A seed germination agent prepared from the metabolites of Paecilomyces variotii

Abstract

The invention discloses a seed germination agent prepared from a metabolite of Paecilomyces variotii, and a large amount of Paecilomyces variotii fermentation liquid is prepared by a three-stage amplification fermentation system using microbial fermentation technology, and the fermentation liquid is filtered and vacuum concentrated to obtain a concentrated solution of Paecilomyces variotii metabolites; then the concentrated solution of Paecilomyces variotii metabolites, 5-aminolevulinic acid, ethanol, dimethyl sulfoxide, and sterile water are compounded according to a certain weight portion, and are fully mixed to obtain a seed germination agent. The present invention utilizes microbial fermentation technology and a fermentation system to prepare a large amount of Paecilomyces variotii metabolites, and the obtained metabolites have the effects of softening seed coats and relieving dormancy. The seed germination agent obtained by compounding with 5-aminolevulinic acid has a significant promoting effect on seed germination, radicle elongation, lateral root growth, and soil-breaking speed.

Description

Technical Field

[0001] The invention belongs to the technical field of application of microbial metabolites in agricultural production, and particularly relates to a seed germination agent prepared from metabolites of Paecilomyces variotii. Background Art

[0002] The germination rate of plant seeds is easily affected by external factors such as water, oxygen, temperature, light, and internal factors such as embryo development, nutrient reserves, and dormancy. The germination rate of seeds further affects plant growth and crop yield, and is one of the problems that need to be solved in agricultural production.

[0003] The seed germination agent prepared with the metabolites of Paecilomyces variotii has the effect of softening the seed coat and releasing seed dormancy. It can effectively promote seed germination and the growth of radicle and lateral roots, and increase the speed of seedlings breaking through the soil and the resistance of seedlings.

[0004] After inquiry, "Effect of Paecilomyces variotii extract on cherry radish yield and quality" (Jia Chunhua et al., Journal of Agricultural Resources and Environment, Vol. 36, No. 2, pp. 176-183, 20180138), "Study on the mechanism and controlled release effect of Paecilomyces variotii SJ1 extract in regulating crop nitrate nitrogen metabolism" (Wang Qingbin, doctoral dissertation of Shandong Agricultural University, 20211027), "Physiological adaptability of Paecilomyces variotii extract to rice seedlings under salt stress" (Wang Xiaoqi et al., Journal of Agricultural Resources and Environment, Vol. 37, No. 1, pp. 98-105, 20180349), " "Effects of Penicillium extract on chlorophyll fluorescence kinetic parameters of maize leaves under flooding stress" (Xing Yumei et al., Journal of Irrigation and Drainage, Vol. 40, No. 10, pp. 52-57, 20211108), "Effects of Penicillium extract on summer maize yield and nitrogen utilization" (Wang Qingbin et al., Crop Journal, No. 4, pp. 166-171, 20210425), "Effects of different nitrogen treatments combined with Penicillium extract on the growth and nitrogen absorption of pakchoi" (Wang Qingbin et al., Crop Journal, No. 1, pp. 190-195, 20220129), ... "The mechanism of action of extracts in inducing Pakchoi to resist low temperature stress" (Wang Qingbin et al., Journal of Nuclear Agricultural Sciences, Vol. 36, No. 2, pp. 473-480), "Effects of several biostimulants on the growth and stress resistance of cherry radish and wheat" (Jia Chunhua, Master's thesis of Shandong Agricultural University, 2020), "ZNC extract of Paecilomyces variotii improves the resistance of Pakchoi to salt-alkali stress" (Wang Qingbin et al., Journal of Plant Physiology, Vol. 57, No. 6, pp. 1291-1299, 20200543), "Effect of ZNC extract of Paecilomyces variotii on the quality and yield of ginger" (Wang Shanshan et al., Fertilizer and Health "Kang", Vol. 49, No. 2, pp. 35-40, 2022), "Isolation and Identification of an Endophytic Fungus of Seabuckthorn with Plant Growth-Promoting Effect" (Song Yanyu et al., Liaoning Agricultural Science, No. 2, pp. 19-22, 2016), "Effects of Biogas Slurry Extract and Paecilomyces variotii Complex on Tomato Growth and Fruit Quality" (Tang Yuanqiang et al., Chinese Vegetables, Vol. 34, No. 3, pp. 36-41, 20210056), "A Paecilomyces variotii Strain SJ1 and Its Application" (CN104745483A20150701) all mentioned Paecilomyces variotii or its extracts and applications. However, the Paecilomyces variotii strains used in the above documents are all SJ1 (CGMCC No. 10114), which is different from the strain Paecilomyces variotii (CGMCC No. 3.11554) used in the present invention, and their functions and uses are also different. The methods and steps for preparing the extract of Paecilomyces variotii in the above-mentioned documents are significantly different from those of the present invention, and the application of the bacterial extract does not involve any content related to seed germination.Therefore, the Paecilomyces variotii and its extracts and applications described in the above documents have no relevance to the present invention, while the present invention has independent, significant innovation and creativity. Summary of the invention

