A sodium nitrate nanoparticle composition for improving the germination of finger millet seeds (Eleusine coracana)

Abstract

A sodium nitrate nanoparticle composition for improving the germination of finger millet seeds (Eleusine coracana), comprising sodium nitrate nanoparticles dispersed in an aqueous medium, a) wherein the sodium nitrate nanoparticles are synthesized by reacting sodium nitrate and sodium hydroxide, each at a concentration of 1 millimolar or 2 millimolar in aqueous medium, b) wherein polyethylene glycol is present at a concentration of 1 percent as a stabilizing agent to prevent aggregation and maintain the stability of the nanoparticles, c) wherein the reaction mixture is continuously stirred and then stabilized at room temperature for 15 days to form stable sodium nitrate nanoparticles, d) wherein the composition is configured to enable a sustained and controlled release of nitrate ions with improved bioavailability during seed germination, while preventing rapid dissolution and leaching into the environment, and e) wherein the finger millet (Eleusine coracana) seeds with the composition lead to improved germination performance, including an optimization of the sprout-to-root ratio to about 1.04 at a concentration of 1 millimolar, an increase in carbohydrate content to up to about 0.24 milligrams per 0.5 grams per milliliter, an increase in protein content to up to about 95 milligrams per milliliter, an increase in total chlorophyll content to up to about 22.0666 milligrams per gram and the maintenance of an antioxidant capture capacity of at least 95.9 percent compared to untreated seeds.

Description

[0001] The present invention relates to the field of agricultural nanotechnology. In particular, the invention relates to a sodium nitrate nanoparticle composition that can be used as a seed treatment to improve germination performance, early germination vigor, biochemical performance, and uniform stand development in finger millet (Eleusine coracana) seeds.

[0002] Finger millet (Eleusine coracana) is an important nutraceutical cereal crop widely cultivated in semi-arid and rain-fed regions. Despite its high nutritional value and resilience, large-scale cultivation of finger millet is often limited by poor, delayed, and uneven seed germination. Suboptimal germination directly impacts early crop establishment, plant density, and yield stability.

[0003] Conventional seed treatment methods use bulk fertilizers or chemical germination promoters to improve germination. However, these methods have several limitations, including low nutrient uptake efficiency, rapid dissolution, leaching losses, and inconsistent performance under stressful conditions such as low soil moisture and nutrient-poor soils. These drawbacks reduce the effectiveness of nutrient delivery during the critical germination phase.

[0004] Sodium nitrate is a well-known nitrogen source that can stimulate metabolic activity during germination. However, in large quantities, sodium nitrate only penetrates the seed coat to a limited extent and requires higher application rates, which can lead to nutrient leaching, soil imbalance, and environmental problems. Consequently, existing technologies fail to deliver nitrate precisely, efficiently, and sustainably to germinating seeds.

[0005] Recent advances in agricultural nanotechnology demonstrate that nanoparticle-based nutrient formulations can significantly improve nutrient bioavailability, permeability, and controlled release. Nanoparticles offer a larger surface area, enhanced interaction with biological tissues, and reduced chemical consumption. Accordingly, there is a need for a sodium nitrate nanoparticle composition specifically designed to overcome the limitations of bulk fertilizers and improve germination and early seedling development in finger millet.

[0006] The main objective of the present invention is to provide a sodium nitrate nanoparticle composition that improves the germination and early germination viability of finger millet seeds (Eleusine coracana).

[0007] Another objective of the invention is to improve the bioavailability and controlled release of nitrate ions during seed germination, thereby maximizing nutrient uptake efficiency while minimizing nutrient losses due to leaching and rapid dissolution.

[0008] Another objective of the invention is to reduce the amount of chemical nutrients required for seed treatment by using sodium nitrate on a nanoscale with improved penetration of the seed coat.

[0009] Another aim of the invention is to improve the balance between shoot and root growth, resulting in an optimized shoot-to-root ratio that is essential for healthy seedling development.

[0010] Another objective of the invention is to improve biochemical parameters such as carbohydrate content, protein content, reducing sugars and lipid mobilization in germinating seeds.

[0011] Another objective of the invention is to modulate oxidative stress reactions in a concentration-dependent manner while maintaining antioxidant defense mechanisms during germination.

[0012] Another objective of the invention is to improve photosynthesis efficiency by increasing the content of chlorophyll a, chlorophyll b and total chlorophyll in treated seedlings.

