Fresh-keeping method for lavender cut flowers and application of fresh-keeping method

Abstract

The invention provides a fresh-keeping method for lavender cut flowers, which can effectively delay aging of the lavender cut flowers, effectively delay reduction of fresh weight of the cut flowers, maintain moisture balance and control increase of conductivity of petals by adopting specific systematic treatment processes such as harvesting, reduced-pressure fumigation treatment combination, airing, refrigeration and the like. The highest flowering rate and the larger flower diameter are kept under each refrigeration condition, and the comprehensive performance is optimal. The vase life of the fresh lavender cut flowers can be effectively prolonged, so that the ornamental value of the fresh lavender cut flowers is improved, the economic benefit and the market preference degree are improved, and the method has the characteristics of high efficiency, no toxicity, no pollution and the like and is suitable for large-scale popularization. In addition, the invention provides a certain scientific basis for developing a novel, efficient and environment-friendly flower preservation technology, and has far-reaching professional significance for promoting the technological progress of the lavender cut flower industry and improving the market competitiveness.

Description

Technical Field

[0001] The invention relates to the technical field of fresh-keeping of fresh flowers, and in particular to a method for preserving lavender cut flowers. Background Art

[0002] Lavender (Lavandula angustifolia Mill.), a globally important economic crop, has traditionally been primarily used for essential oil extraction and dried flower production. However, with the explosive growth in consumer demand for immersive sensory experiences, lavender cut flowers, with their linear flower spike form, sustained aromatic release, and therapeutic properties, have become an emerging category in the fresh cut flower market. However, factors such as imbalanced water metabolism, a burst of reactive oxygen species, and rapid ethylene accumulation limit lavender's vase life to just one to two days. Petal shrinkage and flower wilting severely impact lavender's commercial value.

[0003] While commonly used flower preservatives like 8-hydroxyquinoline and its salts, silver thiosulfate, and sucrose can kill bacteria, reduce ethylene sensitivity, and alleviate physiological blockage in the vascular tissues of flower stems, they can accelerate the dissolution of petal pigments, causing them to fade. Conventional gas fumigants, such as 1-methylcyclopropene, only target ethylene signals and lack a bactericidal effect. They require a long-term maintenance of the gas composition to achieve a preservative effect.

[0004] Hydrogen sulfide (H2S), an important endogenous signaling molecule in plants, plays a key role in multiple postharvest processes and plant responses to environmental stress. H2S negatively regulates flower senescence, inhibiting ethylene production and signal transduction, maintaining hormone metabolism, and inhibiting pathogen infection, thereby improving the vase life of flowers such as chrysanthemums, carnations, and roses. Traditional methods for preserving cut flowers rely on vase solutions prepared with donors such as sodium hydrosulfide (NaHS), which are then absorbed by the flower stems to achieve a sustained release effect. However, the decomposition rate of the donor compound is affected by environmental factors such as pH and temperature, making H2S release kinetics uncontrollable and potentially leading to respiratory metabolic disorders and programmed cell death in petals. Furthermore, continuous immersion can clog the xylem of flower stems, impairing water transport efficiency. Currently reported H2S treatment processes rely on individualized vase handling, making them difficult to adapt to the demands of modern postharvest flower grading and packaging lines and the large-scale, intensive production of postharvest flower processing. The use of H2S gas fumigation technology can accurately control the treatment time and gas concentration, avoid the toxic effects of cut flowers caused by excessive accumulation of free radicals, and carry out large-scale application of cut flower preservation technology.

[0005] Decompression technology accelerates the diffusion of gas molecules through a negative pressure environment, improving H2S utilization efficiency and reducing fumigation concentration and duration. However, existing research has primarily focused on applications in decompression storage and insecticide sterilization, with no reports on its application in the preservation of cut flowers. Currently, research on lavender fresh flower preservation techniques is lacking. The development and application of preservation technologies is crucial for the lavender industry's transition from one-time processing to continuous viewing, as well as for filling the market gap for aromatic, long-spike cut flowers.

[0006] In view of this, the present invention provides a lavender cut flower preservation method and application to solve the deficiencies in the prior art. Summary of the Invention

[0007] To address the technical problem that there are few reported technical solutions for preserving fresh cut lavender flowers in the prior art, the present invention provides a method for preserving lavender cut flowers. By adopting a systematic treatment process consisting of a specific combination of harvesting, vacuum fumigation, air-drying, and refrigeration, the present invention effectively delays senescence and weight loss of cut flowers, maintains water balance, controls the increase in petal conductivity, and maintains the highest flowering rate and largest flower diameter under various refrigeration conditions, achieving optimal overall performance. This method can effectively extend the vase life of fresh cut lavender flowers, thereby enhancing their ornamental value, economic benefits, and market popularity. Furthermore, the method is highly efficient, non-toxic, and pollution-free, making it suitable for large-scale promotion.

