Nano-iron salt-resistant germination-promoting elsholtzia sibirica seed priming method

Abstract

The invention discloses a nano-iron salt-resistant germination-promoting elsholtzia sibirica seed priming method, and belongs to the technical field of seed processing, and the method comprises the following specific implementation steps: S1, preparing a nano-iron suspension; s2, selecting siberian wildrye seeds; s3, performing nano-iron initiation; s4, obtaining siberian wildrye seeds with salt resistance; according to the method, the siberian wildrye seeds are subjected to priming treatment by using a seed nano-priming technology and exogenous nano-iron, and the salt stress resistance of the siberian wildrye seeds can be effectively improved by controlling the concentration, time and the like of the priming treatment; the technical method is simple and convenient, materials are saved, operation is easy, and procedures are standardized.

Description

Technical Field

[0001] The invention relates to the technical field of seed processing, in particular to a method for priming nano iron salt-tolerant germination-promoting old wheat seeds. Background Art

[0002] Saline-alkali soil, a widespread soil type on Earth, is a general term for various salinized and alkaline soils. It refers to land where plants cannot grow normally due to excessively high salt content. Currently, soil salinization has become a global agricultural and ecological problem, seriously affecting arable land and food production. The Qaidam Basin, located in the arid northwest region, categorizes its soils into non-salinized, lightly salinized, moderately salinized, heavily salinized, and saline soils based on the different salinity types specified in the soil salinization classification standard. Salt content in the Qaidam Basin soils primarily exists in the form of chloride ions combined with metal ions.

[0003] Seeds are the foundation of plant growth and development, the foundation of agricultural production and development, and hold unparalleled importance. Due to its diverse habitats, my country's E. sibiricum has developed a diverse genetic resource. In the subalpine meadows of the Qinghai-Tibet Plateau, E. sibiricum, as an important forage, plays a significant role in grassland animal husbandry. In recent years, it has become one of the most widely cultivated and utilized grass species in the region. As a high-quality grass species for ecological restoration and forage production, E. sibiricum boasts soft stems, rich nutrition, and strong cold tolerance. It now plays a vital role in grazing, artificial grassland establishment, forage improvement, and breeding.

[0004] Seed priming, a simple, safe, and time-saving seed pretreatment technique, holds broad application potential. It is based on the biological mechanisms of seed germination and aims to improve seed quality, promote germination, ensure uniform and robust seedlings, and enhance seed resistance. Priming primarily involves artificially controlled methods such as osmotic regulation, temperature regulation, and hormone regulation, allowing seeds to slowly absorb water under controlled conditions (such as slow, quantitative water absorption and gradual drying), thereby physiologically preparing for germination. Numerous seed priming methods exist, including water priming, roller priming, osmotic priming, and solid matrix priming.

[0005] Nanopriming, a form of seed priming, uses a nanosuspension as a medium. Nanomaterials have varying physical and chemical properties, such as size, charge, and shape, which directly affect their absorption and transport efficiency in plants. This technique uses nanomaterials (NMS) as seed pretreatment agents to slowly imbibe seeds and physiologically prepare them for germination. Nanomaterials are materials with at least one dimension in the nanoscale (1.0-100.0 nm) or composed of nanomaterials as basic units. Common types of nanomaterials include carbon-based nanomaterials (graphene, carbon nanotubes, and fullerenes), metal-based nanomaterials (such as elemental or oxidized nanometals), and composite materials. Using nanomaterials to prime seeds can enhance seed vigor, water and fertilizer absorption, promote root growth and metabolism, and improve plant resistance to pests and diseases, as well as multiple stresses, beyond the existing agronomic traits of the variety, thereby increasing yield and improving quality.

[0006] Iron, an essential micronutrient, plays a positive role in electron transport during plant respiration and photosynthesis. In recent years, nanoiron materials have been widely used in agriculture. Nanoiron exhibits excellent adsorption and reducibility, showing promising application potential in environmental remediation, water pollution control, and soil restoration. However, research on nanoiron-induced treatment technology in related fields, such as grass seed germination and seedling growth, is limited. Summary of the Invention

[0007] The present invention aims to provide a method for priming seeds of Elymus sibiricus with nano-iron salt-tolerance and accelerated germination, so as to solve the problems raised in the above background technology.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A method for priming Elymus sibiricus seeds with nano-iron salt-tolerant germination promotion, comprising the following steps:

[0010] S1: Preparation of nano-iron suspension: nano-iron was added to deionized water to prepare a suspension with a concentration of 100 mg / L, and dissolved by ultrasonic vibration for 1 h;

[0011] S2: Select old sibiricum seeds, select old sibiricum seeds with uniform weight and fullness, weigh and record;

[0012] S3: Perform nano-iron initiation. Place the nano-iron suspension in a culture dish with three layers of filter paper, add Elymus sibiricus seeds, and place three layers of filter paper moistened with the nano-iron suspension on top of the seeds. Place the mixture at 25°C for 4 hours.

