Use of actinomyces s36

Abstract

This invention discloses the use of actinomycete S36. The actinomycete of this invention (… Streptomyces rochei S36 or its microbial preparations are applied to at least one of the following (1)-(6): (1) improving seed germination rate; (2) preparing a product for improving seed germination rate; (3) promoting plant growth; (4) preparing a product for promoting plant growth; (5) controlling bacterial fruit spot disease and / or fungal wilt disease of watermelon; (6) preparing a product for controlling bacterial fruit spot disease and / or fungal wilt disease of watermelon. The method for improving seed germination rate in this invention includes the following steps: during seed initiation treatment, the above-mentioned actinomycete ( Streptomyces rochei Seeds are soaked in S36 or a microbial preparation thereof, then dried and germinated to improve the germination rate. The actinomycete S36 in this invention can effectively improve the germination rate of watermelons, the growth rate of plants after germination, and reduce the occurrence and / or alleviate disease symptoms.

Description

Technical Field

[0001] This invention belongs to the field of biological control technology for plant diseases, and relates to the use of actinomycete S36. Background Technology

[0002] Watermelon (Citrullus lanatus), as an important economic crop, occupies a dominant position in the summer consumer market and is also an indispensable raw material for light industry. Currently, large-scale watermelon cultivation is powerfully driving watermelon seedling production towards intensification. With the continuous upgrading and transformation of the industry, the importance of intensive seedling cultivation technology is becoming increasingly significant. Cultivating high-quality, robust seedlings and effectively preventing disease occurrence has become an inevitable trend in the development of the watermelon industry.

[0003] Microbial preparations are biological products made primarily from microorganisms and are a product of microbial science and technology. Their development is highly technical, requiring the synergistic effect of numerous integrated technologies, including bioengineering, fermentation technology, and modern pharmaceutical processes. The main application areas of microbial preparations are agricultural production, environmental protection, and medicine.

[0004] Actinomycetes are a group of Gram-positive bacteria, a special group of prokaryotes capable of forming branched hyphae and conidia. They grow in a hyphal form and primarily reproduce by spores, named for the radial colony pattern. Actinomycetes are widely distributed in nature, existing mainly as spores or hyphae in soil, air, and water, especially abundant in soils with low moisture content, rich organic matter, and neutral or slightly alkaline pH. Some actinomycetes produce a wide variety of secondary metabolites during their metabolism (such as zeatin, kinetin, antibiotics, auxins, and biotin), which can promote cell division, chlorophyll and protein synthesis, and enhance plant tolerance and disease resistance. Summary of the Invention

[0005] The purpose of this invention is to provide the uses of actinomycete S36. Actinomycete S36 of this invention can effectively improve the germination rate of watermelons, the growth rate of plants after germination, and reduce the occurrence of diseases and / or alleviate disease symptoms.

[0006] The first aspect of the present invention provides actinomycetes ( Streptomyces rochei The use of S36 or its microbial preparations in at least one of the following (1)-(6): (1) Improve seed germination rate; (2) Prepare products to improve seed germination rate; (3) Promotes plant growth; (4) Prepare products to promote plant growth; (5) Control of bacterial fruit spot disease and / or fungal disease wilt of watermelon; (6) Prepare products for the prevention and control of bacterial fruit spot disease and / or fungal wilt disease of watermelon.

[0007] In this invention, the actinomycetes ( Streptomyces rochei S36, this strain belongs to Streptomyces, its accession number at the China General Microbiological Culture Collection Center is CGMCC No. 32928, the accession date is December 5, 2024, see Chinese invention patent CN120060081B for details.

[0008] In the above applications, improving seed germination rate is reflected in promoting seed germination and / or increasing seed vigor.

[0009] In the above applications, promoting plant growth is manifested in increasing the fresh weight and / or dry weight of the plant.

[0010] In the above applications, the seeds or plants are watermelon seeds or plants; this includes not only watermelons, but also other cucurbitaceous plants.

[0011] In the above applications, the control of bacterial fruit spot disease and / or fungal wilt disease of watermelon is manifested in: having an antagonistic effect on bacterial fruit spot pathogens and / or fungal wilt pathogens of watermelon, as well as reducing the occurrence of the disease and / or alleviating the symptoms of the disease.

[0012] In the above applications, the microbial preparation contains actinomycetes ( Streptomyces rochei S36 and / or Actinomycetes ( Streptomyces rochei S36 bacterial solution.

