Seed aging method

Abstract

The invention provides a seed aging method, and particularly belongs to the technical field of seed treatment. The seed aging method comprises the following steps: aging seeds under the conditions of normal temperature, low humidity and high pressure; the normal temperature is 5-35 DEG C, and the low humidity is to keep the water activity of the seeds at 0.2-0.6; the high-pressure condition is that compressed air or oxygen-enriched air is added until the pressure is 0.21-300 bar. The seed aging method is carried out under the condition of conventional seed storage temperature and relative humidity, and compared with the condition of high temperature and high humidity, the seed aging method can better simulate the natural aging process of the seeds and is used for researching the physiological and biochemical process of seed aging.

Description

Technical Field

[0001] The invention belongs to the technical field of seed treatment, and in particular relates to a seed aging method. Background Art

[0002] Seed aging during storage may lead to delayed seed germination, and eventually abnormal seedlings or even failure to germinate. For seeds stored in gene banks, seed aging may lose genetic diversity. Seed vitality gradually aging from the vigorous period to the final death, which is a complex continuous process from quantitative change to qualitative change. When stored seeds deteriorate, germination is delayed and seedling growth potential is reduced, which is mainly due to the accumulation of oxidative damage. The main factors affecting seed life are temperature, humidity and oxygen. The traditional seed aging method is to test seeds under AA and CD conditions. When seeds are placed at high temperature and relative humidity of 100% for a certain period of time, this is called accelerated aging (AA). When seeds are placed at a relative humidity of 50-85% and a temperature of 30-45°C for a certain period of time, this is called controlled deterioration (CD). In relatively expensive commercial horticultural seed storage, the temperature of the warehouse is often 15-20°C and the relative humidity is 30-35%. For genetic preservation, seeds are often stored under dry (5-35%) and cold (-20-5°C) conditions. Both AA and CD methods study seed aging and test seed life under high temperature and high humidity conditions. Since the physiological and biochemical changes inside seeds will change with the changes in seed moisture content and temperature, the physiological and biochemical changes inside seeds tested under high temperature and high humidity conditions cannot truly reflect the physiological and biochemical changes of seeds under normal storage conditions. Therefore, it is necessary to find a seed aging method that can simulate the natural aging process of seeds. Summary of the invention

[0003] The purpose of the present invention is to provide a seed aging method. The seed aging method of the present invention is carried out under normal temperature and low humidity conditions. Compared with high temperature and high humidity conditions, the present invention can better simulate the natural aging process of seeds and is used to study the physiological and biochemical processes of seed aging.

[0004] The present invention provides a seed aging method, comprising the following steps: aging seeds under normal temperature, low humidity and high pressure conditions; the normal temperature is 5-35°C, the drying is to keep the water activity of the seeds at 0.2-0.6; the high pressure is to add compressed air or oxygen-enriched air to a pressure of 0.21-300 bar.

[0005] Preferably, the device used for seed aging includes a device for storing seeds and a device for providing pressure.

[0006] Preferably, the seed storage device comprises a perforated tube and a plug.

[0007] Preferably, the device for providing pressure comprises a steel bottle, an aluminum bottle or a carbon fiber bottle.

[0008] Preferably, the device used for seed aging further contains a material for regulating humidity; the material for regulating humidity includes silica gel.

[0009] Preferably, the amount of silica gel used is 100-200 g / L.

[0010] Preferably, after the seed aging is completed, the pressure is released to normal pressure.

[0011] Preferably, the pressure release rate is 0.5-1% of the relative pressure per minute.

[0012] Preferably, the seeds include any one of lettuce seeds, cabbage seeds, tomato seeds and rice seeds.