[0013] S4: Obtain old Elymus sibiricus seeds with salt tolerance. The primed seeds were rinsed three times with distilled water, the surface moisture was absorbed with filter paper, and the seeds were allowed to dry at room temperature.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The nano-iron priming technology for E. sibiricum seeds provided by the present invention can effectively improve the germination rate of E. sibiricum seeds, promote the growth of E. sibiricum seeds during the seedling period, and improve the salt tolerance of E. sibiricum seeds under chloride-based saline soil (inland salt stress).

[0016] The present invention uses nano-priming technology in grass seeds for the first time and significantly improves the ability of grass seeds to resist abiotic stress.

[0017] 3. The technical method of the present invention is simple, saves materials, is easy to operate and has standardized procedures. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the effects of mixed stress treatments on the germination characteristics of Elymus sibiricus seeds (different lowercase letters indicate significant differences at the 0.05 level);

[0019] Figure 2 Schematic diagram of the effects of mixed stress treatments on the growth of Elymus sibiricus seedlings (different lowercase letters indicate significant differences at the 0.05 level);

[0020] Figure 3 This is a schematic diagram of the imbibition curve of Elymus sibiricus seeds;

[0021] Figure 4 This is a schematic diagram of the effect of nano-iron on the germination characteristics of Elymus sibiricus seeds under salt stress (different lowercase letters indicate significant differences at the 0.05 level, * indicates significant differences at the 0.05 level);

[0022] Figure 5 This is a schematic diagram showing the effect of nano-iron on the growth of Elymus sibiricus seedlings under salt stress;

[0023] Figure 6 Schematic diagram of the effects of nano-iron priming treatment on antioxidant enzyme activities in Elymus sibiricus seedlings under salt stress;

[0024] Figure 7 The present invention is a flowchart of the steps of a method for promoting the germination of Elymus sibiricus seeds by using nano-iron to promote salt-tolerance. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0026] like Figure 7 The method for promoting the germination of Elymus sibiricus seeds by using nano-iron salt-tolerant method includes the following steps:

[0027] S1: Preparation of nano-iron suspension: nano-iron was added to deionized water to prepare a suspension with a concentration of 100 mg / L, and dissolved by ultrasonic vibration for 1 h;

[0028] S2: Select old sibiricum seeds, select old sibiricum seeds with uniform weight and fullness, weigh and record;

[0029] S3: Perform nano-iron initiation. Place the nano-iron suspension in a culture dish with three layers of filter paper, add Elymus sibiricus seeds, and place three layers of filter paper moistened with the nano-iron suspension on top of the seeds. Place the mixture at 25°C for 4 hours.

[0030] S4: Obtain old Elymus sibiricus seeds with salt tolerance. The primed seeds were rinsed three times with distilled water, the surface moisture was absorbed with filter paper, and the seeds were allowed to dry at room temperature.

[0031] This study uses seed nanopriming technology to prime Elymus sibiricus seeds with exogenous nano-iron. By controlling the concentration and duration of the priming treatment, the seeds' resistance to salt stress can be effectively improved. Seed germination rates and seedling growth indicators before and after treatment are shown in Table 1. The recovery rates of various indicators in Elymus sibiricus seeds after nano-iron priming under salt stress, compared to those without stress, are shown in Table 2.

[0032] Table 1 Summary of growth rates of various germination indicators of seeds after nanopriming treatment

[0033]

[0034] Note: The values ​​in the table are the increase rates of various germination and seedling growth indicators of the effective priming treatments compared with the control (NS175) under salt stress.

[0035] Table 2 Summary of recovery rates of various germination indicators of seeds after nanopriming treatment

[0036]

[0037] Note: The values ​​in the table are the recovery rates of various germination seedling growth indicators after effective nano-iron priming treatment under salt stress compared with the control (CK) under normal conditions.

[0038] The specific steps of the screening test process are as follows:

[0039] 1. Cl - 、SO4 2- Screening of mixed salt stress conditions with a solution ratio of 5:1

[0040] Set NaCl as the main component and Na2SO4 as the secondary component of two neutral salts for double salt treatment, set Cl - 、SO4 2-The seeds of Elymus sibiricus were treated with mixed salt solutions with a solution ratio of 5:1 and salt concentrations of 0, 50, 100, 125, 150, 175, and 200 mmol / L, respectively. The sand bed germination test was conducted in accordance with the National Standard of the People's Republic of China for the Inspection of Grass Seeds (GB / T2930.4-2017), and the germination rates were calculated as follows:

[0041] (1) Germination rate (%) = number of normal seedlings at the last count / total number of test seeds × 100%.

