A method for improving seed germination characteristics of wild soybean

Abstract

This invention proposes a method for improving the germination characteristics of wild soybean seeds, belonging to the field of seed germination treatment technology. The method includes the following steps: pre-cooling and rewarming treatment of wild soybean seeds. The pre-cooling treatment involves storing the wild soybean seeds at -2℃ to 2℃ for 6 to 8 days to obtain pre-cooled seeds. The rewarming treatment involves rewarming the pre-cooled seeds at 10℃ to 30℃ for at least 7 days to obtain pre-cooled and rewarmed seeds. The pre-cooled and rewarmed seeds are then subjected to a first contact treatment with 98% concentrated sulfuric acid for 10 to 50 minutes. After rinsing with water, dormant seeds are obtained. This method can improve the germination rate, germination potential, germination index, and vigor index of wild soybean seeds, and is simple to operate and easy to promote and apply.

Description

Technical Field

[0001] This invention belongs to the field of seed germination treatment technology, specifically, this invention relates to a method for improving the germination characteristics of wild soybean seeds. Background Technology

[0002] Wild soybean (Glycine soja Siebold & Zucc.) is a closely related ancestral species of soybean, possessing excellent characteristics such as high protein content, wide adaptability, strong resistance to adverse conditions, and a high number of pods per plant. It is an important germplasm resource for breeding high-quality, high-yield, and multi-resistant soybean varieties. However, wild soybeans are impermeable to water and have a hard seed coat, which hinders the absorption of water and nutrients, thus affecting germination and severely limiting their breeding value. Therefore, the germination problem of untreated wild soybean seeds urgently needs to be solved.

[0003] Existing technologies include various treatment methods for wild soybeans or similar hard-seeded plants. For example, CN104620720B discloses a method for improving the germination rate of wild soybean seeds, which involves mixing wild soybeans with river sand or quartz sand at a mass ratio of 1:3 and grinding for 2–4 minutes, followed by soaking in a seed treatment agent at 20°C for 8–10 hours; the seed treatment agent includes ethyl phenyl polyethylene glycol, astragalus extract, glycerin, and distilled water. This method relies on mechanical grinding and a specific compound treatment agent. CN104737668A discloses a method for improving the germination rate and survival rate of wild soybean seeds, which involves treating with 80%–98% concentrated sulfuric acid for 9–11 minutes, anhydrous ethanol or 95% ethanol for 15–20 seconds, and sodium hypochlorite with an effective chlorine content of 3%–6% for 3–5 minutes, followed by cultivation at 22°C for 18–24 hours after imbibition. This method emphasizes a continuous disinfection / dormancy-breaking combination of strong acid, ethanol, and sodium hypochlorite.

[0004] It is evident that existing technologies either rely on complex mechanical grinding and compound reagents, or employ multi-step treatments using strong acids, organic solvents, and disinfectants, making the overall operation quite cumbersome. Therefore, it is necessary to develop a wild soybean seed treatment method that combines ease of operation with germination-promoting effects. Summary of the Invention

[0005] This invention aims to at least partially solve the technical problems existing in the prior art. To this end, this invention proposes a method for improving the germination characteristics of wild soybean seeds. This method can improve the germination rate, germination potential, germination index, and vigor index of wild soybean seeds, and is simple to operate. When combined with technologies such as seed storage, seed germination, and uniform seedling emergence, it has high application value.

[0006] For wild soybean seeds that have been pre-cooled at low temperatures and then warmed back to a specific moisture content, a continuous treatment scheme combining short-term 98% concentrated sulfuric acid treatment with low-concentration gibberellin soaking has not been publicly disclosed in the prior art. Through extensive experiments, the inventors discovered that while pre-cooling and warming alone, sulfuric acid treatment alone, or gibberellin treatment alone can improve germination, the combined treatment of "7 days of 0℃ refrigeration, 7 days of warming, and 20 minutes of 98% concentrated sulfuric acid" and "7 days of 0℃ refrigeration, 7 days of warming, 20 minutes of 98% concentrated sulfuric acid, and 6 hours of 50 mg / L gibberellin" further improved the germination rate, germination potential, germination index, and vigor index of wild soybeans.

