Innovative integrated method for stress-resistant seed treatment of late-sowing wheat in coastal saline-alkali soil and functional seed product

Abstract

The invention discloses a stress-resistant seed treatment integration method for late-sowing wheat in coastal saline-alkali soil and a functional seed product. According to the integrated method, the safe sowing window period of the seeds after germination acceleration is systematically prolonged to 6 days from 3 days through the four steps of seed soaking activation, precise moisture regulation and control, low-temperature preservation window extension and composite stress resistance function construction which are executed in sequence, and the seeds are endowed with strong salt resistance. The obtained functional seed product has specific water content and composite stress-resistant coating, and shows high seedling rate and strong seedling quality under the condition of late sowing in coastal saline-alkali soil. Unification of the technology, functions and products is achieved, and the problem of seedling protection during late sowing of the saline-alkali soil is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of agricultural planting technology, specifically to an innovative integrated method for stress-resistant seed treatment, and in particular to an integrated treatment method and product for improving the salt resistance of wheat seeds, extending the window period for the preservation of their physiological activity, and ultimately obtaining high-performance functional seed products under late-sowing conditions in coastal saline-alkali land. Background Technology

[0002] In rice-wheat rotation areas such as the middle and lower reaches of the Yangtze River, the delayed harvest of the previous rice crop often postpones the sowing of wheat until mid-November or later, resulting in a severe deficiency of accumulated temperature before winter. To maximize the accumulated temperature, the "seed soaking and germination" technique is widely used. For example, the technical solution proposed by Zhu Xinkai et al. in "Advantages and Key Technologies of Soaking and Germinating Late-Sown Wheat Seeds" (2020) includes soaking seeds in clean water, germinating at a suitable temperature, and sowing after drying. It also clearly requires that the germinated seeds be sown within 3 days to prevent a decline in vigor.

[0003] However, when the above-mentioned general technologies are directly applied to coastal saline-alkali lands with harsh soil environments, the following insurmountable drawbacks exist: 1. Poor tolerance for timing errors in farming: The strict "3-day sowing window" is often not guaranteed in the autumn sowing season due to factors such as weather and machinery, and the vigor of seeds stored beyond the time limit declines significantly.

[0004] 2. Salt damage combined with the vulnerable germination period: After the seed germinates and the radicle emerges, it loses the protection of the seed coat and is directly exposed to the high salt and high osmotic pressure soil solution, which makes it very easy for salt damage to cause bud rot and stunted seedlings.

[0005] 3. Vague process parameters: The key step of "moderate drying" lacks quantitative standards, and improper moisture control directly affects sowing operations and seed viability.

[0006] 4. Limited salt resistance measures: Subsequent treatments rely heavily on chemical pesticides, lacking physical isolation and physiological induction mechanisms against salt stress. This results in limited effectiveness in heavily salted areas, making it difficult to obtain seeds with stable stress resistance.

[0007] Therefore, there is an urgent need in this field for an integrated treatment technology that can systematically extend the safety window of active seeds, integrate multiple salt resistance barriers, and ultimately obtain highly stress-resistant functional seeds. Summary of the Invention

[0008] This invention aims to overcome the shortcomings of existing technologies and provide an integrated seed treatment method to systematically solve the problem of seedling survival for late-sown wheat in coastal saline-alkali land. The core objective of this method is to significantly extend the safe sowing window of seeds through the synergy of "physiological activation - precise water regulation - low-temperature preservation," and on this basis, endow seeds with strong stress resistance through a triple synergistic compound treatment of "chemical-physiological-physiological" processes.

[0009] Another object of the present invention is to provide a wheat seed product with specific physiological state and excellent stress resistance function obtained by the above-described integrated method.

[0010] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: In a first aspect, a method for integrating seed treatment to enhance stress resistance in late-sown wheat in coastal saline-alkali land is provided, characterized in that the salinity of the topsoil in the coastal saline-alkali land is 0.2%-0.45%, and the pH value is 8.0-8.6; the integrated method includes the following steps executed sequentially and in synergy: (a) Soaking and germination activation steps: Soak wheat seeds in clean water at 15-20℃ for 8-10 hours, drain for 8-10 hours, and germinate at 16-22℃ under moist conditions for 12-18 hours until the seed whitening rate is ≥85% and the radicle length is ≤0.5mm, thus completing physiological activation. (b) Precise moisture control steps: Spread the seeds treated in step (a) out to dry, and precisely control their moisture content to 28% to 30% (by wet basis weight) through ventilation and turning. (c) Activity maintenance and window period extension steps: The seeds regulated in step (b) are stored in a well-ventilated and dry environment at 8°C to 20°C for 3 to 6 days; (d) Steps for constructing compound stress resistance: One to two days before sowing, the seeds preserved in step (c) are coated with a compound functional seed dressing agent to construct multiple stress resistance barriers; the compound functional seed dressing agent consists of the following three essential components: - Chemical protection unit: fungicides and insecticides containing difenoconazole, fludioxonil, and thiamethoxam; -Physical barrier unit: selected from at least one porous mineral carrier of diatomite and bentonite; - Physiological induction unit: seaweed extract.

