Composite preservative solution for prolonging preservation period of rhododendron cut flowers and preparation method thereof

Abstract

The application relates to the field of postharvest preservation of flowers and cut flower vase planting and maintenance technology, in particular to a composite preservative liquid for prolonging the preservation period of cut rhododendron flowers and a preparation method thereof. The method comprises the following steps: taking part of deionized water, sequentially adding trehalose, sucrose and potassium nitrate, stirring and dissolving to obtain a sugar salt water phase; taking part of deionized water, adding citric acid and stirring and dissolving, then adding ferrous sulfate, stirring in the dark to obtain a ferrous salt acidification pre-solution; slowly adding the ferrous salt acidification pre-solution into the sugar salt water phase, mixing under stirring to obtain a composite water phase; dissolving gibberellin in ethanol to prepare a gibberellin mother liquor, and adding the gibberellin mother liquor into the composite water phase; adding diluted sec-butylamine into the obtained solution, stirring and mixing; adding the remaining deionized water to constant volume; filtering and sterilizing the adjusted solution, filling and sealing to obtain the composite preservative liquid. The application can inhibit the reproduction of botrytis cinerea and maintain the good state of cut flowers.

Description

Technical Field

[0001] This application relates to the field of postharvest preservation of flowers and vase care of cut flowers, and in particular to a compound preservative solution for extending the shelf life of azalea cut flowers and its preparation method. Background Technology

[0002] Azaleas, as important woody ornamental flowers, play a vital role in the vase preservation of cut flowers in the flower market and home decoration. Current cut flower preservation technologies typically use water-based solutions as a carrier, maintaining the ornamental quality of cut flowers by adding sugars to provide energy, acidifying agents to adjust pH, bactericides to inhibit microorganisms, and plant growth regulators to delay aging. For woody cut flowers, common preservation solutions often involve mixing sucrose, citric acid, hypochlorite, or 8-hydroxyquinoline in specific proportions. This utilizes sugars to replenish respiration, an acidic environment to promote water absorption and inhibit bacterial growth, and bactericides to reduce physical blockage of the vascular bundles at the stem base. These existing technologies are widely used for herbaceous cut flowers such as roses and carnations, forming a relatively mature sugar-acid bactericidal compound system.

[0003] However, in the existing technology, for specific varieties such as azaleas with highly lignified branches, petals that are sensitive to gray mold, and leaves that are prone to yellowing, general-purpose preservative solutions often cannot simultaneously solve multiple concurrent problems such as vascular blockage, pathogen infection, water imbalance, and mineral nutrient deficiency. As a result, cut flowers are prone to bending, brown spots and rotting of petals, and premature aging of leaves during vase life, which limits their ornamental life and commercial value. Summary of the Invention

[0004] This application provides a compound preservative solution for extending the shelf life of cut azalea flowers and its preparation method to solve the above-mentioned problems.

[0005] In a first aspect, this application provides a composite preservative solution for extending the shelf life of cut azalea flowers. The composite preservative solution is a water-based system and, based on the total volume of the composite preservative solution, comprises the following components:

[0006] Sec-butylamine 0.5-1.5 g / L, gibberellin 50-80 mg / L, trehalose 10-20 g / L, sucrose 10-25 g / L, potassium nitrate 3-7 g / L, ferrous sulfate 0.5-1.5 g / L, citric acid 0.5-1.5 g / L, and deionized water balance;

[0007] The mass ratio of trehalose to sucrose is 0.6:1-1.5:1, the mass ratio of citric acid to ferrous sulfate is 0.8:1-1.5:1, and the pH of the compound preservative solution is 5.5-6.5.

[0008] The sec-butylamine is used to inhibit the reproduction of gray mold pathogens on the stem base and petal surface of azalea cut flowers. The trehalose and sucrose together form a low-sugar water-retaining and energy-supplying system. The potassium nitrate, ferrous sulfate and citric acid together form a weakly acidic mineral stabilizing system to reduce stem base blockage, petal dehydration and wrinkling, and leaf yellowing during the vase arrangement of azalea cut flowers.

