Drought-resistant seedling-strengthening awnless brome coated seed and preparation method thereof

Abstract

The invention discloses a drought-resistant seedling-strengthening awnless brome coated seed and a preparation method thereof, and belongs to the technical field of seed processing. According to the coated seed prepared in the invention, the coating comprises three layers, namely an initial coating layer, a composite active layer and a protective layer in sequence from inside to outside, and the components of the composite active layer comprise bentonite, talcum powder, sodium polyacrylate and ammonium molybdate. Wherein sodium polyacrylate and ammonium molybdate can generate a synergistic effect to improve the drought resistance of the seeds and the drought resistance and seedling strengthening capability of the seedlings; growth indexes such as germination rate, seedling root length and seedling height of the coated seeds are obviously improved, and agricultural development in arid or semi-arid regions is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of seed processing, and particularly relates to a drought-resistant and strong-seedling type Bromus inermis Leyss. coated seeds and a preparation method thereof. Background Art

[0002] Seeds are the foundation of agricultural production and the basis for food production, economic crop cultivation, and ecological improvement. Bromus inermis Leyss. belongs to the genus Bromus of the Gramineae family and is a dominant species in mountain meadow pastures. Its stems are brittle and tender, its leaves are wide, long, and soft, and it has strong palatability. It is one of the forages favored by herbivorous livestock and can be used for the improvement of natural grasslands, the construction of artificial forage bases, and ecological environmental protection. With the adjustment of the rural industrial structure and the need for ecological environment governance, the cultivation area of Bromus inermis Leyss. has increased, and the demand for seeds has shown an upward trend.

[0003] The impact of drought is very obvious in all phenological stages of plant growth and development. Among them, the stages of seed germination and seedling growth are the most sensitive periods to drought stress. Drought may lead to a decrease in seed germination potential and germination rate, reduce the photosynthetic capacity of plants, reduce photosynthetic products, cause metabolic disorders, and affect seed germination and normal seedling growth. Drought significantly delays or inhibits seed germination by inhibiting seed water absorption and reducing the activity of various enzymes, reducing the germination rate of seeds. After seed germination, the growth and development of seedlings are also restricted to a certain extent. Therefore, in order to improve the emergence rate and survival rate of crops, it is very important to improve the drought resistance of seeds.

[0004] Therefore, there is a need to develop an effective method that is low-cost, environmentally friendly, and can promote the germination of Bromus inermis Leyss. seeds under drought conditions and enhance the drought resistance of its seedlings. Summary of the Invention

[0005] In view of the above-mentioned prior art, the present invention discloses a drought-resistant and strong-seedling type Bromus inermis Leyss. coated seeds and a preparation method thereof to solve the technical problems of low seed germination rate of existing Bromus inermis Leyss. seeds under drought conditions and weak drought resistance and seedling protection ability of seedlings.

[0006] To achieve the above object, the technical solution adopted by the present invention is: to provide a drought-resistant and strong-seedling type Bromus inermis Leyss. coated seeds, the coating of the coated seeds from the inside to the outside is successively an initial coating layer, a composite active layer, and a protective layer; the seed coating has three layers; the initial coating layer and the protective layer are composed of powder A and an adhesive, and powder A includes bentonite and talcum powder; the composite active layer is composed of powder B and the adhesive, and powder B includes bentonite, talcum powder, sodium polyacrylate, and ammonium molybdate; the adhesive is a carboxymethyl cellulose salt solution.

[0007] On the basis of the above technical solution, the present invention can also be improved as follows.

[0008] Further, the carboxymethyl cellulose salt solution is an aqueous solution of sodium carboxymethyl cellulose with a concentration of 1-1.5 wt%.

[0009] Further, the mass ratio of bentonite to talc powder in powder A is 1:1; the ratio of powder A to the adhesive in the initial coating layer and the protective layer is 10 g:2 mL.

[0010] Further, the mass ratio of bentonite, talc powder, sodium polyacrylate and ammonium molybdate in powder B is 5:5:1:0.05; the ratio of powder B to the adhesive in the composite active layer is 11.05 g:6 mL.

