Cotton salt-tolerant yield-increasing quality-improving regulator and application thereof

Abstract

This invention discloses a cotton salt-tolerant yield-increasing and quality-improving regulator and its application. The regulator is prepared from cotton boll husk powder and magnesium oxide, with magnesium-doped carbon quantum dots as the active ingredient and water as the matrix. When applied as a foliar spray, the effective concentration for enhancing cotton salt tolerance is 50-600 mg / L, sprayed once each at the seedling, bud, and flowering / boll-forming stages. Under salt stress, compared to the water control, spraying this regulator significantly reduces the accumulation of reactive oxygen species in cotton leaves, increases photosynthetic pigment content, improves net photosynthetic rate, and enhances salt tolerance; the number of bolls per plant increases by 48.8%, and seed cotton yield increases by 52.7%. Simultaneously, fiber length and strength increase by 15.6% and 19.4%, respectively. Its effect on improving yield and quality is significantly better than magnesium oxide alone or carbon quantum dots directly prepared from boll husks, demonstrating the synergistic advantages of magnesium nutrient supply and carbon dot nanocarriers. This regulator is simple to synthesize, convenient to use, low in cost, highly effective, and environmentally friendly, with broad prospects for promotion.

Description

Technical Field

[0001] This invention relates to the field of crop stress growth regulation technology, and more specifically to a cotton salt tolerance and yield-increasing regulator and its application. Background Technology

[0002] Cotton is considered to have a certain degree of salt tolerance and is a pioneer crop for improving saline-alkali land, with its cultivation areas gradually shifting towards saline-alkali drylands. However, the moderate to severe salt stress brought by saline-alkali land (soil electrical conductivity: 7.7 dSm) -1 -17 dSm -1 This severely restricts cotton production, specifically manifested in inhibited cotton growth, reduced number of cotton buds, increased boll shedding rate, and decreased boll weight, ultimately leading to a reduction in seed cotton yield of approximately 10%-50% and a decline in quality.

[0003] In recent years, nanomaterials have been applied to enhance crop salt tolerance and improve crop yield and quality. While existing crop salt tolerance regulators using nanomaterials as active ingredients can effectively improve crop salt tolerance, they have several drawbacks. In terms of efficacy, single-element nanomaterials such as phosphorus nanoparticles (P-NPs) and magnesium nanoparticles (Mg-CDs) have limited functions, limited enzyme-like activity, low catalytic efficiency, and poor dispersibility. Regarding cost, the synthesis processes of nanomaterials such as selenium nanoparticles (Se-NPs) and silver nanoparticles (Ag-NPs) are complex, and large-scale production is difficult, resulting in high application costs and hindering widespread adoption in field applications. Environmentally, cerium nanoparticles (Ce-NPs) and copper nanoparticles (Cu-NPs) easily accumulate in soil, inhibiting crop root growth, disrupting soil microbial communities, interfering with soil nutrient cycling and ecological balance, and accumulating within crops, threatening human health. These issues limit the large-scale promotion of traditional nano-regulators, requiring technological optimization to overcome these bottlenecks. Summary of the Invention

[0004] In view of this, the present invention provides a novel green cotton salt-tolerant yield-increasing and quality-improving nano-regulator and its application technology. Starting from several aspects such as reducing the accumulation of reactive oxygen species in cotton leaves, increasing the content of photosynthetic pigments in leaves, increasing the photosynthetic capacity of leaves, and increasing the number of bolls, the present invention creates a salt-tolerant yield-increasing and quality-improving nano-regulator, thereby achieving the two major goals of developing and utilizing saline-alkali land and improving the yield and quality of cotton seed cotton.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] First, the present invention provides a cotton salt-tolerant yield-increasing and quality-improving regulator, which uses water as a solvent and the effective component is magnesium-doped carbon quantum dots (Mg-CDs), wherein the concentration of Mg-CDs is 50-600 mg / L.

[0007] Preferably, the concentration of Mg-CDs is 200 mg / L.

[0008] Preferably, the regulator further includes a surfactant with a volume concentration of 0.05%-0.1%.