[0009] The above technical solution, by setting a specific concentration of sec-butylamine as the main antibacterial agent, can directly kill or inhibit Botrytis cinerea at the base of the stem and on the surface of the petals, thus blocking the physical blockage of the vascular bundles and petal rot caused by pathogenic microorganisms at the source. Simultaneously, utilizing the synergistic effect of trehalose and sucrose within a mass ratio range of 0.6:1-1.5:1, trehalose, as a non-reducing disaccharide, plays an osmotic regulation role, maintaining the turgor pressure of petal cells and reducing free water activity, while an appropriate amount of sucrose provides the carbon source required for respiratory metabolism. This low-sugar water-retaining and energy-supplying system avoids the explosive proliferation of microorganisms induced by high concentrations of sucrose. This not only prevents energy deficiency and premature petal senescence caused by low sugar content, but also, by combining citric acid and ferrous sulfate with potassium nitrate in a ratio of 0.8:1-1.5:1, a weakly acidic mineral stability system is constructed. Citric acid not only maintains the pH of the system at 5.5-6.5 to inhibit bacterial growth, but also acts as a chelating agent to prevent the oxidation and precipitation of ferrous ions, ensuring that iron is absorbed by the cut flowers in a soluble state to delay leaf yellowing. Potassium ions help maintain cell osmotic balance. Through a multi-pathway synergistic mechanism of antibacterial, water-retaining, energy-supplying, mineral supplementation and pH regulation, the components significantly extend the vase life of azalea cut flowers.

[0010] Optionally, the total volume of the composite preservative solution includes 0.8-1.2 g / L of sec-butylamine, 60-70 mg / L of gibberellin, 13-18 g / L of trehalose, 15-20 g / L of sucrose, 4.5-5.5 g / L of potassium nitrate, 0.8-1.2 g / L of ferrous sulfate, 0.8-1.2 g / L of citric acid, and the balance of deionized water, wherein the pH of the composite preservative solution is 5.8-6.2.

[0011] By further narrowing the concentration range of each component to the aforementioned optimal range through the above technical solution, the antibacterial efficacy of sec-butylamine is at its optimal window while avoiding phytotoxic stimulation to the petal tissue. The gibberellin concentration and the medium concentration of sec-butylamine are optimally matched to delay aging without causing abnormal growth. The ratio of trehalose to sucrose is closer to the golden balance point of 1:1, maximizing the synergistic effect of water retention and energy supply. At the same time, the optimized mineral salt ratio and pH value of 5.8-6.2 further enhance the chemical stability of iron salts and the biocompatibility of the system, thereby achieving better batch consistency and overall preservation effect under conventional indoor vase conditions.

[0012] Optionally, the mass ratio of trehalose to sucrose is 0.8:1-1.2:1, and the mass ratio of citric acid to ferrous sulfate is 0.9:1-1.2:1, so that the composite preservative liquid forms a low-sugar water-retaining and energy-supplying system and a weakly acidic iron salt stabilizing system.

[0013] By strictly controlling the mass ratio of trehalose to sucrose between 0.8:1 and 1.2:1, the above technical solution ensures the dominant role of trehalose in osmotic regulation, effectively reducing the water transpiration rate and stabilizing cell membrane structure, while retaining sufficient sucrose to support flower opening metabolism. Furthermore, limiting the mass ratio of citric acid to ferrous sulfate to 0.9:1-1.2:1 ensures that citric acid molecules are sufficient to completely complex ferrous ions, forming a stable soluble complex in a weakly acidic environment. This prevents Fe²⁺ from oxidizing to Fe³⁺, producing a reddish-brown precipitate that clogs the vascular bundles or contaminates the petals. This precise ratio design enhances the intrinsic stability of the preservative solution at the molecular interaction level, significantly reducing turbidity and the risk of stem base blockage in the later stages of vase ...

[0014] Optionally, the compound preservative solution also includes 40-120 mg / L of chitosan oligosaccharide, which is used to reduce the formation of microbial film at the base of azalea cut flower stems and the risk of cut blockage.

