as to solve the problems existing in the above-mentioned prior art. The application of the biocontrol agent provided by the present invention can successfully prevent and treat root rot of Xanthoceras sorbifolia and improve the survival rate of Xanthoceras sorbifolia plants.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The invention provides a biocontrol bacteria composition for preventing and treating Xanthoceras sorbifolia root rot, wherein the biocontrol bacteria composition is composed of Streptococcus thermophilus and Desulfovibrio vulgaris.

[0007] Among them, the thermophilic Streptococcus has a preservation number of CGMCC NO.15822, a preservation date of May 28, 2018, and is preserved in the General Microbiology Center of the China Culture Collection Administration, and the preservation address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing; the common Desulfovibrio is deposited with a preservation number of CGMCC NO.15859, a preservation date of June 4, 2018, and is preserved in the General Microbiology Center of the China Culture Collection Administration, and the preservation address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0008] The invention provides application of the biocontrol bacteria composition in preparing a biocontrol bacteria agent for preventing and treating Xanthoceras sorbifolia root rot.

[0009] The present invention also provides a biocontrol agent for preventing and treating Xanthoceras sorbifolia root rot, wherein the active ingredient of the biocontrol agent includes the biocontrol agent composition; the biocontrol agent also includes a carrier and an auxiliary material, and the mass ratio of the biocontrol agent, the carrier and the auxiliary material is 2:4:1.

[0010] Preferably, the ratio of the effective viable bacteria count of the thermophilic streptococcus to the common desulfurization vibrio in the biocontrol agent is 1:1, and the effective viable bacteria counts of the thermophilic streptococcus and the common desulfurization vibrio are not less than 1.4×10 6 CFU / g.

[0011] Preferably, the carrier is straw biochar.

[0012] Preferably, the auxiliary materials are composed of 5 parts of maltodextrin, 2 parts of sodium lauryl sulfate, 0.3 parts of sodium dihydrogen phosphate, 0.7 parts of disodium hydrogen phosphate and 2 parts of sodium alginate in parts by weight.

[0013] The present invention also provides a method for preparing the biocontrol agent, comprising the following steps:

[0014] The thermophilic Streptococcus and the common Desulfovibrio were activated and cultured to the logarithmic growth phase, and the cells were collected by centrifugation, washed, and diluted to 2×10 7 CFU / mL, to obtain a bacterial solution; the bacterial solution of the thermophilic Streptococcus and the bacterial solution of the common Desulfovibrio are evenly mixed in a volume ratio of 1:1 to obtain a mixed bacterial solution;

[0015] The wheat straw is subjected to high temperature oxygen-limited carbonization treatment to obtain straw biomass charcoal;

[0016] According to weight parts, 5 parts of maltodextrin, 2 parts of sodium lauryl sulfate, 0.3 parts of sodium dihydrogen phosphate, 0.7 parts of disodium hydrogen phosphate and 2 parts of sodium alginate are uniformly mixed to obtain an auxiliary material;

[0017] The straw biomass charcoal is added to the mixed bacterial solution at a mass ratio of 2:1, and then the biocontrol agent auxiliary material is added to the mixed bacterial solution at a mass ratio of 1:2, and the mixture is mixed evenly to obtain the biocontrol agent.

[0018] Preferably, the high-temperature oxygen-limited carbonization treatment is carried out at a temperature of 600° C., an oxygen content of 8%, and a treatment time of 5 hours.

[0019] The present invention also provides application of the biocontrol fungus composition or the biocontrol fungus agent in preventing and controlling Xanthoceras sorbifolia root rot.

[0020] The present invention also provides a method for preventing and controlling Xanthoceras sorbifolia root rot, comprising the steps of applying the biocontrol fungus composition or the biocontrol fungus agent to the growth environment of Xanthoceras sorbifolia before and after planting Xanthoceras sorbifolia.

