A kind of elymus nutans seed initiator and its preparation method and application

Abstract

This invention discloses a seed initiator for *Triticum aestivum* (also known as *Triticum aestivum*) that addresses the problems of low germination rate, inhibited germination process, decreased vigor, and aggravated oxidative damage in *Triticum aestivum* seeds under drought stress, along with its preparation method and applications. The seed initiator utilizes a specific concentration of nano-magnesium oxide suspension for seed initiation. This specific concentration does not simply rely on a linear promotion effect from increasing nanomaterial concentration, but rather represents a suitable regulatory threshold that mitigates oxidative damage during seed germination. Systematic demonstrations under PEG-simulated drought stress have shown that it significantly improves germination quality, optimizes the state of antioxidant enzymes and non-enzymatic antioxidants, reduces membrane lipid peroxidation levels, and enhances the germination ability and antioxidant homeostasis of *Triticum aestivum* seeds under moderate drought stress. Furthermore, the preparation process of this invention is simple and does not involve the synthesis of precious metals or complex composite materials. It is suitable for widespread application in the field of forage cultivation technology.

Description

Technical Field

[0001] This invention relates to the field of forage planting technology, specifically to an initiator for old wheat seeds, its preparation method, and its application. Background Technology

[0002] Elymus sibiricus L., a perennial high-quality forage grass belonging to the genus Elymus in the Poaceae family, is characterized by its strong adaptability, high nutritional value, and outstanding ecological restoration value. It has significant potential for widespread application in arid, semi-arid, and high-altitude regions of Northwest, North, and the Qinghai-Tibet Plateau of my country. The seed germination period is one of the most water-deficient stages in the establishment of Elymus sibiricus. Drought stress reduces water absorption rate, inhibits radicle breakthrough, delays germination, and induces the accumulation of reactive oxygen species and membrane lipid peroxidation, resulting in a significant decrease in germination rate, germination index, and seedling vigor.

[0003] Seed initiation is a technique that improves seed germination uniformity and stress adaptability through pre-sowing water or chemical regulation. In recent years, nanomaterials, due to their size effect, high specific surface area, and strong interfacial activity, have been used in agricultural applications such as seed initiation, nutrient delivery, and stress regulation. Existing nano-seed treatment technologies are mostly concentrated on cash crops such as rice, cucumber, tomato, and soybean. The material systems often involve precious metal nanoparticles, composite nanomaterials, or carbon-based quantum dots. Some processes are complex and costly, and there is insufficient application basis for drought germination of forage seeds, especially the model species *Triticum aestivum*, in high-altitude and cold regions.

[0004] Existing technologies have at least the following shortcomings: First, there are few drought-resistant seed initiation technologies for high-quality forage grasses such as *Leymus chinensis* in cold regions; second, existing nanomaterial treatments mostly emphasize aboveground growth or single germination indicators, with insufficient evidence on antioxidant regulation and membrane damage mitigation during germination under drought stress; third, low-cost nano-initiators suitable for large-scale promotion, simple to prepare, and not dependent on complex composite processes still need to be developed; fourth, nanomaterials have a significant concentration effect, and high concentrations may induce secondary stress, thus it is necessary to determine the effective concentration window for *Leymus chinensis* seeds. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an initiator for old wheat seeds that can solve the problems of low germination rate, inhibited germination process, decreased vigor and aggravated oxidative damage of old wheat seeds under drought stress.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: the old wheat seed initiator is composed of an aqueous suspension of MgO-NPs, wherein the concentration of the aqueous suspension of MgO-NPs is 50-400 mg / L, the particle size of MgO-NPs is 30-80 nm, and the purity of MgO-NPs is ≥99.9%.

[0007] Furthermore, the concentration of the MgO-NPs aqueous suspension is 200 mg / L.

[0008] This invention also provides a method for preparing an initiator for old wheat seeds, wherein the method for preparing the MgO-NPs aqueous suspension includes the following steps:

[0009] A. Weigh a certain amount of MgO-NPs particles, then pour the MgO-NPs into a beaker and add a certain volume of distilled water to obtain a MgO-NPs suspension with a concentration of 50-400 mg / L.