[0011] In a second aspect, a functional wheat seed product obtained by processing according to the integration method described in the first aspect is provided, characterized in that the seed product simultaneously possesses the following attributes: -Specific physiological state: water content of 28% to 30% (on a wet basis); - Composite functional coating: The surface is uniformly coated with a composite coating layer consisting of chemical protective units, physical barrier units and physiological induction units; - High stress resistance: Under late sowing conditions in coastal saline-alkali land with a topsoil salt content of 0.2%-0.45%, it exhibits a high seedling survival rate and strong seedling quality.

[0012] Compared with the prior art, the integration method and the functional seed product obtained by the present invention have the following substantial features and significant progress: This invention achieves a systematic integration and breakthrough in the seed treatment process: For the first time, it systematically integrates the three stages of "physiological activation," "precise moisture regulation," and "low-temperature preservation," and discovers the key control point of 28%-30% moisture content. This significantly extends the safe storage period of pre-germinated seeds from 3 days to 6 days, with optimal sowing uniformity on the 6th day. This is not an improvement of a single step, but the result of the synergistic effect of multiple steps, solving a core bottleneck in large-scale production.

[0013] A synergistic stress-resistance system integrating chemistry, physics, and physiology has been constructed: This innovative composite functional seed dressing agent is not simply a mixture of its three units. The chemical unit provides basic protection; the physical unit isolates salt through adsorption; and the physiological unit induces systemic resistance. The three work synergistically to produce a "1+1+1>3" synergistic effect under salt stress (as shown in the examples), thus building strong internal and external stress-resistance capabilities for the seeds.

[0014] This invention creates a new seed product that combines specific physiological states with multiple functions: through this integrated method, the resulting seeds are no longer merely germination carriers, but functional products with precise moisture content control and composite stress-resistant coating. Even under highly saline conditions (0.42% salt content), they maintain a seedling survival rate of over 72.5%, demonstrating superior product performance.

[0015] A standardized integration solution that is quantifiable and replicable has been developed: This integration method precisely quantifies each key parameter, forms a standard operating procedure, ensures a high degree of repeatability of technical effects, and is easy to promote. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0017] Example 1: Application in typical coastal saline-alkali land (topsoil salinity 0.28-0.35%) Location and conditions: Tiaobei 3-4 District, Dongtai City, Jiangsu Province. The soil is coastal saline soil with a topsoil salinity of 0.28-0.35% and a pH of 8.4-8.6. The previous rice crop was harvested in early November. The wheat variety tested was 'Yangmai 39'.

[0018] Integration method steps: 1. Soaking and Germination Activation: Take Yangmai 39 seeds, place the whole bag in 18℃ water and soak for 9 hours. Remove and drain while keeping moist to promote germination for 15 hours. The white sprouting rate was 92%, and the average length of the radicle was 0.4mm, indicating that physiological activation was completed.

[0019] 2. Precise Moisture Control: The seeds are spread out in a thin layer on a cement floor to dry, and a rapid moisture meter is used to monitor the moisture content. By controlling the drying time, the seed moisture content is precisely controlled to 29.2%.

[0020] 3. Maintaining activity and extending the window period: Spread the seeds out in a thin layer of 10 cm thickness for storage.

[0021] 4. Construction of Compound Stress Resistance Function: The seeds are stored until 6-12 hours before sowing and then coated. Compound functional seed dressing formulation (per 100kg seeds): Chemical protection unit (27% phenyl ether•pyrrolizidine•thiamethoxam suspension) 300mL; Physical barrier unit (diatomaceous earth, 325 mesh) 100g; Physiological induction unit (commercial seaweed extract) 50mL. Mix thoroughly using a coating machine to complete the preparation of the functional seed product.

[0022] 5. Sowing and Results: Sow the day after seed dressing. The obtained functional seed products achieved a field germination rate of 91.7%, and the seedlings were robust.

[0023] Confirmatory experiment (window period optimization): To determine the optimal sowing time, comparative experiments were conducted under the same conditions, with storage periods of 3, 4, 5, 6, and 7 days. The results showed that the uniformity of seedlings sown on the 6th day of storage (coefficient of variation 6.8%) was significantly better than that at other time points, proving that it was the optimal window in the integrated method.