[0021] The present invention discloses the following technical effects:

[0022] The biocontrol agent prepared by the present invention can significantly control the occurrence and progression of Xanthoceras sorbifolia root rot, reduce the incidence and disease index of Xanthoceras sorbifolia root rot, and improve the survival rate of Xanthoceras sorbifolia, which is significantly better than the commonly used fungicide oxazolidinone. The present invention prepares a mixed bacterial liquid by combining thermophilic Streptococcus and common Desulfovibrio to prevent and treat Xanthoceras sorbifolia root rot, which has an excellent effect on the prevention and treatment of Xanthoceras sorbifolia root rot. Compared with the agent prepared by a single bacterium, the biocontrol agent combination has an obvious synergistic effect. The biocontrol agent prepared by the present invention includes straw biomass charcoal as a carrier, which enhances the prevention and treatment effect of the biocontrol agent combination. The present invention provides a brand-new biocontrol agent for preventing and treating Xanthoceras sorbifolia root rot, and it has a wide source, is simple to prepare, and has a wide range of application prospects. DETAILED DESCRIPTION

[0023] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0024] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0025] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0026] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0027] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0028] In the present invention, Streptococcus thermophilus with a preservation number of CGMCC NO.15822 and Desulfovibrio vulgaris with a preservation number of CGMCC NO.15859 were purchased from the General Microbiological Center of China National Committee for the Preservation of Microorganisms. The public can purchase the above strains from the above preservation institutions.

[0029] The composition and preparation method of the culture medium for culturing thermophilic Streptococcus: 1.0 g of glucose, 1.0 g of yeast extract, 1.0 g of soy peptone, 12 mL of tomato juice, 0.4 g of xylo-oligosaccharide, 0.4 g of isomaltooligosaccharide, 0.4 g of soy oligosaccharide, 92 mL of distilled water, 0.2 g of KH2PO4 and 0.05 mL of Tween 80, sterilized, adjusted to pH 7.0-7.2.

[0030] The composition and preparation method of the culture medium for culturing common Desulfovibrio spp. are as follows: KH2PO4 0.5 g, NH4Cl 1.0 g, CaCl2·2H2O 0.1 g, Na2SO4 1.0 g, MgSO4·7H2O 2.0 g, 70% sodium lactate 25 mL, yeast extract 5.0 g, distilled water 1000 mL, FeSO4·7H2O 15 g, ascorbic acid 0.1 g, sodium thioglycolate 0.1 g, cysteine ​​0.5 g are added after sterilization, and the pH value is adjusted to 8.0-8.5.

[0031] Example 1

[0032] The preparation of 350 g of the biocontrol agent of the present invention is taken as an example.

[0033] The Streptococcus thermophilus with the preservation number of CGMCC NO.15822 and the Desulfovibrio vulgaris with the preservation number of CGMCC NO.15859 were activated and cultured to the logarithmic growth phase, and the cells were collected by centrifugation, washed, and diluted to 2×10 7 CFU / mL; take 50mL of bacterial solution respectively, mix well, and get 100mL of mixed bacterial solution;

[0034] The wheat straw was treated at a temperature of 600°C and an oxygen content of 8% for 5 hours to obtain straw biochar;

[0035] Mix 25 g of maltodextrin, 10 g of sodium lauryl sulfate, 1.5 g of sodium dihydrogen phosphate, 3.5 g of disodium hydrogen phosphate and 10 g of sodium alginate to obtain an auxiliary material;

[0036] Add 200 g of straw biochar to 100 mL of mixed bacterial solution and mix well. Then add the above auxiliary materials (50 g) to the mixed bacterial solution and mix well to obtain the biocontrol agent.

[0037] Comparative Example 1

[0038] The difference from Example 1 is that 100 mL of Streptococcus thermophilus culture solution with a preservation number of CGMCC NO.15822 is used to replace the above mixed culture solution.

[0039] Comparative Example 2

[0040] The difference from Example 1 is that 100 mL of bacterial solution of common Desulfovibrio sulphuridis with a preservation number of CGMCC NO.15859 is used to replace the above mixed bacterial solution.

