Chrysosporium merdarium qm and its application

Abstract

The application discloses a strain of Chaetomium globosum QM, which is named as Chaetomium globosum, and has been preserved in the China General Microbiological Culture Collection Center (CGMCC) (address: No. 1, Xibaheyanli 3, Chaoyang District, Beijing, China Institute of Microbiology) on May 22, 2024, and the strain preservation number is CGMCC NO.41324. The application is a kind of Chaetomium globosum QM separated and purified from wild forest area of Yangshu in Taishan, which is made into fungus powder by using solid fermentation, drying and crushing raw materials, and is applied to crops by seed dressing or flushing, has the effects of promoting growth, disease resistance, stress resistance and the like, and the whole production process does not produce three wastes, has low cost and high benefit, and meets the social needs of environmental protection and grain safety production.

Description

Technical Field

[0001] This invention belongs to the field of microbial technology, and in particular relates to a strain of Chaetomium globosum QM and its applications. Background Technology

[0002] Endophytic fungi are microorganisms that live within plants without causing obvious infection symptoms. They have a mutualistic symbiotic relationship with plants. Among fungi used as biocontrol agents, *Trichoderma* spp., *Gliocladium* spp., and *Coniothyrium minitans* have been extensively studied both domestically and internationally. Other common fungi include *Pythium oligandrum*, non-pathogenic *Fusarium* spp., yeasts (*Candida* spp.), *Chaeromium globosum*, and *C. cochliodes*. Their mechanisms of action mainly include competition, hyperparasitism, antibiotic resistance, and induction of disease resistance, as well as growth-promoting effects on plants.

[0003] Currently, the most studied Chaetomium ND35 exhibits significant growth-promoting effects. Salt stress has a substantial impact on crop growth and development, causing plant damage through osmotic stress and leading to the accumulation of reactive oxygen species within the plant, which is one of the limiting factors for crop growth. However, the effects of Chaetomium ND35 on plant growth and physiological characteristics under salt stress are rarely reported. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention provides a strain of Chaetomium globosum QM and its applications.

[0005] This invention provides a strain of Chaetomium globosum QM, which was deposited on May 22, 2024, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, with accession number CGMCC NO.41324 and classified as Chaetomium globosum.

[0006] This strain was isolated from poplar trees in the wild forest area of ​​Mount Tai, and its optimal growth temperature is 18–25℃. The mycelium on PDA is initially white, later turning light brown. The ascocarps are grayish-brown to olive-brown, medium-sized, scattered or clustered, ovoid, 250–300 × 230–28 μm. Numerous dark olive-brown rootlets attach to the substrate. Lateral appendages are filiform, straight or slightly curved, light olive-brown, slightly rough, septate, 3.5 μm in diameter at the base, gradually tapering and becoming transparent towards the tip. The asci are club-shaped or fusiform, 60–105 × 13–20 μm, containing 8 ascospores, irregularly arranged. The ascospores are lemon-shaped or broadly ovoid with slightly pointed ends, dark brown to olive-brown, 8–12 × 6–8.5 μm.

[0007] This invention also provides the application of the aforementioned Chaetomium globosum QM in crops to promote growth, resist disease, and enhance stress resistance.

[0008] The present invention also provides a *Chaetomium globosum* QM mycelial powder.

[0009] The present invention also provides a method for preparing the *Chaetomium globosum* QM powder, comprising: soaking solid fermentation raw materials in water and sterilizing them at high temperature; after cooling to room temperature, inoculating them with a *Chaetomium globosum* QM spore suspension, culturing them at room temperature, culturing them with aeration, and then drying and pulverizing them to obtain the powder.

[0010] Preferably, the solid fermentation raw materials include corn kernels, wood chips, crushed corn stalks and wheat straw, wheat bran, cottonseed hulls, and superphosphate.

[0011] In an embodiment of the present invention, a specific preparation method is provided, including: using corn kernels, wood chips, crushed corn stalks and wheat straw, wheat bran, cottonseed hulls and superphosphate as solid fermentation raw materials, soaking them in tap water for 20-24 hours, placing them in edible fungus cultivation bags, covering them with a breathable cover, sterilizing them at 121°C for 40 minutes; after cooling, inoculating them with QM spore suspension, culturing them at 25°C for one week, opening the cover to ventilate after the bags are full of mycelium, culturing them for another week, drying them, and then crushing the culture medium with a high-speed pulverizer for later use.