[0013] The present invention provides a seed aging method, which is carried out under normal temperature and low humidity conditions, which is similar to conventional seed storage conditions. Compared with high temperature and high humidity conditions, the present invention can better simulate the natural aging process of seeds and is used to study the physiological and biochemical processes of seed aging. The test results show that the germination potential, germination rate, and seedling root length of cabbage and lettuce seeds aged for 2 weeks, 4 weeks, and 8 weeks, and the tomato seeds aged for 2 weeks and 4 weeks decrease, and T50 increases, which indicates that cabbage, lettuce, and tomato seeds have different degrees of aging with the increase of time. Lettuce seeds were subjected to high pressure aging and natural aging respectively (Table 4). Under high pressure conditions, the oxygen pressure in the storage environment increased and the aging speed was accelerated. When stored for 4 weeks under the same other storage conditions, the high pressure conditions accelerated the aging of seeds, reduced the germination rate, and greatly reduced the seedling rate. The performance of high pressure aging is similar to that of natural aging, with delayed germination, reduced total germination rate, and smaller seedlings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0015] Figure 1 The germination diagrams of the unaged and high-pressure aged cabbage, lettuce and tomato provided by the present invention are shown (the unaged seeds are obtained by sealing the seeds in aluminum foil bags and storing them at -20°C). DETAILED DESCRIPTION

[0016] The present invention provides a seed aging method, comprising the following steps: aging seeds under normal temperature, low humidity and high pressure conditions; the normal temperature is 5-35°C, the low humidity is to keep the water activity of seeds at 0.2-0.6; the high pressure is to add compressed air or oxygen-enriched air to a pressure of 0.21-300 bar. The traditional seed aging method is a high temperature and high humidity condition, while the present invention adopts normal temperature, low humidity and high pressure conditions. In the present invention, the normal temperature is preferably 10-25°C, more preferably 20°C. The present invention adjusts the water activity of seeds to 0.2-0.6 by adding silica gel. In the present invention, the pressure of the high pressure is preferably 0.21-300 bar, more preferably 200 bar. In the present invention, the oxygen-enriched air is air containing 21%-99.5% oxygen, more preferably air containing 21%-93% oxygen. In the present invention, the seeds preferably include any one of lettuce seeds, cabbage seeds, tomato seeds and rice seeds.

[0017] In the present invention, the device used for seed aging preferably includes a device for storing seeds and a device for providing pressure. In the present invention, the device for storing seeds preferably includes a perforated tube and a plug. In the present invention, the material of the perforated tube preferably includes polystyrene or paper material. In the present invention, the material of the plug preferably includes polyethylene. In the present invention, the pore size of the hole is preferably not more than 1mm. The present invention does not specifically limit the volume of the perforated tube. In one embodiment, the volume of the perforated tube is preferably 13mL. In the present invention, the polyethylene is preferably low-density polyethylene. In the present invention, the device for providing pressure preferably includes a steel bottle or an aluminum bottle or a carbon fiber bottle. In the present invention, the device used for seed aging also contains a material for regulating humidity; the material for regulating humidity includes silica gel, which regulates the relative humidity in the tank. In the present invention, the amount of the silica gel is preferably 100-200g / L, more preferably 133g / L. In the present invention, the silica gel preferably has the same water activity as the seeds. In the present invention, after placing a perforated tube (with a stopper plugged at the tube mouth) storing seeds into a steel cylinder, the present invention places silica gel into the steel cylinder. Afterwards, the present invention preferably slowly fills the steel cylinder with compressed air or oxygen-enriched air. In the present invention, the steel cylinder is preferably a 1.5L steel cylinder. In the present invention, the time for filling with compressed air or oxygen-enriched air is preferably 0.8 to 1.2 hours, more preferably 1 hour. There is air in the steel cylinder originally, and the present invention introduces compressed air or oxygen-enriched air into the steel cylinder containing air until the pressure is 0.21 to 300 bar. After the inflation is completed, the present invention preferably places the steel cylinder at room temperature, more preferably at 20°C.

