Actinactinomyces reveromyces 3-10 and application thereof in prevention and treatment of plant diseases

Abstract

The invention belongs to the technical field of microbial pesticides, and particularly relates to acidophilic actinomycetes Actinacdiphila reveromyces 3-10 and application of the acidophilic actinomycetes 3-10 in prevention and treatment of plant diseases. The technical problem to be solved by the invention is to provide a new choice for biological control of plant diseases. According to the technical scheme, the acidophilic actinomycete is acidophilic actinomycete 3-10, and the preservation number of the acidophilic actinomycete 3-10 is CCTCC (China Center for Type Culture Collection) NO: M 20242102. The invention also provides an application of the acidophilic actinomycetes Actinacdiphila reveromyces 3-10 in the prevention and treatment of plant diseases, and the acidophilic actinomycetes Actinacdiphila reveromyces 3-10 can be applied to the prevention and treatment of plant diseases. According to the acidophilic actinomycete, the fact that the fermentation liquor of the acidophilic actinomycete 3-10 can be used for effectively preventing and treating plant epidemic diseases, damping-off and fusarium wilt is found for the first time.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial pesticides, and particularly relates to acidophilic actinomycetes Actinacidiphilareveromycinica 3-10 and application thereof in preventing and controlling plant diseases. Background Art

[0002] Plant diseases seriously affect plant growth, leading to a decline in yield and quality, and are one of the main threats to agricultural production (Wang Xinge et al., 2006). Plant fungal diseases such as wilt caused by Fusarium oxysporum and damping-off caused by Rhizoctonia solani account for more than 70% of all plant diseases and are the most important biological factors in the occurrence of plant diseases (Huang Ruihuan et al., 2020). Plant oomycete diseases are important pathogens that cause vegetable diseases. Among them, the diseases caused by Phytophthora have a short incubation period, a high number of re-infections, and a rapid onset, which can easily cause epidemics and lead to serious losses in vegetable production.

[0003] In agricultural production, chemical pesticides are still widely used to prevent and control plant diseases, but the long-term and large-scale use of chemical pesticides will lead to increased resistance of pathogens, excessive pesticide residues, environmental pollution and other problems. Agricultural control methods such as crop rotation, soil sun exposure, drip irrigation, high ridges and mulching can only reduce the occurrence of diseases. Once the disease occurs and spreads rapidly, it cannot be quickly controlled. The use of microorganisms for biological control can not only have a good control effect on plant diseases, but also reduce environmental pollution and is not easy to produce drug resistance. It has become a research hotspot for plant disease control at home and abroad.

[0004] Actinomycetes are a special group of prokaryotes that can form branched hyphae and HYPERLINK“https: / / baike.baidu.com / item / %E5%88%86%E7%94%9F%E5%AD%A2%E5%AD%90 / 3447344?fromModule=lemma_inlink”; “https: / / baike.baidu.com / item / %E6%94%BE%E7%BA%BF%E8%8F%8C / _blank”; conidia. They grow in hyphae and mainly reproduce by spores. Actinomycetes are widely distributed in the soil and are widely used in the biological control of plant diseases because they can produce a variety of rich secondary metabolites (Bérdy, 2005). For example, Li Qingmeng et al. isolated and screened the antagonistic actinomycete Streptomyces naraensis from Davidia involucrata in Lushan, Jiangxi Province, and its relative inhibition rate against plant pathogenic fungi such as Magnaporthe oryzae was as high as over 90% (Li Qingmeng et al., 2013). Sun Yanzhong et al. found that Wuyi mycin produced by Streptomyces ahygroscopicus var. wuyiensis had significant preventive effect on vegetable fungal diseases such as cucumber powdery mildew and gray mold (Sun Yanzhong et al., 2003). Mao Liangju et al. found that Mycostop, an actinomycete active agent produced by Streptomyces griseovidis, can be used to prevent and control some soil-borne plant diseases caused by Pythium spp. and Fusarium spp. (Mao Liangju et al., 2016). Acidophilic actinomycetes (Actinacidiphila reveromycinica) are a type of actinomycetes that can grow in acidic environments. They have unique physiological characteristics and ecological functions, but there are currently no reports on the use of acidophilic actinomycetes in preventing and controlling plant diseases. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a new option for biological control of plant diseases.