[0012] This invention also provides the application of the aforementioned Chaetomium globosum QM powder in crops to promote growth, resist disease, and enhance stress resistance.

[0013] The present invention also provides the application of the aforementioned Chaetomium globosum QM powder as a seed coating agent and seed dressing agent for crops.

[0014] The crops mentioned include corn, wheat, rice, soybeans, cucumbers, peppers, and tomatoes.

[0015] The present invention also provides a coated seed comprising mycelium powder and crop seeds.

[0016] Furthermore, in the coated seeds, the ratio of mycelium powder to corn seeds is 0.5–0.9:40 g / g, and the ratio of mycelium powder to wheat seeds is 0.5–0.9:5 g / g.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. This invention isolates and purifies a type of Chaetomium globosum (QM) from wild poplar trees in Taishan. It utilizes solid-state fermentation, dries and pulverizes the raw materials to make fungal powder, which can be mixed with seeds or applied to crops. It has the effects of promoting growth, resisting diseases and stress on crops. Moreover, no waste is generated in the entire production process, which is low-cost and high-efficiency, and meets the social needs of environmental protection and food security production.

[0019] 2. The *Chaetoceros globosum* QM prepared by the present invention into a seed powder has a significant growth-promoting effect on wheat and corn, a significant control effect on cucumber damping-off disease, and a good maintenance effect on pepper seedling growth even at salt concentrations as high as 200 mmol / L. It can also significantly promote wheat seedling growth under drought stress and effectively improve the low-temperature stress resistance and cold resistance of crop seedlings. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 : Colony morphology diagram of QM strain in Example 1.

[0022] Figure 2 The morphology of the perithecia, ascospores and hyphae of the QM strain in Example 1 is shown in (a) 40×0.65 and (b) 100×1.4.

[0023] Figure 3 The phylogenetic tree diagram of strain QM in Example 1 was established by ITS sequence analysis.

[0024] Figure 4 Example 4: Effect of Chaetomium globosum QM on cucumber damping-off disease.

[0025] Figure 5 Figure 5 shows the effect of Chaetomium globosum QM on the physicochemical properties of pepper seedlings under salt stress.

[0026] Figure 6 The effect of Chaetomium globosum QM on the physicochemical indicators of wheat drought resistance under different moisture conditions in Example 6. Detailed Implementation

[0027] Unless otherwise specified, the instruments, reagents, and materials used in the following embodiments are all conventional instruments, reagents, and materials already available in the prior art and can be obtained through legitimate commercial channels. Unless otherwise specified, the experimental methods and detection methods used in the following embodiments are all conventional experimental methods and detection methods already available in the prior art.

[0028] Example 1: Isolation and Identification of Strains

[0029] 1. Isolation and screening of strains:

[0030] (1) Isolation of strains

[0031] Fresh poplar roots from the wild forests of Mount Tai were thoroughly rinsed with running water, then sterilized with 75% ETOH for 40 seconds, followed by 0.5% NaClO for 5 minutes. Finally, they were rinsed 4-5 times with sterile water and placed on sterile filter paper to absorb surface moisture. The roots were then cut into approximately 1 cm segments using sterile scissors and inoculated onto PDA medium that had been autoclaved at 121°C for 30 minutes. The samples were incubated upright at 25°C for 3-4 days, and the growth of endophytic bacteria was observed. Hyphae were observed growing from the cut edges of the samples. The bacteria were repeatedly isolated and purified using plates until each plate contained only a single colony with uniform characteristics. Finally, a single strain was obtained and designated QM.

[0032] (2) PDA culture medium formula: 200g potato, 20g glucose, 20g agar, 1000mL distilled water.

[0033] 2. Morphological determination of strain QM

[0034] When strain QM was placed on PDA medium, it initially appeared as a dense, white colony, later turning light brown with a woolly edge. After one week of incubation at 25°C, the colonies reached a diameter of 85–90 mm, and ascocarps gradually formed from the center outwards, changing color from olive green to olive brown. After two weeks, multiple mature ascocarps clustered together, densely covering the entire PDA plate, with sparse, radiating, light-colored hyphae visible above the clustered ascocarps. This fungus exhibits characteristics of the genus *Chaetomium*, and was preliminarily identified as *Chaetomium globosum*. (The colony morphology of this fungus is as follows...) Figure 1 As shown, the morphology of ascospores and hyphae at different magnifications is as follows: Figure 2 As shown (the left image has a magnification of 40×0.65, and the right image has a magnification of 100×1.4).