[0009] Preferably, the surfactant is one or more of Silwet L-77 and Tween 60.

[0010] Preferably, the magnesium-doped carbon quantum dots (Mg-CDs) are synthesized from cotton boll shell powder and MgO via a hydrothermal method, comprising the following steps:

[0011] Cotton boll shell powder was dispersed in ultrapure water, and then MgO powder was added and stirred thoroughly to obtain a suspension. The suspension was transferred to a tetrafluoroethylene reactor and reacted at 180°C for 6 h. After the reaction was completed, the mixture was cooled to room temperature, and the supernatant was collected by centrifugation. The supernatant was filtered through a filter membrane, and finally the filtrate was transferred to a dialysis bag and dialyzed in ultrapure water to obtain a purified Mg-CDs suspension. After freeze-drying, Mg-CDs powder was obtained.

[0012] Furthermore, the mass ratio of the cotton boll shell powder to the MgO powder is (10-40):1.

[0013] Furthermore, the filter membrane has a pore size of 20-100 nm, and the dialysis bag has a molecular weight of 100D-500D.

[0014] Furthermore, the dialysis time is 24-36 hours, and the freeze-drying time is 96 hours.

[0015] The present invention also provides an application of the cotton salt tolerance and quality improvement regulator described in the above technical solution in enhancing the salt tolerance of cotton.

[0016] Preferably, the cotton salt-tolerant yield-increasing and quality-improving regulator is applied once each during the cotton seedling stage, bud stage, and boll-forming stage. When applying the regulator, the foliar spray should be carried out in rainless weather, at 9:00-11:00 am or 2:00-4:00 pm, and the application rate is 20 L / mu.

[0017] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a cotton salt-tolerant yield-increasing and quality-improving regulator and its application, which has the following beneficial effects:

[0018] The cotton salt-tolerant, yield-enhancing, and quality-improving nano-regulator provided by this invention is simple to prepare and low in cost. Synthesized from cotton boll husks and doped with MgO, it fully utilizes biological waste while reducing the risk of excessive metal ion accumulation. Furthermore, this nano-regulator exhibits higher catalytic activity and demonstrates a greater advantage in enhancing cotton salt tolerance. In addition, this regulator has a significant synergistic effect; under salt stress, it reduces the accumulation of reactive oxygen species in leaves while increasing the photosynthetic pigment content in cotton leaves, improving net photosynthetic rate, increasing the number of bolls per plant, and ultimately increasing cotton seed yield. Under salt stress, this regulator can significantly improve cotton fiber strength and fiber length. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 The physicochemical properties of the magnesium-doped carbon quantum dot nanoparticle modulators (Mg-CDs) prepared in Example 1 were determined; wherein, Figure 1 Image a is a transmission electron microscopy image of the morphology of Mg-CDs. Figure 1 b represents the size distribution of Mg-CDs. Figure 1 c represents the surface potential of Mg-CDs. Figure 1 d represents the fluorescence properties of Mg-CDs;

[0021] Figure 2 Screening for suitable concentrations of magnesium-doped carbon quantum dot nano-modifiers (Mg-CDs) to enhance the salt tolerance of cotton in Example 2; wherein, Figure 2 'a' represents the effect of different Mg-CDs concentrations on cotton growth performance under salt stress. Figure 2 b represents the effect of different Mg-CDs concentrations on cotton plant height under salt stress. Figure 2 c represents the effect of different Mg-CDs concentrations on the fresh weight of cotton under salt stress. Figure 2 d represents the effect of different Mg-CDs concentrations on the dry weight of cotton under salt stress.

[0022] Figure 3 The intrinsic effect of magnesium-doped carbon quantum dot nanoscale modulators (Mg-CDs) on enhancing the salt tolerance of cotton; among which, Figure 3 In equation 'a', the effect of magnesium oxide (MgO) solution on the growth performance, fresh weight, and dry weight of cotton under salt stress is represented. Figure 3b represents the effect of undoped magnesium carbon quantum dot (CDs) solution on cotton growth performance, fresh weight, and dry weight under salt stress.

