Trichoderma longibrachiatum A-1 and application thereof

Abstract

The invention belongs to the technical field of microorganisms, and relates to trichoderma longibrachiatum A-1 and application thereof. The Trichoderma longibrachiatum A-1 provided by the invention has the preservation number of CGMCC (China General Microbiological Culture Collection Center) No.41510, the preservation number of the Trichoderma longibrachiatum A-1 is CGMCC No.41510, and the Trichoderma longibrachiatum A-1 is a Trichoderma longibrachiatum A-1. The preservation address is No.3, Yard 1, Beichen West Road, Chaoyang District, Beijing. The trichoderma longibrachiatum A-1 has an antagonistic effect on multiple pathogenic bacteria and inhibits reproduction of the multiple pathogenic bacteria, sterile fermentation liquor of the trichoderma longibrachiatum A-1 has a remarkable inhibiting effect on mycelial growth, sporulation quantity, spore germination and bud tube elongation of fusarium oxysporum, and the strain or a fermentation product of the trichoderma longibrachiatum A-1 has remarkable advantages in the aspect of preventing and treating plant root rot.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and in particular relates to a long-branch Trichoderma A-1 and an application thereof. Background Art

[0002] Root rot is considered a systemic disease. When it occurs, the vascular tissue of the plant turns brown and necrotizes, and the whole plant dies. Therefore, it is extremely harmful to production and is known as "plant cancer". The main cause of root rot is infection by pathogenic fungi. There are many types of pathogenic fungi of root rot and they are extremely destructive. They have affected the growth of many economic crops and caused huge losses.

[0003] Most of the pathogens of root rot in Solanaceae belong to the genus Fusarium. For example, the main pathogen of tomato root rot is Fusarium oxysporum, and the main pathogens of wolfberry root rot are Fusarium oxysporum, Fusarium solani, Phytophthora parasiticus and Rhizoctonia solani. The dominant pathogens of wolfberry root rot in Ningxia production area are reported to be Fusarium oxysporum and Fusarium solani. At present, chemical reagents such as carbendazim and thiophanate-methyl are mainly used to prevent and control wolfberry root rot, but they are almost ineffective. In addition, the large-scale use of chemical pesticides not only causes drug resistance of pathogens, but also leads to problems such as pesticide residues and excessive heavy metals, which endangers the edible safety of wolfberry and is increasingly resisted by consumers. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a long-branched Trichoderma A-1 and an application thereof. The strain is derived from the root of wolfberry, has antagonistic effects on a variety of pathogenic bacteria, and its sterile fermentation liquid has a significant inhibitory effect on the hyphae growth, spore production, spore germination and germ tube elongation of Fusarium oxysporum. The strain or its fermentation product has a preventive and therapeutic effect on plant root rot caused by Fusarium oxysporum, Fusarium solani, Fusarium dimerum and Fusarium equiseti.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0006] A strain of Trichoderma longibrachiatum A-1, whose classification name is Trichoderma longibrachiatum, was deposited in the General Microbiology Center of China Microorganism Culture Collection on September 18, 2024, and its deposit number is CGMCC No.41510; the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0007] Its rDNA-ITS sequence (as shown in SEQ ID No.3) is as follows:

[0008] .

[0009] In a second aspect, the present invention also provides a fermentation product of the above-mentioned Trichoderma longibrachiatum A-1 strain, wherein the fermentation product is obtained by fermenting the Trichoderma longibrachiatum A-1 strain.

[0010] The fermentation products include but are not limited to the sterile fermentation broth, the bacteria-containing fermentation broth and the spore suspension of Trichoderma longibrachiatum A-1.

[0011] Exemplarily, a method for preparing a fermentation broth containing Trichoderma longibrachiata A-1 is provided, comprising the following steps:

[0012] The long-branch Trichoderma A-1 is inoculated into a liquid culture medium, and the culture conditions are 25-30°C and 150-180r / min shaking culture for 5-7 days to obtain the long-branch Trichoderma A-1 live bacteria fermentation liquid, and the long-branch Trichoderma A-1 sterilized fermentation liquid is obtained after sterilization treatment.