[0006] The technical solution of the invention is acidophilic actinomycetes Actinacidiphila reveromycinica 3-10, and its preservation number is CCTCC NO:M 20242102.

[0007] The invention also provides application of acidophilic actinomycetes Actinacidiphila reveromycinica 3-10 in preventing and controlling plant diseases.

[0008] Specifically, the plant disease is blight, damping-off and / or wilt.

[0009] Furthermore, the host of the disease is a plant of the Solanaceae family; Furthermore, the solanaceous plants include but are not limited to peppers, eggplants and tomatoes; Furthermore, the host of the damping-off disease is a plant of the family Cruciferae; Furthermore, the cruciferous plants include but are not limited to rapeseed, Chinese cabbage, cabbage and mustard, etc.; Further, the host of the wilt disease is a plant of the Cucurbitaceae family; Furthermore, the cucurbitaceae plants include but are not limited to cucumber, loofah and bitter gourd.

[0010] Wherein, the pathogen of the disease is Phytophthora capsici.

[0011] Particularly, the pathogen of damping-off disease is Rhizoctonia solani.

[0012] Specifically, the pathogen of the wilt disease is Fusarium oxysporum.

[0013] Specifically, the plant diseases are caused by Rhizoctonia solani, Sclerotiniasclerotiorum, Sclerotium hydrophilum, Botrytis cinerea, Monilinia fructicola, Alternaria alternata, Aspergillus flavus, Verticillium dahliae, Magnaporthe oryzae, Verticillium longisporum, Colletotrichum higginsianum, Colletotrichum fructicola, Leptosphaeria biglobosa, Fusarium graminearum and / or Ustilaginoidea virens.

[0014] The present invention also provides a preparation for preventing and controlling plant diseases, the main component of which is acidophilic actinomycetes Actinacidiphila reveromycinica 3-10, spore liquid of acidophilic actinomycetes Actinacidiphila reveromycinica 3-10, secretion of acidophilic actinomycetes Actinacidiphila reveromycinica 3-10 or fermentation liquid of acidophilic actinomycetes Actinacidiphila reveromycinica 3-10.

[0015] The invention also provides a method for preventing and controlling plant diseases, comprising the following steps: irrigating the roots of plants with spore liquid, fermentation liquid or secretion of acidophilic actinomycete Actinacidiphila reveromycinica 3-10.

[0016] Further, the concentration of the spore solution of the acidophilic actinomycete Actinacidiphila reveromycinica 3-10 is 10 5 spores / mL.

[0017] Specifically, the plant is pepper.

[0018] Wherein, the pathogen of the disease is Phytophthora capsici.

[0019] The invention also provides a method for preventing and controlling plant damping-off disease, comprising the following steps: irrigating the roots of plants with spore liquid, fermentation liquid or secretion of acidophilic actinomycete Actinacidiphila reveromycinica 3-10.

[0020] Specifically, the plant is rapeseed.

[0021] The invention also provides a method for preventing and controlling plant wilt disease, comprising the following steps: irrigating the roots of plants with spore liquid, fermentation liquid or secretion of acidophilic actinomycete Actinacidiphila reveromycinica 3-10.

[0022] Further, the concentration of the spore solution of the acidophilic actinomycete Actinacidiphila reveromycinica 3-10 is 10 7 spores / mL.

[0023] Specifically, the plant is cucumber.

[0024] The invention has the beneficial effects that the invention firstly finds that the fermentation liquid of acidophilic actinomycetes Actinacidiphilareveromycinica 3-10 can effectively inhibit plant disease pathogens, including rice sheath blight fungus Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotiumhydrophilum, Phytophthora capsici, Botrytis cinerea, Monilinia fructicola, Rhizoctonia solani, Alternariaalternata, Fusarium oxysporum, Aspergillus flavus, Verticillium dahliae, Magnaporthe oryzae, Verticillium longisporum, Colletotrichum higginsianum, Colletotrichum fructicola, Leptosphaeria biglobosa, Fusarium graminearum, and Ustilaginoidea virens. In addition, the present invention first discovered that the fermentation liquid of acidophilic actinomycetes Actinacidiphila reveromycinica 3-10 can effectively prevent and treat plant blight, damping-off and wilt. Among them, the therapeutic effect and preventive effect of pepper plants treated with 3-10 fermentation liquid on pepper blight were 58% and 86% respectively; the therapeutic effect and preventive effect of rapeseed plants treated with 3-10 fermentation liquid on rapeseed damping-off were 68.61% and 79.07% respectively; the preventive effect of cucumber plants treated with 3-10 fermentation liquid on cucumber wilt was 100%.