[0010] B. The MgO-NPs suspension was subjected to magnetic stirring.

[0011] C. The MgO-NPs suspension treated in step B is subjected to ultrasonic treatment at room temperature to obtain an aqueous suspension of MgO-NPs, which is the initiator for old wheat seeds.

[0012] Furthermore, in step B, a magnetic stirrer is used for magnetic stirring, with the magnetic stirrer rotating at 800 rpm, the temperature at 35°C, and the processing time at 10 min.

[0013] Furthermore, in step C, the ultrasonic frequency of the ultrasonic treatment is 30 kHz, and the treatment time is 30 min.

[0014] This invention also provides the application of an initiator for old wheat seeds in promoting the germination of old wheat seeds under drought stress.

[0015] The beneficial effects of this invention are as follows: The seed initiator of *Triticum aestivum* described in this invention uses a specific concentration of nano-magnesium oxide suspension to initiate the germination of *Triticum aestivum* seeds. This specific concentration does not simply rely on a linear promoting effect due to an increase in nanomaterial concentration, but rather is at a suitable regulatory threshold. On the one hand, it significantly improves the germination rate, germination index, and vigor index under drought stress; on the other hand, it reduces oxidative damage during seed germination by decreasing excessive stress-related SOD / CAT activity, enhancing POD activity, restoring AsA levels, regulating GSH accumulation, and reducing MDA content. Furthermore, under PEG-simulated drought stress, it has been systematically demonstrated to significantly improve germination quality, optimize the state of antioxidant enzymes and non-enzymatic antioxidants, reduce membrane lipid peroxidation levels, and enhance the germination ability and antioxidant homeostasis of *Triticum aestivum* seeds under moderate drought stress. This provides an feasible technical solution for the establishment of artificial grasslands for *Triticum aestivum* in arid and semi-arid regions, pre-sowing seed treatment, and the development of related products. In addition, the preparation process of this invention is simple and does not involve the synthesis of precious metals or complex composite materials, making it suitable for pre-sowing seed treatment of *Triticum aestivum* and applications in the establishment of artificial grasslands in arid and semi-arid regions. Attached Figure Description

[0016] Figure 1 The growth and germination of *Strombocys edulis* seedlings under different treatments on day 12 in different embodiments;

[0017] Figure 2 Germination rates of *Triticum aestivum* seeds under different treatments in different embodiments;

[0018] Figure 3 Germination index of *Triticum aestivum* seeds under different treatments in different embodiments;

[0019] Figure 4 Vigor index of old wheat seeds under different treatments in different embodiments;

[0020] Figure 5 Root and leaf lengths of *Triticum aestivum* seeds under different treatments in different embodiments;

[0021] Figure 6 Antioxidant enzyme activity of old wheat seeds under different treatments in different embodiments;

[0022] Figure 7 Antioxidant content of old wheat seeds under different treatments in different embodiments;

[0023] Figure 8 The malondialdehyde content of old wheat seeds under different treatments in different embodiments. Detailed Implementation