[0005] The present invention is to increase the concentration of Paecilomyces variotii metabolites, enhance the effect of promoting seed germination, and increase the operability of use, and discloses a seed germination agent prepared from the metabolites of Paecilomyces variotii. The seed germination agent has the effects of softening the seed coat and relieving seed dormancy, can effectively promote seed germination and the growth of radicle and lateral roots, and improve the soil-breaking speed of seedlings and seedling resistance.

[0006] The first object of the present invention is to provide a method for preparing a metabolite of Paecilomyces variotii, comprising the following steps:

[0007] (1) The Paecilomyces variotii strains were activated to prepare seed solution: ① The strains were coated on PDA solid culture medium and cultured at 27-32°C for 20-24 h to rejuvenate; ② The rejuvenated single strains were streaked and inoculated onto LB slant culture medium and cultured and stored at 4°C; ③ The strains from the LB slant culture medium were inoculated into Sabouraud liquid culture medium, and cultured in a 250 mL triangular shake flask at 160-200 rpm and 30-37°C for 20-24 h to form Paecilomyces variotii fermentation seed solution.

[0008] (2) The seed liquid was fermented in a three-stage fermentation tank system to prepare the Paecilomyces variotii fermentation liquid: ① The Paecilomyces variotii fermentation seed liquid was inoculated in a 10L fermentation tank at an inoculation ratio of 8% to 15% (v / v); ② After fermentation at 100 to 150 rpm, 32 to 37°C, pH 6.8 to 8.9, and dissolved oxygen 6% to 14% for 20 to 28 hours, it was inoculated in a 100L fermentation tank at an inoculation ratio of 8% to 15% (v / v); ③ After fermentation at 80 to 120 rpm, 30 to 3 ④ After fermentation at 60-100 rpm, 28-32 ℃, pH 6.8-8.9, and dissolved oxygen 6%-14% for 48 hours, continue fermentation at 50-90 rpm, 28-32 ℃, pH 7.2-9.2, and dissolved oxygen 6%-10% for 48-72 hours to obtain the fermentation liquid of Pseudomonas variotii.

[0009] (3) The fermentation broth of Paecilomyces variotii was filtered through a filter membrane with a pore size of 2 to 10 μm, and the obtained filtrate was the metabolites of Paecilomyces variotii. The filtrate was further concentrated under vacuum pressure of -0.1 MPa, at a temperature of 60 to 75°C, and with a concentration volume of 3 / 4 of the original solution to obtain a concentrated solution of the metabolites of Paecilomyces variotii.

[0010] Furthermore, the Paecilomyces variotii in step (1) is purchased from China General Microbiological Culture Collection Center (CGMCC 3.11554). The coating, streaking and inoculation in steps (1) and (2) are all performed under a sterile environment.

[0011] The second object of the present invention is to provide the use of the above-mentioned Paecilomyces variotii metabolites in the preparation of seed germination agents, and the formula is as follows: 0.2-0.5 parts of concentrated solution of Paecilomyces variotii metabolites, 0.05-0.2 parts of 5-aminolevulinic acid, 1-5 parts of anhydrous ethanol, 0.5-2 parts of dimethyl sulfoxide, 500 parts of sterile water, and mixing to obtain a seed germination agent.