[0013] Furthermore, the liquid culture medium is PDB culture medium.

[0014] Furthermore, the culture conditions are 30° C. and 180 rpm with shaking for 5 to 7 days.

[0015] Furthermore, the inoculation method of Trichoderma longibrachiatum A-1 is bacterial cake inoculation, spore suspension inoculation or mycelium inoculation.

[0016] Furthermore, 3 to 5 fresh cakes of long-branch Trichoderma A-1 with a diameter of 5 mm were inoculated into 100 to 150 mL of liquid culture medium.

[0017] Furthermore, 1 to 5 mL of the spore suspension of Trichoderma longifolia A-1 is inoculated into 100 to 150 mL of liquid culture medium; each mL of the spore suspension of Trichoderma longifolia A-1 contains 10 6 ~10 8 Spores.

[0018] Exemplarily, a method for preparing a sterile fermentation broth of Trichoderma longibrachiatum A-1 is provided, comprising the following steps:

[0019] The long-branch Trichoderma A-1 was inoculated into a liquid culture medium, and the culture was shaken at 25-30°C and 150-180 r / min for 5-7 days to obtain a long-branch Trichoderma A-1 bacterial solution; the bacterial solution was centrifuged at 8000-10000 r / min for 10-20 min, the supernatant was aspirated, and then filtered with a 0.22 μm sterile microporous filter membrane to obtain a sterile fermentation liquid.

[0020] Exemplarily, a method for preparing a spore suspension of Trichoderma longibrachiatum A-1 is provided, comprising the following steps:

[0021] The long-branch Trichoderma A-1 was inoculated into a liquid culture medium, and after shaking and culturing at 25-30°C and 150-180 r / min for 5-7 days, the spores were collected by filtering with sterile gauze, and the spores were diluted with sterile water to a preset concentration to obtain a long-branch Trichoderma A-1 spore suspension.

[0022] In a third aspect, the present invention also provides an application of the above-mentioned long-branch Trichoderma A-1 strain in the preparation of products for preventing and controlling plant root rot, wherein the long-branch Trichoderma A-1 strain, a microbial composition comprising the long-branch Trichoderma A-1 strain and / or a fermentation product obtained by fermenting the long-branch Trichoderma A-1 are used to prepare products for preventing and controlling plant root rot.

[0023] Preferably, the pathogen of plant root rot is Fusarium solani and / or Fusarium oxysporum and / or Fusarium dimerum and / or Fusarium equiseti.

[0024] In a fourth aspect, the present invention further provides an agent for preventing and treating plant root rot, wherein the active ingredient comprises the fermentation product of the above-mentioned Trichoderma longibrachiatum A-1.

[0025] Preferably, the agent for preventing and treating plant root rot is an agent for preventing and treating wolfberry root rot.

[0026] Preferably, the fermentation product is the fermentation broth containing Trichoderma longibrachiata A-1.

[0027] In a fifth aspect, the present invention further provides a Trichoderma agent for preventing and controlling plant root rot, comprising the above-mentioned Trichoderma longibrachiatum A-1.

[0028] The microbial agent may also contain one or more other biocontrol microorganisms, utilizing the metabolic characteristics and advantages of long-branch Trichoderma A-1 and different bacterial species to synergistically control wolfberry root rot. Preferably, the biocontrol microorganism is one or more Trichoderma, including but not limited to Trichoderma harzianum, Trichoderma viride, Trichoderma spinulosa, Trichoderma hooked, Trichoderma longbranch and Trichoderma koningii.

[0029] The long-branch Trichoderma A-1 can be prepared into different dosage forms of bacterial agents by selecting suitable carriers and / or auxiliary materials to improve the stability, activity and use effect of the bacterial agent to meet different production needs. The dosage forms of the bacterial agent include but are not limited to liquid, powder, and granular types.