[0007] Therefore, in a first aspect, the present invention proposes a method for improving the germination characteristics of wild soybean seeds. According to an embodiment of the present invention, the method includes the following steps: pre-cooling and rewarming wild soybean seeds, wherein the pre-cooling treatment includes refrigerating the wild soybean seeds at -2℃ to 2℃ for 6 to 8 days to obtain pre-cooled seeds; the rewarming treatment includes rewarming the pre-cooled seeds at 10℃ to 30℃ for at least 7 days to obtain pre-cooled and rewarmed seeds; and subjecting the pre-cooled and rewarmed seeds to a first contact treatment with 98% concentrated sulfuric acid for 10 to 50 minutes, followed by rinsing with water to obtain dormant seeds. Wild soybean seeds treated by the method of the present invention exhibit significantly improved germination characteristics, such as germination rate, germination potential, germination index, and vigor index, in subsequent germination cultivation or sowing. Therefore, the method of the present invention has a significant germination-promoting effect on wild soybean seeds, is simple to operate, and has good prospects for widespread application.

[0008] In some embodiments, the precooling temperature is -2°C to 2°C. Exemplarily, the precooling temperature can be -2°C, -1.5°C, -1°C, -0.5°C, 0°C, 0.5°C, 1°C, 1.5°C, or 2°C. In some embodiments, the precooling time is 6 days, 7 days, or 8 days, where "d" represents the time unit "day".

[0009] In some embodiments, the temperature of the rewarming treatment is 10°C to 30°C. For example, the temperature of the rewarming treatment can be 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, or 30°C.

[0010] Through a series of experiments, the inventors discovered that wild soybean seeds can achieve good germination results after being warmed at a temperature of 10℃ to 30℃ for more than 7 days.

[0011] In some embodiments, the rewarming treatment time is 7 to 28 days. For example, the rewarming treatment time is 7 days, 8 days, 9 to 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, or 28 days.

[0012] In some embodiments, the rewarming process takes 7 to 14 days.

[0013] According to an embodiment of the present invention, the temperature of the rewarming treatment is 10℃~25℃, and the time is 7 days.

[0014] In some embodiments, the first contact treatment time is 10 to 50 minutes. For example, the first contact treatment time can be 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, or 50 minutes.

[0015] The first contact treatment described in this invention, namely sulfuric acid treatment, serves the following purposes: Utilizing the corrosive properties of sulfuric acid, it corrodes the cuticle and waxy layers of wild soybeans, removing the hydrophobic layer and exposing hydrophilic cells; it disrupts the surface cell tissue of the seed coat, opening channels for water and oxygen to enter the seed; it reduces the activity of abscisic acid (ABA), increases the proportion of gibberellins within the seed, and promotes embryo development; simultaneously, sulfuric acid also has a disinfecting and bactericidal effect, reducing the rate of mold growth during seed germination. The sulfuric acid treatment time is related to the seed size and moisture content: larger seeds with higher moisture content require shorter treatment times, and vice versa. Ideally, the embryo should not be exposed after sulfuric acid treatment.

[0016] The dormancy-breaking seeds described in this invention refer to wild soybean seeds in a dormant state as raw materials, which, after undergoing the pre-cooling treatment, warming treatment, and first contact treatment described in this invention, have had their physiological dormancy and / or hard dormancy broken or partially broken, and their germination characteristics improved; wherein, the seed germination characteristics include germination rate, germination potential, germination index, and / or vigor index.

[0017] In some embodiments, the method further includes the following step: subjecting the dormant seeds to a second contact treatment with a 40–400 mg / L gibberellin solution for 5–13 hours to obtain seeds ready for germination. Exemplarily, the concentration of the gibberellin solution can be 50 mg / L, 55 mg / L, 60 mg / L, 70 mg / L, 80 mg / L, 100 mg / L, 150 mg / L, 200 mg / L, 250 mg / L, 300 mg / L, 350 mg / L, or 400 mg / L.

[0018] In some embodiments, the moisture content of the pre-cooled and warmed seeds is 10.0% to 12.0%. For example, the moisture content can be 10%, 10.2%, 10.4%, 10.6%, 10.8%, 11%, 11.2%, 11.4%, 11.6%, 11.8%, or 12%.

[0019] According to an embodiment of the present invention, the moisture content of the pre-cooled and warmed seeds is 11.0%.

[0020] In some embodiments, the pre-cooling treatment is carried out at a refrigeration temperature of -1°C to 1°C for 6 to 8 days.

[0021] According to an embodiment of the present invention, the refrigeration temperature of the pre-cooling treatment is 0°C and the time is 7 days.

[0022] According to an embodiment of the present invention, the first contact treatment includes: immersing the pre-cooled and rewarmed seeds in the concentrated sulfuric acid, or spraying the concentrated sulfuric acid onto the surface of the pre-cooled and rewarmed seeds.