[0012] Furthermore, the specific order of mixing in the ratio is: ① mixing the concentrated solution of metabolites of Paecilomyces variotii with anhydrous ethanol; ② mixing 5-aminolevulinic acid with dimethyl sulfoxide; ③ thoroughly mixing the two mixtures with sterile water.

[0013] The benefits of the present invention are as follows: the seed germination agent of the present invention has a simple preparation method, a mature process flow that is easy to operate, high bacterial strain activity, large fermentation capacity, and low production cost, and can achieve rapid mass production of the seed germination agent; the seed germination agent of the present invention has stable properties, good water solubility, and a simple and diverse use method, which is convenient for transportation, use, and promotion, and can effectively promote seed germination and seedling breaking through the soil in agricultural production, save agricultural costs, and increase agricultural benefits. DETAILED DESCRIPTION

[0014] The principles and features of the present invention are described below in conjunction with examples. The examples are only used to explain the present invention and are not used to limit the scope of the present invention. The parts described in the specific implementation manner are parts by weight.

[0015] The Paecilomyces variotii used in the examples of the present invention was purchased from China General Microbiological Culture Collection Center (CGMCC 3.11554), and 5-aminolevulinic acid was purchased from Yangling Ciyuan Biotechnology Co., Ltd.

[0016] Example 1

[0017] A seed germination agent prepared from the metabolites of Paecilomyces variotii, the preparation of which comprises the following steps:

[0018] (1) The Paecilomyces variotii strain (purchased from China General Microbiological Culture Collection Center CGMCC3.11554) was activated to prepare seed solution: ① The strain was coated on PDA solid culture medium and cultured at 27°C for 24 h to be rejuvenated; ② The rejuvenated single strain was streaked and inoculated on LB slant culture medium and cultured and stored at 4°C; ③ The LB culture medium strain was inoculated into Sabouraud liquid culture medium, and cultured in a 250 mL triangular shake flask at 160 rpm and 30°C for 24 h to form the Paecilomyces variotii fermentation seed solution.

[0019] (2) The seed liquid was fermented in a three-stage fermentation tank system to prepare Paecilomyces variotii fermentation liquid: ① The Paecilomyces variotii fermentation seed liquid was inoculated in a 10L fermentation tank at a 10% (v / v) inoculation ratio; ② After fermentation at 150 rpm, 35°C, pH 6.8, and 14% dissolved oxygen for 20 h, it was inoculated in a 100L fermentation tank at a 10% (v / v) inoculation ratio; ③ After fermentation at 120 rpm, 35°C, pH 6.8, and 14% dissolved oxygen for 20 h, it was inoculated in a 1000L fermentation tank at a 10% (v / v) inoculation ratio; ④ After fermentation at 100 rpm, 32°C, pH 7.0, and 10% dissolved oxygen for 48 h, it was further fermented at 90 rpm, 32°C, pH 8.0, and 9% dissolved oxygen for 48 h to obtain Paecilomyces variotii fermentation liquid.

[0020] (3) The fermentation liquid of Paecilomyces variotii was filtered through a filter membrane with a pore size of 2 μm, and the obtained filtrate was the metabolites of Paecilomyces variotii, which was further concentrated by vacuum decompression at a concentration pressure of -0.1 MPa, a temperature of 75°C, and a concentration volume of 3 / 4 of the volume of the original liquid to obtain a concentrated liquid of the metabolites of Paecilomyces variotii;

[0021] (4) 0.2 parts by weight of the concentrated solution of the metabolites of Paecilomyces variotii, 0.05 parts by weight of 5-aminolevulinic acid, 1 part by weight of anhydrous ethanol, 0.5 parts by weight of dimethyl sulfoxide, and 500 parts by weight of sterile water were mixed and uniformly mixed to obtain a seed germination agent.

[0022] Example 2

[0023] A seed germination agent prepared from the metabolites of Paecilomyces variotii, the preparation of which comprises the following steps:

[0024] (1) The Paecilomyces variotii strain (purchased from China General Microbiological Culture Collection Center CGMCC3.11554) was activated to prepare the seed solution: ① The strain was coated on PDA solid culture medium and cultured at 30°C for 22 h to be rejuvenated; ② The rejuvenated single strain was streaked and inoculated on LB slant culture medium and cultured and stored at 4°C; ③ The LB culture medium strain was inoculated into Sabouraud liquid culture medium, and cultured in a 250 mL triangular shake flask at 180 rpm and 35°C for 22 h to form the Paecilomyces variotii fermentation seed solution.