[0024] To address the problems of low germination rate, inhibited germination process, decreased vigor, and increased oxidative damage in *Triticum aestivum* seeds under drought stress, this invention provides a seed initiator for *Triticum aestivum*. This seed initiator uses a specific concentration of nano-magnesium oxide suspension to initiate germination in *Triticum aestivum* seeds. The specific concentration does not simply rely on a linear promoting effect from increasing nanomaterial concentration, but rather is at an appropriate regulatory threshold: on the one hand, it significantly improves germination rate, germination index, and vigor index under drought stress; on the other hand, it reduces stress-related SOD / CAT activity, enhances POD activity, restores AsA levels, regulates GSH accumulation, and reduces MDA content, thereby mitigating oxidative damage during seed germination. Systematic demonstrations under PEG-simulated drought stress have shown that it can significantly improve germination quality, optimize the state of antioxidant enzymes and non-enzymatic antioxidants, reduce membrane lipid peroxidation levels, and enhance the germination ability and antioxidant homeostasis of *Triticum aestivum* seeds under moderate drought stress. This provides an feasible technical solution for the establishment of artificial grasslands for *Triticum aestivum* in arid and semi-arid regions, pre-sowing seed treatment, and the development of related products. The described *Ophiopogon japonicus* seed initiator is composed of an aqueous suspension of MgO-NPs, with a concentration of 50-400 mg / L, a particle size of 30-80 nm, and a purity of ≥99.9%. Under PEG-simulated moderate drought stress, 200 mg / L MgO-NPs significantly improved germination rate, germination index, and vigor index, and was superior to water-based initiation.

[0025] This invention also provides a method for preparing an initiator for old wheat seeds, wherein the method for preparing the MgO-NPs aqueous suspension includes the following steps:

[0026] A. Weigh a certain amount of MgO-NPs particles, then pour the MgO-NPs into a beaker and add a certain volume of distilled water to obtain a MgO-NPs suspension with a concentration of 50-400 mg / L.

[0027] B. The MgO-NPs suspension was subjected to magnetic stirring treatment; a magnetic stirrer was used for magnetic stirring treatment, the speed of the magnetic stirrer was 800 rpm, the temperature was 35℃, and the treatment time was 10 min;

[0028] C. The MgO-NPs suspension treated in step B is subjected to ultrasonic treatment at room temperature to obtain an aqueous suspension of MgO-NPs, which is the initiator for old wheat seeds. The ultrasonic frequency of the ultrasonic treatment is 30 kHz, and the treatment time is 30 min.

[0029] The above preparation process is simple and does not involve the synthesis of precious metals or complex composite materials, making it suitable for pre-sowing seed treatment of wheat and for the establishment of artificial grasslands in arid and semi-arid regions.

[0030] This invention also provides the application of *Triticum aestivum* seed initiator in promoting the germination of *Triticum aestivum* seeds under drought stress. The verification method for promoting the germination of *Triticum aestivum* seeds under drought stress includes: selecting plump, uniformly sized, and disease-free *Triticum aestivum* seeds; soaking the seeds in an aqueous suspension of MgO-NPs and initiating them at 25°C in the dark for 24 hours, shaking once every 3 hours during this period; after initiation, removing the seeds, draining or wiping off surface moisture, and air-drying them at room temperature to their original weight; placing the treated seeds in a germination medium containing 12.5% ​​PEG-6000 and germinating them at 25°C under 8 hours of light / 16 hours of darkness.

[0031] Example 1 - Effect of Mg400: 400 mg / L MgO-NPs aqueous suspension on seeds of *Triticum aestivum*

[0032] Step 1: Weigh 100 mg of MgO-NPs particles, then pour the MgO-NPs into a beaker and add distilled water to make up to 250 mL to obtain a ZnO-NPs suspension with a concentration of 200 mg / L.

[0033] Step 2: The MgO-NPs suspension is magnetically stirred using a magnetic stirrer at a speed of 800 rpm, a temperature of 35°C, and a processing time of 10 min.

[0034] Step 3: The MgO-NPs suspension treated in step B is subjected to ultrasonic treatment at room temperature to obtain an aqueous suspension of MgO-NPs, which is the initiator for old wheat seeds. The ultrasonic frequency of the ultrasonic treatment is 30 kHz and the treatment time is 30 min.

[0035] Step 4: Select plump, uniformly sized, and disease-free old wheat seeds; soak the seeds in MgO-NPs aqueous suspension and initiate them at 25℃ in the dark for 24 hours, shaking once every 3 hours during this period; after initiation, remove the seeds, drain or wipe off the surface moisture, and air dry at room temperature until the original weight is achieved.