[0030] Preferably, the Trichoderma agent for controlling plant root rot is a Trichoderma agent for controlling wolfberry root rot.

[0031] In a sixth aspect, the present invention also provides a method for preventing and controlling plant root rot, comprising the following steps: applying the above-mentioned agent for preventing and controlling plant root rot or the above-mentioned Trichoderma agent for preventing and controlling plant root rot to the roots of the plants.

[0032] In a seventh aspect, the present invention also provides the use of the above-mentioned Trichoderma longibrachiatum A-1 strain in the preparation of pathogen inhibitors, wherein the pathogens include Neocosmospore rubicola, Fusarium solani, Fusarium oxysporum, Fusarium dimerum and Aspergillus carneus.

[0033] In an eighth aspect, the present invention further provides a pathogen inhibitor, the active ingredients of which include the above-mentioned Trichoderma longibrachiatum A-1 and / or its fermentation product.

[0034] Preferably, the pathogen inhibitor is a pathogen inhibitor capable of inhibiting the hyphae growth of pathogens.

[0035] Preferably, the pathogen inhibitor is a pathogen inhibitor capable of inhibiting the spore production of pathogens.

[0036] Preferably, the pathogen inhibitor is a pathogen inhibitor capable of inhibiting the germination of pathogen spores.

[0037] Preferably, the pathogen inhibitor is a pathogen inhibitor capable of inhibiting the elongation of spore germ tubes of pathogens.

[0038] The present invention discloses the following technical effects:

[0039] 1. The long-branched Trichoderma A-1 provided by the present invention has a relatively obvious antagonistic effect on five soil-borne pathogenic fungi. In a single confrontation experiment between the long-branched Trichoderma A-1 strain and the target pathogen, the inhibition rates of Neocosmospore.rubicola, Fusarium solani, Fusarium oxysporum, Fusarium monoseptum and Aspergillus carnosus were 50.53%, 47.53%, 37.87%, 57.23% and 51.67% respectively.

[0040] 2. The long-branch Trichoderma A-1 sterile fermentation liquid provided by the present invention can significantly inhibit the growth of Fusarium oxysporum, and the mycelial growth, spore production, spore germination, and germ tube elongation of Fusarium oxysporum are significantly increased with the increase of the addition amount of the long-branch Trichoderma A-1 sterile fermentation liquid. When the concentration of the sterile fermentation liquid is 50%, the inhibition rates of mycelial growth, spore production, spore germination, and germ tube elongation of Fusarium oxysporum reach 68.40%, 76.41%, 68.85%, and 63.73%, respectively. It shows that the metabolites of long-branch Trichoderma A-1 also have a strong inhibitory effect on Fusarium oxysporum.

[0041] 3. The long-branch Trichoderma A-1 provided by the present invention has a good control effect on plant root rot. The present invention constructs a wolfberry root rot plant caused by a mixed fungus of Fusarium solani, Fusarium oxysporum, Fusarium monoseptum and Fusarium equisetum, and finds that compared with the control group, the leaves of the wolfberry plants treated with long-branch Trichoderma A-1 only show symptoms such as slight yellowing and curling of individual leaf tips, and there is no yellowing and falling phenomenon. Most of the leaves are green and healthy, and the roots grow more vigorously. The above results show that long-branch Trichoderma A-1 has a good control effect on wolfberry root rot, and can also play a good control role on other plant root rots caused by the same pathogen.

[0042] 4. The long-branch Trichoderma A-1 provided by the present invention is obtained by screening the rhizosphere of wolfberry in a wolfberry plantation where root rot is more serious. This indicates that the long-branch Trichoderma A-1 is non-pathogenic to the roots of wolfberry, has good safety, has a strong ability to antagonize pathogens, has good environmental adaptability and symbiotic ability with wolfberry, and provides a new biocontrol fungus species for the biological control of wolfberry root rot. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The inhibitory effect of Trichoderma longifolia A-1 strain on the growth of plant root rot pathogens (A: Neocosmosporerubicola versus A-1; B: Fusarium monoseptum versus A-1; C: Fusarium solani versus A-1; D: Fusarium oxysporum versus A-1; E: Aspergillus carnosus versus A-1);