[0011] The present invention also discloses a method for preparing the above drought-resistant and seedling-strengthening coated seeds, which comprises the following steps:

[0012] S1: Pour the seeds into a coating machine and make the seeds rotate at a constant speed. Then, wet the surface of the seeds with an aqueous solution of sodium carboxymethylcellulose with a concentration of 1 wt%. Then, alternately add powder A and the adhesive to the coating machine. After all of powder A is added, the seeds wrapped with the initial coating layer are obtained.

[0013] S2: Let the seeds wrapped with the initial coating layer rotate empty in the coating machine for 1 - 2 min, then alternately add powder B and the adhesive. After all of powder B is added, the seeds wrapped with the composite active layer are obtained.

[0014] S3: Let the seeds wrapped with the composite active layer rotate empty in the coating machine for 2 - 3 min, then alternately add powder A and the adhesive. After all of powder A is added, the seeds wrapped with the protective layer are obtained, and they are obtained after drying or natural air drying.

[0015] Based on the above technical solutions, the present invention can also be improved as follows.

[0016] Further, the rotation speed of the coating machine is 550 - 650 rpm.

[0017] The beneficial effects of the present invention are:

[0018] 1. The bromegrass coated seeds prepared by the present invention have a three-layer coating structure, including an initial coating layer, a composite active layer and a protective layer. The initial coating layer provides mechanical strength for the seeds and enhances the adhesion effect between the coating and the seeds; the composite active layer further increases the overall thickness of the coating and also contains functional components. Especially through the synergistic effect of sodium polyacrylate and ammonium molybdate, the drought resistance of the seeds is significantly improved. Sodium polyacrylate creates a stable moisture environment for the seed roots and promotes root development, and the developed roots can efficiently absorb the water and MoO4 released from the composite active layer 2- , forming a virtuous cycle mechanism for water absorption and utilization; MoO4 2- can enhance the antioxidant capacity of plants by regulating the synthesis of signaling molecules to cope with drought stress; the protective layer can improve the coating integrity and long-term storage stability.

[0019] 2. Film coating treatment significantly improves the germination rate of smooth bromegrass seeds, accelerates the emergence rate, and promotes the robust growth of seedlings. In addition, it enhances the development of the root system, making it more developed, capable of penetrating deep into the soil, greatly enhancing the water and nutrient absorption capacity, effectively enhancing the stress resistance of seedlings, and increasing the fresh weight and biomass of plants. Film coating treatment also helps optimize the physiological metabolism of plants, improve their drought tolerance, enabling smooth bromegrass to still grow vigorously in an environment with limited water, providing a solid guarantee for ecological restoration and forage production.

[0020] 3. Film coating treatment changes the morphology of smooth bromegrass seeds, making them more regular, and increasing their volume and weight, thus overcoming the mechanical sowing problems brought about by traditional seeds with small size, light weight, and irregular shape, providing a reliable guarantee for the precise sowing and efficient cultivation of smooth bromegrass seeds. Description of the Drawings

[0021] Figure 1 It is a comparison diagram before and after the film coating treatment of smooth bromegrass seeds. Detailed Embodiments

[0022] Test materials: The polyacrylate product was purchased from Shanghai Macklin Biochemical Co., Ltd.

[0023] The following combines examples to make a detailed description of the specific embodiments of the present invention. The components and ratios of the seed coating composite active layer in the examples and comparative examples are shown in Table 1.