[0036] Step 5: Line a 11.5×11.5cm petri dish with 3 layers of filter paper and add 10 mL of 12.5% ​​PEG-6000 solution;

[0037] Step 6: Arrange the seeds treated in steps 1 to 4 evenly (spaced ≥ 1 cm), 50 seeds per dish, with 4 replicates;

[0038] Step 7: Place the petri dish at 25℃ under 8 hours of light and 16 hours of darkness for germination culture; during the culture period, replenish the corresponding amount of solution every 3-4 days to maintain humidity;

[0039] Step 8: Perform germination testing on old wheat seeds according to the standards of the International Seed Testing Association (ISTA), and record the number of seeds showing white sprouts every 24 hours;

[0040] Step 9: On day 12, measure the leaf length (LL), root length (RL), and fresh weight (FW) of the old wheat seedlings, with 10 seedlings measured in each replicate.

[0041] Step 10: After sampling, the antioxidant enzyme activity and antioxidant content of old wheat seeds were determined using kits purchased from Beijing Solarbio Technology Co., Ltd. and Suzhou Keming Biotechnology Co., Ltd.

[0042] Example 2 - Effect of Mg200: 200 mg / L MgO-NPs aqueous suspension on old wheat seeds

[0043] Step 1: Using a 100ml graduated cylinder, accurately measure 100 mL of 400 mg / L MgO-NPs aqueous suspension and add distilled water to 200 mL to dilute it to 200 mg / L MgO-NPs aqueous suspension.

[0044] Step 2: Select plump, uniformly sized, and disease-free old wheat seeds; soak the seeds in MgO-NPs aqueous suspension and initiate them at 25℃ in the dark for 24 hours, shaking once every 3 hours during this period; after initiation, remove the seeds, drain or wipe off the surface moisture, and air dry at room temperature until the original weight is achieved.

[0045] Step 3: Line a 11.5×11.5cm petri dish with 3 layers of filter paper and add 10 mL of 12.5% ​​PEG-6000 solution;

[0046] Step 4: Arrange the seeds treated in steps 1 to 4 evenly (spaced ≥ 1 cm), 50 seeds per dish, with 4 replicates;

[0047] Step 5: Place the petri dish at 25℃ under 8 hours of light and 16 hours of darkness for germination culture; during the culture period, replenish the corresponding amount of solution every 3-4 days to maintain humidity;

[0048] Step 6: Perform germination testing on old wheat seeds according to the standards of the International Seed Testing Association (ISTA), and record the number of seeds showing white sprouts every 24 hours;

[0049] Step 7: On day 12, measure the leaf length (LL), root length (RL), and fresh weight (FW) of the old wheat seedlings, with 10 seedlings measured in each replicate.

[0050] Step 8: After sampling, the antioxidant enzyme activity and antioxidant content of old wheat seeds were determined using kits purchased from Beijing Solarbio Technology Co., Ltd. and Suzhou Keming Biotechnology Co., Ltd.

[0051] Example 3 - Effect of Mg100: 100 mg / L MgO-NPs aqueous suspension on old wheat seeds

[0052] Step 1: Using a 100ml graduated cylinder, accurately measure 100 mL of 200 mg / L MgO-NPs aqueous suspension and add distilled water to 200 mL to dilute it to 100 mg / L MgO-NPs aqueous suspension.

[0053] Step 2: Select plump, uniformly sized, and disease-free old wheat seeds; soak the seeds in MgO-NPs aqueous suspension and initiate them at 25℃ in the dark for 24 hours, shaking once every 3 hours during this period; after initiation, remove the seeds, drain or wipe off the surface moisture, and air dry at room temperature until the original weight is achieved.