[0035] 3. Molecular biological identification of strain QM

[0036] Using ITS1 and ITS4 as primers, the fungal strain QM isolated from the roots of wild poplar was amplified, and the amplified products were sequenced. Based on blast search, *Dichotomopilus pseudofunicol* was selected as an outgroup, and sequences from species and strains of the same genus with high homology and coverage with the studied strain were compared. A phylogenetic tree was constructed using Mega 7.0 software with ML algorithm and 500 bootstrap iterations (e.g., ...). Figure 3 (As shown).

[0037] The results showed that this strain had 100% similarity to Chaetomium globosum CBS:666.82 (accession number MT588864.1).

[0038] Based on morphological and molecular biological identification, strain QM was ultimately identified as *Chaetomium globosum*.

[0039] The isolated strain was named Chaetomium globosum QM and was deposited on May 22, 2024, at the China General Microbiological Culture Collection Center (CGMCC, address: No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences), with accession number CGMCC NO.41324.

[0040] Example 2: Application of Chaetomium globosum QM in promoting maize growth

[0041] 1. Test method:

[0042] Preparation method of QM powder of Chaetomium globosum: Use 10-15% corn kernels, 20-30% sawdust, 5-15% crushed corn stalks and wheat straw, 10-20% wheat bran, 15-25% cottonseed hulls, and 0.5-1% superphosphate as solid fermentation raw materials. Soak in tap water for 20-24 hours, then pack into edible mushroom cultivation bags, cover with a breathable lid, and sterilize at 121℃ for 40 minutes. After cooling, inoculate with QM spore suspension and incubate at 25℃ for one week. Once the bags are fully covered with mycelium, open the lid for ventilation, incubate for another week, and then dry. Finally, pulverize the culture medium using a high-speed pulverizer for later use.

[0043] Seedling trays filled with nutrient substrate were placed in plastic trays, with 45 cells per tray and a total of 5 treatments. The corn seeds for each treatment were moistened with tap water and then treated with Chaetomium tumefaciens powder. Treatment T1 was a blank control CK (0g) without seed treatment. The amount of seed treatment agent used in treatments T2 to T4 were 0.5g, 0.7g, and 0.9g, respectively (40g of corn seeds were sown per treatment).

[0044] 2. Experimental Results:

[0045] The experimental results are shown in Table 1. The seed dressing agent combined with 0.7g of bacterial powder / 40g of corn seeds had the most significant effect on promoting corn growth. Compared with the control group, the corn plant height, root length, stem diameter, maximum leaf area, aboveground and root fresh weight increased by 21.26%, 26.46%, 4.00%, 28.83%, 32.14%, and 2.27%, respectively. The second most effective combination was 0.5g of bacterial powder / 40g of corn seeds, which increased the corn plant height, root length, maximum leaf area, aboveground and root fresh weight by 10.61%, 1.64%, 4.98%, 3.32%, and 0.46%, respectively.

[0046] Table 1. Effects of different dosages of Chaetoceros foetida powder on maize growth.

[0047]

[0048] Example 3: Application of Chaetomium globosum QM in promoting wheat growth

[0049] 1. Test method:

[0050] Small flowerpots filled with planting soil were placed in a large plastic basin to absorb water from the bottom. Four treatments were set up. For each treatment, 5g of wheat seeds were placed on moist filter paper to absorb water for 30 minutes before being treated with the seed dressing agent. The dosage of seed dressing agent for treatments T1–T3 was 0.5g, 0.7g, and 0.9g, respectively (each treatment used approximately 100 wheat seeds, about 5g). Treatment T4 served as a blank control (CK) without seed dressing.

[0051] 2. Experimental Results:

[0052] The experimental results are shown in Table 2. Compared with the control (CK), all three different dosages of microbial powder for seed treatment promoted wheat growth. The 0.7g microbial powder / 5g wheat seed had the most significant effect on promoting wheat root growth, with wheat root length increasing by 20.96% compared with the control. The 0.9g microbial powder / 5g wheat seed had the most significant effect on promoting wheat plant height, stem diameter, aboveground fresh weight, and root dry weight, with wheat plant height, stem diameter, aboveground fresh weight, and root dry weight increasing by 19.55%, 60.31%, 39.62%, 34.47%, and 40.15% respectively compared with the control.