[0015] Through the above technical solution, by introducing chitosan oligosaccharide, a natural cationic oligosaccharide, it forms a triple antibacterial defense line with the existing sec-butylamine and weakly acidic environment in the system. Chitosan oligosaccharide can specifically interfere with the formation of microbial biofilm by destroying the bacterial cell membrane structure and inhibiting the synthesis of extracellular polysaccharides, thereby physically reducing the biomass accumulation and vascular blockage probability at the stem base cut. At the same time, it induces the cut flower itself to produce a defense response, further enhancing its water absorption capacity and stress resistance under high microbial load conditions.

[0016] Optionally, the composite preservative solution is a high-humidity antibacterial preservative solution, comprising, by total volume, 1.2-1.5 g / L of sec-butylamine, 50-65 mg / L of gibberellin, 16-20 g / L of trehalose, 10-18 g / L of sucrose, 4-6 g / L of potassium nitrate, 0.6-1.0 g / L of ferrous sulfate, 1.0-1.5 g / L of citric acid, and the remainder being deionized water, and the pH of the composite preservative solution is 5.5-5.8.

[0017] By using the above technical solution, increasing the concentration of sec-butylamine to 1.2-1.5 g / L and combining it with a lower pH value (5.5-5.8), a strong antibacterial environment is created to cope with the high risk of gray mold outbreaks in high humidity and poor ventilation scenarios. At the same time, the trehalose content is appropriately increased to compensate for tissue stress and water loss that may be caused by the strong antibacterial environment, and the sucrose content is moderately reduced to reduce the substrate for microbial reproduction. This targeted formulation strategy ensures strong disease control while maintaining the physiological balance of cut flowers by adjusting the ratio of hormones and sugars. It is particularly suitable for harsh conditions such as cold chain transportation or humid and hot display.

[0018] Secondly, this application provides a method for preparing a compound preservative solution to extend the shelf life of cut azalea flowers, the method comprising:

[0019] S1. Take a portion of deionized water, add trehalose, sucrose and potassium nitrate in sequence, stir to dissolve, and obtain a sugar-salt phase;

[0020] S2. Take another portion of deionized water, add citric acid and stir to dissolve, making the local solution acidic. Then add ferrous sulfate, stir in the dark, and obtain the iron salt acidification pre-solution.

[0021] S3. Slowly add the iron salt acidification pre-solution to the sugar-salt water phase and mix under stirring to obtain a composite aqueous phase;

[0022] S4. Dissolve gibberellin in ethanol to prepare gibberellin mother liquor, and add the gibberellin mother liquor to the composite aqueous phase;

[0023] S5. Dilute the sec-butylamine and add it to the solution obtained in step S4 at a system temperature not exceeding 30°C, and stir to mix.

[0024] S6. Add the remaining deionized water to make up the volume, and adjust the pH of the system to 5.5-6.5 using an acid-base adjuster;

[0025] S7. The adjusted solution is filtered through a 0.22μm microporous membrane for sterilization, then filled and sealed to obtain the composite preservative solution;

[0026] In this process, by first forming the iron salt acidified pre-solution, then combining it with sugar-salt water, and adding sec-butylamine at a low temperature in the later stage, the ferrous sulfate is kept stable in the weak acid system, while reducing the impact of sec-butylamine volatilization loss and local pH changes on the applicability of gibberellin and rhododendron cut flower tissue.

[0027] The above technical solution solves the compatibility problem of multi-component compounding through a step-by-step preparation process: In step S2, ferrous sulfate is pre-acidified and dissolved, and the strong chelating effect of citric acid on ferrous ions in a local low pH environment is utilized to fundamentally avoid the direct oxidation and precipitation of iron salts in neutral sugar solution; In step S4, ethanol is used to help dissolve gibberellin, overcoming its poor water solubility and ensuring uniform dispersion of hormones; In step S5, a strategy of adding sec-butylamine at the end of the low temperature is adopted to effectively inhibit the loss of this volatile component and avoid the destruction of gibberellin stability by drastic local pH fluctuations. This process logic of "phase separation pretreatment - sequential merging - end addition - fine-tuning filtration" ensures that the finished preservation liquid is clear and transparent, has a high retention rate of active ingredients, and has good long-term storage stability.