[0054] Step 3: Line a 11.5×11.5cm petri dish with 3 layers of filter paper and add 10 mL of 12.5% ​​PEG-6000 solution;

[0055] Step 4: Arrange the seeds treated in steps 1 to 4 evenly (spaced ≥ 1 cm), 50 seeds per dish, with 4 replicates;

[0056] Step 5: Place the petri dish at 25℃ under 8 hours of light and 16 hours of darkness for germination culture; during the culture period, replenish the corresponding amount of solution every 3-4 days to maintain humidity;

[0057] Step 6: Perform germination testing on old wheat seeds according to the standards of the International Seed Testing Association (ISTA), and record the number of seeds showing white sprouts every 24 hours;

[0058] Step 7: On day 12, measure the leaf length (LL), root length (RL), and fresh weight (FW) of the old wheat seedlings, with 10 seedlings measured in each replicate.

[0059] Step 8: After sampling, the antioxidant enzyme activity and antioxidant content of old wheat seeds were determined using kits purchased from Beijing Solarbio Technology Co., Ltd. and Suzhou Keming Biotechnology Co., Ltd.

[0060] Example 4 - Effect of Mg50: 50 mg / L MgO-NPs aqueous suspension on old wheat seeds

[0061] Step 1: Using a 100ml graduated cylinder, accurately measure 100 mL of 100 mg / L MgO-NPs aqueous suspension and add distilled water to 200 mL to dilute it to 50 mg / L MgO-NPs aqueous suspension.

[0062] Step 2: Select plump, uniformly sized, and disease-free old wheat seeds; soak the seeds in MgO-NPs aqueous suspension and initiate them at 25℃ in the dark for 24 hours, shaking once every 3 hours during this period; after initiation, remove the seeds, drain or wipe off the surface moisture, and air dry at room temperature until the original weight is achieved.

[0063] Step 3: Line a 11.5×11.5cm petri dish with 3 layers of filter paper and add 10 mL of 12.5% ​​PEG-6000 solution;

[0064] Step 4: Arrange the seeds treated in steps 1 to 4 evenly (spaced ≥ 1 cm), 50 seeds per dish, with 4 replicates;

[0065] Step 5: Place the petri dish at 25℃ under 8 hours of light and 16 hours of darkness for germination culture; during the culture period, replenish the corresponding amount of solution every 3-4 days to maintain humidity;

[0066] Step 6: Perform germination testing on old wheat seeds according to the standards of the International Seed Testing Association (ISTA), and record the number of seeds showing white sprouts every 24 hours;

[0067] Step 7: On day 12, measure the leaf length (LL), root length (RL), and fresh weight (FW) of the old wheat seedlings, with 10 seedlings measured in each replicate.

[0068] Step 8: After sampling, the antioxidant enzyme activity and antioxidant content of old wheat seeds were determined using kits purchased from Beijing Solarbio Technology Co., Ltd. and Suzhou Keming Biotechnology Co., Ltd.

[0069] Comparative Example 1-CG0: Non-inducible and non-stressful old wheat seeds

[0070] Step 1: Line a 11.5×11.5cm petri dish with 3 layers of filter paper and add 10mL of distilled water;

[0071] Step 2: Arrange the selected plump, uniform-sized, and disease-free old wheat seeds evenly (spaced ≥ 1 cm), with 50 seeds per dish, and repeat 4 times.

[0072] Step 3: Place the petri dish at 25℃ under 8 hours of light and 16 hours of darkness for germination culture; during the culture period, replenish the corresponding amount of solution every 3-4 days to maintain humidity;

[0073] Step 4: Perform germination testing on old wheat seeds according to the standards of the International Seed Testing Association (ISTA), and record the number of seeds showing white sprouts every 24 hours;

[0074] Step 5: On day 12, measure the leaf length (LL), root length (RL), and fresh weight (FW) of the old wheat seedlings, with 10 seedlings measured in each replicate.

[0075] Step 6: After sampling, the antioxidant enzyme activity and antioxidant content of old wheat seeds were determined using kits purchased from Beijing Solarbio Technology Co., Ltd. and Suzhou Keming Biotechnology Co., Ltd.

[0076] Comparative Example 2-CG1: Stress alone does not induce the growth of old wheat seeds

[0077] Step 1: Line a 11.5×11.5cm petri dish with 3 layers of filter paper and add 10 mL of 12.5% ​​PEG-6000 solution;

[0078] Step 2: Arrange the selected plump, uniform-sized, and disease-free old wheat seeds evenly (spaced ≥ 1 cm), with 50 seeds per dish, and repeat 4 times.