[0023] Figure 4 This is a phenotypic graph showing the effect of magnesium-doped carbon quantum dot nanoparticles (Mg-CDs) on increasing the salt tolerance of cotton at an appropriate concentration in Example 3. Figure 4 The value of 'a' represents the growth performance of cotton with increased salt tolerance due to an appropriate concentration of Mg-CDs. Figure 4 b represents the plant height of cotton plants with enhanced salt tolerance at appropriate concentrations of Mg-CDs. Figure 4 c represents the fresh weight of cotton plants with enhanced salt tolerance due to an appropriate concentration of Mg-CDs. Figure 4 d represents the dry weight of cotton plants with appropriate concentrations of Mg-CDs that enhance salt tolerance.

[0024] Figure 5 This is a graph showing the determination of reactive oxygen species content in cotton leaves at appropriate concentrations, illustrating how magnesium-doped carbon quantum dot nanoparticles (Mg-CDs) increased the salt tolerance of cotton in Example 3. Figure 5 The value of 'a' represents the change in hydrogen peroxide content in cotton leaves at a suitable concentration of Mg-CDs to enhance salt tolerance. Figure 5 b represents the change in superoxide anion content in cotton leaves at a suitable concentration of Mg-CDs to enhance salt tolerance.

[0025] Figure 6 This is a graph showing the determination of photosynthetic pigments in cotton at an appropriate concentration, as determined by magnesium-doped carbon quantum dot nanoparticles (Mg-CDs) in Example 3, which enhance the salt tolerance of cotton. Figure 6 The value of 'a' represents the leaf condition of cotton enhanced salt tolerance by an appropriate concentration of Mg-CDs. Figure 6 b represents the chlorophyll a expression in cotton leaves where a suitable concentration of Mg-CDs enhances salt tolerance. Figure 6 c represents the chlorophyll b expression in cotton leaves where a suitable concentration of Mg-CDs enhances salt tolerance. Figure 6 d represents the carotenoid expression in cotton leaves where a suitable concentration of Mg-CDs enhances salt tolerance;

[0026] Figure 7 This is a graph showing the photosynthetic performance of magnesium-doped carbon quantum dot nanoparticles (Mg-CDs) in increasing the salt tolerance of cotton at appropriate concentrations in Example 3; where, Figure 7 The value of 'a' represents the net photosynthetic rate of cotton leaves that enhances salt tolerance with an appropriate concentration of Mg-CDs. Figure 7 b represents the stomatal conductance of cotton leaves that enhance salt tolerance with appropriate concentrations of Mg-CDs. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1

[0030] Preparation of magnesium-doped carbon quantum dot nanomodifiers (Mg-CDs):

[0031] First, weigh 1.0 g of bell shell powder and dissolve it in 60 mL of ultrapure water, stirring thoroughly for 10 min. Next, weigh 50 mg of MgO powder and dissolve it in the bell shell powder suspension, stirring thoroughly for 15 min. Transfer the mixture to a 100 mL capacity tetrafluoroethylene reactor, place the reactor in an oven at 180 °C for 6 h, and after the reaction, cool to room temperature. Centrifuge the resulting solution at 5000 rpm for 15 min and collect the supernatant. Filter the supernatant through a 100 nm pore size membrane. Then, transfer the filtrate to a 500 D molecular weight dialysis bag and dialyze it in ultrapure water for 24 h to obtain a purified Mg-CDs suspension. Freeze-dry the suspension to obtain Mg-CDs powder for concentration calculation.

[0032] The morphology and size of Mg-CDs were observed by transmission electron microscopy. The surface potential of Mg-CDs was measured by nanoparticle size potentiometer. The ultraviolet spectrum, excitation spectrum and emission spectrum of Mg-CDs were measured by ultraviolet spectrophotometer and steady-state fluorescence spectrometer, respectively.