[0028] Optionally, in step S1, the amount of deionized water used is 60%-70% of the target volume of the composite preservative solution, the water temperature is controlled at 25-35℃, trehalose, sucrose and potassium nitrate are added in sequence and stirred for 15-30 minutes to obtain a clear sugar-salt water phase.

[0029] By controlling the amount of solvent to reserve space for subsequent feeding, and using a suitable water temperature of 25-35℃ to accelerate the dissolution of sugars without causing thermal degradation, coupled with sufficient stirring time, the uniformity and clarity of the sugar-salt water phase are ensured, providing a good background environment for the stable addition of iron salts and avoiding crystallization or precipitation problems caused by excessively high local concentrations or insufficient dissolution.

[0030] Optionally, in step S2, after adding citric acid to adjust the pH of the local solution to 3.5-4.5, ferrous sulfate is added, and the solution is stirred for 5-15 minutes under light-protected conditions to form an iron salt acidification pre-solution.

[0031] By adjusting the local pH to a strong acid range of 3.5-4.5 before adding ferrous sulfate, favorable thermodynamic conditions for inhibiting Fe²⁺ oxidation are created. Combined with light-protected operation to prevent photocatalytic oxidation, this promotes the full complexation of citric acid and ferrous ions to form a stable soluble complex. This technical feature directly determines the effectiveness and stability of iron in the final product and prevents the formation of reddish-brown ferric hydroxide precipitate.

[0032] Optionally, in step S4, the gibberellin mother liquor is prepared by dissolving gibberellin in ethanol, and the concentration of gibberellin in the gibberellin mother liquor is 5-20 g / L; in step S5, sec-butylamine is added at a system temperature of 20-30℃ and stirred in a closed state for 5-15 min.

[0033] The above technical solution involves pre-preparing gibberellin into a high-concentration ethanol mother liquor and using organic solvents to improve its dispersibility, thus avoiding agglomeration and precipitation caused by direct feeding. At the same time, the addition of sec-butylamine under low-temperature and closed conditions of 20-30℃ controls the volatilization rate and reduces the loss during operation, ensuring the efficient loading and uniform distribution of the two key active ingredients in the system, thereby improving the bioactivity and safety of the product.

[0034] Optionally, after step S7, the method further includes using the obtained composite preservative solution for vase preservation of azalea cut flowers, wherein the vase preservation step includes:

[0035] Cut the azalea stems at a 45° angle to create a 2-3cm incision. Then, insert them into the compound preservative solution, ensuring the solution level is 3-5cm below the bottom of the stem. Maintain the vase temperature at 10-15℃. Replace the compound preservative solution every 2-3 days and trim the bottom of the stems by 0.5cm.

[0036] Through the above technical solutions, the water absorption area is increased and air plugs are removed by standardized incision treatment. Combined with appropriate immersion depth and low temperature environment to reduce transpiration and metabolic rate, and regular liquid changing and root trimming to remove blockages and refresh the agent concentration, this scientific application method, together with the aforementioned formula and preparation process, forms a complete technical closed loop. This maximizes the antibacterial, water-retaining and anti-aging effects of the compound preservative solution, and significantly extends the vase life of azalea cut flowers. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 A flowchart illustrating a method for preparing a composite preservative solution to extend the shelf life of cut azalea flowers, as provided in an embodiment of this application.

[0039] Figure 2 A schematic diagram illustrating the synergistic control mechanism of the composite preservative solution on "water loss-disease-aging-clogging" of cut azalea flowers provided in an embodiment of this application;

[0040] Figure 3 A diagram illustrating the synergistic relationship between trehalose, sucrose, gibberellin, and sec-butylamine in a composite preservative solution provided in an embodiment of this application;

[0041] Figure 4 This is a flowchart illustrating a method for using a composite preservative solution according to an embodiment of this application.

[0042] Figure 5 This is a comparison chart of vase life and gray mold incidence provided in one embodiment and a comparative example of this application. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0044] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0045] The embodiments of this application will now be described in further detail with reference to the accompanying drawings.