[0023] In some implementations, the first contact treatment takes 15 to 35 minutes.

[0024] In other embodiments, the first contact treatment takes 20 to 30 minutes.

[0025] According to an embodiment of the present invention, the first contact treatment time is 20 min.

[0026] According to an embodiment of the present invention, concentrated sulfuric acid is discarded before the water rinsing.

[0027] In some embodiments, the water rinsing is performed 3 to 5 times.

[0028] According to an embodiment of the present invention, the rinsing solution is distilled water.

[0029] In some embodiments, the first contact process further includes a stirring operation.

[0030] According to an embodiment of the present invention, the second contact treatment includes: immersing the dormant seeds in the gibberellin solution, or spraying the gibberellin solution onto the surface of the dormant seeds.

[0031] In some embodiments, the concentration of the gibberellin solution is 40–60 mg / L.

[0032] According to an embodiment of the present invention, the concentration of the gibberellin solution is 50 mg / L.

[0033] In some embodiments, the second contact treatment takes 5 to 7 hours.

[0034] According to an embodiment of the present invention, the second contact treatment time is 6 hours.

[0035] In some embodiments, the second contact process further includes a stirring operation.

[0036] In some embodiments, the wild soybean seeds selected in the pre-cooling treatment are sieved through a 10-20 mesh sieve and / or have a 100-seed weight of 12.0-13.0g.

[0037] According to an embodiment of the present invention, the wild soybean seeds have a 100-seed weight of 12.5 g, an average length of 1.65 mm, an average width of 2.14 mm, and an average roundness of 0.70.

[0038] In some embodiments, the germination rate of the dormant seeds is not less than 91%, and / or the germination potential is not less than 89%, and / or the germination index is not less than 36, and / or the vigor index is not less than 3.4; wherein, during the germination period of the dormant seeds, the number of germinated seeds is recorded daily, the germination potential (Gv) is calculated on the 4th day, and the germination rate (G) and germination index (GI) are calculated on the 7th day. After continuous cultivation for 7 days, the hypocotyl length, radicle length, and fresh weight of the seeds are measured, and the fresh weight of the germinated wild soybean seedlings is weighed using an electronic balance to calculate the vigor index (VI); the germination potential is calculated according to the following formula: Gv(%)=Gt / Gn×100 (Formula I), the germination rate is calculated according to the following formula: G(%)=Ga / Gn×100 (Formula II), the germination index is calculated according to the following formula: GI=∑Gt / Dt (Formula III), and the vigor index is calculated according to the following formula: VI=GI× S (Formula IV); where Gt represents the number of seeds that germinate normally within t days; Gn represents the number of seeds tested; Ga represents the total number of normally germinated seeds at the end of germination; Dt represents the number of germination days; and S represents the fresh weight of soybean seedlings that germinated on day 7.

[0039] In other embodiments, the germination rate of the seeds to be germinated is not less than 95%, and / or the germination potential is not less than 95%, and / or the germination index is not less than 40, and / or the vigor index is not less than 4.8; wherein, the number of germinated seeds is recorded daily during the germination period of the seeds to be germinated, the germination potential (Gv) is calculated on the 4th day, and the germination rate (G) and germination index (GI) are calculated on the 7th day. After continuous cultivation for 7 days, the hypocotyl length, radicle length and fresh weight of the seeds are measured, and the fresh weight of the germinated wild soybean seedlings is weighed using an electronic balance to calculate the vigor index (VI); the germination potential is calculated according to the following formula: Gv(%)=Gt / Gn×100 (Formula I), the germination rate is calculated according to the following formula: G(%)=Ga / Gn×100 (Formula II), the germination index is calculated according to the following formula: GI=∑Gt / Dt (Formula III), and the vigor index is calculated according to the following formula: VI=GI× S (Formula IV); where Gt represents the number of seeds that germinate normally within t days; Gn represents the number of seeds tested; Ga represents the total number of normally germinated seeds at the end of germination; Dt represents the number of germination days; and S represents the fresh weight of soybean seedlings that germinated on day 7.

[0040] In a second aspect, the present invention provides a wild soybean seed ready for germination. According to an embodiment of the present invention, the wild soybean seed ready for germination is obtained by the aforementioned method. According to an embodiment of the present invention, the wild soybean seed ready for germination exhibits high germination rate, germination potential, germination index, vigor index, and other seed germination characteristics, resulting in good germination performance.

[0041] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0042] The present invention will be explained below with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0043] Unless otherwise specified, the germination test conditions in this embodiment of the invention are a temperature of 25°C and a humidity of 75%.