[0053] Table 2. Effects of different dosages of Chaetoceros foetida powder on wheat growth.

[0054]

[0055]

[0056] Example 4: Application of Chaetomium globosum QM in the prevention of cucumber damping-off disease

[0057] 1. Test strains

[0058] Biocontrol bacteria: Chaetomium globosum QM strain

[0059] Pathogen: Pythium aphanidermatum strain, the causal agent of cucumber damping-off;

[0060] All the strains were provided by Shandong Pengbo Biotechnology Co., Ltd. Each strain was selected and inoculated onto a PDA plate, incubated in a 25℃ constant temperature incubator for two weeks, and then stored in a 4℃ refrigerator for later use.

[0061] 2. Test methods:

[0062] Sow cucumber seeds in flowerpots filled with nutrient substrate. When seedlings reach the 2-leaf-1-heart stage, inoculate the roots with QM mycelium cakes, 10 cakes per plant, ensuring the mycelial side is against the root. Three days after QM inoculation, inoculate the roots of cucumber seedlings with cultured cucumber damping-off pathogen. A control group was prepared by inoculating only the cucumber damping-off pathogen without QM mycelium cakes. Five pots were used per treatment, with three seedlings per pot. Disease incidence was assessed after 4 days.

[0063] Prevention and control efficacy % = (Incidence rate in control group - Incidence rate in prevention and control group) / Incidence rate in control group × 100%

[0064] 3. Experimental Results:

[0065] The test results are shown in Figure 4 The disease incidence rates of cucumber seedlings inoculated with QM and the uninoculated control were 7.50% and 70.63%, respectively, with a control efficacy of 89.4%. This indicates that QM has a significant effect on controlling cucumber damping-off under cultivation conditions. This is because QM, inoculated into cucumber seedlings 3 days in advance, can colonize the plant roots, stimulating the plant's disease resistance and defense response.

[0066] Example 5: Application of Chaetomium globosum QM in salt-resistant pepper seedlings

[0067] 1. Test Methods

[0068] 1.1 Select chili seeds with uniform color, plumpness, and consistent size. Soak them in a water bath at 55℃ for 20 minutes, stirring constantly until the water temperature drops to 30℃. Continue soaking for another 10 hours, then place them in a 30℃ incubator for germination treatment. Once the seeds show white sprouts, transfer them to flowerpots for seedling cultivation. Inoculation treatment involves adding 10g of the following dosage (2×10⁶) to the substrate in each flowerpot. 8 Mix CFU / g of Chaetomium globulus QM inoculum. When the seedlings reach the four-leaf stage, select seedlings of uniform growth (60 inoculated and 60 uninoculated seedlings) and transplant them into flowerpots to continue the salt stress experiment.

[0069] Five salt concentrations were set up for the pepper salt stress experiment. When the seedlings had 3-4 true leaves, they were treated with NaCl at final concentrations of 0, 50, 100, 150, and 200 mmol / L. Simultaneously, inoculation with *Chaetomium globosum* QM and no inoculation were set as controls (CK). Each treatment was repeated three times, with 12 pots per treatment, two seedlings per pot, randomly arranged. All other management practices during the pepper seedling growth period were consistent.

[0070] 1.2 Indicator determination: Root-to-shoot ratio (R / T), malondialdehyde (MDA) content, proline (Pro) content, superoxide dismutase (SOD) activity, and peroxidase (POD) activity.

[0071] 2. Experimental Results:

[0072] 2.1 Effects of Chaetomium globosum QM on the growth of pepper seedlings under salt stress

[0073] The experimental results are shown in Table 3. With increasing NaCl concentration, the stress on pepper seedling growth became more severe, with both aboveground and belowground fresh weight showing a decreasing trend, and the root-to-shoot ratio gradually decreasing. Under the same salt stress concentration, the aboveground and belowground fresh weights of pepper seedlings inoculated with *Chaetomium globosum* QM were superior to those of the control group. With increasing salt concentration, the aboveground fresh weight of peppers increased by 82.47%, 75.17%, 93.44%, 78.95%, and 71.43% compared to the control (CK), respectively, while the belowground fresh weight increased by 104.65%, 87.50%, 65.63%, 56.67%, and 40.00% compared to the control (CK), respectively.