[0044] Figure 2 The colony and bacterial morphology characteristics of the long-branched Trichoderma A-1 strain;

[0045] Figure 3 This is the phylogenetic tree of Trichoderma longibrachiata A-1 strain based on ITS sequences;

[0046] Figure 4 The results are as follows for the potted plant protection of the fermentation liquid of Trichoderma longibrachiatum A-1 in Example 3 against wolfberry root rot caused by Fusarium oxysporum, Fusarium solani, Fusarium monoseptum, and Fusarium equisetum. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0048] The strains used in the following examples of the present invention are derived from the following:

[0049] The long-branch Trichoderma A-1 strain was deposited in the General Microbiology Center of the China Microorganism Culture Collection Administration on September 18, 2024, and its deposit number is CGMCC No.41510; the deposit address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing.

[0050] Neocosmospore.rubicola, Fusarium dimerum, Fusarium solani, Fusarium oxysporum, and Aspergillus carneus were obtained from the Laboratory of Cell Biology of Northern University for Nationalities.

[0051] The culture medium used in the following examples of the present invention is as follows:

[0052] PDA medium: 200g peeled potatoes, 20g glucose, 20g agar powder, 1000mL water, natural pH. Weigh 200g peeled potatoes, add 1000mL water, boil for 30min. After filtering, add 20g glucose and 20g agar powder, and sterilize at 121℃ high temperature steam for 15min.

[0053] PDB medium: 300g potato extract powder, 20g glucose, 1000mL water, pH 5.6±0.2. Dissolve the above ingredients in 1000mL distilled water or pure water. Stir, heat and boil until completely dissolved, divide into portions, sterilize at 121℃ for 15min, and cool for later use.

[0054] Example 1

[0055] This example provides a strain of Trichoderma longibrachiatum A-1, which is isolated from the crushed root system of wolfberry.

[0056] 1. Isolation and screening of Trichoderma longifolia A-1

[0057] 1.1 The experimental materials were taken from the wolfberry plantation of Yinchuan Botanical Garden, Ningxia (38°54′59.50″N, 116°23′49.66″E). The wolfberry in the plantation was planted in 2014. The root rot is currently serious. In May 2022, the root parts of healthy wolfberries and diseased wolfberries were taken to ensure that about 0.5 mm thick soil samples were left around the roots. The soil samples were wrapped in tin foil and quickly brought back to the laboratory for isolation, purification and identification of rhizosphere microorganisms.

[0058] 1.2 Isolation and purification of antagonistic bacteria

[0059] Shake off the rhizosphere soil of the diseased roots and place it in a ventilated place to dry naturally, then pass it through a 20-mesh sieve. Take 10g of the sieved soil, add 90mL of sterile water and sterilized glass beads, place it in a 32℃ constant temperature shaker, and shake at 180rpm for 20-30min to obtain a soil suspension. Dilute the soil suspension to 10 -7 , spread on PDA medium, and culture in a constant temperature incubator at 32°C. When the colonies grow to an appropriate size, streak for separation and purification. Repeat several times until a single colony is obtained. A total of 27 strains were isolated and purified.

[0060] 1.3 Screening of antagonistic bacteria

[0061] Using five pathogenic bacteria, including Neocosmospore rubicola, Fusarium dimerum, Fusarium solani, Fusarium oxysporum and Aspergillus carneus, as indicator bacteria, the confrontation method was used to screen antagonistic strains from rhizosphere microorganisms.

[0062] Experimental group: Use a sterile cork borer to take a 5 mm pathogen cake, transfer it to the center of the PDA culture medium plate with an inoculation spatula, and inoculate 4 purified single strains of rhizosphere microorganisms symmetrically 3 cm from the edge of the plate. Repeat each treatment 5 times, culture at 28°C, measure the growth after 5 days and calculate the inhibition rate.