[0046] Example 1

[0047] This embodiment provides a standard rhododendron cut flower composite preservative solution and its preparation method, aiming to verify the comprehensive preservation effect of the technical solution of the present invention under normal indoor environment.

[0048] Weigh 15g of trehalose, 18g of sucrose, and 5g of potassium nitrate, add them to 650mL of deionized water at 30℃, and stir for 20min until completely dissolved to obtain a clear sugar-salt phase. Separately, take 50mL of deionized water, add 1g of citric acid, and stir to dissolve. Adjust the local pH to 4.0 with dilute hydrochloric acid, then add 1g of ferrous sulfate heptahydrate, and stir for 10min under light-protected conditions to obtain a pale green ferric acid pre-solution. Figure 1 As shown, Figure 1 The preparation process of the composite preservative solution of this invention is demonstrated. The above-mentioned iron salt acidified pre-solution is slowly poured into the sugar-salt water phase while stirring at 300 rpm until homogeneous, resulting in a composite aqueous phase. 65 mg of gibberellin is weighed and dissolved in 5 mL of anhydrous ethanol to prepare a mother liquor, which is then slowly added to the composite aqueous phase while continuously stirring. 1.0 g of sec-butylamine is diluted with a small amount of water and added to the solution under sealed conditions at 25°C, stirring for 10 min. Finally, the remaining deionized water is added to bring the volume to 1 L, the pH is adjusted to 6.0 with dilute NaOH solution, and the solution is filtered through a 0.22 μm microporous membrane for sterilization, then bottled and sealed for storage.

[0049] The prepared compound preservative solution is a clear and transparent liquid with no visible sediment. The pH value is 6.0. After being placed at room temperature in the dark for 30 days, no obvious stratification or sedimentation occurs.

[0050] This embodiment successfully prepared a standard composite preservative solution. All components were fully dissolved, and the system showed good stability, demonstrating the feasibility and reproducibility of the preparation process of this invention.

[0051] Example 2

[0052] This embodiment aims to verify the technical effect under the conditions of lower limit of sec-butylamine concentration and upper limit of trehalose / sucrose ratio.

[0053] Under the same preparation conditions as in Example 1, only the component amounts were adjusted: 0.5g of sec-butylamine, 20g of trehalose, and 13.3g of sucrose were weighed (to make the trehalose / sucrose mass ratio approximately 1.5:1), and the remaining components (50mg of gibberellin, 3g of potassium nitrate, 0.5g of ferrous sulfate, and 0.5g of citric acid) were adjusted to the lower limit of 1 or the corresponding proportion, and the volume was brought to 1L. The pH was then adjusted to 5.5.

[0054] The prepared preservative solution was clear with a pH of 5.5. Vase experiments showed that the formula effectively inhibited gray mold, and the petals exhibited excellent water retention, without excessive viscosity or microbial imbalance caused by sugar imbalance.

[0055] The results show that even under the conditions of the lower limit of sec-butylamine concentration and the upper limit of trehalose dominance, the technical solution of the present invention can still achieve the expected antibacterial and water-retaining effects, proving the feasibility of the parameter range.

[0056] Example 3

[0057] This embodiment aims to verify the technical effect under the conditions of the upper limit of sec-butylamine concentration and the lower limit of citric acid / ferrous sulfate ratio.

[0058] Under the same preparation conditions as in Example 1, only the component amounts were adjusted: 1.5g of sec-butylamine, 1.5g of ferrous sulfate, and 1.2g of citric acid were weighed (to make the citric acid / ferrous sulfate mass ratio 0.8:1). The remaining components (80mg of gibberellin, 10g of trehalose, 16.7g of sucrose, and 7g of potassium nitrate) were adjusted to the upper limit of 1 or the corresponding proportion, and the volume was brought to 1L. The pH was then adjusted to 6.5.

[0059] The prepared preservative solution was clear and transparent, with no iron salt precipitation and a pH of 6.5. Despite the high concentration of sec-butylamine, no significant phytotoxicity to the petals was observed, and the iron salts remained stable at the higher pH threshold.

[0060] The results show that, at the other extreme of the parameter range, the present invention still maintains good chemical stability and biological safety, further supporting its broad-ranging effectiveness.