[0033] like Figure 1 As shown in Figure 1, the prepared magnesium-doped carbon quantum dot nanoparticles (Mg-CDs) are spherical particles with a diameter of 3.67 ± 0.18 nm and a surface potential of 2.46 ± 0.27 mV. Under natural light, Mg-CDs appear brownish-yellow, while under ultraviolet light, they appear blue. The peak value of the ultraviolet absorption spectrum of Mg-CDs is 281 nm, the optimal excitation wavelength is 365 nm, and the maximum absorption wavelength is 475 nm.

[0034] Example 2

[0035] Screening for suitable concentrations of Mg-CDs to improve cotton growth under salt stress:

[0036] Using Zhongmian 425 as the test variety, disinfected cotton seeds were germinated in seedling trays. Once the cotton reached the two-leaf stage, uniformly growing seedlings were selected and transplanted into hydroponic boxes filled with Hoagland's nutrient solution (6L per box, 12 seedlings per box). After the seedlings had adapted for one week, NaCl was added to the nutrient solution to achieve a concentration of 150mM NaCl. Following salt stress, 0.1% (v / v) of Tween 60 was used as a surfactant to spray the cotton seedling leaves with 0, 50, 100, 200, 400, and 600 mg / L of Mg-CDs. Simultaneously, to eliminate the influence of synthetic raw materials, two treatments were set up, one sprayed with MgO solution and the other with undoped carbon quantum dot (CD) solution. Therefore, this experiment included 8 treatments, with 36 seedlings per treatment, totaling 288 cotton seedlings. Seven days after salt stress treatment, the plant height, fresh weight, and dry weight of the cotton seedlings under each treatment were recorded.

[0037] like Figure 2 As shown in Figure 1, Mg-CDs exhibit a concentration effect. Intermediate concentrations of Mg-CDs effectively improve the growth performance of cotton seedlings under salt stress, while excessively low or high concentrations weaken the promoting effect. Specifically, under salt stress conditions, compared to foliar spraying with 0 mg / L Mg-CDs (water), foliar spraying with 50, 100, 200, 400, and 600 mg / L Mg-CDs increased cotton seedling height by 7.6%, 19.4%, 24.4%, 16.0%, and 6.9%, respectively; increased fresh weight by 24.9%, 48.2%, 78.5%, 46.1%, and 20.9%, respectively; and increased dry weight by 26.8%, 39.0%, 68.3%, 24.3%, and 7.3%, respectively.

[0038] like Figure 3 As shown in Figure ab, compared with foliar spraying of 0 mg / L Mg-CDs (water), foliar spraying of MgO had no significant effect on the growth status of cotton seedlings, and the fresh weight and dry weight of cotton seedlings did not change significantly. Compared with foliar spraying of 0 mg / L Mg-CDs (water), foliar spraying of CDs improved cotton seedling growth, increasing the fresh weight of cotton seedlings by 32.7%, but the dry weight of cotton seedlings did not change significantly.

[0039] Therefore, the optimal concentration of Mg-CDs to improve cotton growth under salt stress was determined to be 200 mg / L, and the interference of synthetic raw materials on the effect of this novel nano-regulator on enhancing cotton salt tolerance was eliminated.

[0040] Example 3

[0041] The cultivation of cotton seedlings was the same as in Experiment 2. Once the seedlings reached the two-leaf-one-heart stage, they were transplanted into hydroponic boxes for a hydroponic experiment. After the seedlings had adapted to growth for one week, NaCl was added to the culture medium of half of the seedlings to reach a concentration of 150 mM NaCl, while the other half grew under normal conditions. After salt stress, 0.1% Tween 60 was used as a surfactant, and 200 mg / L Mg-CDs was sprayed onto the half of the seedlings under salt stress treatment, while the other half was sprayed with water. Similarly, the half of the seedlings under normal conditions were sprayed with 200 mg / L Mg-CDs, while the other half was sprayed with water. A total of four treatments were set up, with 48 seedlings in each treatment, for a total of 192 seedlings. After 7 days of treatment, the plant height, fresh weight, and dry weight of the seedlings under each treatment were recorded; the levels of hydrogen peroxide (H2O2) and superoxide anion (O2) in the second true leaf were measured. .- The relative contents of chlorophyll a, chlorophyll b, and carotenoids in the second true leaf were determined; the net photosynthetic rate (P0.05) of the second true leaf was measured. n ) and porosity (G) s ).