[0025] The acidophilic actinomycetes used in the present invention are specifically the Actinacidiphilareveromycinica 3-10 strain, which was deposited in the China Center for Type Culture Collection (address: Wuhan University, Wuhan, China, Postal Code 430072) on September 27, 2024, with the collection number: CCTCC NO:M 20242102. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1The figure shows the morphological characteristics and phylogenetic tree of Actinacidiphila reveromycinica 3-10. A: Morphology of culture on ISP2 medium for 14 days (front); B: Morphology of culture on ISP2 medium for 14 days (back); C: Morphology of single colony on ISP2 medium for 14 days; D: Spore chain observed under optical microscope; E: Phylogenetic tree of 3-10 based on 16S rDNA sequence.

[0027] Figure 2 The fermentation liquid of acidophilic actinomycete Actinacidiphila reveromycinica 3-10 is used to inhibit plant disease pathogens such as Sclerotinia sclerotiorum, Sclerotium hydrophilum, Phytophthora capsici, Botrytis cinerea, Monilinia fructicola, Rhizoctonia solani, Alternaria alternata, Fusarium oxysporum, Aspergillus flavus, Verticillium dahliae, Magnaporthe oryzae, Verticillium longisporum, Colletotrichum higginsianum, Colletotrichum fructicola, Leptosphaeria biglobosa, and Fusarium graminearum. graminearum, and mycelial growth inhibition results of Ustilaginoidea virens (3-7 dpi). Compared with the CK control, the addition of 3-10 fermentation broth at a ratio of 1% and 5% to PDA plates had a better inhibitory effect on the mycelial growth of various plant pathogens.

[0028] Figure 3The in vivo efficacy of Actinacidiphila reveromycinica 3-10 against pepper blight was determined (5 dpi). Compared with peppers inoculated with only Phytophthora capsici, root irrigation with fermented liquid of Actinacidiphila reveromycinica 3-10 before and after inoculation with Phytophthora capsici significantly reduced leaf shedding and seedling death caused by Phytophthora capsici. The therapeutic and preventive effects of Actinacidiphila reveromycinica 3-10 on pepper blight were 58% and 86%, respectively.

[0029] Figure 4 The in vivo efficacy of Actinacidiphila reveromycinica 3-10 against Rhizoctonia solani was determined (10 dpi). Compared with the rapeseed inoculated with Rhizoctonia solani alone, root irrigation with fermented liquid of Actinacidiphila reveromycinica 3-10 before and after inoculation with Rhizoctonia solani significantly reduced the shrinkage and wilting of the base of the rapeseed stem and the wilting of the whole plant caused by Rhizoctonia solani. The therapeutic and preventive effects of Actinacidiphila reveromycinica 3-10 against Rhizoctonia solani were 68.61% and 79.07%, respectively.

[0030] Figure 5 The in vivo efficacy of Actinacidiphila reveromycinica 3-10 against cucumber wilt was determined (5 dpi). Compared with cucumbers inoculated with Fusarium oxysporum alone, root irrigation with fermented liquid of Actinacidiphila reveromycinica 3-10 before inoculation with Fusarium oxysporum significantly reduced the phenomenon of wilt and seedling death caused by Fusarium oxysporum, and the preventive effect of Actinacidiphila reveromycinica 3-10 against cucumber wilt reached 100%. DETAILED DESCRIPTION

[0031] There is no report on the biocontrol effect of acidophilic actinomycetes Actinacidiphila reveromycinica 3-10 on plant diseases. The applicant conducted relevant experiments on the function of acidophilic actinomycetes Actinacidiphila reveromycinica 3-10 in preventing and controlling plant diseases, and the results showed that the new strain has a significant control effect on plant diseases.

[0032] In order to better explain the present invention, the main contents of the present invention are further explained below in conjunction with specific examples, but the contents of the present invention are not limited to the following examples. The technical solutions involved in the embodiments of the present invention, if not otherwise specified, are all conventional solutions in the art; the reagents or materials, if not otherwise specified, are all derived from commercial channels.