[0061] Example 4

[0062] This embodiment provides an anti-clogging composite preservative liquid containing chitosan oligosaccharides.

[0063] Based on Example 1, after the formation of the composite aqueous phase in step S3 and before adding the gibberellin mother liquor, 80 mg of chitosan oligosaccharide was added and stirred until completely dissolved. Subsequent steps were the same as in Example 1.

[0064] The resulting preservative solution was clear, with a slight increase in viscosity but good fluidity. The addition of chitosan oligosaccharide did not affect the solubility and stability of other components.

[0065] This embodiment demonstrates the compatibility of introducing chitosan oligosaccharides into the basic formulation. This modified formulation is expected to further reduce the risk of microbial biofilm formation and enhance anti-clogging performance.

[0066] Example 5

[0067] This embodiment provides a high-humidity antibacterial compound preservative liquid, which aims to verify the effect of the special formula under high humidity conditions.

[0068] Weigh out 1.3g of sec-butylamine, 60mg of gibberellin, 18g of trehalose, 15g of sucrose, 5g of potassium nitrate, 0.8g of ferrous sulfate, and 1.2g of citric acid. Following the preparation steps in Example 1, first prepare a sugar-salt phase and a pre-acidified iron salt solution (adjusting the pH locally to 3.8). Combine these, add the gibberellin ethanol stock solution, and finally add sec-butylamine at 25°C. Make up to 1L and adjust the pH to 5.6.

[0069] The resulting solution was clear with a pH of 5.6. This formulation provides a stronger acidic environment and a higher concentration of antibacterial agent, simulating the application requirements under high humidity stress conditions.

[0070] This embodiment demonstrates the feasibility of adjusting the formula parameters for specific environments. This high-humidity antibacterial preservative solution enhances the ability to prevent and control early-stage diseases while maintaining the stability of its components.

[0071] Example 6

[0072] This embodiment is a performance and effect verification experiment, which aims to quantify the technical advantages of the composite preservative liquid of the present invention through comparative testing.

[0073] Cut flower branches of 'Azalea' with uniform growth were selected and randomly divided into 7 groups of 10 branches each. These branches were then inserted into the preservative solutions prepared in Examples 1, 2, and 4, as well as the control solutions of Comparative Examples 1-4. The comparative examples were set as follows: Comparative Example 1 was water; Comparative Example 2 contained only sucrose (20 g / L) and gibberellin (65 mg / L); Comparative Example 3 was the formulation of Example 1 without trehalose (replaced with an equal amount of sucrose); and Comparative Example 4 was the formulation of Example 1 without sec-butylamine. All groups were managed in the same vase arrangement manner (45° angled cut, immersion in liquid for 3-5 cm, temperature 12℃, liquid changed and roots trimmed every 2 days).

[0074] The test indicators included vase life (days), gray mold incidence rate on day 7 (%), OD600 value of the vase solution on day 7 (turbidity), and SPAD value of the leaves on day 7 (relative chlorophyll content). Specific test results are shown in Table 1.

[0075] Table 1. Results of vase arrangement performance tests for azalea cut flowers in different treatment groups.

[0076] Example 1 Standard Preservative Liquid 18.5 5.2 0.12 42.5 Example 2 Parameter boundary sample A 17.8 6.5 0.15 41.8 Example 4 Chitosan oligosaccharide type 19.2 3.8 0.09 43.1 Comparative Example 1 Clear water 8.2 65.4 0.85 28.3 Comparative Example 2 Sucrose + Gibberellin 11.5 42.1 0.68 35.6 Comparative Example 3 Trehalose-free 13.4 18.5 0.35 32.4 Comparative Example 4 sec-butylamine-free 12.8 55.3 0.72 38.9