[0024] Example 2: Application in severely salted areas (topsoil salt content 0.3.5%) Implementation location and conditions: Fields 423-426 in the same area, with local topsoil salinity of 0.35% and pH of 8.6.

[0025] Integration method steps: The basic process is the same as in Example 1. To cope with higher salinity, the formulation was strengthened in the composite stress resistance function construction step: the amount of physical barrier unit (diatomaceous earth) was increased to 150g / 100kg of seeds, and the amount of physiological induction unit (seaweed extract) was increased to 75mL / 100kg of seeds.

[0026] Results: Under this high salinity stress, the functional seed products prepared by this integrated method still achieved a seedling survival rate of 72.5%, which is significantly better than any conventional treatment.

[0027] Comparative Example 1: The Effects of Water Regulation Failure Two groups were set up with moisture contents of 25% and 35%, with the rest being the same as in Example 1. The results showed that both groups exhibited a significant decrease in viability after storage, demonstrating that precise control of the moisture content between 28% and 30% is a key prerequisite for the effectiveness of the integrated method.

[0028] Comparative Example 2: Validation of the absence of stress-resistance functional units A pot experiment was conducted at a salinity of 0.35%, with four groups: chemical unit only, chemical + physical unit, chemical + physiological unit, and three-unit integration (full formulation). The seedling survival rates were 38.2%, 45.7%, 41.5%, and 72.5%, respectively. The full formulation group showed significantly higher efficacy than the other groups (P<0.01), and the synergistic effect far exceeded linear summation, demonstrating that the synergistic effect of the three units is a necessary condition for constructing seed stress resistance.

[0029] Parameter range and compatibility description Those skilled in the art should understand that, within the scope of the core principles and technical concepts disclosed in this invention, some non-critical auxiliary parameters in the above embodiments can be conventionally optimized. However, the sequence of core steps as defined in the claims of this invention, the water content range in step (b), the temperature-time range in step (c), and the synergistic use of the three types of functional units in step (d) are essential technical features for realizing the integrated method for stress-resistant seed treatment of this invention and obtaining breakthrough effects in functional seed products. Any substantial deviation will result in the loss of the core functions of extended window period and synergistic stress resistance.

Claims

1. An integrated method for stress-resistant seed treatment of late-sown wheat in coastal saline-alkali land, the integrated method comprising the following steps performed sequentially: (a) Soaking and germination activation steps: Soak wheat seeds in clean water at 15-20℃ for 8-10 hours, drain the water, and germinate them at 16-22℃ under moist conditions for 12-18 hours until the seed whitening rate is ≥85% and the radicle length is ≤0.5mm; (b) Precise moisture control steps: Spread out the seeds treated in step (a) to dry, and control their moisture content to 28% to 30% (based on wet basis weight). (c) Step for constructing composite stress resistance function: The seeds preserved in step (c) are coated with a composite functional seed dressing agent; the composite functional seed dressing agent contains fungicides and insecticides, porous mineral carriers and seaweed-derived biostimulants.

2. The integration method according to claim 1, characterized in that, In step (b), the seed moisture content is controlled at 29% ± 1%.

3. The integration method according to claim 1, characterized in that, The storage conditions in step (c) are a well-ventilated and dry environment with a temperature of 6°C to 20°C.

4. The integration method according to claim 1, characterized in that, The shelf life of step (c) is 3-6 days.

5. The integration method according to claim 4, characterized in that, The composite stress resistance function construction step and subsequent sowing were carried out on days 3-6 of the storage period.

6. The integration method according to claim 1, characterized in that, The porous mineral carrier is selected from diatomaceous earth, bentonite, or a combination thereof, and its dosage is 100g to 150g per 100kg of seeds.

7. The integration method according to claim 1, characterized in that, The seaweed-derived biostimulant is a seaweed extract, and its dosage is 40 mL to 80 mL per 100 kg of seeds.

8. The integration method according to claim 1, characterized in that, The fungicides and insecticides include difenoconazole, fludioxonil, and thiamethoxam.

9. The integration method according to claim 1, characterized in that, Step (d) is performed 6–12 hours before sowing.

10. The integration method according to claim 1, characterized in that, It is suitable for areas with a topsoil salt content of 0.2% to 0.35%, wherein the amount of the porous mineral carrier is 120g to 150g per 100kg of seeds and / or the amount of the seaweed-derived biostimulant is 60mL to 80mL per 100kg of seeds.