[0079] Step 3: Place the petri dish at 25℃ under 8 hours of light and 16 hours of darkness for germination culture; during the culture period, replenish the corresponding amount of solution every 3-4 days to maintain humidity;

[0080] Step 4: Perform germination testing on old wheat seeds according to the standards of the International Seed Testing Association (ISTA), and record the number of seeds showing white sprouts every 24 hours;

[0081] Step 5: On day 12, measure the leaf length (LL), root length (RL), and fresh weight (FW) of the old wheat seedlings, with 10 seedlings measured in each replicate.

[0082] Step 6: After sampling, the antioxidant enzyme activity and antioxidant content of old wheat seeds were determined using kits purchased from Beijing Solarbio Technology Co., Ltd. and Suzhou Keming Biotechnology Co., Ltd.

[0083] Comparative Example 3-WT: Water-induced post-stressed wheat seeds

[0084] Step 1: Select plump, uniform-sized, and disease-free old wheat seeds, immerse the seeds in a petri dish containing 25mL of distilled water, and place them in a light incubator under dark conditions for 24 hours, shaking once every 3 hours.

[0085] Step 2: After 24 hours, take out the seeds, wash them, wipe them dry, spread them flat on filter paper, and let them dry at room temperature until the moisture content returns to the original level.

[0086] Step 3: Line a 11.5×11.5cm petri dish with 3 layers of filter paper and add 10 mL of 12.5% ​​PEG-6000 solution;

[0087] Step 4: Arrange the treated seeds evenly (spaced ≥ 1 cm), 50 seeds per dish, with 4 replicates;

[0088] Step 5: Place the petri dish in a constant temperature incubator for germination, and add an equal amount of PEG-6000 solution every 3-4 days to maintain humidity;

[0089] Step 6: Perform germination testing on old wheat seeds according to the standards of the International Seed Testing Association (ISTA), and record the number of seeds showing white sprouts every 24 hours;

[0090] Step 7: On day 12, measure the leaf length (LL), root length (RL), and fresh weight (FW) of the old wheat seedlings, with 10 seedlings measured in each replicate.

[0091] Step 8: After sampling, the antioxidant enzyme activity and antioxidant content of old wheat seeds were determined using kits purchased from Beijing Solarbio Technology Co., Ltd. and Suzhou Keming Biotechnology Co., Ltd.

[0092] The MgO-NPs mentioned in the above embodiments were purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., with a purity of ≥99.9%, a particle size of 30-80 nm, and a specific surface area of ​​21.5 m² / g. The old awned wheat seeds were "Chuancao No. 2" old awned wheat, and seeds with plump grains, uniform size, and free from diseases and pests were selected for the experiment.

[0093] Germination rate (%) = (Number of all normal seedlings in the experiment / Number of seeds tested) × 100%;

[0094] Germination index GI = Σ(Gt / Dt), where Gt is the number of germinated germinations on day t and Dt is the corresponding number of germination days;

[0095] Vitality index VI = Σ(Gt / Dt) × FW, where FW is the fresh weight of the seedling.

[0096] All data were analyzed using SPSS 26 one-way ANOVA, and multiple comparisons were performed using Duncan's new multiple range method. The significance level was P<0.05.

[0097] Comparative Example 1 (CG0) was the control group without initiation and stress; Comparative Example 2 (CG1) was the control group without initiation but under stress; Comparative Example 3 (WT) was the control group initiated with distilled water and then under stress. Table 1 shows the effects of MgO-NPs on the germination rate, germination index, and vigor index of *Triticum aestivum*.

[0098] Table 1. Effects of MgO-NPs on germination rate, germination index, and vigor index of *Triticum aestivum*.

[0099]

[0100] Note: Different lowercase letters indicate that the differences between the means in the same column are significant at the P<0.05 level.