[0063] Control group: Use a sterile puncher to take a 5mm pathogen cake and transfer it to the PDA medium plate with an inoculation needle. Each pathogen was replicated 3 times and cultured at 28℃ for the same time as the experimental group.

[0064] The average diameter of the control group was calculated, and the inhibition rate of the antagonistic strains on the pathogenic bacteria was calculated respectively. The average value of the colony diameter of the control group was calculated by the difference method.

[0065] Inhibition rate = (colony diameter of control group - colony diameter of treatment group) / colony diameter of control group × 100%.

[0066] After 5 days of confrontation culture, a strain with the highest inhibitory effect on plant root rot pathogens was selected and named A-1. The inhibition rate of this strain on pathogenic bacteria was higher than 35% (Table 1).

[0067] Table 1A-1 Inhibition rate of pathogenic bacteria by strains

[0068]

[0069] 2. Identification of Trichoderma longibrachiatum A-1 strain

[0070] 2.1A-1 Colony and Morphological Characteristics

[0071] The A-1 strain grows faster on PDA plate medium, produces conidia earlier and more, and can also produce thick-walled spores. The conidia clusters of this strain are loose wool-like to tight blister-like structures. The conidiophores have a relatively simple branching system, usually with 1 to 2 right-angle branches, solitary or sometimes paired. The phialides are irregularly distributed on the side, often solitary, ampoule-shaped or columnar, and the base is often constricted but not obvious; conidia are single-celled, rectangular to oval, green, smooth ( Figure 2 The strain was preliminarily identified as Trichoderma longibrachiatum.

[0072] 2. Molecular biological identification of 2A-1 strain

[0073] The DNA of strain A-1 was used as a template, and PCR amplification was performed using primers of the fungal internal transcribed spacer (ITS), and then connected to the T vector for sequencing, and sequenced by Beijing Liuhe BGI Technology Co., Ltd. The amplification primers were:

[0074] ITS1 (SEQ ID NO.1): 5'-TCCGTAGGTGAACCTGCGG-3',

[0075] ITS4 (SEQ ID NO. 2): 5'-TCCTCCGCTTATTGATATGC-3'.

[0076] The sequencing result is shown in SEQ ID NO.3.

[0077] SEQ ID NO.3:

[0078] .

[0079] The obtained ITS sequences were compared with the published sequences in GenBank by BLAST, and the phylogenetic tree was constructed using the software MEGA 11 ( Figure 3 ), strain A-1 was clustered with the Trichoderma longibrachiatum strain with GenBank accession number MK 910067.1, and the homology was as high as 100%.

[0080] In summary, combined with morphological characteristics and molecular biological analysis, strain A-1 was identified as a long-branched Trichoderma (Trichoderma.longibrachiatum) strain and named as long-branched Trichoderma A-1. The strain was deposited in the China Center for Typical Microbiological Collection on September 18, 2024, with the deposit number CGMCC No.41510; the deposit address is No. 3, No. 1, Beichen West Road, Chaoyang District, Beijing.

[0081] Example 2 Inhibitory effect of sterile fermentation broth of Trichoderma longifolia A-1 on the growth of Fusarium oxysporum

[0082] Preparation of sterile fermentation broth: Add 100 mL of PDB culture medium into a 250 mL conical flask, inoculate 3 small blocks of long-branch Trichoderma A-1 with a diameter of 5 mm, and shake culture at 30°C and 180 r / min for 5 days to obtain long-branch Trichoderma A-1 bacterial solution; centrifuge the bacterial solution at 10000 r / min for 10 min, absorb the supernatant, and then filter twice with a 0.22 μm sterile microporous filter membrane to obtain sterile fermentation broth.

[0083] Preparation of spore suspension of Fusarium oxysporum: Take 3 pieces of fresh Fusarium oxysporum cake with a diameter of 5 mm, inoculate them into 120 mL of PDB medium (250 mL conical flask), shake and incubate at 25 °C and 180 r / min for 7 days, filter with sterile gauze to collect spores, and dilute with sterile water to a volume of 1 × 10 7 CFU / mL, to the spore suspension of Fusarium oxysporum.