[0025] (2) The seed liquid was fermented in a three-stage fermentation tank system to prepare Paecilomyces variotii fermentation liquid: ① The Paecilomyces variotii fermentation seed liquid was inoculated in a 10L fermentation tank at a 12% (v / v) inoculation ratio; ② After fermentation at 120 rpm, 35°C, pH 6.8, and 12% dissolved oxygen for 24 h, it was inoculated in a 100L fermentation tank at a 10% (v / v) inoculation ratio; ③ After fermentation at 100 rpm, 33°C, pH 7.0, and 12% dissolved oxygen for 24 h, it was inoculated in a 1000L fermentation tank at a 10% (v / v) inoculation ratio; ④ After fermentation at 80 rpm, 30°C, pH 7.4, and 12% dissolved oxygen for 48 h, it was further fermented at 80 rpm, 30°C, pH 8.0, and 9% dissolved oxygen for 72 h to obtain Paecilomyces variotii fermentation liquid.

[0026] (3) The fermentation liquid of Paecilomyces variotii was filtered through a filter membrane with a pore size of 6 μm, and the obtained filtrate was the metabolites of Paecilomyces variotii, which was further concentrated by vacuum decompression at a concentration pressure of -0.1 MPa, a temperature of 65°C, and a concentration volume of 3 / 4 of the volume of the original liquid to obtain a concentrated liquid of the metabolites of Paecilomyces variotii;

[0027] (4) 0.5 parts of concentrated solution of metabolites of Paecilomyces variotii, 0.2 parts of 5-aminolevulinic acid, 5 parts of anhydrous ethanol, 2 parts of dimethyl sulfoxide, and 500 parts of sterile water were mixed by weight to obtain a seed germination agent.

[0028] Comparative Example 1

[0029] Refer to Example 1 and the comparative documents "Effect of Paecilomyces variotii extract on cherry radish yield and quality" (Jia Chunhua et al., Journal of Agricultural Resources and Environment, Vol. 36, No. 2, pp. 176-183, 20180138), "Study on the mechanism and controlled release effect of Paecilomyces variotii SJ1 extract regulating crop nitrate nitrogen metabolism" (Wang Qingbin, PhD dissertation of Shandong Agricultural University, 20211027), "Physiological adaptability of Paecilomyces variotii extract to rice seedlings under salt stress" (Wang Xiaoqi et al., Journal of Agricultural Resources and Environment, Vol. 37, No. 1, pp. 98-105, 20 180349), "Effects of Paecilomyces variotii extract on chlorophyll fluorescence kinetic parameters of maize leaves under flooding stress" (Xing Yumei et al., Journal of Irrigation and Drainage, Vol. 40, No. 10, pp. 52-57, 20211108), "Effects of Paecilomyces variotii extract on summer maize yield and nitrogen utilization" (Wang Qingbin et al., Crop Journal, No. 4, pp. 166-171, 20210425), "Effects of different nitrogen treatments combined with Paecilomyces variotii extract on growth and nitrogen absorption of pakchoi" (Wang Qingbin et al., Crop Journal, No. 1, pp. 190-195, 20220129), "The mechanism of action of Paecilomyces variotii extract in inducing resistance of pakchoi to low temperature stress" (Wang Qingbin et al., Journal of Nuclear Agricultural Sciences, Vol. 36, No. 2, pp. 473-480), "Effects of several biostimulants on the growth and stress resistance of cherry radish and wheat" (Jia Chunhua, Master's thesis of Shandong Agricultural University, 2020), "Paecilomyces variotii extract (ZNC) improves the resistance of pakchoi to salt-alkali stress" (Wang Qingbin et al., Journal of Plant Physiology, Vol. 57, No. 6, pp. 1291-1299, 20200543), "Effect of Paecilomyces variotii extract ZNC on the growth and stress resistance of cherry radish and wheat" (Jia Chunhua, Master's thesis of Shandong Agricultural University, 2020), "The effect ... "Effects of the combination of biogas slurry extract and Paecilomyces variotii on tomato growth and fruit quality" (Tang Yuanqiang et al., Chinese Vegetables, Vol. 34, No. 3, pp. 36-41, 20210056), "A Paecilomyces variotii strain SJ1 and its application" (CN104745483 A 20150701), replacing the Paecilomyces variotii strain CGMCC No. 3.11554 (purchased from China General Microbiological Culture Collection Administration Center) with the Paecilomyces variotii strain CGMCC No. 10114 (purchased from Shandong Pengbo Biotechnology Co., Ltd.);

[0030] The remaining technical features are the same as those of Example 1.