[0044] Example 1: Screening of Seed Pre-cooling and Warming Treatment and Sulfuric Acid Treatment Conditions

[0045] The wild soybean seeds were discovered by the inventor in April 2024 during an experiment conducted in Pidu District, Chengdu City. Seedlings and seeds of wild soybeans were found at the edge of a field. A small quantity of seeds were collected, propagated, and used for scientific research. The experiment selected plump, mold-free, disease-free wild soybean seeds that passed through a 10-mesh sieve. The test material consisted of air-dried wild soybean seeds that passed through a 10-mesh sieve, were uniform in size, and had plump grains. The weight of 100 seeds was 12.5 g, with an average length of 1.65 mm, an average width of 2.14 mm, and an average roundness of 0.70.

[0046] 1. Screening of Seed Pre-cooling and Warming Treatment Conditions

[0047] 1.1 Pre-cooling treatment at different temperatures

[0048] 1.1.1 Test Treatment

[0049] The experimental material was air-dried seeds from storage containers with a moisture content of 9%. The seeds were uniform in size after passing through a 10-mesh sieve. The seeds were not pre-cooled or warmed up. Five treatments were set up for the experiment: (1) CK, no treatment, germination test was performed directly; (2) frozen at -20℃ for 7 days; (3) refrigerated at 0℃ for 7 days; (4) refrigerated at 5℃ for 7 days; (5) refrigerated at 10℃ for 7 days.

[0050] 1.1.2 Experimental Data Collection

[0051] Seed germination indices: The number of germinated seeds was recorded daily during germination. Germination potential (Gv) was calculated on day 4, and germination rate (G) and germination index (GI) were calculated on day 7. After 7 days of continuous culture, the hypocotyl length, radicle length, and fresh weight of the seeds were measured. The fresh weight of germinated wild soybean seedlings was weighed using an electronic balance, and the vigor index (VI) was calculated. The calculation formula is as follows:

[0052] Germination potential Gv(%) = Gt / Gn × 100

[0053] Germination rate G(%) = Ga / Gn × 100

[0054] Germination index GI = ∑Gt / Dt

[0055] Vitality Index VI = GI × S

[0056] In the formula, Gt: number of seeds that germinate normally within t days; Gn: number of seeds tested; Ga: total number of seeds that germinate normally at the end of germination; Dt: number of germination days; S: fresh weight of soybean seedlings that germinate on day 7.

[0057] 1.1.3 Results and Analysis

[0058] The results are shown in Table 1.

[0059] Table 1 Results of the investigation on the germination performance of wild soybean seeds under different pre-cooling temperatures

[0060] Treatment Germination potential Germination rate % Germination index Vigor index CK, no treatment 17.33 18.00 6.11 0.58 Freeze at -20℃ for 7 days 52.00 56.67 10.28 1.15 Refrigerate at 0℃ for 7 days 54.00 55.33 19.71 2.62 Refrigerate at 5℃ for 7 days 17.33 17.33 4.25 0.49 Refrigerate at 10℃ for 7 days 29.33 32.00 13.18 1.44

[0061] Germination potential: Wild soybean seeds pretreated at different temperatures showed the highest germination potential at 0℃ for 7 days (54.00%), significantly higher than the control (CK, no treatment) at 29.33%. This was followed by seeds frozen at -20℃ for 7 days (52.00%), 5℃ for 7 days (17.33%), and 10℃ for 7 days (29.33%).

[0062] Germination rate: The germination rate after freezing at -20℃ for 7 days was 56.67%, higher than the germination rate after refrigeration at 0℃ for 7 days (55.33%). The germination rate of the control (CK) was the same as that after refrigeration at 10℃ for 7 days, both at 32.00%. The worst was after refrigeration at 5℃ for 7 days, with a germination rate of only 17.33%.

[0063] Germination index: The highest germination index (GI) was observed after 7 days of refrigeration at 0℃, at 19.71, which was 1.85 times that of the control (CK) germination index (10.65) and significantly better than all other treatments. Next, the germination index after 7 days of refrigeration at 10℃ was 13.18. The germination index after 7 days of freezing at -20℃ was 10.28, which was not significantly different from the CK germination index (10.65). The worst result was achieved after 7 days of refrigeration at 5℃, with a germination index of 4.25, less than half that of the control.