[0033] Example 1 Isolation, Identification and Biological Characteristic Analysis of Actinacidiphila reveromycinica 3-10 1.1 Isolation of strain 3-10: Rice samples were collected from the rice fields of Huazhong Agricultural University. The roots of the rice were rinsed with tap water to remove the surface soil. 1 g of each of the roots, leaf sheaths, leaves, and panicles of rice were taken and rinsed three times with sterile water. They were placed in a sterilized mortar and 10 mL of sterile water containing 0.1% Tween 20 and an appropriate amount of quartz sand were added. After grinding thoroughly, 1 mL of grinding liquid was taken and placed in a water bath at 80°C for 10 min. The grinding liquid was diluted to 10 with sterile water. -6 times, take 100 μL of the dilution and evenly spread it on the PDA plate. Culture at 28℃ for 3 days under light, pick a single bacterial colony and transfer it to the PDA slant, culture at 28℃ for 3 days, and store it at 4℃ for later use. Pick a single colony of each strain and culture it against Rhizoctonia solani, and after primary screening and rescreening, a bacterial strain with significant inhibitory effect on Rhizoctonia solani was obtained, named 3-10.

[0034] 1.2 Morphological characteristics of strain 3-10: 3-10 After 14 days of cultivation on ISP2 medium, abundant aerial hyphae were produced ( Figure 1 A, B), the colony color is gray to white, a single colony is dome-shaped, the edge of the colony is serrated, no soluble pigment is produced, and the center of the colony is wrinkled ( Figure 1 C), under an optical microscope, aerial hyphae branches mature and differentiate into linear spore chains, which break to form spores, which are short rods ( Figure 1 D).

[0035] 1.3 Identification of the taxonomic properties of strain 3-10: The strain 3-10 was inoculated into ISP-2 culture medium and cultured at 150 r / min for 3 days. The filtrate was removed by centrifugation, and the mycelium was washed twice with physiological saline. The genomic DNA of 3-10 was extracted by CTAB method (Liu Binghui et al., 2008). Colony PCR was performed using 16S rDNA universal amplification primers (SEQ ID No.1, 27 F: 5′-AGAGTTTGATCCTGGCTCAG-3′; SEQ ID No.2, 1492 R: 5′-TACGGCTACCTTGTTACGAC TT-3′). The PCR reaction conditions were: pre-denaturation at 95℃ for 5 min; denaturation at 95℃ for 1 min, annealing at 56℃ for 1.5 min, extension at 72℃ for 30 s, 35 cycles, and extension at 72℃ for 10 min. The PCR product was detected by 1% agarose gel electrophoresis, and the PCR product was recovered and purified using the DNA recovery kit of Axygen Company. The sequencing results were submitted to the NCBI nucleic acid database for Blast comparison. The 16S rDNA sequences of related actinomycetes (Komaki H., 2024) and an outgroup strain Catenulispora acidiphila DSM44928 were selected, and the sequences were multiple aligned using MEGA 7.0 software. The phylogenetic tree was constructed using the neighbor-joining method to finally determine the taxonomic status of the strain.

[0036] The results of constructing the phylogenetic tree showed that strain 3-10 and Actinacidiphilareveromycinica SN-593 were clustered in the same branch ( Figure 1 E), combined with the morphological characteristics of 3-10, strain 3-10 was finally identified as Actinacidiphila reveromycinica.

[0037] SEQ ID No.3 Actinacidiphila reveromycinica 3-10 16S rDNA sequence:

[0038] Strain 3-10 was deposited in the China Center for Type Culture Collection (address: Wuhan University, Wuhan, China) on September 27, 2024, with the collection number: CCTCC M 20242102.

[0039] Example 2 Determination of the Antagonistic Activity of Fermentation Broth of Actinacidiphila reveromycinica 3-10 against Plant Pathogens The 3-10 strain stored in the laboratory was taken out from the -80°C refrigerator, and the 3-10 strain was streaked on the ISP-2 solid medium for activation. After culturing at 28°C for 7 days, the 3-10 bacteria were scraped with sterile water, filtered and diluted with three layers of lens paper to obtain the 3-10 bacterial solution (10 8 The 3-10 bacterial culture was inoculated into PDB culture medium at a ratio of 1% (v / v) and fermented in a shaker at 28°C and 180 rpm for 7 days to obtain the 3-10 strain shaking culture fermentation liquid.

[0040] Preparation of PDB liquid culture medium (1 L): 200 g peeled potatoes, 20 g glucose, 1000 mL distilled water, sterilize at 121°C for 30 min, and store at 4°C.