[0031] Comparative Example 2

[0032] Referring to Example 2, the amplified fermentation step of the three-stage fermentation tank system was removed and replaced with fermentation under natural conditions;

[0033] The remaining technical features are the same as those of Example 2.

[0034] Comparative Example 3

[0035] Referring to Example 1, the metabolites of Paecilomyces variotii were replaced with sterile water;

[0036] The remaining technical features are the same as those of Example 1.

[0037] Comparative Example 4

[0038] Referring to Example 2, 5-aminolevulinic acid was replaced with sterile water;

[0039] The remaining technical features are the same as those of Example 2.

[0040] Comparative Example 5

[0041] Referring to Example 2, the anhydrous ethanol was replaced with sterile water;

[0042] The remaining technical features are the same as those of Example 2.

[0043] Comparative Example 6

[0044] Referring to Example 2, dimethyl sulfoxide was replaced with sterile water;

[0045] The remaining technical features are the same as those of Example 2.

[0046] Test 1

[0047] In December 2021, "Jimai 22" wheat seeds were used as test materials, and individuals with full grains and undamaged epidermis were selected, with 60 grains as a group, divided into Example 1 group, Comparative Example 1 group, Comparative Example 2 group, Comparative Example 3 group, Comparative Example 4 group, Comparative Example 5 group, Comparative Example 6 group, and blank control group, a total of 8 groups with a total of 480 wheat seeds. Each group of the embodiment and the comparative example was treated with an aqueous solution diluted 800 times with the seed germination agent prepared in the corresponding example, and the blank control group was treated with an equal amount of sterile water to soak the wheat seeds of each group.

[0048] Soak the wheat seeds of each group in the corresponding solution for 4.5 hours, then take them out and use absorbent paper to dry the surface moisture of the seeds. Plant 20 wheat seeds in each pot, 3 pots in each group, and a total of 24 pots in a seedling pot, and place them in a constant temperature and humidity tissue culture room at 27°C, relative humidity 10%, and light intensity 800lx. On the 14th day, count the number of seedlings in each group and calculate the seedling rate.

[0049] The data results are shown in Table 1:

[0050] Table 1 Seedling emergence of wheat seeds 14 days after soaking in different solutions

[0051]

[0052] As shown in Table 1, compared with Example 1, the emergence rate of wheat in Comparative Examples 4, 5, and 6 after soaking for 14 days did not reach a significant difference (P < 0.05), but reached a very significant difference (P < 0.01) with the blank control and Comparative Examples 1, 2, and 3. Compared with the blank control, the emergence rate of wheat in Comparative Examples 1, 2, and 3 after soaking for 14 days did not reach a significant difference (P < 0.05). It is proved that the soaking of seeds in Example 1 and Comparative Examples 4, 5, and 6 can significantly promote the germination rate of wheat seeds, while the soaking of seeds in Comparative Examples 1, 2, and 3 has no significant promoting effect on the germination rate of wheat seeds.

[0053] Test 2

[0054] In December 2021, "Zhengdan 958" corn seeds were used as test materials, and individuals with full grains and uniform size were selected, with 90 grains as a group, divided into Example 2 group, Comparative Example 1 group, Comparative Example 2 group, Comparative Example 3 group, Comparative Example 4 group, Comparative Example 5 group, Comparative Example 6 group, and blank control group, a total of 8 groups with a total of 720 corn seeds. Each group of the embodiment and the comparative example was treated with an aqueous solution diluted 1000 times with the seed germination agent prepared in the corresponding example, and the blank control group was treated with an equal amount of sterile water to soak the corn seeds of each group.