[0084] 1. Inhibitory effect of Trichoderma longifolia A-1 fermentation broth on the mycelial growth of Fusarium oxysporum

[0085] After the melted PDA medium was cooled to 50°C, 10%, 20%, 30%, 40% and 50% of the sterile fermentation broth of Trichoderma longifolia A-1 were added thereto in turn, and 20 mL was poured into the medium after being fully shaken to prepare a drug-containing plate, and the PDA medium without fermentation filtrate was used as a control. Three replicates were performed for each treatment. A 5 mm diameter Fusarium oxysporum cake was inoculated in the center of the above plate, and after constant temperature culture at 28°C for 5 days, the colony diameter was measured by the cross method, and the mycelial growth inhibition rate was calculated. The results are shown in Table 2.

[0086] Inhibition rate = (colony diameter of control group - colony diameter of treatment group) / colony diameter of control group × 100%.

[0087] As shown in Table 2, compared with the control, different concentrations of Trichoderma longifolia A-1 fermentation broth treatment had significant differences in the growth of Fusarium oxysporum hyphae (P<0.05), and the inhibition rate showed a continuous upward trend with the increase of the volume concentration of the antagonistic strain fermentation broth. When the concentration of the treatment group was 50%, the inhibition rate of Fusarium oxysporum hyphae growth was the largest, which was 68.40%, and the minimum value corresponded to a concentration of 10%, which was 13.62%.

[0088] 2. Effect of sterile fermentation broth of Trichoderma longifolia A-1 on spore production of Fusarium oxysporum

[0089] After the melted PDA medium was cooled to 50°C, 10%, 20%, 30%, 40% and 50% of the sterile fermentation broth of Trichoderma longifolia A-1 were added thereto in turn, and 20 mL was poured into the sterile fermentation broth after being fully shaken to prepare a drug-containing plate. The PDA medium without fermentation filtrate was used as a control. Six replicates were used for each treatment. A 5 mm diameter Fusarium oxysporum cake was inoculated in the center of the above plate. After constant temperature culture at 28°C for 5 days, 3 cakes of the same size were taken from each culture dish. After repeated washing with sterile water, the spore concentration and spore production inhibition rate were calculated with the help of a blood cell counting plate. The results are shown in Table 2.

[0090] Spore production inhibition rate = (spore production of control - spore production of treatment) / spore production of control × 100%.

[0091] As can be seen from Table 2, when the fermentation filtrate of Trichoderma longifolia A-1 was used to treat Fusarium oxysporum, the spore production gradually decreased with the increase of concentration. Under the blank control, the spore production was the largest, which was 7.45×10 7 There was no significant difference in the conidia production among the three groups when the concentration was 10%, 20%, and 30%, which were 6.33×10 7 / mL, 5.35×10 7 / mL, 5.62×10 7 When the treatment concentration was 40% and 50%, the spore production showed a strong inhibitory effect, among which when the treatment concentration was 40%, the spore production inhibition rate was the largest, which was 76.41%.

[0092] 3. Effect of Trichoderma longifolia A-1 fermentation broth on spore germination of Fusarium oxysporum

[0093] 10%, 20%, 30%, 40% and 50% of the sterile fermentation liquid of Trichoderma longifolia A-1 were added to the spore suspension of Fusarium oxysporum, and an equal volume mixture of PDB medium and spore suspension of Fusarium oxysporum was used as a control. After thorough mixing, an appropriate amount of the mixture was pipetted and dropped onto a concave glass slide, and cultured at 28°C to keep the moisture. After 6 hours, the spore germination was examined under a microscope. Each treatment was repeated 3 times, and 150 to 200 spores were examined under a microscope each time. The spore germination rate and spore germination inhibition rate were calculated, respectively. The results are shown in Table 2.