[0041] Preparation of ISP-2 liquid culture medium (1 L): 4 g yeast extract, 10 g malt extract, 4 g glucose, 1000 mL distilled water, pH 6.5-7.0, high temperature sterilization at 121°C for 30 min, and storage at 4°C.

[0042] The shake-cultured 3-10 strain PDB fermentation broth was centrifuged at high speed (12,000 rpm, 15 min) to remove the bacteria. The sterile fermentation broth was filtered twice with a 0.22 μm bacterial filter and then added to the PDA culture medium at a ratio of 1% and 5% to prepare the poisonous plates. The control was the PDA plate without the addition of the 3-10 strain fermentation broth. The activated pathogens (Sclerotinia sclerotiorum, Sclerotiumhydrophilum, Phytophthora capsici, Botrytis cinerea, Monilinia fructicola, Rhizoctonia solani, Alternariaalternata, Fusarium oxysporum, Aspergillus flavus, Verticillium dahliae, Magnaporthe oryzae, Verticilliumlongisporum, Colletotrichum higginsianum, Colletotrichumfructicola, Leptosphaeria oleracea) on PDA medium were punched with a 5 mm diameter borer. biglobosa, Fusarium graminearum, and Ustilaginoidea virens were punched for later use. After inoculating mycelium blocks of various plant pathogens on different plates, the plates were placed at the optimal growth temperature of various pathogens (20-28°C) for 3-7 days for culturing, and the diameter of the lesions was counted, and the mycelium inhibition rate of 3-10 against various pathogens was calculated. Mycelium growth inhibition rate (%) = 100% × (control lesion diameter - treatment lesion diameter) / control lesion diameter.

[0043] The results are as follows Figure 2As shown in Table 1, after 3-7 days of cultivation, the 3-10 fermentation broth could significantly inhibit the mycelial growth of plant pathogens compared with the CK control. The plate containing 5% 3-10 fermentation broth had a high inhibition rate of 70%-100% on the mycelial growth of Sclerotiniasclerotiorum, Botrytis cinerea, Fusarium oxysporum, Aspergillus flavus, Leptosphaeria biglobosa and Colletotrichum higginsianum. It also had a high inhibition rate of 70%-100% on the mycelial growth of Phytophthora capsici, Monilinia fructicola, Rhizoctonia solani, Alternaria alternata, Verticillium dahliae, Magnaporthe oryzae and Colletotrichum higginsianum. fructicola mycelium growth inhibition rate was moderate, ranging from 40% to 70%; the mycelium growth inhibition rate for Sclerotium hydrophilum, Verticillium longisporum, Fusarium graminearum, and Ustilaginoidea virens was relatively low, ranging from 25% to 40%.

[0044] Table 1. Results of the inhibition rate of 3-10 fermentation liquid on the mycelial growth of plant pathogens (3-7 dpi) Example 3 Determination of the in vivo efficacy of the fermentation broth of acidophilic actinomycetes Actinacidiphila reveromycinica 3-10 against pepper blight One-month-old pepper seedlings were transplanted into plastic pots filled with culture soil (nutrient soil: matrix soil: vermiculite = 8:4:1). After culturing in the dark for 7 days, pepper seedlings of uniform growth size were selected for the experiment. Preparation of pepper spore suspension: Take pepper spores that have grown all over the plate on the PDA plate, add 15 mL of 10% V8 culture solution, and culture in the dark at 25 °C for 3 days. Discard the culture solution, add 10 mL of sterile water to cover the mycelium, continue to culture, and change the sterile water every 12 hours for a total of 3 times. Place in a 4 °C refrigerator for 15 min and 25 °C for 15 min. Alternate hot and cold to stimulate the zoosporangium to release zoospores. Dilute the spore suspension to 10 with sterile water.5 spores / mL for later use.

[0045] The experiment was divided into 5 treatments, all of which involved stabbing the base of the pepper stem: 1. 3-10 treatment: peppers were only irrigated with 3 mL of 3-10 fermentation liquid; 2. Sterile water (CK) treatment: peppers were only irrigated with 3 mL of sterile water; 3. Pepper Phytophthora treatment: peppers were only irrigated with 3 mL of pepper Phytophthora spore suspension; 4. Preventive treatment: peppers were irrigated with 3 mL of 3-10 fermentation liquid and then irrigated with 3 mL of pepper Phytophthora spore suspension 24 hours later; 5. Curative treatment: peppers were irrigated with 3 mL of pepper Phytophthora spore suspension 24 hours later and then irrigated with 3 mL of 3-10 fermentation liquid.