[0042] like Figure 4 As shown in Figure 1, under normal growth conditions, compared with the foliar spraying with water, foliar spraying with Mg-CDs did not significantly alter the growth status of cotton seedlings; plant height, fresh weight, and dry weight showed no significant changes. Under salt stress conditions, compared with the foliar spraying with water, foliar spraying with Mg-CDs significantly improved the growth status of cotton seedlings, increasing plant height, fresh weight, and dry weight by 13.2%, 34.0%, and 43.2%, respectively.

[0043] like Figure 5 As shown in Figure ab, under normal growth conditions, compared with the foliar spraying with water, the foliar spraying of Mg-CDs did not significantly change the H2O2 content in the leaves, but it increased the O2 content. .- The content decreased by 50.5%. Under salt stress conditions, compared with the foliar spraying with water, the foliar spraying of Mg-CDs reduced the levels of H2O2 and O2 in the leaves. .- The contents decreased by 40.7% and 32.8%, respectively.

[0044] like Figure 6 As shown in Figure 1, under normal growth conditions, compared with the foliar spraying with water, foliar spraying with Mg-CDs did not significantly alter the growth status of cotton leaves, and the contents of chlorophyll a, chlorophyll b, and carotenoids showed no significant changes. Under salt stress conditions, compared with the foliar spraying with water, foliar spraying with Mg-CDs significantly improved the growth status of cotton seedling leaves, with chlorophyll a, chlorophyll b, and carotenoid contents increasing by 28.9%, 28.6%, and 28.3%, respectively.

[0045] like Figure 7As shown in Figure ab, under normal growth conditions, compared with the foliar spraying with water, foliar spraying with Mg-CDs did not significantly change the net photosynthetic rate (A) and stomatal conductance (g) of cotton leaves. s Under salt stress, compared with foliar spraying with water, foliar spraying with Mg-CDs reduced the levels of A and G in cotton leaves. s These figures increased by 31.5% and 33.3% respectively.

[0046] Example 4

[0047] Using Zhongmian 425 as the test variety, the study was conducted in 2025 in a rainproof greenhouse at the Binjiang Campus of Nanjing Agricultural University, Nanjing, Jiangsu Province (118°50′E, 32°02′N), with pot cultivation as the planting method. The soil salinity for salt stress treatment was set at 0.45% NaCl, while the soil for normal growth was left untreated. Once cotton seedlings reached the two-leaf-one-heart stage, seedlings with uniform growth were transplanted into both types of soil. The salt-stressed and normally growing seedlings were each divided into four groups. Subsequently, using 0.1% Tween 60 as a surfactant, the four groups of cotton seedlings under salt stress and normal growth conditions were sprayed with water, 200 mg / L Mg-CDs solution, MgO solution, and CDs solution, respectively. Spraying with equal concentrations of MgO and CDs solution was to eliminate interference from synthetic raw materials on the effectiveness of the nano-regulators. A total of eight treatments were applied, once each at the seedling, budding, and flowering / bolling stages. After the cotton matures, indicators such as the number of bolls per plant, boll weight, seed cotton yield per plant, and fiber quality are measured.

[0048] The results of this embodiment are shown in Table 1-2.

[0049] Table 1. Effects of salt-tolerant yield-increasing nano-regulators on yield composition and seed cotton yield per plant in normal and salt-stressed cotton varieties.

[0050]

[0051] Note: The data in the table are averages for 10 cotton plants. Different lowercase letters indicate differences between treatments under the same growing conditions, with a p-value < 0.05. Seed cotton yield variation was calculated by comparing the treatment treated with water spraying under the same growing conditions.

[0052] Table 2. Effects of salt-tolerant yield-increasing nano-regulators on fiber quality of normal and salt-stressed cotton.

[0053]

[0054] Note: The data in the table are the average of 6-10 replicates. Different lowercase letters indicate that the difference between different treatments under the same growth conditions is P<0.05.