[0077] As shown in Table 1, the preservative solutions prepared in Examples 1-4 are significantly superior to the comparative examples in all indicators. In particular, compared with Comparative Example 1 (water), the vase life of Example 1 was extended by approximately 125%, and the incidence of gray mold was reduced by 92%. Compared with Comparative Example 2 (traditional sugar + hormone), Example 1 significantly reduced the turbidity of the vase solution (OD600 decreased from 0.68 to 0.12), indicating that the low-sugar water-retaining and energy-supplying system of the present invention effectively inhibited microbial reproduction. Compared with Comparative Example 3 (without trehalose), the SPAD value of the leaves in Example 1 was higher, and the petals were less wrinkled, confirming the key role of trehalose in maintaining cell turgor pressure and water retention. Compared with Comparative Example 4 (without sec-butylamine), the incidence of gray mold in Example 1 was extremely low, highlighting the core role of sec-butylamine in inhibiting gray mold pathogens.

[0078] like Figure 5 As shown, Figure 5 This is a comparison chart of the vase life and gray mold incidence of the embodiments and comparative examples of the present invention. It can be clearly seen from the chart that the bar charts for Examples 1, 2, and 4 are significantly taller (representing vase life) than those for the comparative examples, and the line charts show that the gray mold incidence is much lower than that of the comparative examples. This confirms that the present invention, through the synergistic effect of multiple components, has unexpected technical effects in extending the ornamental period and controlling diseases. Furthermore, as... Figure 2 As shown, Figure 2 This diagram illustrates the synergistic control mechanism of the composite preservative solution of this invention on the "water loss-disease-aging-clogging" process in azalea cut flowers. Combined with experimental data, it is clear that this invention achieves a comprehensive improvement in cut flower quality by blocking the four major decay pathways shown in the diagram. Figure 3 As shown, Figure 3 The study revealed the synergistic functional relationship between trehalose, sucrose, gibberellin, and sec-butylamine. The fact that Example 1 was superior to Comparative Examples 2 and 3 in the experimental results strongly corroborates the effectiveness of the "low sugar water retention" and "antibacterial energy supply" balance mechanism shown in the figure.

[0079] During the vase-arranging process, follow as follows Figure 4 The usage method is illustrated in the flowchart, which involves 45° oblique cutting, controlling the liquid level, and regularly changing the liquid and pruning the roots. Combined with the use of the preservative solution of this invention, the cut flowers maintain good water absorption and physiological activity throughout their vase life. Experimental results show that the composite preservative solution prepared in this invention exhibits excellent preservation effects in azalea cut flower vase models, significantly extending vase life, reducing the incidence of gray mold, and maintaining leaf greenness and petal fullness. Therefore, it can be used to prepare preservative drugs or maintenance agents for the prevention and / or treatment of post-harvest decay and gray mold in azalea cut flowers.

[0080] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A compound preservative solution for extending the shelf life of cut azalea flowers, characterized in that, The composite preservative solution is a water-based system, and based on its total volume, it comprises the following components: Sec-butylamine 0.5-1.5 g / L, gibberellin 50-80 mg / L, trehalose 10-20 g / L, sucrose 10-25 g / L, potassium nitrate 3-7 g / L, ferrous sulfate 0.5-1.5 g / L, citric acid 0.5-1.5 g / L, and deionized water balance; The mass ratio of trehalose to sucrose is 0.6:1-1.5:1, the mass ratio of citric acid to ferrous sulfate is 0.8:1-1.5:1, and the pH of the compound preservative solution is 5.5-6.

5. The sec-butylamine is used to inhibit the reproduction of gray mold pathogens on the stem base and petal surface of azalea cut flowers. The trehalose and sucrose together form a low-sugar water-retaining and energy-supplying system. The potassium nitrate, ferrous sulfate and citric acid together form a weakly acidic mineral stabilizing system to reduce stem base blockage, petal dehydration and wrinkling, and leaf yellowing during the vase arrangement of azalea cut flowers.

2. The composite preservative liquid according to claim 1, characterized in that, The total volume of the compound preservative solution includes 0.8-1.2 g / L of sec-butylamine, 60-70 mg / L of gibberellin, 13-18 g / L of trehalose, 15-20 g / L of sucrose, 4.5-5.5 g / L of potassium nitrate, 0.8-1.2 g / L of ferrous sulfate, 0.8-1.2 g / L of citric acid, and the balance of deionized water. The pH of the compound preservative solution is 5.8-6.