[0041] Comparative Example 3

[0042] The difference from Example 1 is that the straw biomass charcoal is replaced by 200 g of crushed and dried wheat straw.

[0043] Comparative Example 4

[0044] The difference from Example 1 is that the culture medium for culturing thermophilic Streptococcus and the culture medium for culturing common Desulfovibrio are mixed in equal volumes to replace the mixed bacterial solution.

[0045] Comparative Example 5

[0046] A 400-fold diluted solution of 98% carbendazim was used as a pesticide for preventing and controlling the root rot of Xanthoceras sorbifolia.

[0047] Effect Example 1

[0048] 1. Xanthoceras sorbifolia seedling cultivation

[0049] Wrap the seeds of Xanthoceras sorbifolia with sterile wet gauze and put them in a fresh-keeping box. The fresh-keeping box is placed in a light incubator at 25±1℃, set to 90% relative humidity and 12h light and dark alternation to germinate. After 10 days, remove the seeds that have not germinated or have weak sprouts, and the remaining part is used for the cultivation of Xanthoceras sorbifolia seedlings. Sow the seeds selected after germination treatment in the seedling tray, 2 seeds per hole, and the hole depth is 4cm. After sowing, place the seedling tray in a controllable greenhouse at 28±2℃ and 12h light and dark alternation for 2 months to obtain healthy and disease-free Xanthoceras sorbifolia seedlings for field planting.

[0050] 2. Field planting

[0051] Xanthoceras sorbifolia was planted in Yinchuan City, Ningxia Hui Autonomous Region, with a cultivation pattern of 3×4m plant spacing, 30 mu of forest land, and sandy loam with normal fertility. The experiment started in March, and the forest land was divided into 5 large areas, each of which was further divided into 6 small areas. The 6 small areas in each large area were treated with the bacterial agent or the pharmaceutical agent prepared according to any one of Example 1 or Comparative Examples 1-5.

[0052] Before planting, a planting pit with a diameter of 30 cm and a depth of 40 cm was dug, with a pit spacing of 2.5 meters. The biocontrol agent or agent prepared in Example 1 or any one of Comparative Examples 1-5 was poured into the planting pit in an amount of 7 kg per pit.

[0053] During the budding period of Xanthoceras sorbifolia in spring and summer, a circular ditch with a depth of 30 cm and a width of 35 cm was opened 50 cm below the crown and 50 cm from the main trunk. The biocontrol agent or agent prepared in Example 1 or any one of Comparative Examples 1-5 was poured into the circular ditch at a dosage of 35 kg per plant.

[0054] All fields were managed using the same practices, including appropriate water and fertilizer management, pruning and cleaning, and conventional methods for integrated disease control except for root rot.

[0055] 3. Statistics

[0056] In late September, after the fruits were picked, the incidence rate was counted and the diseased plant rate was recorded on a plant basis. According to the disease grading standards, the number of diseased plants with root rot at each level was counted and the disease index was calculated. The specific grading standards are shown in Table 1. The survival rate of Xanthoceras sorbifolia in each treatment was also counted.

[0057] Table 1 Disease classification standards for Xanthoceras sorbifolia root rot

[0058]

[0059] Calculation formula:

[0060] Disease index = Σ(number of diseased plants at each level × relative level value) / (total number of plants surveyed × highest level representative value) × 100%;

[0061] Incidence rate = number of diseased plants / total number of plants investigated × 100%;

[0062] Survival rate = number of surviving plants / total number of plants surveyed × 100%

[0063] 4. Experimental Results

[0064] The results are shown in Table 2. It can be seen that the biocontrol agent prepared in Example 1 of the present invention can significantly control the occurrence and progression of Xanthoceras sorbifolia root rot, reduce the incidence and disease index of Xanthoceras sorbifolia root rot, and improve the survival rate of planted Xanthoceras sorbifolia, which is significantly better than the commonly used fungicide oxazolidinone.