[0046] Each group was set up with 10 replicates. The disease situation was investigated and the disease index was calculated 5 days after inoculation, and the seedling mortality rate was investigated 10 days after inoculation. The pepper blight disease index grade was graded according to the grading standard of Zhang et al. (2010): Grade 0: no obvious symptoms; Level 1: A small number of brown spots appear at the base of the seedling stems; Level 2: The lesions on the stem extend to the heart leaves or surround the entire stem, and the plant slightly falls over; Level 3: The plant fell over, and most leaves were obviously wilted or turned yellow; Level 4: The plant fell over and the whole plant wilted; Level 5: The whole plant is dead.

[0047] Disease index = ∑ number of diseased plants at each level × ∑ representative value of each level / (total number of plants investigated × representative value of the highest level) × 100; Prevention and treatment effect (%) = (disease index of control group - disease index of treatment group / disease index of control group) × 100%.

[0048] The results are as follows Figure 3 As shown in Table 2, the treatment of inoculation with acidophilic actinomycetes 3-10 alone had no adverse effects on pepper itself. Compared with the treatment of inoculation with spore suspension of pepper phytophthora, acidophilic actinomycetes 3-10 had a significant control effect on pepper blight. After 5 days of inoculation with pepper phytophthora, the preventive effect and therapeutic effect of acidophilic actinomycetes 3-10 on pepper blight reached 86% and 58%, respectively. After 10 days of inoculation with pepper phytophthora, the death rate of pepper seedlings inoculated with pepper phytophthora alone was 100%, while the death rate of pepper seedlings treated and prevented by acidophilic actinomycetes 3-10 was only 40% and 10%.

[0049] Table 2. The control effect of 3-10 fermentation liquid on pepper blight (5 dpi) Example 4 Determination of the in vivo efficacy of acidophilic actinomycetes Actinacidiphila reveromycinica 3-10 against rapeseed damping-off disease The rapeseed seeds were disinfected, and the disinfection process was as follows: 75% alcohol disinfection for 3 min, 5% sodium hypochlorite disinfection for 3 min, and sterile water rinsed 3 times. The disinfected rapeseed seeds were placed in a sterile glass culture dish covered with sterilized filter paper, and an appropriate amount of sterile water was added to soak the filter paper. The seeds were germinated in a 20 °C culture room for 5 days. After the rapeseed germinated, the strong seedlings were selected and transferred to plastic pots. After 14 days of cultivation in a greenhouse under the culture conditions of 24 °C, 16 h light / 8 h dark, the inoculation test was carried out. Punch holes (d=9 mm) in newly activated Rhizoctonia solani that had grown for 3 days with a borer, inoculate the bacterial cake into PDB medium (100 mL in a 250 mL bottle), inoculate 5 bacterial cakes per bottle, and culture in the dark at 25 °C, 120 rpm for 3 days to allow the mycelium to grow to a certain amount. Filter the mycelium with sterile gauze, dry it naturally, take 2 g of mycelium, add it to 200 mL of sterile water, and use a soybean milk maker to break it into a bacterial suspension for later use.

[0050] The experiment was divided into 5 treatments: 1. 3-10 treatment: rapeseed was only irrigated with 3 mL of 3-10 fermentation liquid; 2. Sterile water (CK) treatment: rapeseed was only irrigated with 3 mL of sterile water; 3. Rhizoctonia solani treatment: rapeseed was only irrigated with 3 mL of Rhizoctonia solani suspension; 4. Preventive treatment: rapeseed was irrigated with 3 mL of 3-10 fermentation liquid and then inoculated with 3 mL of Rhizoctonia solani suspension 24 hours later; 5. Curative treatment: rapeseed was irrigated with 3 mL of 3-10 fermentation liquid and then inoculated with 3 mL of 3-10 fermentation liquid 24 hours later.