2.

3. The composite preservative liquid according to claim 1, characterized in that, The mass ratio of trehalose to sucrose is 0.8:1-1.2:1, and the mass ratio of citric acid to ferrous sulfate is 0.9:1-1.2:1, so that the composite preservative liquid forms a low-sugar water-retaining and energy-supplying system and a weakly acidic iron salt stabilizing system.

4. The composite preservative liquid according to claim 3, characterized in that, The compound preservative solution also includes 40-120 mg / L of chitosan oligosaccharide, which is used to reduce the formation of microbial film at the base of azalea cut flower stems and the risk of cut blockage.

5. The composite preservative liquid according to claim 1, characterized in that, The compound preservative solution is a high-humidity antibacterial preservative solution. Based on the total volume of the compound preservative solution, it includes 1.2-1.5 g / L of sec-butylamine, 50-65 mg / L of gibberellin, 16-20 g / L of trehalose, 10-18 g / L of sucrose, 4-6 g / L of potassium nitrate, 0.6-1.0 g / L of ferrous sulfate, 1.0-1.5 g / L of citric acid, and the balance of deionized water. The pH of the compound preservative solution is 5.5-5.

8.

6. A method for preparing a compound preservative solution to extend the shelf life of cut azalea flowers, characterized in that, For preparing the composite preservative liquid as described in claim 1, comprising: S1. Take a portion of deionized water, add trehalose, sucrose and potassium nitrate in sequence, stir to dissolve, and obtain a sugar-salt phase; S2. Take another portion of deionized water, add citric acid and stir to dissolve, making the local solution acidic. Then add ferrous sulfate, stir in the dark, and obtain the iron salt acidification pre-solution. S3. Slowly add the iron salt acidification pre-solution to the sugar-salt water phase and mix under stirring to obtain a composite aqueous phase; S4. Dissolve gibberellin in ethanol to prepare gibberellin mother liquor, and add the gibberellin mother liquor to the composite aqueous phase; S5. Dilute the sec-butylamine and add it to the solution obtained in step S4 at a system temperature not exceeding 30°C, and stir to mix. S6. Add the remaining deionized water to make up the volume, and adjust the pH of the system to 5.5-6.5 using an acid-base adjuster; S7. The adjusted solution is filtered through a 0.22μm microporous membrane for sterilization, then filled and sealed to obtain the composite preservative solution; In this process, by first forming the iron salt acidified pre-solution, then combining it with sugar-salt water, and adding sec-butylamine at a low temperature in the later stage, the ferrous sulfate is kept stable in the weak acid system, while reducing the impact of sec-butylamine volatilization loss and local pH changes on the applicability of gibberellin and rhododendron cut flower tissue.

7. The method according to claim 6, characterized in that, In step S1, the amount of deionized water used is 60%-70% of the target volume of the composite preservative solution, the water temperature is controlled at 25-35℃, trehalose, sucrose and potassium nitrate are added in sequence and stirred for 15-30 minutes to obtain a clear sugar-salt water phase.

8. The method according to claim 6, characterized in that, In step S2, citric acid is added to adjust the local solution pH to 3.5-4.5, then ferrous sulfate is added and stirred for 5-15 minutes under light-protected conditions to form an iron salt acidification pre-solution.

9. The method according to claim 6, characterized in that, In step S4, the gibberellin mother liquor is prepared by dissolving gibberellin in ethanol, and the concentration of gibberellin in the gibberellin mother liquor is 5-20 g / L; in step S5, sec-butylamine is added at a system temperature of 20-30℃ and stirred in a closed state for 5-15 min.

10. The method according to claim 6, characterized in that, Step S7 is followed by a step of using the obtained composite preservative solution for vase preservation of azalea cut flowers, wherein the vase preservation step includes: Cut the azalea stems at a 45° angle to create a 2-3cm incision. Then, insert them into the compound preservative solution, ensuring the solution level is 3-5cm below the bottom of the stem. Maintain the vase temperature at 10-15℃. Replace the compound preservative solution every 2-3 days and trim the bottom of the stems by 0.5cm.

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