[0094] Spore germination rate = number of spore germination / total number of spores investigated × 100%;

[0095] Treatment-corrected spore germination rate = treatment spore germination rate / blank control spore germination rate × 100%;

[0096] Spore germination inhibition rate = (spore germination rate of blank control - spore germination rate corrected by treatment) / spore germination rate of blank control × 100%.

[0097] As shown in Table 2, compared with the control, there were significant differences in the spore germination rate of Fusarium oxysporum under the treatment of different concentrations of long-branch Trichoderma A-1 fermentation filtrate (P<0.05), and the spore germination rate gradually decreased with the increase of the fermentation liquid concentration; the blank control had the highest spore germination rate, 89.40%, and when the treatment concentration was 50%, the spore germination rate was the lowest, 37.17%. Correspondingly, the spore germination inhibition rate increased with the increase of the long-branch Trichoderma A-1 treatment concentration, and when the treatment concentration was 50%, the spore germination inhibition rate was the largest, 68.85%.

[0098] 4. Effect of the fermentation broth of strain Trichoderma longibrachiata A-1 on the germ tube elongation of Fusarium oxysporum

[0099] 10%, 20%, 30%, 40% and 50% of the sterile fermentation liquid of Trichoderma longifolia A-1 were added to the spore suspension of Fusarium oxysporum, and an equal volume mixture of PDB medium and Fusarium oxysporum spore suspension was used as a control. After thorough mixing, an appropriate amount of the mixture was pipetted and dropped onto a concave glass slide, and cultured at 28°C with moisture retention. Each treatment was repeated 3 times, and the elongation of the germ tube was measured by microscopic examination after 6 hours. 50 conidia were randomly selected and measured (the germ tube length of the spore was greater than the short radius of the spore was considered to be germinated), and the inhibition rate of germ tube elongation was calculated. The results are shown in Table 2.

[0100] Germ tube elongation inhibition rate = (germ tube length of control group - germ tube length of treatment group) / germ tube length of control group × 100%.

[0101] As shown in Table 2, compared with the control group, different concentrations of Trichoderma longifolia A-1 fermentation filtrate treatment had a certain inhibitory effect on the elongation of Fusarium oxysporum germ tubes, among which the best inhibitory effect on the elongation of spore germ tubes was achieved when the concentration was 50%. The inhibition rate of spore germ tube elongation in each treatment increased with the increase of the fermentation filtrate treatment concentration. When the treatment concentration was 50%, the inhibition rate of germ tube elongation was the largest, which was 63.73%.

[0102] Table 2 Inhibitory effect of Trichoderma longifolia A-1 fermentation broth on the growth of Fusarium oxysporum

[0103]

[0104]

[0105] In summary, the metabolites of Trichoderma longibrachiatum A-1 have a strong inhibitory effect on Fusarium oxysporum.

[0106] Example 3 Control effect of Trichoderma longifolia A-1 on wolfberry root rot caused by Fusarium oxysporum

[0107] The long-branch Trichoderma A-1 was inoculated into PDB fermentation medium and cultured at 30°C and 180r / min for 5 days to obtain the long-branch Trichoderma A-1 culture solution; Fusarium oxysporum, Fusarium solani, Fusarium equisetum and Fusarium monoseptum were inoculated into PDB medium respectively and cultured at 28°C and 150r / min for 72 hours to obtain the culture solution of Fusarium oxysporum, Fusarium solani, Fusarium equisetum and Fusarium monoseptum, and the four bacterial solutions were mixed in a volume ratio of 1:1:1:1 to obtain the pathogen culture solution.