[0101] Figure 1 The growth and germination of *Strombocys edulis* seedlings under different treatments on day 12 in different embodiments; Figure 2 Germination rates of *Triticum aestivum* seeds under different treatments in different embodiments; Figure 3 Germination index of *Triticum aestivum* seeds under different treatments in different embodiments; Figure 4 The vigor index of *Triticum aestivum* seeds under different treatments in different embodiments; as shown in Table 1 and... Figure 1-4It was found that 12.5% ​​PEG-6000 significantly inhibited the germination of *Triticum aestivum* seeds, reducing the germination rate, germination index, and vigor index of CG-peg to 15.33%, 16.40, and 79.15, respectively. Compared with CG-peg, MgO-NPs initiation treatment generally improved the germination quality under drought stress, with Mg200 showing the most significant effect, increasing the germination rate, germination index, and vigor index by 182.6%, 108.2%, and 136.5%, respectively. Compared with water-initiated CG-WT, Mg200 increased the germination rate and vigor index by approximately 103.1% and 74.6%, respectively. Mg50 performed well in terms of germination index, but its germination rate and vigor index were lower than those of Mg200. The germination rate of Mg400 treatment was not significantly better than that of CG-peg, suggesting that excessively high concentrations are not suitable as a preferred option. Therefore, 200 mg / L is the preferred concentration of this invention.

[0102] Table 2 Effects of MgO-NPs on fresh weight, root length and leaf length of *Triticum aestivum* seedlings

[0103]

[0104] Note: Different lowercase letters indicate that the differences between the means in the same column are significant at the P<0.05 level.

[0105] Figure 5 The root and leaf lengths of *Triticum aestivum* seeds under different treatments in different embodiments are shown in Table 2. Figure 5 It was found that PEG stress significantly reduced the fresh weight, root length, and leaf length of *Triticum aestivum* seedlings. Each MgO-NPs treatment showed a certain recovery trend in root length, with Mg200 treatments showing higher root and leaf length values ​​compared to the MgO-NPs treatment groups, but without significant differences compared to CG-peg. These results indicate that the main technical effect of this invention focuses on improving seed germination quality and early vigor under drought stress, rather than directly and significantly promoting seedling biomass accumulation on day 12. This description avoids using seedling growth indicators that did not reach significant levels as the core protective effect, thus making the technical effect more consistent with the experimental data.

[0106] Table 3 Effects of MgO-NPs on the antioxidant enzyme activity of old wheat bran

[0107]

[0108] Note: Different lowercase letters indicate that the differences between the means in the same column are significant at the P<0.05 level.

[0109] Figure 6 The antioxidant enzyme activities of *Triticum aestivum* seeds under different treatments in different embodiments; as shown in Table 3 and... Figure 6The results show that drought stress induces increased activities of SOD, POD, and CAT, reflecting oxidative stress in *Triticum aestivum* seeds. Different concentrations of MgO-NPs exhibited differentiated regulatory characteristics: Mg50, Mg100, and Mg200 significantly reduced SOD activity, bringing it close to the normal control level; Mg200 reduced CAT activity compared to CG-peg, and significantly lower than Mg400; simultaneously, Mg200 significantly increased POD activity, approximately 65.3% higher than CG-peg. Although Mg400 further increased POD and APX activities, its SOD and CAT levels remained high, suggesting that high concentrations may be accompanied by a stronger stress response. These results indicate that Mg200 can enhance POD-mediated scavenging capacity while reducing excessive stress responses, creating a more favorable antioxidant state for germination.

[0110] Table 4. Effects of MgO-NPs on malondialdehyde and antioxidant content in old wheat.

[0111]

[0112] Note: Different lowercase letters indicate that the differences between the means in the same column are significant at the P<0.05 level.