[0024] Table 1

[0025]

[0026] Example 1

[0027] A drought-resistant and seedling-strengthening type of smooth bromegrass coated seeds and its preparation method, including the following steps:

[0028] S1: Select 5 g of smooth bromegrass seeds with similar size, uniform and plump. Then pour the seeds into a 5XW-110A type seed coating machine, and adjust the rotation speed of the coating machine to 550 rpm, so that the seeds rotate uniformly along the inner wall to form an obvious oval circle, and ensure that the seeds can touch the baffle. Then place the atomization disk in the card slot, add 0.4 mL of a 1 wt% sodium carboxymethylcellulose aqueous solution to the atomization disk, and make the solution evenly spray on the surface of the seeds. After the surface of the seeds is evenly wetted, alternately and slowly add powder A and a 1 wt% sodium carboxymethylcellulose aqueous solution to the coating machine. The total amount of powder A is 10 g (5 g bentonite + 5 g talc powder), and the total volume of the sodium carboxymethylcellulose aqueous solution is 2 mL. After all the powder A is added, the seeds wrapped with the initial coating layer are obtained;

[0029] S2: Keep the seeds coated with the initial coating layer idling in the coating machine for 1 min, then alternately and slowly add powder B and an aqueous solution of sodium carboxymethylcellulose with a concentration of 1.5 wt% into the coating machine. The total amount of powder B is 11.05 g (5 g bentonite + 5 g talc + 1 g sodium polyacrylate + 0.05 g ammonium molybdate), and the total volume of the aqueous solution of sodium carboxymethylcellulose is 6 mL. After all of powder B is added, the seeds coated with the composite active layer are obtained;

[0030] S3: Keep the seeds coated with the composite active layer idling in the coating machine for 2 min, then alternately and slowly add powder A and an aqueous solution of sodium carboxymethylcellulose with a concentration of 1.5 wt% into the coating machine. The total amount of powder A is 3 g (1.5 g bentonite + 1.5 g talc), and the total volume of the aqueous solution of sodium carboxymethylcellulose is 1 mL. After all of powder A is added, the seeds coated with the protective layer are obtained. After taking out the seeds, dry them in the air at room temperature for 24 h to obtain the product.

[0031] Example 2

[0032] A drought-resistant and strong-seedling type Bromus inermis Leyss. coated seeds and its preparation method, including the following steps:

[0033] S1: Select 5 g of Bromus inermis Leyss. seeds with similar size, uniform and plump. Then pour the seeds into a 5XW-110A type seed coating machine, and adjust the rotation speed of the coating machine to 650 rpm to make the seeds rotate uniformly along the inner wall to form an obvious ellipse, and ensure that the seeds can touch the baffle. Then place the atomization disc in the card slot, add 0.4 mL of an aqueous solution of sodium carboxymethylcellulose with a concentration of 1.5 wt% into the atomization disc, and make the solution evenly spray on the surface of the seeds. After the surface of the seeds is evenly wetted, alternately and slowly add powder A and an aqueous solution of sodium carboxymethylcellulose with a concentration of 1 wt% into the coating machine. The total amount of powder A is 10 g (5 g bentonite + 5 g talc), and the total volume of the aqueous solution of sodium carboxymethylcellulose is 2 mL. After all of powder A is added, the seeds coated with the initial coating layer are obtained;

[0034] S2: Keep the seeds coated with the initial coating layer idling in the coating machine for 2 min, then alternately and slowly add powder B and an aqueous solution of sodium carboxymethylcellulose with a concentration of 1.5 wt% into the coating machine. The total amount of powder B is 11.05 g (5 g bentonite + 5 g talc + 1 g sodium polyacrylate + 0.05 g ammonium molybdate), and the total volume of the aqueous solution of sodium carboxymethylcellulose is 6 mL. After all of powder B is added, the seeds coated with the composite active layer are obtained;

[0035] S3: Keep the seeds wrapped with the composite active layer idling in the coating machine for another 3 min, then alternately and slowly add powder A and an aqueous solution of sodium carboxymethylcellulose with a concentration of 1.5 wt% into the coating machine. The total amount of powder A is 3 g (1.5 g bentonite + 1.5 g talc powder), and the total volume of the aqueous solution of sodium carboxymethylcellulose is 1 mL. After all of powder A is added, the seeds with a protective layer are obtained. After taking out the seeds, air-dry them at room temperature for 24 h to obtain the product.

[0036] The preparation method of the coated seeds in the comparative example is the same as that in the example.