[0013] In the above applications, the actinomycetes ( Streptomyces rochei The bacterial culture of S36 was obtained by culturing actinomycete S36 in a bacterial fermentation medium.

[0014] A second aspect of the present invention provides a method for improving seed germination rate, comprising the following steps: during seed priming treatment, using the aforementioned actinomycetes ( Streptomyces rochei Seeds are soaked in S36 or its microbial preparations, dried, and germinated to improve the germination rate.

[0015] In the above method, the soaking time can be 8 to 13 hours, specifically 12 hours, and the time for the seeds to dry after soaking is 20 to 36 hours, specifically 24 hours.

[0016] A third aspect of the present invention provides a method for promoting plant growth, comprising the following steps: during seed priming treatment, using the aforementioned actinomycetes ( Streptomyces rocheiSeeds were soaked in S36 or its prepared microbial preparations, dried, germinated, and then sown; during the seedling stage, the actinomycetes (S36 or its prepared microbial preparations) were sprayed. Streptomyces rochei S36 or its microbial preparations are used to promote seedling growth.

[0017] The fourth aspect of this invention provides a method for preventing and controlling bacterial fruit spot disease and / or fungal wilt disease of watermelon, comprising the following steps: observing the antagonistic effect of S36 on the two pathogens in a plate inhibition test; spraying the above-mentioned actinomycetes (S36) before and after artificial inoculation of seedlings. Streptomyces rochei S36 or its microbial preparations are used to reduce the occurrence of diseases and / or alleviate disease symptoms.

[0018] The present invention has the following beneficial effects: 1. Promotes seed germination, enhances seed vigor, and encourages earlier seed germination.

[0019] 2. Promotes plant growth and improves plant fresh weight, dry weight and other growth indicators.

[0020] 3. Non-toxic and harmless, it can replace chemical pesticides.

[0021] 4. Its cultivation conditions are easy to control, its preservation methods are diverse, and its usage is flexible.

[0022] 5. After screening and cultivation in industry, it can be used in fermenters to expand the cell volume and synthesize products, showing great application potential. Attached Figure Description

[0023] Figure 1 Figure showing the effect of S36-induced treatment on watermelon seed germination; Figure 1 In the middle, A to E are comparison charts of seed germination, initiation effect, germination rate, germination potential, and germination index, respectively.

[0024] Figure 2 Figure showing the effect of S36 treatment on the overall growth of watermelon seedlings; Figure 2 Figures A through F show comparisons of overall seedling growth, plant height, stem base width, fresh weight, dry weight, and dry-to-fresh weight ratio, respectively.

[0025] Figure 3 The effect of S36 treatment on the leaf size of watermelon seedlings is shown in the figure. Figure 3 The images in the middle A through G represent comparisons of cotyledon and true leaf effects, true leaf length, true leaf width, cotyledon length, cotyledon width, true leaf area, and cotyledon area, respectively.

[0026] Figure 4 Figure showing the effect of S36 treatment on the root system of watermelon seedlings; Figure 4Figures A through F show comparisons of root system performance, root length, root surface area, number of lateral roots, root volume, and root vitality, respectively.

[0027] Figure 5 This is a diagram showing the antagonistic effect of S36 on bacterial fruit spot disease of watermelon.

[0028] Figure 6 This is a diagram showing the antagonistic effect of S36 on Fusarium wilt.

[0029] Figure 7 An image illustrating the effectiveness of S36 in controlling bacterial fruit spot disease in watermelons; Figure 7 In the diagram, AB represents the prevention and control effect, C represents the incidence rate, and D represents the disease index.

[0030] Figure 8 This is an illustration showing the effect of S36 in controlling Fusarium wilt pathogens. Figure 8 In the diagram, A, B, and C represent the prevention and control effect, incidence rate, and disease index, respectively. Detailed Implementation

[0031] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0032] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0033] In the following examples, actinomycetes ( Streptomyces rochei S36, this strain belongs to Streptomyces, its accession number at the China General Microbiological Culture Collection Center is CGMCC No. 32928, the accession date is December 5, 2024, see Chinese invention patent CN120060081B for details.

[0034] In the following examples, the watermelon seed variety is Huaxin.