[0042] (2) Root length, seedling length, and seedling fresh weight: After 12 days of germination, 10 seedlings were randomly selected from each replicate of each treatment to measure the root and seedling length (cm) and fresh weight (g), and this was repeated four times.

[0043] After the above tests, we draw the following conclusions:

[0044] The results of germination assay showed that ( Figure 1 ), in Cl - 、SO4 2- Under the treatment of mixed salt solution with a ratio of 5:1, the germination rate of E. sibiricum and Festuca australis seeds showed a downward trend with the increase of the concentration of mixed salt solution. The concentration of 150mmol / L mixed salt solution was used as a dividing point for E. sibiricum seeds. When the concentration was less than 150mmol / L, salt stress had little effect on the germination of E. sibiricum seeds. When the concentration was greater than 150mmol / L, the germination rate and germination index of E. sibiricum seeds under mixed salt solution concentration decreased significantly (P<0.05). When the concentration was 175mmol / L, the germination rate dropped from 94% to 71%. The seedling results showed that ( Figure 2 ), when the concentration of the mixed salt solution was 150-200 mmol / L, the root length and seedling length of Elymus sibiricus seedlings decreased significantly (P<0.05) with the increase of salt concentration.

[0045] In summary, the mixed salt solution of 175 mmol / L was selected as the stress treatment condition in subsequent experiments.

[0046] 2. Preliminary screening of nano-iron priming technology to improve the ability of Elymus sibiricus seeds to resist salt stress

[0047] 1) Drawing of swelling curve

[0048] 1000 seeds of Elymus sibiricum with a water content of 10% were randomly selected and cultured according to the germination test of grass seeds (GB / T2930.4-2017). The imbibition curve of Elymus sibiricum seeds was drawn based on the water absorption. During the imbibition process of Elymus sibiricum seeds, the water absorption of seeds showed a staged change pattern. The results showed that ( Figure 3), the three stages of the germination process of the old barley seeds used in the experiment were 0-6h, 6-42h and after 42h. Based on this result, 4h and 30h were selected as the initiation time.

[0049] 2) Nano-initiator

[0050] 5.0 mg, 7.5 mg, 10 mg, and 12.5 mg of nanoparticles were weighed, dissolved and diluted to 100 mL with deionized water by ultrasonication. The mother solutions were prepared into 50 mg / L, 75 mg / L, 100 mg / L, and 125 mg / L, respectively. The mother solutions were ultrasonicated in a water bath at about 20°C for 1 hour, and then diluted into 100 mL of suspensions of different concentrations. The nanosuspensions of each concentration were placed under light conditions for 1 day and stored at room temperature. In this experiment, nanoiron was selected as the initiator, 4 concentrations were set, and 2 initiation times were determined based on the imbibition curve. Each treatment was repeated 4 times, with the salt stress treatment as the CKO control, for a total of 24 treatments (Table 3).

[0051] Table 3 Different priming treatment concentrations and treatment times

[0052]

[0053] After priming with nanosuspensions of varying concentrations for varying lengths of time, paper culture germination tests were conducted under salt stress conditions and in accordance with the Grass Seed Inspection Procedure Germination Test (GB / T2930.4-2017). The effects of nanoiron on the germination of Elymus sibiricus seeds under salt stress were investigated. The following indicators were measured: seed germination-related indices (germination rate, average germination time, germination index); seedling growth-related indices (root length, seedling length, seedling fresh weight, and vigor index).

[0054] Germination rate (%) = number of normal seedlings at the last count / total number of test seeds × 100%.

[0055] (1) Average germination time = ∑nt / ∑n, where n is the number of seeds whose radicle breaks through the seed coat by 2 mm at time t, and t is the germination time.

[0056] (2) Germination index = ∑(Gt / Dt), where Gt is the number of germinations on day t and Dt is the number of days to germination (d).

[0057] (3) Vitality index = ∑(nt / t) × FW, where t is the number of days to germination (d), nt is the number of germinations on the tth day, and FW is the fresh weight (g).

[0058] (4) Root length, seedling length, and seedling fresh weight: After 10 days of germination, 10 seedlings were randomly selected from each replicate of each treatment to measure the root and seedling length (cm) and fresh weight (g), and this was repeated 4 times.