[0108] The sterilized mixed soil (vermiculite: nutrient soil: perlite = 1:3:1) was placed in a flower pot with a diameter of 11 cm, about 0.5 kg (dry mass) per pot, and one-year-old wolfberry plant Zhongke No. 1 was transplanted at room temperature, with an average of 3 seedlings per pot. Fifteen pots of healthy wolfberry seedlings with consistent growth were selected and divided into three groups (control group, pathogen treatment group, pathogen + long-branch Trichoderma A-1 treatment group), cultivated outdoors, and watered once every 3 days. After 7 days, except for the control group, the other two groups were inoculated with 50 mL of pathogen culture solution using the "root injury + root irrigation" method, the control group was inoculated with 50 mL of sterile PDB culture medium, and the pathogen + long-branch Trichoderma A-1 treatment group was inoculated with 50 mL of long-branch Trichoderma A-1 culture solution. Culture for 14 days in the same way as before, and observe the aboveground phenotype of wolfberry. The results are as follows Figure 4 shown.

[0109] After 14 days, compared with the control inoculated with PDB medium, the wolfberry plants in the group treated with Trichoderma longifolia A-1 showed symptoms such as slight yellowing and curling of individual leaf tips, and no other changes, while the wolfberry plants in the pathogen treatment group had leaves withering, falling off in large numbers, and black roots. The leaves of the wolfberry plants treated with the culture solution of Trichoderma longifolia A-1 showed almost no yellowing or falling off, and most of the leaves were green and healthy, and the roots grew more vigorously. This shows that the strain Trichoderma longifolia A-1 has a certain preventive and therapeutic effect on wolfberry root rot.

[0110] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A strain of Trichoderma longibrachiatum A-1, characterized in that: Its classification name is Trichoderma longibrachiatum. It was deposited in the General Microbiology Center of China Microorganism Culture Collection on September 18, 2024. Its deposit number is CGMCC No. 41510. The deposit address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing.

2. The fermentation product of the long-branch Trichoderma A-1 strain according to claim 1, characterized in that: The fermentation product is obtained by fermenting the long-branch Trichoderma A-1 strain.

3. The use of the long-branch Trichoderma A-1 according to claim 1 in preparing a product for preventing and treating plant root rot, characterized in that: The long-branch Trichoderma A-1 strain, the microbial composition comprising the long-branch Trichoderma A-1 and / or the fermentation product obtained by fermenting the long-branch Trichoderma A-1 are used to prepare a product for preventing and controlling plant root rot.

4. The use according to claim 3, characterized in that: The pathogenic bacteria of the plant root rot are Fusarium solani and / or Fusarium oxysporum and / or Fusarium dimerum and / or Fusarium equiseti.

5. A medicament for preventing and treating plant root rot, characterized in that: The active ingredients include the fermentation product of the long-branch Trichoderma A-1 according to claim 2; preferably, the agent for preventing and treating plant root rot is an agent for preventing and treating wolfberry root rot.

6. A Trichoderma agent for preventing and treating plant root rot, characterized in that: It comprises the long-branch Trichoderma A-1 described in claim 1; preferably, the Trichoderma agent for controlling plant root rot is a Trichoderma agent for controlling wolfberry root rot.

7. A method for preventing and controlling plant root rot, characterized in that: The method comprises the following steps: applying the agent for preventing and controlling plant root rot according to claim 5 or the Trichoderma agent for preventing and controlling plant root rot according to claim 6 to the roots of the plants.

8. Use of the long-branch Trichoderma A-1 strain according to claim 1 in the preparation of pathogen inhibitors, characterized in that: The pathogens include Neocosmospore rubicola, Fusarium solani, Fusarium oxysporum, oxysporum), Fusarium dimerum, and Aspergillus carnosus (Aspergillus carneus).

9. A pathogen inhibitor, characterized in that: The effective ingredients include the long-branch Trichoderma A-1 and / or its fermentation product as described in claim 1.

10. The pathogen inhibitor according to claim 9, characterized in that The pathogen inhibitor is a pathogen inhibitor used to inhibit the hyphae growth of pathogens; and / or The pathogen inhibitor is a pathogen inhibitor used to inhibit the spore production of pathogens; and / or The pathogen inhibitor is a pathogen inhibitor used to inhibit the spore germination of pathogens; and / or The pathogen inhibitor is a pathogen inhibitor used to inhibit the elongation of spore germ tubes of pathogens.

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