[0035] Example 1 This embodiment provides an evaluation method for actinomycetes ( Streptomyces rochei The S36 has the following capabilities for phosphorus solubilization, nitrogen fixation, potassium release, and IAA production: The specific operating steps are as follows: Phosphorus solubilization, nitrogen fixation, and potassium solubilization capacity determination: Using a sterile toothpick, pick up well-grown strain S36 from the plate and inoculate the strain onto Monkina medium, Asbby medium, and silicate bacteria medium, respectively. Observe the growth status of the strain in the petri dishes. The presence of a clear zone indicates that the strain has this function. The specific steps for the IAA production colorimetric reaction are as follows: Use a sterile inoculation loop to pick up well-grown strain S36 from the plate and inoculate it into an Erlenmeyer flask or test tube containing Czapek's liquid medium. Incubate at 30℃ and 200rpm for 2-7 days in a constant temperature shaker. Remove the cultured bacterial solution, transfer 5ml to a sterile centrifuge tube, centrifuge at 10000rpm for 5 minutes, and collect 1mL of the supernatant. Add 1mL of Salkowski colorimetric reagent. After mixing thoroughly, place the test tube in a dark place at room temperature for 30 minutes to allow the IAA to fully react with the colorimetric reagent. Observe whether the mixed solution turns red; a red mixed solution indicates IAA production.

[0036] The results showed that actinomycetes ( Streptomyces rochei S36 has the ability to fix nitrogen and produce IAA, but it does not have the ability to dissolve phosphorus and potassium, as shown in Table 1 below.

[0037] Table 1. Results of strain screening

[0038] Note: "+" indicates that it has an effect, and "-" indicates that it has no effect.

[0039] Example 2 This embodiment provides actinomycetes ( Streptomyces rochei The preparation process of S36 microbial inoculant, and the specific operating steps are as follows: Actinomycetes ( Streptomyces rochei S36 was cultured in LB liquid medium at 28°C and 180 r / min for 2 days to obtain S36 fermentation broth. The fermentation broth was diluted 100 times with sterile water and set aside for later use.

[0040] The LB liquid culture medium formula is 10 g tryptone, 5 g yeast extract, and 5 g NaCl, adjusted to pH 7.0, balanced with 1 L of distilled water, and sterilized at 121℃ for 20 min.

[0041] Example 3 This embodiment provides the actinomycetes prepared in Embodiment 2 of the present invention (… Streptomyces rochei The application experiment of S36 microbial inoculant to improve the germination rate of watermelon seeds is as follows: Huaxin watermelon seeds were soaked in sterile water and a 100-fold diluted S36 fermentation solution for 12 hours each. The treated seeds were then allowed to dry at room temperature (25℃) for 24 hours. After drying, 50 seeds were evenly placed in petri dishes lined with moist germination paper, with three replicates per dish. All petri dishes were placed in a 30℃ incubator for germination experiments, and the germination rate, germination potential, and germination index were recorded.

[0042] The sterile water treatment group was set as the control group (denoted as CK), and the S36 fermentation broth treatment group diluted 100 times was set as the experimental group.

[0043] Germination potential = (Number of germinated seeds in 2 days / Total number of seeds) × 100% (Equation 1) Germination rate (Gs) = Number of germinated seeds after 7 days / Total number of seeds × 100% (Equation 2) Germination index (Gi) = ∑ Gt / Dt (Equation 3) In equation (3), Gt is the number of seeds that germinate in Dt days, and Dt is the corresponding number of germination days.

[0044] The test results are as follows Figure 1 As shown, from Figure 1 The results show that after using S36 initiation treatment, the germination rate increased by about 17.89%, the germination potential increased by 31.48%, and the germination index increased by 22.03%.

[0045] Example 4 This embodiment provides the actinomycetes prepared in Embodiment 2 of the present invention (… Streptomyces rochei The application experiment of S36 microbial inoculant to promote the overall growth of watermelon seedlings is as follows: Watermelon seeds of the Huaxin variety were placed in clean water and in a solution of actinomycetes diluted 100 times. Streptomyces rochei Watermelon seeds were soaked in S36 fermentation broth for 12 hours, then dried at room temperature for 24 hours. The dried seeds were then sown in trays containing substrate, with three replicates, and cultured in a greenhouse until the two-leaf-one-heart stage. During this period, the seeds were sprayed with a 100-fold diluted S36 fermentation broth three times. Plant growth indicators (plant height, stem base width, fresh weight, dry weight, and dry-to-fresh ratio) were then measured.