[0018] The present invention preferably determines the required aging time according to the degree of aging, and then releases the pressure to take out the seeds. In the present invention, after the seed aging is completed, the pressure is released to normal pressure. In the present invention, the speed of releasing the pressure is preferably 0.5-1% relative pressure per minute, more preferably 0.8% relative pressure, to prevent the seed coat from rupturing. By adjusting the aging time, the present invention can obtain aged seeds with different degrees of reduced germination potential, germination rate, and seedling root length, and different degrees of increased T50, providing a research method for studying seed vitality repair technology and studying the effects of different oxygen levels on seed storage.

[0019] In order to further illustrate the present invention, a seed aging method provided by the present invention is described in detail below in conjunction with the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0020] Example 1

[0021] Take three portions of 2 grams of lettuce seeds (seed water activity 0.3) and place them in 13 mL polystyrene tubes with holes (polyethylene tubes are perforated with holes with a diameter of no more than 1 mm) and plug the tubes with low-density polyethylene (tube and cap model: Tube, 13 ml, 95x16.8mm, PS, Sarstedt, Germany), place a polystyrene tube and 200g of silica gel in a 1.5L cylinder, slowly fill the 1.5L cylinder with compressed air until the pressure reaches 180bar, which takes about 1 hour, and place the cylinder at room temperature 20°C. After 2 weeks, 4 weeks, and 8 weeks, one cylinder was connected to a computer flow rate controller, and the pressure was released to normal pressure at a rate of 1% per minute to obtain lettuce seeds with different aging degrees.

[0022] Example 2

[0023] Take three portions of 2 grams of cabbage seeds (polyethylene tubes with holes, seed water activity 0.3) and place them in 13 mL polystyrene tubes with holes (hole diameter not exceeding 1 mm) and plug the tube mouth with low-density polyethylene. Place the polystyrene tube and 200 grams of silica gel in a 1.5 L steel cylinder. Slowly fill the 1.5 L steel cylinder with compressed air until the pressure reaches 180 bar, which takes about 1 hour. Place the steel cylinder at room temperature 20°C. After 2 weeks, 4 weeks, and 8 weeks, connect one steel cylinder to a computer flow rate controller and release the pressure at a rate of 1% per minute to obtain cabbage seeds with different aging degrees.

[0024] Example 3

[0025] Take three portions of 2 grams of tomato seeds (polyethylene tubes with holes, seed water activity 0.3) and place them in 13 mL polystyrene tubes with holes (hole diameter not exceeding 1 mm) and plug the tube mouth with low-density polyethylene. Place the polystyrene tube and 200 grams of silica gel in a 1.5 L steel cylinder. Slowly fill the 1.5 L steel cylinder with compressed air until the pressure reaches 180 bar, which takes about 1 hour. Place the steel cylinder at room temperature 20°C. After 2 weeks and 4 weeks, connect one steel cylinder to a computer flow rate controller and release the pressure at a rate of 1% per minute to obtain tomato seeds with different aging degrees.

[0026] Experimental results:

[0027] Table 1 Effects of different aging times on cabbage seed germination and seedling growth

[0028] 3-day germination potential (%) Germination rate (%) T50(h) Seedling root length (mm) Comparison 99.4 100.0 35.5 2.14 Aging 2 weeks 55.6 90.0 59.8 1.00 Aging 4 weeks 50.0 89.4 67.3 0.80 Aging 8 weeks 35.0 80.0 79.2 0.64

[0029] The control was obtained by sealing the seeds in aluminum foil bags and storing them at -20°C, and the same applies to the following. T50 is the time required for 50% of the seeds to germinate.