[0037] Experimental Example

[0038] ① Screening of Bromus inermis seeds under drought stress conditions

[0039] Randomly select 100 Bromus inermis seeds respectively, record the initial total weight of the whole plate, weigh them daily and supplement distilled water, cover the container to prevent water evaporation, and conduct a sand bed germination test; the size of the germination box is 12 cm × 12 cm × 6 cm, and 300 g of sieved clean sand with a size of 0.8 cm is laid at the bottom; then add distilled water with mass ratios of 2%, 5%, 8%, and 11% to the sand bed respectively, and then place the coated seeds 2 cm above the sand surface respectively, and supplement the evaporated water daily. According to the seed inspection standards of ISTA "International Rules for Seed Testing 2023", determine the germination rate, root length, seedling height, fresh weight and other indexes of the seeds to determine the most suitable drought stress conditions.

[0040] (1) Germination rate (%) = number of normal seedlings counted at the last count / total number of tested seeds × 100%.

[0041] (2) Root length, seedling length, and seedling fresh weight: After the Bromus inermis seeds germinate for 14 d, randomly select 10 seedlings from each repetition of each treatment to measure the root and seedling lengths (cm) and fresh weights (g), with 4 repetitions. The measurement results are shown in Table 2.

[0042] Table 2

[0043] Substrate water content (%) Germination rate (%) Root length (cm) Seedling length (cm) Fresh weight (g) 11 75±1.7a 4.9±1.85a 7.8±1.26a 0.179±0.009a 8 61±1.7b 3.9±1.79b 6.7±1.19b 0.154±0.010b 5 52±3.1c 2.1±0.73c 6.1±1.16b 0.137±0.015bc 2 30±1.7d 2.0±0.48c 3.8±1.07c 0.132±0.008c

[0044] Note: Different lowercase letters indicate significant differences between treatments at the 0.05 level.

[0045] It can be seen from Table 2 that the germination indexes (germination rate, root length, seedling length, and fresh weight) of Bromus inermis seeds all gradually decrease with the decrease of the substrate moisture. Through comprehensive analysis, 8% substrate moisture content is determined as the most suitable drought stress condition for Bromus inermis seeds.

[0046] ② Experiment on the drought stress tolerance of coated Bromus inermis seeds

[0047] Under drought stress conditions, germination indexes such as germination rate, root length, seedling height and fresh weight of the coated bromegrass seeds in Example 1 and Comparative Examples 1-10 were measured; CK-1 was the normal treatment under non-stress conditions, and CK-2 was the non-coated treatment of seeds under drought stress conditions. The results are shown in Table 3.

[0048] Table 3

[0049] Sample Germination rate (%) Root length (cm) Seedling height (cm) Fresh weight of seedlings (g) CK-1 85 4.9 7.8 0.179 CK-2 61 3.9 6.8 0.153 Example 1 83 5.4 8.2 0.188 Comparative Example 1 70 4.7 7.0 0.178 Comparative Example 2 80 5.0 7.5 0.191 Comparative Example 3 63 4.3 6.5 0.168 Comparative Example 4 72 4.9 7.0 0.180 Comparative Example 5 64 4.0 7.0 0.180 Comparative Example 6 66 3.6 6.3 0.172 Comparative Example 7 70 4.2 7.0 0.177 Comparative Example 8 77 4.1 7.8 0.185 Comparative Example 9 67 4.5 6.8 0.180 Comparative Example 10 67 4.1 6.0 0.178

[0050] As can be seen from Table 3, under drought stress conditions, the seeds treated with coating in Example 1 showed significant improvement in various growth indexes, and the improvement effect was more obvious than that of the comparative examples.

[0051] ③Coating quality detection of coated bromegrass seeds

[0052] The comparison diagram of the seeds before and after coating in Example 1 is as Figure 1 shown. It can be seen from the figure that the coating technology can change the morphology of the seeds, make them more regular, and increase the volume and weight, thus overcoming the mechanical sowing problems brought by the small size, light weight and irregular shape of traditional seeds.