[0064] Viability Index: The trend of differences in viability index (VI) values ​​among treatments was consistent with that of the germination index. The viability index of treatment refrigerated at 0℃ for 7 days was 2.62, significantly higher than other treatments. The second highest was 1.44 for treatment refrigerated at 10℃ for 7 days, which was not significantly different from the viability index of 1.15 for treatment frozen at -20℃ for 7 days. The viability indices of the control (CK) and the treatment refrigerated at 5℃ for 7 days were both poor, at 0.99 and 0.49, respectively.

[0065] In summary, refrigeration at 0℃ for 7 days significantly improved germination potential, germination index, and vigor index, effectively promoting the germination of wild soybean seeds.

[0066] 1.2 Temperature recovery treatment

[0067] 1.2.1 Test Materials

[0068] Wild soybean seeds were collected during a resource survey. The experiment selected plump, mold-free, disease-free wild soybean seeds that passed through a 10-mesh sieve. The test material consisted of air-dried wild soybean seeds that passed through a 10-mesh sieve, were uniform in size, and had plump grains. The weight of 100 seeds was 12.5g, the average length was 1.65 mm, the average width was 2.14 mm, and the average roundness was 0.70.

[0069] 1.2.2 Test Treatment

[0070] The experimental material was air-dried seeds taken from storage containers without pre-cooling and warming treatment, with a seed moisture content of 9%. Three treatments were set up for the experiment: (1) CK, no treatment, germination test was performed directly; (2) 0℃ cold storage for 7 days, warmed for 7 days and then germination test was performed; (3) 0℃ cold storage for 7 days, germination test was performed directly.

[0071] The temperature for the warming treatment is 10℃~25℃.

[0072] 1.2.3 Results and Analysis

[0073] The results are shown in Table 2.

[0074] Table 2 Effects of rewarming treatment on the germination performance of wild soybean seeds

[0075] Treatment Germination potential Germination rate % Germination index Vigor index CK, perform germination test directly without treatment. 10.00 10.00 1.81 0.17 After refrigerating at 0℃ for 7 days and then bringing the germinated food back to room temperature for 7 days, a germination test was conducted. 56.67 59.33 21.63 3.41 After refrigerating at 0℃ for 7 days, a germination test was conducted directly. 48.67 52.00 18.50 2.52

[0076] As can be seen from the data in Table 2, the germination potential was the highest after 7 days of refrigeration at 0℃ and 7 days of thaw, reaching 56.67%, which was significantly higher than that of the control CK (10.00%) and the germination potential after 7 days of refrigeration at 0℃ (48.67%).

[0077] Germination rate: After 7 days of refrigeration at 0℃ and 7 days of thaw, the germination rate was 59.33%, which was higher than the germination rate of 7 days of refrigeration at 0℃ (52.00%) and the CK germination rate (10.00%).

[0078] Germination index: The germination index (GI) value was the highest after 7 days of refrigeration at 0℃ and 7 days of thawing, which was 21.63, significantly better than CK (1.81) and germination index value of 7 days of refrigeration at 0℃ (18.50).

[0079] Viability index: The viability index of 7 days after refrigeration at 0℃ and 7 days after thawing was 3.41, which was significantly higher than that of CK (0.17) and 7 days after refrigeration at 0℃ (2.52).

[0080] Tests showed that after being refrigerated at 0℃ for 7 days and then placed at room temperature for 7 days, the seed moisture content was approximately 11%.

[0081] In summary, refrigeration at 0℃ for 7 days followed by warming significantly improved germination potential, germination index, and vigor index, effectively promoting the germination of wild soybean seeds.

[0082] 2. Screening of Sulfuric Acid Treatment Conditions

[0083] 2.1 Experimental Design for Sulfuric Acid Treatment

[0084] 2.1.1 Dry seeds were directly treated with sulfuric acid, and the seed moisture content was 9.0%.

[0085] Air-dried seeds taken from storage containers and not pre-cooled or reheated were treated with 98% concentrated sulfuric acid. The seeds were passed through a 10-mesh sieve and had a moisture content of approximately 9.0%. The treatment times were CK, 2 min (N2), 4 min (N4), 8 min (N8), 10 min (N10), 20 min (N20), 30 min (N30), 40 min (N40), 50 min (N50), 60 min (N60), 70 min (N70), 80 min (N80), 90 min (N90), 100 min (N100), 120 min (N120), and 140 min (N140). During the treatment, the seeds were gently stirred with a glass rod. Then, the 98% concentrated sulfuric acid was discarded, and the seeds were rinsed 3–5 times with distilled water.

[0086] 2.1.2 Results and Analysis

[0087] The results are shown in Table 3.