[0046] The test results are as follows Figure 2 As shown, from Figure 2 The presented data clearly shows that, through actinomycetes ( Streptomyces rochei After treatment with S36 fermentation broth, the plant growth was significantly improved, specifically with a significant increase in plant height, stem base width, fresh weight, and dry weight. This was in contrast to treatment without actinomycete initiation (…). Streptomyces rocheiCompared with the control group (CK) treated with S36 fermentation broth, the plant height increased by approximately 21.27%, the stem base width increased by approximately 43.55%, the fresh weight increased by approximately 66.48%, and the dry weight increased by approximately 74.10%. However, although the dry-to-fresh ratio increased slightly, it did not show a significant difference.

[0047] Example 5 This embodiment provides the actinomycetes prepared in Embodiment 2 of the present invention (… Streptomyces rochei The application experiment of S36 microbial inoculant as a plant growth regulator to promote leaf growth in watermelon seedlings was conducted, and the specific operating steps are as follows: Following the detailed operating steps described in Embodiment 4 of this invention, watermelon seedlings are carefully cultivated until they reach the two-leaf-one-heart stage. At this stage, representative watermelon seedlings with relatively consistent growth are selected, and their cotyledons and first true leaves are carefully harvested. Subsequently, the leaf width and length of the harvested cotyledons and first true leaves are measured, and their leaf surface areas are calculated using the following formula.

[0048] Area of ​​a single leaf = leaf length × leaf width × 0.73 (4) The test results are as follows Figure 3 As shown, from Figure 3 The results showed that after initiation treatment with S36 fermentation broth, the leaf size of the watermelon plants in the treated group was significantly larger than that of the control group (CK) without S36 fermentation broth treatment. Specifically, the cotyledons and first true leaves of the watermelon seedlings in the treated group showed significant improvements in key morphological indicators such as leaf width, leaf length, and leaf surface area. Compared with the control group (CK), the leaf width of the cotyledons in the treated group increased by 22.99%, the leaf length increased by 23.44%, and the leaf surface area increased by 51.88%; while the leaf width, leaf length, and leaf surface area of ​​the first true leaves increased by 26.73%, 37.93%, and 73.58%, respectively.

[0049] Example 6 This embodiment provides the actinomycetes prepared in Embodiment 2 of the present invention (… Streptomyces rochei The application experiment of S36 microbial inoculant as a plant growth regulator to promote root growth in watermelon seedlings was conducted, and the specific operating steps are as follows: First, watermelon seedlings were carefully cultivated according to the method in Example 4 of this invention. After they grew to the two-leaf-one-heart stage, representative plants were selected, and root samples were carefully taken out, taking care to avoid damaging the root hairs and delicate parts such as the root tips. The root samples were placed in a high-transparency root placement tray, ensuring that the roots were spread out and not overlapping. Then, a root scanner (STD4800 type) was used to scan them to obtain relevant root growth index data.

[0050] As the main organs for plants to absorb water and mineral nutrients, roots also participate in the synthesis, assimilation, and transformation of important substances such as amino acids and hormones. Their growth status and physiological activity directly affect the overall growth, nutritional status, and yield of the plant. Therefore, accurately assessing root vitality is of significant practical importance.

[0051] This experiment used the TTC method to determine root activity. The principle is as follows: TTC (2,3,5-triphenyltetrazolium chloride) can be reduced by hydrogen to form a water-insoluble red product, TTF (triphenylformazan), which has a characteristic absorption peak at 485 nm. When the TTC solution permeates into the plant root tissue, reducing substances produced by respiration can reduce it back to TTF, turning the root tissue red. Root activity can be quantified by the amount of TTC reduced; this method actually reflects the activity of plant root dehydrogenases.

[0052] For specific testing procedures, please refer to the instruction manual for Solarbio's Plant Root Vitality Test Kit (TTC Method) with catalog number BC5270.

[0053] The test results are as follows Figure 4 As shown, from Figure 4 The results showed that after initiation treatment with S36 fermentation broth, the root distribution of watermelon plants in the treatment group was significantly better than that in the group without actinomycetes ( Streptomyces rochei The control group (CK) treated with S36 fermentation broth showed a highly significant increase. Specifically, the root length, root surface area, number of root tips, root volume, and root activity of the watermelon seedlings in the treatment group were significantly improved. Compared with the control group (CK), the root length of the watermelon seedlings in the treatment group increased by 32.87%, the root surface area increased by 28.92%, the number of root tips increased by 10.97%, the root volume increased by 41.57%, and the root activity increased by 27.06%.