[0030] Table 2 Effects of different aging times on lettuce seed germination and seedling growth

[0031] Germination potential in 1 day (%) Germination rate (%) T50(h) Seedling root length (mm) Comparison 98.3 100 16.0 0.87 Aging 2 weeks 97.8 98.3 16.7 0.75 Aging 4 weeks 92.2 97.8 18.1 0.68 Aging 8 weeks 33.9 100 25.7 0.56

[0032] Table 3 Effects of different aging times on tomato seed germination and seedling growth

[0033] 3-day germination potential (%) Germination rate (%) T50(h) Seedling root length (mm) Comparison 27.8 98.9 79.8 0.94 Aging 2 weeks 13.3 98.3 90.2 0.58 Aging 4 weeks 13.0 93.3 89.9 0.39

[0034] It can be seen from Tables 1, 2 and 3 that compared with the control, the germination potential, germination rate and seedling root length of cabbage and lettuce seeds aged for 2, 4 and 8 weeks and tomato seeds aged for 2 and 4 weeks decreased, while T50 increased, which indicates that cabbage, lettuce and tomato seeds have achieved different degrees of aging with the increase of time.

[0035] Figure 1 They are respectively the germination diagrams of cabbage seeds (control), cabbage seeds aged under high pressure for 8 weeks, lettuce seeds (control), lettuce seeds aged under high pressure for 8 weeks, tomato seeds (control), and tomato seeds aged under high pressure for 4 weeks in Example 1, Example 2, and Example 3.

[0036] Example 4

[0037] High-pressure aging (180 bar): Take 3 portions of 2 grams of lettuce seeds (seed water activity 0.35) and place them in 13 mL polystyrene tubes with holes (polyethylene tubes are perforated with holes with a diameter not exceeding 1 mm) and plug the tube mouth with low-density polyethylene. Place the polystyrene tube and 200 grams of silica gel in a 1.5 L steel cylinder. Slowly fill the 1.5 L steel cylinder with compressed air until the pressure reaches 180 bar, which takes about 1 hour. Place the steel cylinder at room temperature 20°C. After storage for 4 weeks, connect the steel cylinder to a computer flow rate controller and release the pressure to normal pressure at a rate of 1% per minute. Natural aging (1 bar): Take another 3 portions of the same lettuce seeds (seed water activity 0.35) and place them at 20°C and 35% relative humidity for 4 weeks.

[0038] Table 4 Effects of different aging times on lettuce seed germination and seedling formation

[0039] Germination rate (%) Seedling rate (%) Natural aging 4 weeks 100 96％ High pressure aging for 4 weeks 98.3 70％

[0040] Lettuce seeds were aged under high pressure and naturally (Table 4). Under high pressure, the oxygen pressure in the storage environment increased and the aging rate accelerated. When stored for 4 weeks under the same other storage conditions, high pressure oxygen conditions accelerated seed aging, reduced germination rate, and greatly reduced seedling rate. The performance of high pressure oxygen aging was similar to natural aging, with delayed germination, reduced total germination rate, and smaller seedlings.

[0041] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A seed aging method, characterized in that: The following steps are involved: The seeds are aged under normal temperature, low humidity and high pressure conditions; the normal temperature is 5-35°C, the low humidity is to maintain the water activity of the seeds at 0.2-0.6; the high pressure is to add compressed air or oxygen-enriched air to a pressure of 0.21-300 bar.

2. The seed aging method according to claim 1, characterized in that: The device used for seed aging comprises a device for storing seeds and a device for providing pressure.

3. The seed aging method according to claim 2, characterized in that: The seed storage device includes a tube with holes and a plug.

4. The seed aging method according to claim 2, characterized in that: The device for providing pressure includes a steel bottle, an aluminum bottle or a carbon fiber bottle.

5. The seed aging method according to claim 2, characterized in that: The device for seed aging also contains a material for regulating humidity; the material for regulating humidity includes silica gel.

6. The seed aging method according to claim 5, characterized in that: The amount of the silica gel is 100-200 g / L.

7. The seed aging method according to claim 1, characterized in that: After the seed aging is completed, the pressure is released to normal pressure.

8. The seed aging method according to claim 7, characterized in that: The speed of releasing the pressure is 0.5-1% of the relative pressure per minute.

9. The seed aging method according to claim 1, characterized in that: The seeds include any one of lettuce seeds, cabbage seeds, tomato seeds and rice seeds.

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