[0088] Table 3 Germination indices of dried wild soybean seeds treated with concentrated sulfuric acid for different durations

[0089] Processing Number Germination potential % Germination rate % Germination Index Vitality Index Treatment number Ger mination potential Ger mination rate Germination index Vigor index CK 8.00 10.67 1.94 0.13 N2 8.67 12.00 3.41 0.23 N4 11.33 13.33 3.27 0.23 N8 10.00 13.33 3.05 0.20 N10 18.67 28.67 5.98 0.44 N20 44.67 62.67 13.86 1.28 N30 70.00 74.67 22.91 2.26 N40 78.00 84.67 30.90 3.26 N50 88.00 91.33 34.38 3.37 N60 88.00 89.33 34.64 2.98 N70 90.67 90.67 38.67 3.35 N80 91.33 92.00 39.86 3.37 N90 93.33 94.00 42.26 3.74 N100 92.00 93.33 45.28 3.67 N120 92.00 93.33 44.30 3.44 N140 92.67 93.33 45.01 3.50

[0090] As can be seen from the data in Table 3, considering the germination effect, treatment efficiency and seed embryo damage risk, 50 min can be regarded as one of the better treatment times for direct sulfuric acid treatment of dry seeds.

[0091] Example 2: Screening of the optimal combination of seed pre-cooling and warming treatment and sulfuric acid treatment

[0092] The experimental material consisted of air-dried wild soybean seeds that were uniform in size and plump, having passed through a 10-mesh sieve. After being refrigerated at 0℃ for 7 days, the seeds were warmed to 18℃–25℃ for 7 days, and then treated with 98% concentrated sulfuric acid. The moisture content of the seeds was approximately 11.0%. The specific treatment plan is as follows:

[0093] CK (treated with 98% sulfuric acid for 0 min), N8 (treated with 98% sulfuric acid for 8 min), N10 (treated with 98% sulfuric acid for 10 min), N15 (treated with 98% sulfuric acid for 15 min), N20 (treated with 98% sulfuric acid for 20 min), N30 (treated with 98% sulfuric acid for 30 min), and N40 (treated with 98% sulfuric acid for 40 min). During the treatment, the mixture was gently stirred with a glass rod. Then, the 98% sulfuric acid was discarded, and the mixture was rinsed with distilled water 3 to 5 times.

[0094] The results are shown in Table 4.

[0095] Table 4. Effects of different concentrated sulfuric acid treatment durations on germination indices of wild soybean seeds after pre-cooling and rewarming.

[0096] deal with Germination potential % Germination rate % Germination Index Vitality Index CK 29.33 32.00 10.65 0.99 N8 36.00 40.00 11.59 1.01 N10 58.00 65.33 19.32 1.65 N15 77.33 80.67 28.76 2.37 N20 88.67 90.00 36.98 3.45 N30 92.67 93.33 38.54 2.96 N40 87.33 89.33 37.04 2.84

[0097] As shown in Table 4, wild soybean seeds treated with 98% sulfuric acid for 20–30 min after being refrigerated at 0℃ for 7 days and then thawed for 7 days yielded the best results. Tests revealed that the moisture content of wild soybean seeds treated with 98% concentrated sulfuric acid after refrigeration for 7 days and thawed for 7 days was approximately 11.0%.

[0098] Example 3 Screening of Gibberellin Treatment Conditions

[0099] 1. Screening of gibberellin soaking concentration and soaking time

[0100] The experimental material was: wild soybean seeds that had not been frozen, and the seeds were uniform in size and passed through a 10-mesh sieve. The seeds were placed at room temperature (10℃~30℃) for a period of time, and the seed moisture content was 11.0%.

[0101] Experimental design: Direct germination of unfrozen seeds served as the control (CK). Five gibberellin concentrations were set: 50 mg / L (GA1), 100 mg / L (GA2), 200 mg / L (GA3), 300 mg / L (GA4), and 400 mg / L (GA5). Two gibberellin soaking times were set: 6 h and 12 h. When treating wild soybean seeds with gibberellin, the seeds were completely immersed in the corresponding concentration of gibberellin solution.

[0102] 2. Results and Analysis

[0103] The results are shown in Table 5.

[0104] Table 5. Effects of different gibberellin concentrations and soaking times on the germination of wild soybean seeds.