[0054] Example 7 The actinomycetes prepared in Example 2 of this invention ( Streptomyces rochei The antagonistic experiment between strain S36 and *Varicella simonii* (a common strain derived from the Vegetable Research Institute of Beijing Academy of Agricultural and Forestry Sciences) was conducted, and the specific operating steps are as follows: This embodiment uses the plate confrontation method to conduct an antagonistic test on the two bacteria mentioned above. Before the test, plates containing LB medium were prepared. The shaken bacterial suspension of watermelon bacterial fruit spot disease was evenly spread on the plate, and a hole was punched in the center of the plate using a strictly sterilized 8mm punch. The pure culture of the test bacteria was then inoculated into the hole. Finally, the plate was placed in a 28℃ incubator for dark incubation. During the incubation process, the plate was observed regularly to observe the formation of inhibition zones.

[0055] The test results are as follows Figure 5 As shown, fromFigure 5 The results show that a distinct inhibition zone was formed in the center of the plate. Therefore, it can be concluded that actinomycetes (… Streptomyces rochei S36 has an inhibitory effect on the growth of fruit spot pathogens.

[0056] Example 8 This embodiment provides the actinomycetes prepared in Embodiment 2 of the present invention (… Streptomyces rochei The antagonistic experiment between S36 and a strain of Fusarium wilt (a common strain, sourced from the Vegetable Research Institute of Beijing Academy of Agricultural and Forestry Sciences) was conducted, and the specific operating steps are as follows: This embodiment uses the plate confrontation method to conduct an antagonistic experiment between two bacteria. Before the experiment, plates containing PDA medium were prepared in advance. Using a sterile inoculation loop, pure culture of S36 was taken and drawn in straight lines on both sides of the plate with uniform and moderate pressure. During the drawing process, it is important to ensure that the S36 is evenly inoculated on the plate. After completing the S36 inoculation, the plates were incubated at 28°C for 1-2 days. Next, using a strictly sterilized 8mm punch, mycelial discs were precisely cut from the tested Fusarium wilt pathogen culture and carefully transferred to the predetermined position in the center of the plate (the untreated group inoculated with S36, and the control group without S36), ensuring the mycelial discs were placed stably and accurately. After completing the above inoculation steps, the used inoculation loop and punch were immediately sterilized by thoroughly flaming them over an alcohol lamp to avoid interference from residual bacteria in subsequent experiments, ensuring the aseptic nature and accuracy of each operation. Finally, the plates were placed stably in a 28°C incubator for dark incubation. During the incubation period, the plates were observed regularly, and the growth of the wilt pathogen under different conditions was recorded in detail, including the morphological characteristics and size of the colonies.

[0057] The test results are as follows Figure 6 As shown, from Figure 6 The results showed that, compared with the size of the mycelial disc of Fusarium wilt growing alone, the size of the mycelial disc of Fusarium wilt was significantly smaller when S36 and Fusarium wilt were in the same culture environment. Therefore, it can be concluded that S36 has an inhibitory effect on the growth of Fusarium wilt.

[0058] Example 9 This embodiment provides the actinomycetes prepared in Embodiment 2 of the present invention (… Streptomyces rochei The indoor control efficacy test of S36 against bacterial fruit spot disease of watermelon was conducted, and the specific operating steps are as follows: Pre-germinated watermelon seeds were sown one seed at a time into seedling pots filled with nutrient soil, ensuring each pot contained only one seed. The seedling pots were then transferred to an incubator set at 25-30℃ and carefully cultivated according to standard management practices until the cotyledons of the watermelon seedlings just unfolded. Next, a 100-fold diluted S36 fermentation solution was evenly sprayed onto the watermelon seedlings, ensuring each seedling received full and even contact with the treatment solution. A control group of seedlings treated with sterile water was also established for subsequent comparative analysis. Spraying was performed every 3 days for a total of 3 applications. After the third spraying, the seedlings were allowed to stand for 24 hours before being artificially inoculated with the pathogen of watermelon bacterial fruit spot disease. After inoculation, the seedlings were closely observed for disease incidence, and the disease incidence and disease index were calculated accordingly.