[0065] Combined with Comparative Examples 2-4, it can be found that the biocontrol bacteria combination selected by the present invention, the mixed bacterial solution of thermophilic Streptococcus and common Desulfovibrio has excellent effect on the prevention and treatment of Xanthoceras sorbifolia root rot, and the control effect of using a single bacterial solution is significantly worse than that of the mixed bacterial solution, indicating that the biocontrol bacteria combination has a synergistic effect. The biocontrol bacteria agent prepared by the present invention includes straw biomass charcoal as a carrier, which enhances the control effect of the biocontrol bacteria combination.

[0066] Table 2 Statistics of the incidence, disease index and survival rate of Xanthoceras sorbifolia root rot

[0067]

[0068] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A biocontrol bacterial composition for preventing and treating Xanthoceras sorbifolia root rot, characterized in that: The biocontrol bacteria composition is composed of Streptococcus thermophilus and Desulfovibrio vulgaris; The accession number of the thermophilic Streptococcus is CGMCC NO.15822; the accession number of the common Desulfovibrio is CGMCC NO.15859.

2. Use of the biocontrol fungus composition according to claim 1 in the preparation of a biocontrol agent for preventing and treating Xanthoceras sorbifolia root rot.

3. A biocontrol agent for preventing and treating Xanthoceras sorbifolia root rot, characterized in that: The active ingredient of the biocontrol agent includes the biocontrol composition according to claim 1; The biocontrol agent further comprises a carrier and an auxiliary material, and the mass ratio of the biocontrol agent, the carrier and the auxiliary material is 2:4:

1.

4. The biocontrol agent according to claim 3, characterized in that The ratio of the effective viable bacteria count of the thermophilic streptococcus to the common desulfurization vibrio in the biocontrol agent is 1:1; the effective viable bacteria counts of the thermophilic streptococcus and the common desulfurization vibrio are both not less than 1.4×10 6 CFU / g.

5. The biocontrol agent according to claim 3, characterized in that The carrier is straw biomass charcoal.

6. The biocontrol agent according to claim 3, characterized in that The auxiliary materials are composed of 5 parts of maltodextrin, 2 parts of sodium lauryl sulfate, 0.3 parts of sodium dihydrogen phosphate, 0.7 parts of disodium hydrogen phosphate and 2 parts of sodium alginate in parts by weight.

7. The method for preparing the biocontrol agent according to any one of claims 3 to 6, characterized in that: The following steps are involved: The thermophilic Streptococcus and the common Desulfovibrio were activated and cultured to the logarithmic growth phase, and the cells were collected by centrifugation, washed, and diluted to 2×10 7 CFU / mL, to obtain a bacterial solution; the bacterial solution of the thermophilic Streptococcus and the bacterial solution of the common Desulfovibrio are evenly mixed in a volume ratio of 1:1 to obtain a mixed bacterial solution; The wheat straw is subjected to high temperature oxygen-limited carbonization treatment to obtain straw biomass charcoal; According to weight parts, 5 parts of maltodextrin, 2 parts of sodium lauryl sulfate, 0.3 parts of sodium dihydrogen phosphate, 0.7 parts of disodium hydrogen phosphate and 2 parts of sodium alginate are uniformly mixed to obtain an auxiliary material; The straw biomass charcoal is added to the mixed bacterial solution at a mass ratio of 2:1, and then the auxiliary materials are added to the mixed bacterial solution at a mass ratio of 1:2, and the mixture is mixed evenly to obtain the biocontrol agent.

8. The preparation method according to claim 7, characterized in that: The high temperature oxygen-limited carbonization treatment is carried out at a temperature of 600° C., an oxygen content of 8%, and a treatment time of 5 hours.

9. Use of the biocontrol fungus composition according to claim 1 or the biocontrol fungus agent according to any one of claims 3 to 6 in preventing and controlling Xanthoceras sorbifolia root rot.

10. A method for preventing and treating Xanthoceras sorbifolia root rot, characterized in that: The method comprises the steps of applying the biocontrol fungus composition of claim 1 or the biocontrol fungus agent of any one of claims 3 to 6 to the growth environment of Xanthoceras sorbifolia before and after planting.

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