[0105] deal with Processing Number Germination potential % Germination rate % Germination Index Vitality Index No action taken CK 6.67 8.67 1.84 0.20 Treatment with 50 mg / L gibberellin for 6 h 6-GA1 42.00 47.33 14.70 1.88 Treatment with 100 mg / L gibberellin for 6 h 6-GA2 41.33 43.33 13.32 1.64 Treatment with 200 mg / L gibberellin for 6 h 6-GA3 45.33 47.33 14.98 1.93 Treatment with 300 mg / L gibberellin for 6 h 6-GA4 48.67 50.67 14.71 1.79 Treatment with 400 mg / L gibberellin for 6 h 6-GA5 50.00 50.00 15.39 1.79 Treatment with 50 mg / L gibberellin for 12 h 12-GA1 35.33 36.67 11.44 1.15 Treatment with 100 mg / L gibberellin for 12 h 12-GA2 22.67 24.00 7.46 0.80 Treatment with 200 mg / L gibberellin for 12 h 12-GA3 26.00 28.00 7.74 0.77 Treatment with 300 mg / L gibberellin for 12 h 12-GA4 30.67 32.00 9.65 0.98 Treatment with 400 mg / L gibberellin for 12 h 12-GA5 30.67 32.67 8.81 0.87

[0106] As shown in Table 5, 50 mg / L gibberellin treatment is effective for seed germination, with both 6 h and 12 h treatments showing good germination promotion. From the perspective of reducing time and cost, the 50 mg / L, 6 h treatment is the most effective.

[0107] Example 4: Screening of the optimal combination of seed pre-cooling and warming treatment, sulfuric acid treatment, and gibberellin treatment

[0108] The experimental materials were: seeds that passed through a 10-mesh sieve, were of uniform size, and were pre-cooled and warmed up (i.e., refrigerated at 0℃ for 7 days and then warmed up at 10℃~30℃ for 7 days), with a seed moisture content of about 11.0%.

[0109] Experimental design: (1) CK: The pretreated seeds were directly tested for germination; (2) N20: 0℃ cold storage for 7 days, 10℃~30℃ warming for 7 days, then sulfuric acid treatment for 20 min before germination test; (3) 6-GA1: 0℃ cold storage for 7 days, 10℃~30℃ warming for 7 days, 50 mg / L gibberellin treatment for 6 h before germination test; (4) 6-GA1+N20: 0℃ cold storage for 7 days, 10℃~30℃ warming for 7 days, sulfuric acid treatment for 20 min, then 50 mg / L gibberellin treatment for 6 h before germination test.

[0110] The results are shown in Table 6.

[0111] Table 6. Effects of sulfuric acid treatment and gibberellin treatment on germination indices of pre-cooled and rewarmed wild soybean seeds.

[0112] Treatment plan (experimental group number) Germination potential % Germination rate % Germination Index Vitality Index Control: Germination after pre-cooling and warming (CK) 46.00 50.00 15.70 1.45 After pre-cooling and warming, treat with sulfuric acid for 20 min (N2O). 89.33 91.33 36.98 3.45 After pre-cooling and thawing, the sample was treated with 50 mg / L gibberellin for 6 h (6-GA1). 57.33 58.00 22.79 2.30 Pre-cooling and rewarming + sulfuric acid treatment for 20 min + treatment with 50 mg / L gibberellin for 6 h (N2O + 6-GA1) 95.33 95.33 40.22 4.83

[0113] As can be seen from the data in Table 6, compared with N20 and 6-GA1, the N20+6-GA1 group, which was refrigerated at 0℃ for 7 days, warmed for 7 days, treated with sulfuric acid for 20 min, then treated with 50 mg / L gibberellin for 6 h, and finally tested for germination, had the best seed germination effect, with further improvements in germination rate, germination potential, germination index and vigor index.

[0114] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for improving the germination characteristics of wild soybean seeds, characterized in that, Includes the following steps: Wild soybean seeds are subjected to pre-cooling and rewarming treatments. The pre-cooling treatment includes storing the wild soybean seeds at -2℃ to 2℃ for 6 to 8 days to obtain pre-cooled seeds. The rewarming treatment includes rewarming the pre-cooled seeds at 10℃ to 30℃ for a period of 7 days or more to obtain pre-cooled and rewarmed seeds. The pre-cooled and reheated seeds were subjected to a first contact treatment with concentrated sulfuric acid of 98% by mass for 10 to 50 minutes. After rinsing with water, dormant seeds were obtained.

2. The method according to claim 1, characterized in that, It also includes the following steps: The dormant seeds were subjected to a second contact treatment with a 40–400 mg / L gibberellin solution for 5–13 h to obtain seeds ready for germination.

3. The method according to any one of claims 1 or 2, characterized in that, The moisture content of the pre-cooled and warmed seeds is 10.0% to 12.0%, preferably 11.0%.