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

[0009] The present application provides a method for preserving fresh cut lavender flowers, comprising the following steps:

[0010] (1) Select fresh lavender in the budding stage with consistent specifications for harvesting, and select lavender with a stem length of about 45 cm, a stem diameter of about 0.3-0.5 cm, full buds but not yet open, and no pests or mechanical damage; the harvesting time is selected between 6:00 and 8:00 in the morning on a clear day, when the temperature is about 15-18°C; after harvesting, immediately transfer the lavender to a turnover box equipped with a moisturizing sponge, and place the sample in a refrigerated truck preset at 4±0.5°C and a relative humidity of 90±5% for transportation back for subsequent processing;

[0011] (2) The harvested lavender was grouped into 80 plants / bunch, and the bottom of each bunch was appropriately tied with a rubber band, and then subjected to reduced pressure fumigation treatment; after treatment, the lavender was taken out, the surface moisture was dried, and the lavender was placed into a polypropylene turnover frame (50 cm × 35 cm × 20 cm) disinfected with 75% alcohol according to the original grouping, with 5 to 6 bunches placed in each frame, with the stem bases facing the same direction and neatly arranged. A layer of sterile absorbent paper was laid on the bottom and top of the frame to absorb moisture;

[0012] (3) After the water is dried, the lavender is placed in a turnover basket and covered with plastic wrap. The thickness of the plastic wrap is 15-20 μm, the specification is 35 cm × 50 cm, and the material is low-density polyethylene (LDPE) plastic wrap; the cold storage conditions are temperature 4 ° C, humidity 90%, and the cold storage time is 24h-72h. It is then refrigerated in a cold storage.

[0013] The lavender used is "New Lavender No. 4" British blue lavender.

[0014] In step (1), the flower buds are full but not yet opened, which means that about 80% of the flower buds are purple but have not yet opened.

[0015] The reduced pressure fumigation treatment in step (2) is selected from any one of H2S reduced pressure fumigation treatment, 1-MCP reduced pressure fumigation treatment, and pure reduced pressure treatment.

[0016] Preferably, the H2S reduced pressure fumigation treatment is 50-200 μL / L H2S, the fumigation pressure is 6-12 KPa, and the fumigation time is 2-8 hours;

[0017] Preferably, the 1-MCP reduced pressure fumigation treatment is performed at a 1-MCP concentration of 1-5 μL / L, a fumigation pressure of 8-10 KPa, and a fumigation time of 4-6 h;

[0018] Preferably, the pure decompression treatment is performed at a pressure of 8-10 KPa for a time of 4-6 hours.

[0019] Preferably, the air permeability of the fresh-keeping film in step (2) is 8000-10000 mL / m 2 ·24h·atm, transparency ≥92%.

[0020] Furthermore, the present application provides the application of the aforementioned method for preserving lavender cut flowers in preserving lavender cut flowers.

[0021] Through the above technical solutions, this application achieves the following technical effects:

[0022] The present invention discloses a method and application for preserving fresh cut lavender flowers. The parameters include an H2S concentration of 50-200 μl / L, a fumigation pressure of 6-12 kPa, and a fumigation time of 2-8 hours. This method, which involves treating the fresh cut lavender flowers once before storage, significantly prolongs their flowering period, maintains a certain firmness on the pedicels, and slows the withering of the petals. Compared with existing preservation technologies, the present invention has significant advantages: compared with the H2S donor sodium hydrosulfide (NaHS) soaking treatment (40-200 μmol / L), the gas fumigation method of the present invention avoids problems such as uneven water absorption of cut flowers and uncontrollable H2S release rate, and has higher treatment efficiency; compared with 1-MCP reduced pressure fumigation treatment (1-5 μL / L, 8-10 kPa, 4-6 hours), the H2S reduced pressure fumigation of the present invention has a more comprehensive preservation effect; compared with pure reduced pressure treatment (pressure 8-10 kPa, time 4-6 hours), H2S in the H2S reduced pressure fumigation of the present invention, as a new gas signal molecule, can more efficiently penetrate into plant tissues under a reduced pressure environment and exert its unique biological activity. The H2S reduced pressure fumigation preservation method for fresh cut lavender flowers of the present invention can not only better extend the opening time of fresh cut lavender flowers, delay the aging of fresh cut lavender flowers, improve economic benefits and market popularity, but also has the characteristics of high efficiency, non-toxicity, and pollution-free, and is suitable for large-scale promotion. Moreover, the present invention provides a certain scientific basis for developing new, efficient and environmentally friendly flower preservation technology, and has far-reaching professional significance for promoting scientific and technological progress in the lavender cut flower industry and enhancing market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Shown is the effect of 1-day refrigerated lavender fresh cut flowers in a vase.