[0051] All treatments were cultured at 24 °C, 16 h light / 8 h dark, with 10 replicates per group. The disease was investigated and the disease index was calculated 10 days after inoculation, and the seedling mortality rate was investigated 15 days after inoculation. The disease grading standard for rapeseed damping-off disease was set with reference to the disease grading standard for cotton damping-off disease (Hao Yanjun et al., 2005): Level 0: The plant has no disease; Level 1: The lesions on the plant stems are the size of a needle head to 1 / 4 of the stem; Level 3: The lesions are around 1 / 4-1 / 2 of the stem; Level 5: The lesions surround 1 / 2-3 / 4 of the stem; Level 7: The lesions surround the stem and the stem falls over or dies.

[0052] Disease index = ∑ number of diseased plants at each level × ∑ representative value of each level / (total number of plants investigated × representative value of the highest level) × 100; Prevention and treatment effect (%) = (disease index of control group - disease index of treatment group / disease index of control group) × 100%.

[0053] The results are as follows Figure 4 As shown in Table 3, the inoculation of acidophilic actinomycetes 3-10 alone had no adverse effects on rapeseed itself. Compared with the inoculation of Rhizoctonia solani suspension alone, acidophilic actinomycetes 3-10 had a significant control effect on rapeseed damping-off. After 10 days of inoculation with Rhizoctonia solani suspension, the preventive and therapeutic effects of acidophilic actinomycetes 3-10 on rapeseed damping-off reached 79.07% and 68.61%, respectively. After 15 days of inoculation with Rhizoctonia solani suspension, the seedling death rate of rapeseed inoculated with Rhizoctonia solani suspension alone was 100%, while the seedling death rate of rapeseed treated and prevented by acidophilic actinomycetes 3-10 was 0%.

[0054] Table 3. Control effect of 3-10 fermentation liquid on rapeseed blight (10 dpi) Example 5 Determination of the in vivo protective effect of acidophilic actinomycetes Actinacidiphila reveromycinica 3-10 on cucumber wilt The cucumber seeds were disinfected, and the disinfection process was as follows: 75% alcohol disinfection for 3 min, 5% sodium hypochlorite disinfection for 3 min, and sterile water rinsed 3 times. The disinfected cucumber seeds were placed in a sterile glass culture dish covered with sterilized filter paper, and an appropriate amount of sterile water was added to soak the filter paper. The seeds were germinated in a 20 °C culture room for 7 days. After the cucumber seeds germinated, the strong seedlings were selected and transferred to plastic pots. After 14 days of cultivation in a greenhouse under the culture conditions of 24 °C, 16 h light / 8 h dark, the inoculation test was carried out.

[0055] Obtaining spore liquid of Fusarium oxysporum: Take Fusarium oxysporum grown on PDA plate for 7 days, punch the mycelium into PDB culture medium (100 mL in 250 mL bottle) with a 5 mm diameter puncher, inoculate 5 bacterial cakes into each bottle, culture in the dark at 25 °C, 120 rpm for 7 days, filter the mycelium with three layers of sterile lens paper to obtain spore liquid, and dilute the spore liquid to 10 7 / mL for later use.

[0056] The experiment was divided into 4 treatments: 1. 3-10 treatment: after the cucumber roots were injured, they were soaked in 3-10 fermentation liquid for 5 minutes and then transplanted into plastic pots; 2. Sterile water (CK) treatment: after the cucumber roots were injured, they were soaked in sterile water for 5 minutes and then transplanted into plastic pots; 3. Fusarium oxysporum treatment: after the cucumber roots were injured, they were soaked in Fusarium oxysporum spore liquid for 5 minutes and then transplanted into plastic pots; 4. 3-10 treatment for prevention and control of Fusarium oxysporum: after the cucumber roots were injured, they were soaked in Fusarium oxysporum spore liquid for 5 minutes and then transplanted into plastic pots. After transplanting, 3 mL of 3-10 fermentation liquid was irrigated to the roots of each cucumber.

[0057] All treatments were cultured at 24 °C, 16 h light / 8 h dark, with 5 replicates per group. The disease was investigated and the disease index was calculated 5 days after inoculation, and the seedling mortality rate was investigated 10 days later. The disease grading standard was based on the disease grading standard for cucumber seedling wilt (Fang Zhongda, 1998) and the disease grading standard for rapeseed seedling wilt: Grade 0: no symptoms; Level 1: The yellowing or withering area of ​​true leaves and cotyledons does not exceed 50% of the total leaf area; Level 2: The yellowing or withering area of ​​true leaves and cotyledons exceeds 50% of the total leaf area; Level 3: Leaves wilt or die, with only the growing point surviving; Level 4: The whole plant is dead.