[0055] Table 1 shows that under normal conditions, compared with foliar spraying of water, foliar spraying of Mg-CDs increased the yield of seed cotton per plant by 9.4%, while foliar spraying of MgO and CDs had no significant effect on the yield of seed cotton per plant. Under salt stress conditions, compared with foliar spraying of water, foliar spraying of Mg-CDs and CDs increased the yield of seed cotton by 52.7% and 15.1% respectively by increasing the number of bolls per plant, while foliar spraying of MgO had no significant effect on the yield of seed cotton. In summary, this nano-regulator significantly improves the seed cotton yield of cotton under salt stress, and its effect is significantly better than that of synthetic raw materials.

[0056] Table 2 shows that under normal conditions, compared with foliar spraying with water, foliar spraying of Mg-CDs increased fiber length by 6.1% and fiber strength by 8.7%, while foliar spraying of MgO and CDs had no significant effect on fiber length and strength. Under salt stress conditions, compared with foliar spraying with water, foliar spraying of Mg-CDs and CDs increased fiber length by 15.6% and 6.8%, respectively, and fiber strength by 19.4% and 11.4%, respectively, while foliar spraying of MgO had no significant effect on either fiber length or fiber strength. In summary, this regulator significantly improves the fiber quality of cotton under normal and salt stress conditions, and its effect is significantly better than that of synthetic raw materials.

[0057] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cotton salt-tolerant, yield-increasing, and quality-improving regulator, characterized in that, Water is used as the solvent, and the active ingredient is magnesium-doped carbon quantum dots (Mg-CDs), with a concentration of 50-600 mg / L.

2. The cotton salt-tolerant yield-increasing and quality-improving regulator according to claim 1, characterized in that, The concentration of the Mg-CDs was 200 mg / L.

3. The cotton salt-tolerant yield-increasing and quality-improving regulator according to claim 1, characterized in that, The regulator also includes a surfactant, with a surfactant volume concentration of 0.05%-0.1%.

4. The cotton salt-tolerant yield-increasing and quality-improving regulator according to claim 1, characterized in that, The surfactant is one or more of Silwet L-77 and Tween 60.

5. The cotton salt-tolerant yield-increasing and quality-improving regulator according to claim 1, characterized in that, The magnesium-doped carbon quantum dots (Mg-CDs) are synthesized from cotton boll shell powder and MgO via a hydrothermal method, including the following steps: Cotton boll shell powder was dispersed in ultrapure water, and then MgO powder was added and stirred thoroughly to obtain a suspension. The suspension was transferred to a tetrafluoroethylene reactor and reacted at 180°C for 6 h. After the reaction was completed, the mixture was cooled to room temperature, and the supernatant was collected by centrifugation. The supernatant was filtered through a filter membrane, and finally the filtrate was transferred to a dialysis bag and dialyzed in ultrapure water to obtain a purified Mg-CDs suspension. After freeze-drying, Mg-CDs powder was obtained.

6. The cotton salt-tolerant yield-increasing and quality-improving regulator according to claim 5, characterized in that, The mass ratio of cotton boll shell powder to MgO powder is (10-40):

1.

7. The cotton salt-tolerant yield-increasing and quality-improving regulator according to claim 5, characterized in that, The filter membrane has a pore size of 20-100 nm, and the dialysis bag has a molecular weight of 100D-500D.

8. A cotton salt-tolerant yield-increasing and quality-improving regulator according to claim 5, characterized in that, The dialysis time is 24-36 hours, and the freeze-drying time is 96 hours.

9. The application of the cotton salt tolerance and quality improvement regulator according to any one of claims 1-7 in enhancing the salt tolerance of cotton.

10. The application according to claim 8, characterized in that, Apply once each during the cotton seedling stage, bud stage, and boll-forming stage. When applying, spray the cotton salt-tolerant yield-increasing and quality-improving regulator on the leaves during rainless weather. The spraying time is 9:00-11:00 am or 2:00-4:00 pm, and the spraying amount is 20L / mu.

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