[0055] Soak the corn seeds of each group in the corresponding solution for 14 hours, then take them out and use absorbent paper to dry the surface moisture of the seeds. Plant 30 corn seeds in a tray for each group, 3 trays per group, and a total of 24 trays in a seedling tray, and place them in a constant temperature and humidity tissue culture room at 30°C, relative humidity 15%, and light intensity 800lx. On the 10th day, count the number of seedlings in each group and calculate the emergence rate.

[0056] The data results are shown in Table 2:

[0057] Table 2 Seedling emergence of corn seeds 10 days after soaking in different solutions

[0058]

[0059] As shown in Table 2, compared with Example 2, the seedling emergence rate of Comparative Examples 4, 5, and 6 on corn after soaking for 10 days did not reach a significant difference (P < 0.05), but reached a very significant difference (P < 0.01) with the blank control and Comparative Examples 1, 2, and 3. Compared with the blank control, the seedling emergence rate of Comparative Examples 1, 2, and 3 on corn after soaking for 10 days did not reach a significant difference (P < 0.05). It is proved that the seed soaking of Example 2 and Comparative Examples 4, 5, and 6 can significantly promote the germination rate of corn seeds, while the seed soaking of Comparative Examples 1, 2, and 3 has no significant promoting effect on the germination rate of corn seeds.

[0060] Test 3

[0061] In January 2022, "Huayu 22" peanut seeds were used as test materials, double-kernel fruits with regular fruit shape were selected for shelling, and individuals with intact outer skin and full seeds were selected. 90 seeds were grouped into Example 2, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, Comparative Example 5, Comparative Example 6, and a blank control group, a total of 8 groups with a total of 720 peanut seeds. Each group of the Example and the Comparative Example was treated with an aqueous solution diluted 1000 times with the seed germination agent prepared in the corresponding example, and the blank control group was treated with an equal amount of sterile water to soak the peanut seeds of each group.

[0062] Soak the peanut seeds of each group in the corresponding solution for 8 hours, then take them out and use absorbent paper to dry the surface moisture of the seeds. Plant 30 peanut seeds in a tray in each group, 3 trays in each group, a total of 24 trays, in a constant temperature and humidity tissue culture room, at 28°C, 15% relative humidity, and 800lx light intensity. On the 8th day, count the number of seedlings in each group and calculate the emergence rate.

[0063] The data results are shown in Table 3:

[0064] Table 3 Seedling emergence of peanut seeds after 8 days of soaking in different solutions

[0065]

[0066] As shown in Table 3, compared with Example 2, the seedling emergence rates of Comparative Examples 4, 5, and 6 on peanuts 8 days after soaking did not reach a significant difference (P < 0.05), but reached extremely significant differences (P < 0.01) with the blank control and Comparative Examples 1, 2, and 3. Compared with the blank control, the seedling emergence rates of Comparative Examples 1, 2, and 3 on peanuts 8 days after soaking did not reach a significant difference (P < 0.05). It is proved that soaking seeds in Example 2 and Comparative Examples 4, 5, and 6 can significantly promote the germination rate of peanut seeds, while soaking seeds in Comparative Examples 1, 2, and 3 have no significant promoting effect on the germination rate of peanut seeds.

[0067] Test 4

[0068] In April 2022, "Zaoqing No. 2" cucumber seeds were used as test materials, and individuals with full seeds and complete seed shells were selected, with 120 seeds as a group, divided into Example 1 group, Comparative Example 1 group, Comparative Example 2 group, Comparative Example 3 group, Comparative Example 4 group, Comparative Example 5 group, Comparative Example 6 group, and blank control group, a total of 8 groups with a total of 960 cucumber seeds. Each group of the embodiment and the comparative example was diluted 1000 times with an aqueous solution of the seed germination agent prepared in the corresponding example, and the blank control group was soaked with an equal amount of sterile water for seed treatment.

[0069] Soak the cucumber seeds of each group in the corresponding solution for 8 hours, then take them out and use absorbent paper to dry the surface water of the seeds. Plant 40 cucumber seeds in a tray, 3 trays per group, and a total of 24 trays in the seedling tray, and place them in a constant temperature and humidity tissue culture room at 26°C, relative humidity 15%, and light intensity 800lx. On the 7th day, count the number of seedlings in each group and calculate the seedling rate.