[0113] Figure 7 Antioxidant content of old wheat seeds under different treatments in different embodiments; Figure 8 The malondialdehyde (MDA) content of old wheat seeds under different treatments in different embodiments; as shown in Table 4 and... Figure 7-8 It was found that PEG stress significantly increased MDA and GSH content and significantly decreased AsA content, indicating that drought exacerbated membrane lipid peroxidation and caused an imbalance in the non-enzymatic antioxidant system. Mg200 increased AsA content by 206.9% compared to CG-peg, and was significantly higher than water-induced CG-WT. All MgO-NPs treatments reduced the abnormal accumulation of GSH induced by CG-peg, with Mg100 and Mg200 showing better regulatory effects. For MDA, Mg200 reduced it by approximately 24.8% compared to CG-peg, and was lower than CG-WT, indicating that it could effectively alleviate membrane lipid peroxidation damage caused by drought stress. In contrast, the MDA content increased to 28.21% in the Mg400 treatment, significantly higher than that in Mg200, suggesting that excessively high concentrations may cause secondary stress and should not be considered the preferred concentration.

[0114] Based on the comprehensive analysis of germination phenotype, germination indices, and physiological indicators, the preferred technical solution of this invention is a treatment initiated with 200 mg / L MgO-NPs. This concentration does not simply rely on a linear promoting effect from the increase in nanomaterial concentration, but rather falls within a suitable regulatory threshold: on the one hand, it significantly improves the germination rate, germination index, and vigor index under drought stress; on the other hand, it reduces oxidative damage during seed germination by decreasing excessive stress-related SOD / CAT activity, enhancing POD activity, restoring AsA levels, regulating GSH accumulation, and reducing MDA content.

[0115] While low concentrations of Mg50 and Mg100 can improve some germination or antioxidant indicators, their overall improvement effect is not as good as that of Mg200. High concentrations of Mg400 can significantly enhance POD and APX activities, but the increased MDA content and poor germination rate indicate that it may induce additional stress. Therefore, the 200 mg / L MgO-NPs seed priming scheme determined in this invention has a clear basis for concentration selection and outstanding comprehensive technical effects.

[0116] The above embodiments illustrate that the present invention can improve the germination ability and antioxidant homeostasis of *Triticum aestivum* seeds under moderate drought stress by using a simple nano-magnesium oxide suspension initiation treatment method, providing an implementable technical solution for the establishment of artificial grasslands of *Triticum aestivum* in arid and semi-arid regions, pre-sowing seed treatment, and the development of related products.

Claims

1. A seed initiator for old wheatgrass, characterized in that: It is composed of an aqueous suspension of MgO-NPs, wherein the concentration of the aqueous suspension of MgO-NPs is 50-400 mg / L, the particle size of the MgO-NPs is 30-80 nm, and the purity of the MgO-NPs is ≥99.9%.

2. The old awn wheat seed initiator as described in claim 1, characterized in that: The concentration of the MgO-NPs aqueous suspension is 200 mg / L.

3. The method for preparing the old awned wheat seed initiator as described in claim 1, characterized in that: Includes the following steps: A. Weigh a certain amount of MgO-NPs particles, then pour the MgO-NPs into a beaker and add a certain volume of distilled water to obtain a MgO-NPs suspension with a concentration of 50-400 mg / L. B. The MgO-NPs suspension was subjected to magnetic stirring. C. The MgO-NPs suspension treated in step B is subjected to ultrasonic treatment at room temperature to obtain an aqueous suspension of MgO-NPs, which is the initiator for old wheat seeds.

4. The method for preparing the old awned wheat seed initiator as described in claim 3, characterized in that: In step B, a magnetic stirrer is used for magnetic stirring. The magnetic stirrer rotates at 800 rpm, the temperature is 35°C, and the processing time is 10 minutes.

5. The method for preparing the old awned wheat seed initiator as described in claim 3, characterized in that: In step C, the ultrasonic frequency of the ultrasonic treatment is 30 kHz, and the treatment time is 30 min.

6. The application of the old wheat seed initiator as described in claim 1 or 2 in promoting the germination of old wheat seeds under drought stress.

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