[0074] Table 3. Effects of *Cladosporium globosum* QM on the growth of pepper seedlings under salt stress.

[0075]

[0076] 2.2 Effects of Chaetomium globosum QM on antioxidant enzyme activity in pepper seedlings under salt stress

[0077] The results show (e.g.) Figure 5 Under salt stress, reactive oxygen species accumulate in large quantities in plants, producing membrane lipid peroxidation products (mainly malondialdehyde (MDA),) which severely damage plant cells. With increasing NaCl concentration, the MDA content in pepper seedling leaves showed an upward trend. Under the same salt stress, the MDA content in pepper seedling leaves treated with *Chaetomium globosum* QM decreased by 22.37%, 16.25%, 14.46%, 15.91%, and 12.37%, respectively.

[0078] Plants can enhance their tolerance to oxidative stress and reduce cellular oxidative damage by increasing the activity of antioxidant enzymes (SOD and POD) to eliminate excess reactive oxygen species. The activities of POD and SOD generally decreased with increasing NaCl concentration. Under the same salt stress concentration, compared with the control group, the SOD activity in the leaves of pepper seedlings inoculated with *Chaetomium globosum* QM increased by 75.55%, 65.55%, 85.37%, 121.30%, and 109.92%, respectively, while the POD activity increased by 27.00%, 27.58%, 45.33%, 45.56%, and 51.12%, respectively.

[0079] Salt stress affects the osmotic pressure balance of plant cells, leading to water loss. Plants can reduce cell water potential and mitigate drought stress damage indirectly caused by salt stress by increasing the amount of osmotic regulators (such as proline and soluble proteins). The experimental results are shown in Table 4. With increasing NaCl concentration, the soluble protein content in pepper seedling leaves showed a fluctuating upward trend. Under the same salt stress, the soluble protein content in pepper seedling leaves treated with *Chaetomium globosum* QM increased by 51.39%, 22.99%, 49.37%, 34.44%, and 24.39% compared to the control, respectively.

[0080] Example 6: Application of Chaetomium globosum QM in wheat seedlings under drought stress

[0081] 1. Test Methods

[0082] Wheat seeds were germinated at 20℃ with moisture. Seeds with uniform germination were selected and sown in flowerpots. Simultaneously, 0.3g of bacterial powder at a concentration of 5500cfu / g was applied per seed. Four treatments were set up: (1) normal + CK; (2) normal + QM; (3) drought + CK; (4) drought + QM. 150 plants were planted in each treatment, and each plant was weighed and the weight recorded after planting. Water management was carried out according to the quality control method for all treatment groups. Each day, the flowerpots in the drought treatment group and the normal water treatment group were weighed, and water was added until the weight recorded at sowing was constant. Wheat growth was observed during the period, and samples were preserved for subsequent physicochemical index testing.

[0083] 2. Experimental Results:

[0084] As shown in Table 4, compared with normal water management, water stress treatment reduced wheat seedling height, root length, and root activity, but significantly increased the root-to-shoot ratio. In both the normal and dry treatment groups, inoculation with *Chaetomium globosum* QM significantly promoted wheat seedling growth compared with the control group. In the drought group, QM treatment increased wheat seedling height, root length, root-to-shoot ratio, and root activity by 25.41%, 9.87%, 10.00%, and 9.33%, respectively, compared with the control group.

[0085] Table 4. Effects of *QM* on wheat seedling growth under different moisture conditions.

[0086]

[0087]

[0088] like Figure 6 As shown, compared with normal water management, wheat leaves under drought conditions exhibited significantly increased proline and malondialdehyde (MDA) content, significantly increased catalase activity, and significantly decreased leaf water content. In the drought treatment groups, wheat treated with *Chaetomium globosum* QM showed a significant decrease in MDA content, down 50.00% compared to the control (CK); while catalase, proline content, and leaf water content significantly increased, by 40.46%, 64.56%, and 6.28%, respectively, compared to the CK.