4. The method according to any one of claims 1 or 2, characterized in that, The pre-cooling treatment is carried out at a refrigeration temperature of -1℃ to 1℃ for 6 to 8 days. Furthermore, the pre-cooling treatment is carried out at a refrigeration temperature of 0°C for 7 days; Optionally, the rewarming treatment time is 7 to 28 days; Furthermore, the temperature recovery treatment lasts for 7–14 days; Furthermore, the temperature for the rewarming treatment is 10℃~25℃, and the time is 7 days.

5. The method according to claim 3, characterized in that, The first contact treatment includes: immersing the pre-cooled and rewarmed seeds in the concentrated sulfuric acid, or spraying the concentrated sulfuric acid onto the surface of the pre-cooled and rewarmed seeds; Optionally, the first contact treatment time is 15 to 35 minutes, preferably 20 to 30 minutes, and more preferably 20 minutes; Optionally, the concentrated sulfuric acid is discarded before the water rinsing; Optionally, the water rinsing is performed 3 to 5 times; Furthermore, the rinsing solution is distilled water. Furthermore, the first contact process also includes a stirring operation.

6. The method according to claim 2, characterized in that, The second contact treatment includes: immersing the dormant seeds in the gibberellin solution, or spraying the gibberellin solution onto the surface of the dormant seeds; Optionally, the concentration of the gibberellin solution is 40–60 mg / L, preferably 50 mg / L; Optionally, the second contact treatment time is 5 to 7 hours, preferably 6 hours; Furthermore, the second contact process also includes a stirring operation.

7. The method according to claim 1, characterized in that, The wild soybean seeds selected in the pre-cooling treatment are sieved through a 10-20 mesh sieve and / or have a 100-seed weight of 12.0-13.0g; Furthermore, the wild soybean seeds have a 100-seed weight of 12.5 g, an average length of 1.65 mm, an average width of 2.14 mm, and an average roundness of 0.

70.

8. The method according to claim 1, characterized in that, The germination rate of the dormant seeds is not less than 91%, and / or the germination potential is not less than 89%, and / or the germination index is not less than 36, and / or the vigor index is not less than 3.4; wherein, During the germination period of the dormant seeds, the number of germinated seeds was recorded daily. Germination potential (Gv) was calculated on day 4, and germination rate (G) and germination index (GI) were calculated on day 7. After 7 days of continuous culture, the seed hypocotyl length, radicle length and fresh weight were measured, and the fresh weight of the germinated wild soybean seedlings was weighed using an electronic balance to calculate the vigor index (VI). The germination potential is calculated according to the following formula: Gv(%)=Gt / Gn×100 (Formula I). The germination rate is calculated according to the following formula: G(%)=Ga / Gn×100 (Formula II). The germination index is calculated according to the following formula: GI=∑Gt / Dt (Formula III). The vitality index is calculated according to the following formula: VI = GI × S (Formula IV); Where Gt represents the number of seeds that germinated normally within t days; Gn represents the number of seeds tested; Ga represents the total number of normally germinated seeds at the end of germination; Dt represents the number of germination days; and S represents the fresh weight of soybean seedlings that germinated on day 7.

9. The method according to claim 2, characterized in that, The germination rate of the seeds to be germinated shall not be less than 95%, and / or the germination potential shall not be less than 95%, and / or the germination index shall not be less than 40, and / or the vigor index shall not be less than 4.8; wherein, The number of germinated seeds was recorded daily during the germination period. Germination potential (Gv) was calculated on day 4, and germination rate (G) and germination index (GI) were calculated on day 7. After 7 days of continuous culture, the hypocotyl length, radicle length and fresh weight of the seeds were measured, and the fresh weight of the germinated wild soybean seedlings was weighed using an electronic balance to calculate the vigor index (VI). The germination potential is calculated according to the following formula: Gv(%)=Gt / Gn×100 (Formula I). The germination rate is calculated according to the following formula: G(%)=Ga / Gn×100 (Formula II). The germination index is calculated according to the following formula: GI=∑Gt / Dt (Formula III). The vitality index is calculated according to the following formula: VI = GI × S (Formula IV); Where Gt represents the number of seeds that germinated normally within t days; Gn represents the number of seeds tested; Ga represents the total number of normally germinated seeds at the end of germination; Dt represents the number of germination days; and S represents the fresh weight of soybean seedlings that germinated on day 7.

10. A wild soybean seed awaiting germination, characterized in that, The wild soybean seeds to be germinated are obtained by the method described in any one of claims 1 to 7.