[0070] The data results are shown in Table 4:

[0071] Table 4 Seedling emergence of cucumber seeds 7 days after soaking in different solutions

[0072]

[0073] As shown in Table 4, compared with Example 1, the seedling emergence rates of cucumbers in Comparative Examples 4, 5, and 6 after 7 days of seed soaking did not reach significant (P < 0.05) differences, while they all reached extremely significant (P < 0.01) differences with the blank control and Comparative Examples 1, 2, and 3. Compared with the blank control, the seedling emergence rates of cucumbers in Comparative Examples 1, 2, and 3 after 7 days of seed soaking did not reach significant (P < 0.05) differences. It is proved that the seed soaking of Example 1 and Comparative Examples 4, 5, and 6 can significantly promote the germination rate of cucumber seeds, while the seed soaking of Comparative Examples 1, 2, and 3 has no significant promoting effect on the germination rate of cucumber seeds.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A seed germination agent prepared from a metabolite of Paecilomyces variotii, characterized in that: The deposit number of the Paecilomyces variotii is CGMCC No.3.11554, and the preparation steps of the seed germination agent are as follows: Step (1) activating, inoculating and culturing the Paecilomyces variotii strain to prepare a seed solution: ① after the strain is coated with a PDA solid culture medium, it is cultured at a constant temperature of 27-32°C for 20-24 hours to activate and rejuvenate; ② a single rejuvenated strain is selected and streaked onto an LB slant culture medium, and cultured and stored at 4°C; ③ the strain from the LB slant culture medium is selected and inoculated onto a Sabouraud liquid culture medium, and cultured in a 250 mL triangular shake flask at 160-200 rpm and 30-37°C for 20-24 hours to form a Paecilomyces variotii fermentation seed solution; Step (2) the Paecilomyces variotii seed liquid is fermented in a three-stage fermentation tank system to prepare the Paecilomyces variotii fermentation liquid: ① the Paecilomyces variotii fermentation seed liquid is inoculated in a 10L fermentation tank at an inoculation ratio of 8%-15% (v / v), and the tank contains a sterilized Sabouraud liquid culture medium; ② after fermentation for 20-28 hours under fixed conditions of 100-150rpm, 32-37℃, pH6.8-8.9, and dissolved oxygen 6%-14%, the inoculation ratio is inoculated in a 100L fermentation tank at an inoculation ratio of 8%-15% (v / v), and the tank contains a sterilized Sabouraud liquid culture medium; ③ after fermentation at 80-120rpm, the Paecilomyces variotii fermentation seed liquid is inoculated in a 100L fermentation tank at an inoculation ratio of 8%-15% (v / v), and the tank contains a sterilized Sabouraud liquid culture medium. m, 30-35℃, pH6.8-8.9, dissolved oxygen 6%-14% fixed conditions, after fermentation for 20-28h, inoculate in a 1000L fermentation tank with an inoculation ratio of 8%-15% (v / v), the tank contains sterilized Sabouraud liquid medium; ④ After fermentation for 48h at 60-100rpm, 28-32℃, pH6.8-8.9, dissolved oxygen 6%-14%, continue to ferment for 48-72h at 50-90rpm, 28-32℃, pH7.2-9.2, dissolved oxygen 6%-10% fixed conditions to obtain the fermentation liquid of Paecilomyces variotii; Step (3) the fermentation liquid of Paecilomyces variotii is filtered through a filter membrane with a pore size of 2-10 μm, and the obtained filtrate is the metabolites of Paecilomyces variotii, which is further concentrated by vacuum decompression at a concentration pressure of -0.1 MPa, a temperature of 60-75°C, and a concentration volume of 3 / 4 of the volume of the original liquid to obtain a concentrated liquid of the metabolites of Paecilomyces variotii; In step (4), 0.2-0.5 parts of concentrated solution of metabolites of Paecilomyces variotii, 0.05-0.2 parts of 5-aminolevulinic acid, 1-5 parts of anhydrous ethanol, 0.5-2 parts of dimethyl sulfoxide and 500 parts of sterile water are mixed by weight to obtain a seed germination agent.

2. Use of the seed germination agent as claimed in claim 1 in promoting seed germination.

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