[0053] (1) Determination of the particle size of coated seeds

[0054] Randomly select 100 coated seeds, measure the diameter of the coated seeds with a vernier caliper, calculate the average value, in mm, accurate to 0.01 mm.

[0055] (2) Cracking rate

[0056] Randomly select 100 coated seeds, place the seeds on a moist filter paper, and count the number of cracked seeds after 5 minutes. Calculate the percentage of the number of cracked seeds in the total number of tested coated seeds, and set 3 replicates.

[0057] Calculation formula: Cracking rate = number of cracked coated seeds / total number of tested seeds × 100%.

[0058] (3) Single-seed rate

[0059] Randomly select 100 coated seeds, count the number of single seeds (there is only one naked seed in each coated seed), calculate the percentage of the number of single-seed coated seeds in the tested seeds, and the single-seed rate is required to be ≥98.0%.

[0060] (4) Thousand-grain weight of coated seeds

[0061] Randomly select 100 coated seeds, weigh their weights, repeat 8 times, calculate the average weight of 100 seeds, and the thousand-grain weight is 10 times of it.

[0062] (5) Pelleting multiple

[0063] The pelleting multiple refers to the thousand-grain weight of pelleted seeds / the thousand-grain weight of bare seeds.

[0064] The above quality inspection results are shown in Table 4, and it can be seen that the coated seeds all meet the quality requirements.

[0065] Table 4

[0066]

[0067] Although the specific embodiments of the present invention have been described in detail in conjunction with the embodiments, it should not be construed as a limitation on the protection scope of the present invention. Within the scope described in the claims, various modifications and deformations that can be made by those skilled in the art without creative efforts still fall within the protection scope of the present invention.

Claims

1. A drought-resistant and strong seedling type awnless brome coated seed, characterized in that: The coating of the coated seeds is composed of an initial coating layer, a composite active layer and a protective layer from the inside to the outside; the initial coating layer and the protective layer are composed of a powder A and an adhesive, and the powder A includes bentonite and talc; the composite active layer is composed of a powder B and the adhesive, and the powder B includes bentonite, talc, sodium polyacrylate and ammonium molybdate; the adhesive is a carboxymethyl cellulose salt solution.

2. The drought-resistant and strong seedling-strong awnless brome coated seeds according to claim 1, characterized in that: The carboxymethyl cellulose salt solution is a sodium carboxymethyl cellulose aqueous solution with a concentration of 1 to 1.5 wt%.

3. The drought-resistant and strong seedling-strong awnless brome coated seeds according to claim 2, characterized in that: The mass ratio of bentonite to talc in powder A is 1:1; the ratio of powder A to adhesive in the initial coating layer and the protective layer is 10 g:2 mL.

4. The drought-resistant and strong seedling-strong awnless brome coated seeds according to claim 2, characterized in that: The mass ratio of bentonite, talc, sodium polyacrylate and ammonium molybdate in powder B is 5:5:1:0.05; the ratio of powder B and adhesive in the composite active layer is 11.05 g:6 mL.

5. The method for preparing the drought-resistant and strong seedling type awnless brome coated seeds according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: Pour the seeds into a coating machine and rotate the seeds at a constant speed, then use a 1wt% sodium carboxymethyl cellulose aqueous solution to moisten the surface of the seeds, then alternately add powder A and adhesive into the coating machine until all the powder A is added to obtain seeds coated with an initial coating layer; S2: The seeds coated with the initial coating layer are idling in the coating machine for 1 to 2 minutes, and then powder B and adhesive are added alternately until all powder B is added to obtain seeds coated with the composite active layer; S3: The seeds coated with the composite active layer are idling in the coating machine for 2 to 3 minutes, and then powder A and adhesive are added alternately until all powder A is added to obtain seeds coated with a protective layer, which are then dried or naturally dried.

6. The method for preparing the drought-resistant and strong seedling type awnless brome coated seeds according to claim 5, characterized in that: The speed of the coating machine is 550-650rpm.

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