[0059] After the above tests, we draw the following conclusions:

[0060] The germination results showed that ( Figure 4 ). Under salt stress, compared with CK0, the germination rate and germination index of E. sibiricum seeds induced by different nano-iron concentrations for 4 hours increased. Fe-L100 was significantly (P < 0.05) higher than other treatments, increasing the germination rate by 19.72% compared with CK0. Compared with CK0, the average germination time of E. sibiricum seeds induced by CK1 and different nano-iron concentrations for 4 hours was significantly (P < 0.05) shortened. Significant (P < 0.05) differences in the germination rate and germination index of E. sibiricum seeds induced by different nano-iron concentrations were observed at both priming times. Compared with priming for 30 hours, the germination rate and germination index of E. sibiricum seeds induced by nano-iron for 4 hours were significantly (P < 0.05) lower than those induced by nano-iron for 30 hours. Fe-L100 had the best effect. When the nano-iron initiation concentration was 50mmol / L, 100mmol / L and 125mmol / L, there were significant (P<0.05) differences in the average germination time of Elymus sibiricus seeds at the two initiation times, and the average germination time of Elymus sibiricus seeds after 4h of nano-iron initiation was significantly (P<0.05) lower than that after 30h of nano-iron initiation.

[0061] The results of seedling growth showed that ( Figure 5 ), under salt stress, compared with CK0, the fresh weight and vitality index of the old wheat seedlings after 4 hours of induction with different nano-iron concentrations showed an upward trend, among which the seedling fresh weight and vitality index of Fe-L100 were significantly (P<0.05) higher than those of other treatments, and the effect was the best. Compared with CK0, the root length, seedling length, seedling fresh weight and vitality index of the old wheat seedlings with a nano-iron induction time of 4 hours and a induction concentration of 100mmol / L were significantly (P<0.05) increased, among which the seedling root length was about 21.74% of CK0, the seedling length increased by about 62.94% of CK0, and the seedling fresh weight increased by about 52.91% of CK0. In summary, whether it is water induction or nano-induction, the effect of 4 hours of treatment is significantly better than that of 30 hours of induction.

[0062] 2. Nano-iron-triggered technology for improving salt tolerance of Elymus sibiricus under salt stress

[0063] As shown in Table 4, the membership function is used to give the corresponding numerical values ​​of four indicators such as germination rate in the closed interval [0,1], and a single evaluation is made for each indicator. Then, each single factor membership is weighted arithmetic average, and the comprehensive membership is calculated to obtain the index value of the comprehensive evaluation. The closer the result is to 0, the worse it is, and the closer it is to 1, the better it is. Since seed germination rate is the most important criterion for measuring seed quality, the weighted proportion of seed germination rate is set to 40%, and the remaining various indicators account for 10% respectively. Therefore, the subsequent determination of the physiological indicators related to old wheat is carried out, and the individual initiation concentration treatment with nano-iron initiation time of 4h is selected for verification.

[0064] Table 4 Weighted membership function values ​​and comprehensive rankings of nano-iron-induced treatments of E. sibiricum under salt stress

[0065]

[0066] The results of antioxidant enzyme indexes showed that ( Figure 6 Under salt stress, the POD activity of Elymus sibiricum seedlings significantly increased (P<0.05) under nano-iron priming compared with CK0, with Fe-L100 having the best effect. There was no significant (P>0.05) difference in POD activity between CK0 and CK1. Compared with CK0 and CK1, the CAT, SOD, APX, and GR activities of Elymus sibiricum seedlings treated with Fe-L100 were significantly (P<0.05) increased. Except for Fe-L100, there were no significant (P>0.05) changes in CAT, SOD, and GR activities of seedlings after different nano-iron priming treatments compared with CK1 and CK0. Compared with CK1, APX activity of seedlings treated with Fe-L125 was significantly (P<0.05) decreased. Compared with CK0, MDHAR activity was significantly (P<0.05) increased under both Fe-L50 and Fe-L100 treatments.

[0067] After the above tests, we draw the following conclusions:

[0068] The optimal treatment for Elymus sibiricus seeds was 100 mg / L nano-iron for 4 hours. Furthermore, 100 mg / L nano-iron priming for 4 hours increased the germination rate and germination index of Elymus sibiricus seeds under salt stress and shortened the average germination time. It also promoted seedling growth, significantly increasing seedling length, fresh weight, and vigor index.

[0069] The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A method for priming seeds of Elymus sibiricus with nano-iron salt tolerance and germination promotion, characterized in that: The specific steps include: S1: Preparation of nano-iron suspension: nano-iron was added into deionized water to prepare a suspension with a concentration of 100 mg / L, and ultrasonic vibration was used to dissolve for 1 h; S2: Select old sibiricum seeds, select old sibiricum seeds with uniform weight and fullness, weigh and record; S3: Perform nano-iron initiation, take the nano-iron suspension in a culture dish with three layers of filter paper, add old barley seeds into it, and apply three layers of filter paper moistened with the nano-iron suspension on top of the seeds, and place it at 25°C for 4 hours; S4: Obtain old Elymus sibiricus seeds with salt tolerance. Rinse the primed seeds three times with distilled water, absorb surface moisture with filter paper, and dry them at room temperature.

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