[0059] The test results are as follows Figure 7 As shown, from Figure 7 The results show that the use of actinomycetes ( Streptomyces rochei After initiation treatment with S36 fermentation broth, the disease incidence rate of watermelon plants in the treatment group decreased by 40.14%, and the disease index decreased by 66.91%.

[0060] Example 10 This embodiment provides the actinomycetes prepared in Embodiment 2 of the present invention (… Streptomyces rochei The indoor efficacy test of S36 against Fusarium wilt pathogen (from the same source as Example 8 of this invention) is conducted as follows: Sow the pre-germinated watermelon seeds one by one into seedling pots filled with nutrient soil, ensuring that each pot contains only one seed. Then, transfer the seedling pots to an incubator set at 25-30℃ and carefully cultivate them according to standard management practices until the cotyledons of the watermelon seedlings have just unfolded. Next, use a 100-fold diluted solution of actinomycetes (… Streptomyces rochei S36 fermentation broth was used to treat watermelon seedlings by root irrigation, with a control group of seedlings treated with sterile water for subsequent comparative analysis. During the treatment, root irrigation was performed every 3 days, for a total of 3 times. After the third root irrigation, the seedlings were allowed to stand for 3 days, followed by root washing. Immediately after root washing, the seedlings were inoculated with Fusarium wilt pathogens. After inoculation, the disease incidence of the seedlings was closely observed and recorded, and the disease incidence rate and disease index were calculated based on the disease situation.

[0061] The test results are as follows Figure 8 As shown, from Figure 8 The results showed that after initiation treatment with S36 fermentation broth, the disease incidence rate of watermelon plants in the treatment group decreased by 18.20%, and the disease index decreased by 15.96%.

Claims

1. Actinomycetes ( Streptomyces rochei The use of S36 or its microbial preparations in at least one of the following (1)-(6): (1) Improve seed germination rate; (2) Prepare products to improve seed germination rate; (3) Promotes plant growth; (4) Prepare products to promote plant growth; (5) Control of bacterial fruit spot disease and / or fungal disease wilt of watermelon; (6) Prepare products for the prevention and control of bacterial fruit spot disease and / or fungal wilt disease of watermelon.

2. The application according to claim 1, characterized in that, The improvement in seed germination rate is reflected in promoting seed germination and / or increasing seed vigor; The promotion of plant growth is reflected in increasing the fresh weight and / or dry weight of the plants.

3. The application according to claim 1 or 2, characterized in that, The seeds or plants mentioned are watermelon seeds or plants.

4. The application according to any one of claims 1-3, characterized in that, The control of bacterial fruit spot disease and / or fungal wilt disease of watermelon is manifested in: having an antagonistic effect on bacterial fruit spot pathogens and / or fungal wilt pathogens of watermelon, as well as reducing the occurrence of the disease and / or alleviating the symptoms of the disease.

5. The application according to claim 1, characterized in that, The microbial preparation contains actinomycetes ( Streptomyces rochei S36 and / or Actinomycetes ( Streptomyces rochei S36 bacterial solution.

6. The application according to claim 5, characterized in that, The actinomycetes ( Streptomyces rochei The bacterial culture of S36 was obtained by culturing actinomycete S36 in a bacterial fermentation medium.

7. A method for improving seed germination rate, comprising the following steps: during seed priming treatment, using the actinomycete described in any one of claims 1-6 (… Streptomyces rochei Seeds are soaked in S36 or its microbial preparations, dried, and germinated to improve the germination rate.

8. A method for promoting plant growth, comprising the following steps: during seed priming treatment, using the actinomycete described in any one of claims 1-6 (… Streptomyces rochei Seeds soaked in S36 or its microbial preparations, dried, germinated, and then sown; during the seedling stage, the actinomycetes described in any one of claims 1-6 are sprayed. Streptomyces rochei S36 or its microbial preparations are used to promote seedling growth.

9. The method according to claim 7 or 8, characterized in that, The soaking time is 8 to 13 hours, and the seeds are dried again after soaking for 20 to 36 hours.

10. A method for controlling bacterial fruit spot disease and / or fungal wilt disease of watermelon, comprising the following steps: observing the antagonistic effect of S36 on the two pathogens using a plate inhibition test; spraying the actinomycete described in any one of claims 1-6 before and after artificial inoculation of seedlings. Streptomyces rochei S36 or its microbial preparations are used to reduce the occurrence of diseases and / or alleviate disease symptoms.

Images