[0013] Another objective of the invention is to provide a simple, scalable and reproducible method for the synthesis of sodium nitrate nanoparticles under mild conditions using readily available chemicals.

[0014] Another aim of the invention is to support sustainable and environmentally friendly agricultural practices, especially in resource-poor and stress-prone agroclimatic regions.

[0015] The present invention relates to a sodium nitrate nanoparticle composition and a method for its use to improve the germination, biochemical performance, and early seedling growth of finger millet seeds (Eleusine coracana). The nanoparticle composition comprises sodium nitrate nanoparticles synthesized in an aqueous medium using sodium nitrate and sodium hydroxide in the presence of polyethylene glycol as a stabilizing agent.

[0016] Another embodiment of the invention consists in reducing nutrient losses, lowering the need for chemical additives, and providing a scalable and environmentally friendly approach to improving the cultivation and productivity of nutritionally important millet varieties.

[0017] Another embodiment of the invention consists of providing a sodium nitrate nanoparticle composition specifically designed to improve germination and early seedling viability of finger millet (Eleusine coracana). The invention focuses on nanoscale nutrient delivery to enhance the cultivation of nutritionally important cereal crops.

[0018] Another embodiment of the invention involves disclosing a stable nanoparticle formulation synthesized using sodium nitrate and sodium hydroxide in defined concentrations of 1 millimolar or 2 millimolar with polyethylene glycol as a stabilizing agent. The controlled synthesis ensures uniformity and reproducibility at the nanoscale, suitable for agricultural applications.

[0019] Another embodiment of the invention consists in sodium nitrate nanoparticles exhibiting characteristic absorption peaks in the ultraviolet and visible ranges at approximately 235 nanometers and 305 nanometers, respectively, confirming their nanoscale formation. These optical properties differentiate the composition of nitrate formulations in bulk and ensure improved bioavailability.

[0020] Another embodiment of the invention consists in the nanoparticle composition enabling a sustained and controlled release of nitrate ions during the critical germination phase. This controlled nutrient release minimizes rapid dissolution, reduces leaching into the environment, and improves nitrogen uptake efficiency by germinating seeds.

[0021] Another embodiment of the invention consists in the fact that the application of the composition significantly improves the germination rate and the shoot-to-root ratio in finger millet seedlings. In particular, the 1-millimolar formulation optimizes the shoot-to-root ratio, thus supporting uniform emergence and healthy early development of the seedlings.

[0022] Another embodiment of the invention consists in the fact that the invention improves important biochemical parameters during germination, including increased carbohydrate accumulation, improved protein synthesis, and increased reduction sugar levels. These improvements indicate efficient mobilization and utilization of the stored reserves in treated seeds.

[0023] Another embodiment of the invention consists in the nanoparticle composition maintaining strong antioxidant defense mechanisms during germination, with a scavenging capacity exceeding 95 percent. The concentration-dependent catalase activity exhibits a controlled modulation of oxidative stress without causing physiological damage.

[0024] The present invention relates to a sodium nitrate nanoparticle composition and its application for improving germination, biochemical parameters, and early seedling viability in finger millet (Eleusine coracana) seeds. The invention particularly relates to a nanoparticle-based nitrate formulation that improves nitrogen bioavailability during germination while minimizing nutrient loss and environmental dissolution.

[0025] The sodium nitrate nanoparticle composition is synthesized by combining sodium nitrate and sodium hydroxide in an aqueous medium at concentrations of 1 or 2 millimolars. Polyethylene glycol at a concentration of 1 percent is used as a stabilizing agent to prevent aggregation and maintain uniformity at the nanoscale. The reaction mixture is continuously stirred and then stabilized at room temperature for 15 days, resulting in the formation of stable sodium nitrate nanoparticles.

[0026] Characterization of the nanoparticle composition by ultraviolet visible spectrophotometry confirms the formation of nanoparticles. The synthesized nanoparticles exhibit characteristic absorption peaks at approximately 235 nanometers and 305 nanometers, representing hyperchromic or hypochromic shifts relative to the standard absorption peak of nitrate ions at 220 nanometers. These spectral shifts confirm the successful formation of nitrate nanoparticles with nanoscale properties suitable for agricultural applications. At higher concentrations, particularly at 3 millimolar, multiple absorption peaks are observed, indicating impure or unstable components, rendering such concentrations unsuitable for seed treatment. Accordingly, the invention is limited to stable and agriculturally effective nanoparticle concentrations of 1 millimolar and 2 millimolar.