[0058] Disease index = ∑ number of diseased plants at each level × ∑ representative value of each level / (total number of plants investigated × representative value of the highest level) × 100; Prevention and treatment effect (%) = (disease index of control group - disease index of treatment group / disease index of control group) × 100%.

[0059] The results are as follows Figure 5 As shown in Table 4, the treatment with only Acidophilic Actinomycetes 3-10 had no adverse effects on the cucumber itself. Compared with the treatment with only Fusarium oxysporum spore solution, Acidophilic Actinomycetes 3-10 had a significant control effect on cucumber wilt. Five days after inoculation with Fusarium oxysporum spore solution, the control effect of Acidophilic Actinomycetes 3-10 on cucumber wilt reached 100%. Fifteen days after inoculation with Fusarium oxysporum suspension, the death rate of cucumber seedlings inoculated with Fusarium oxysporum spore solution alone was 100%, while the death rate of cucumber seedlings after control of cucumber wilt by Acidophilic Actinomycetes 3-10 was 0%.

[0060] Table 4. Control effect of 3-10 fermentation liquid on cucumber wilt (5 dpi) .

Claims

1. Actinacidiphila reveromycinica 3-10, whose accession number is CCTCC NO:M20242102.

2. Use of the acidophilic actinomycetes (Actinacidiphila reveromycinica) 3-10 according to claim 1 in preventing and controlling plant diseases.

3. The application according to claim 2, characterized in that: The plant diseases are blight, damping-off and / or wilt.

4. The application according to claim 3, characterized in that: The host of the disease is a plant of the Solanaceae family; Furthermore, the Solanaceae plant is pepper, eggplant or tomato; Specifically, the host of the damping-off disease is a plant of the family Cruciferae; Furthermore, the cruciferous plant is rapeseed, Chinese cabbage, cabbage or mustard; Preferably, the host of the wilt disease is a plant of the Cucurbitaceae family; Furthermore, the Cucurbitaceae plant is cucumber, loofah or bitter gourd.

5. The application according to claim 3, characterized in that: The pathogen of the disease is Phytophthora capsici; Particularly, the pathogen of damping-off disease is Rhizoctonia solani; Specifically, the pathogen of the wilt disease is Fusarium oxysporum.

6. The application according to claim 2, characterized in that: The plant diseases are caused by rice sheath blight, sclerotinia sclerotiorum, hydrophilic sclerotium, botrytis cinerea, fruit sclerotium, alternaria, aspergillus flavus, verticillium dahliae, rice blast, verticillium longisporum, higgs thorny disc, fruit anthracnose, rapeseed black shank pathogen, Fusarium graminearum and / or rice smut.

7. A preparation for preventing and controlling plant diseases, characterized in that: Its main components are acidophilic actinomycetes (Actinacidiphila reveromycinica) 3-10, spore liquid of acidophilic actinomycetes (Actinacidiphila reveromycinica) 3-10, secretion of acidophilic actinomycetes (Actinacidiphila reveromycinica) 3-10 or fermentation liquid of acidophilic actinomycetes (Actinacidiphila reveromycinica) 3-10.

8. A method for preventing and controlling plant diseases, characterized in that: The method comprises the following steps: irrigating the roots of plants with 3-10 spore liquid, fermentation liquid or secretion of acidophilic actinomycetes (Actinacidiphila reveromycinica); Furthermore, the concentration of the spore solution of 3-10 Actinacidiphila reveromycinica is 10 5 spores / mL; Specifically, the plant is pepper; Wherein, the pathogen of the disease is Phytophthora capsici.

9. A method for preventing and controlling plant damping-off disease, characterized in that: The method comprises the following steps: irrigating the roots of plants with 3-10 spore liquid, fermentation liquid or secretion of acidophilic actinomycetes (Actinacidiphila reveromycinica); Specifically, the plant is rapeseed.

10. A method for preventing and controlling plant wilt disease, characterized in that: The method comprises the following steps: irrigating the roots of plants with 3-10 spore liquid, fermentation liquid or secretion of acidophilic actinomycetes (Actinacidiphila reveromycinica); Furthermore, the concentration of the spore solution of 3-10 Actinacidiphila reveromycinica is 10 7 spores / mL; Specifically, the plant is cucumber.

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