[0089] Example 7: Application of Chaetomium globosum QM in the resistance of tomato seedlings to low temperature stress

[0090] 1. Test Methods

[0091] Tomato seeds with uniform color, plumpness, and consistent size were selected and soaked in a 55℃ water bath for 20 minutes, stirring constantly until the water temperature dropped to 30℃. The seeds were then soaked for another 10 hours and placed in a 30℃ incubator for germination treatment. Once the seeds showed signs of sprouting, they were transferred to greenhouse pots for sowing. Two treatments were included: inoculation with *Chaetomium globosum* (QM) and no inoculation (CK). Each treatment consisted of 15 pots, with two seedlings per pot, randomly arranged. When the seedlings reached 5 leaves and 1 bud, they were subjected to a low-temperature treatment at 8℃.

[0092] 2. Measurement indicators: The plant height, fresh weight and dry weight of tomato seedlings, malondialdehyde content, proline content, soluble sugar content, superoxide dismutase activity and catalase activity of tomatoes were measured.

[0093] 2. Experimental Results:

[0094] As shown in Table 5, under low temperature stress of 8℃, the plant height, fresh weight, and dry weight of tomato seedlings inoculated with Chaetomium globosum QM increased by 22.58%, 78.40%, and 76.00%, respectively, compared with the uninoculated group. This indicates that inoculation with Chaetomium globosum QM strain under low temperature stress can significantly increase the plant height, fresh weight, and dry weight of tomato seedlings.

[0095] Table 5. Effects of *Cladosporium globosum* QM on tomato seedling growth under low temperature stress.

[0096]

[0097] As shown in Table 6, under low-temperature stress of 8℃, the MDA content in tomato seedlings inoculated with *Chaetomium globosum* QM was significantly reduced, decreasing by 34.11% compared to the control (CK). The proline and soluble sugar contents in tomato seedlings increased by 58.83% and 45.45%, respectively, compared to the uninoculated group. SOD and CAT activities increased by 51.40% and 29.12%, respectively, compared to the uninoculated group. This indicates that inoculation with *Chaetomium globosum* QM can improve the cold resistance of tomatoes by increasing the activity of antioxidant enzymes, reducing cellular oxidative damage, and maintaining cellular osmotic pressure balance, thereby promoting the growth and development of tomato seedlings under low-temperature stress.

[0098] Table 6. Effects of *Cladosporium globosum* QM on cold resistance indices of tomato under low-temperature stress.

[0099]

[0100] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A strain of Chaetomium globosum QM, characterized in that, The *Chaetomium globulum* QM specimen was deposited on May 22, 2024, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, with accession number CGMCC NO. 41324, and classified as *Chaetomium globulum*. Chaetomium globosum .

2. The application of *Chaetoceros globosum* QM as described in claim 1 in the treatment of cucumber damping-off disease, characterized in that, The pathogen causing cucumber damping-off is *Cucumber damping-off bacterium*. Pythium aphanidermatum .

3. A type of Chaetomium globosum QM mycelium powder, characterized in that, The powder is prepared from the *Chaetomium globosum* QM as described in claim 1. The preparation method of the *Chaetomium globosum* QM mycelium powder is as follows: using 10-15% corn kernels, 20-30% sawdust, 5-15% crushed corn stalks and wheat straw, 10-20% wheat bran, 15-25% cottonseed hulls, and 0.5-1% superphosphate as solid fermentation raw materials, soaking them in tap water for 20-24 hours, filling them into edible fungus cultivation bags, covering them with a breathable lid, and sterilizing them at 121℃ for 40 minutes; after cooling, inoculating them with the spore suspension of *Chaetomium globosum* QM, and culturing them at 25℃ for one week, after the bags are full of mycelium, opening the lid to ventilate, culturing them for another week, drying them, and then pulverizing the culture medium with a high-speed pulverizer for later use.

4. The application of the *Chaetomium globosum* QM mycelial powder according to claim 3 in the resistance to cucumber damping-off disease, characterized in that, The pathogen causing cucumber damping-off is *Cucumber damping-off bacterium*. Pythium aphanidermatum .

5. The application of the *Chaetomium globosum* QM mycelium powder according to claim 3 as a corn seed coating agent and seed dressing agent, characterized in that, The ratio of the *Chaetomium globosum* QM mycelium powder to the corn seeds is 0.5–0.7:40 g / g.

6. A coated seed, characterized in that, The mixture comprises the *Chaetoceros globosum* QM mycelium powder as described in claim 3 and corn seeds; the ratio of the *Chaetoceros globosum* QM mycelium powder to the corn seeds is 0.5–0.7:40 g / g.

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