[0027] Finger millet seeds (Eleusine coracana) are superficially sterilized by overnight soaking in water, subsequent treatment with a 1% sodium hypochlorite solution, and subsequent air drying. The sterilized seeds are treated with the sodium nitrate nanoparticle composition and incubated under germination conditions. The nanoparticle composition facilitates the sustained and controlled release of nitrate ions, improves penetration through the seed coat, and increases nitrogen availability during the critical germination phase.

[0028] Germination studies show that treatment with the sodium nitrate nanoparticle composition significantly influences root and shoot development. Untreated control seeds exhibit an average root length of approximately 2.93 centimeters and an average shoot length of 1.56 centimeters, resulting in a shoot-to-root ratio of 0.53. Seeds treated with the 1-millimolar sodium nitrate nanoparticle composition show balanced growth with an average root length of approximately 0.96 centimeters and an average shoot length of approximately 1.005 centimeters, resulting in an optimized shoot-to-root ratio of 1.04. Seeds treated with the 2-millimolar composition exhibit an average root length of approximately 1.20 centimeters and an average shoot length of approximately 0.94 centimeters, resulting in a shoot-to-root ratio of 0.78.

[0029] These results show that the nanoparticle composition, particularly at a concentration of 1 millimolar, supports an improved shoot-to-root ratio.

[0030] Biochemical analysis of germinated seeds treated with the sodium nitrate nanoparticle composition shows a significant improvement in metabolic parameters. Carbohydrate estimation shows that untreated control seeds contain approximately 0.15 milligrams of carbohydrates, while seeds treated with the 1-millimolar nanoparticle composition contain approximately 0.17 milligrams. Seeds treated with the 2-millimolar nanoparticle composition exhibit a significantly higher carbohydrate accumulation of approximately 0.24 milligrams, representing an increase of almost 60 percent compared to the control seeds. This improvement reflects enhanced mobilization and utilization of stored reserves during germination.

[0031] Lipid analysis reveals controlled lipid mobilization in nanoparticle-treated seeds. Untreated control seeds have a lipid content of approximately 0.8 percent. Seeds treated with the 1-millimolar nanoparticle composition show a reduced lipid content of approximately 0.3 percent, indicating efficient utilization of lipid reserves during germination. Seeds treated with the 2-millimolar composition exhibit extensive lipid mobilization, suggesting accelerated metabolic activity and reserve conversion associated with improved germination performance.

[0032] Protein analysis further confirms the positive effect of the sodium nitrate nanoparticle composition. Untreated control seeds have a protein content of approximately 82 milligrams per milliliter. Seeds treated with the 1-millimolar nanoparticle composition show a slight increase to approximately 83 milligrams per milliliter. In contrast, seeds treated with the 2-millimolar nanoparticle composition exhibit a significantly increased protein content of approximately 95 milligrams per milliliter, representing an increase of about 16 percent compared to the control. This increased protein accumulation reflects improved nitrogen assimilation and amino acid biosynthesis, facilitated by the sustained availability of nitrate from the nanoparticle composition.

[0033] Analysis of reducing sugars reveals increased carbohydrate metabolism in nanoparticle-treated seeds. Untreated control seeds exhibit a reducing sugar concentration of approximately 1.32 milligrams per 0.5 grams per milliliter. Seeds treated with the 1-millimolar nanoparticle composition show an increased reducing sugar concentration of approximately 1.79 milligrams per 0.5 grams per milliliter. Seeds treated with the 2-millimolar composition exhibit the highest reducing sugar concentration of approximately 1.82 milligrams per 0.5 grams per milliliter. The elevated reducing sugar levels indicate active mobilization of storage reserves and increased metabolic activity during germination.

[0034] Analysis of antioxidant activity shows that the sodium nitrate nanoparticle composition effectively manages oxidative stress during germination. Untreated control seeds exhibit an antioxidant scavenging capacity of 100 percent. Seeds treated with the 1-millimolar nanoparticle composition show a scavenging capacity of approximately 98.6 percent, while seeds treated with the 2-millimolar composition show a scavenging capacity of approximately 95.9 percent. These results demonstrate that the nanoparticle composition does not impair antioxidant defense mechanisms and supports metabolic activation without causing excessive oxidative damage.

[0035] Measurements of catalase activity further demonstrate a concentration-dependent modulation of oxidative stress. Untreated control seeds and seeds treated with the 1-millimolar nanoparticle composition exhibit negligible catalase activity, indicating minimal oxidative stress. Seeds treated with the 2-millimolar nanoparticle composition show measurable catalase activity, corresponding to approximately 21.4 percent of the standard reference activity, suggesting activation of stress response pathways at higher nanoparticle concentrations. This response reflects the tunable nature of the composition, allowing for concentration optimization based on desired physiological outcomes.

[0036] Germination studies in pots further confirm the efficacy of the sodium nitrate nanoparticle composition. Seedlings derived from untreated control seeds exhibit relatively low chlorophyll accumulation. Seedlings treated with the 1-millimolar nanoparticle composition show significantly improved chlorophyll biosynthesis, with a chlorophyll-a content of approximately 8.6353 milligrams per gram, a chlorophyll-b content of approximately 6.7363 milligrams per gram, and a total chlorophyll content of approximately 22.0666 milligrams per gram, representing an almost fourfold increase compared to the control. Seedlings treated with the 2-millimolar nanoparticle composition exhibit moderate chlorophyll levels, with a total chlorophyll content of approximately 9.3794 milligrams per gram.

[0037] The increased chlorophyll accumulation observed with the sodium nitrate nanoparticle composition, particularly at a concentration of 1 millimolar, indicates improved nitrogen availability, which supports chlorophyll synthesis and the development of the photosynthetic apparatus. This improved photosynthetic efficiency leads to enhanced carbon fixation, biomass accumulation, and overall seedling vigor.

[0038] Accordingly, the sodium nitrate nanoparticle composition of the present invention fulfills important agricultural requirements by enabling a sustainable nitrogen supply, improved germination performance, improved biochemical profiles and robust early seedling development in nutritionally important ancillary cereals such as finger millet. Examples 1. A sodium nitrate nanoparticle composition for improving the germination of finger millet seeds (Eleusine coracana), comprising sodium nitrate nanoparticles dispersed in an aqueous medium, a) wherein the sodium nitrate nanoparticles are synthesized by reacting sodium nitrate and sodium hydroxide, each at a concentration of 1 millimolar or 2 millimolar in aqueous medium, b) wherein polyethylene glycol is present at a concentration of 1 percent as a stabilizing agent to prevent aggregation and maintain the stability of the nanoparticles, c) wherein the reaction mixture is continuously stirred and then stabilized at room temperature for 15 days to form stable sodium nitrate nanoparticles, d) wherein the composition is configured to enable a sustained and controlled release of nitrate ions with improved bioavailability during seed germination, while preventing rapid dissolution and leaching into the environment, and e) wherein the finger millet (Eleusine coracana) seeds with the composition lead to improved germination performance, including an optimization of the sprout-to-root ratio to about 1.04 at a concentration of 1 millimolar, an increase in carbohydrate content to up to about 0.24 milligrams per 0.5 grams per milliliter, an increase in protein content to up to about 95 milligrams per milliliter, an increase in total chlorophyll content to up to about 22.0666 milligrams per gram and the maintenance of an antioxidant capture capacity of at least 95.9 percent compared to untreated seeds.

Claims

[1] A sodium nitrate nanoparticle composition for improving the germination of finger millet seeds (Eleusine coracana), comprising sodium nitrate nanoparticles dispersed in an aqueous medium, a) wherein the sodium nitrate nanoparticles are synthesized by reacting sodium nitrate and sodium hydroxide, each at a concentration of 1 millimolar or 2 millimolar in aqueous medium, b) wherein polyethylene glycol is present at a concentration of 1 percent as a stabilizing agent to prevent aggregation and maintain the stability of the nanoparticles, c) wherein the reaction mixture is continuously stirred and then stabilized at room temperature for 15 days to form stable sodium nitrate nanoparticles, d) wherein the composition is configured to enable a sustained and controlled release of nitrate ions with improved bioavailability during seed germination, while preventing rapid dissolution and leaching into the environment, and e) wherein the finger millet (Eleusine coracana) seeds with the composition lead to improved germination performance, including an optimization of the sprout-to-root ratio to about 1.04 at a concentration of 1 millimolar, an increase in carbohydrate content to up to about 0.24 milligrams per 0.5 grams per milliliter, an increase in protein content to up to about 95 milligrams per milliliter, an increase in total chlorophyll content to up to about 22.0666 milligrams per gram and the maintenance of an antioxidant capture capacity of at least 95.9 percent compared to untreated seeds.