[0024] Figure 2 Shown is the effect of refrigerated 2D lavender fresh cut flowers in a vase.

[0025] Figure 3 Shown is the effect picture of refrigerated 3D lavender fresh cut flowers in a vase. DETAILED DESCRIPTION

[0026] The technical solutions of the present invention are described clearly and completely below with reference to the embodiments. It is obvious that the embodiments described are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0027] Unless otherwise specified in the following embodiments, the technical means used are conventional means well known to those skilled in the art.

[0028] Example 1: A method for preserving fresh cut lavender flowers

[0029] The present application provides a method for preserving fresh cut lavender flowers, comprising the following steps:

[0030] (1) Select fresh lavender in the budding stage with consistent specifications for harvesting, and select lavender with a stem length of about 45 cm, a stem diameter of about 0.3-0.5 cm, full buds but not yet open, and no pests or mechanical damage; the harvesting time is selected between 6:00 and 8:00 in the morning on a clear day, when the temperature is about 15-18°C; after harvesting, immediately transfer the lavender to a turnover box equipped with a moisturizing sponge, and place the sample in a refrigerated truck preset at 4±0.5°C and a relative humidity of 90±5% for transportation back for subsequent processing;

[0031] (2) The harvested lavender was grouped into 80 plants / bunch, and the bottom of each bunch was appropriately tied with a rubber band, and then subjected to reduced pressure fumigation treatment; after treatment, the lavender was taken out, the surface moisture was dried, and the lavender was placed into a polypropylene turnover frame (50 cm × 35 cm × 20 cm) disinfected with 75% alcohol according to the original grouping, with 5 to 6 bunches placed in each frame, with the stem bases facing the same direction and neatly arranged. A layer of sterile absorbent paper was laid on the bottom and top of the frame to absorb moisture;

[0032] (3) After the water is dried, the lavender is placed in a turnover basket and covered with plastic wrap. The thickness of the plastic wrap is 15-20 μm, the specification is 35 cm × 50 cm, and the material is low-density polyethylene (LDPE) plastic wrap; the cold storage conditions are a temperature of 4 ° C, a humidity of 90%, and a cold storage time of 24h-72h. It is then refrigerated in a cold storage.

[0033] The lavender used is "New Lavender No. 4" British blue lavender.

[0034] In step (1), the flower buds are full but not yet opened, which means that about 80% of the flower buds are purple but have not yet opened.

[0035] The reduced pressure fumigation treatment in step (2) is selected from any one of H2S reduced pressure fumigation treatment, 1-MCP reduced pressure fumigation treatment, and pure reduced pressure treatment.

[0036] Preferably, the air permeability of the fresh-keeping film in step (2) is 8000-10000 mL / m 2 ·24h·atm, transparency ≥92%.

[0037] Example 2: A method for preserving fresh cut lavender flowers

[0038] Based on the description in Example 1, the reduced pressure fumigation preservation method for fresh cut lavender flowers comprises the following parameters: H2S concentration 50-100 μL / L, fumigation pressure 6-8 KPa, and fumigation time 2-4 h.

[0039] Example 3: A method for preserving fresh cut lavender flowers

[0040] Based on the description in Example 1, the reduced pressure fumigation preservation method for fresh cut lavender flowers comprises the following parameters: H2S concentration of 100-150 μL / L, fumigation pressure of 8-10 KPa, and fumigation time of 4-6 h.

[0041] Example 4: A method for preserving fresh cut lavender flowers

[0042] Based on the description in Example 1, the reduced pressure fumigation preservation method for fresh cut lavender flowers comprises the following parameters: H2S concentration of 150-200 μL / L, fumigation pressure of 10-12 KPa, and fumigation time of 6-8 h.

[0043] Example 5: A method for preserving fresh cut lavender flowers

[0044] Based on the description in Example 1, the method for preserving fresh cut lavender flowers comprises the following parameters: the concentration of H2S donor sodium hydrosulfide is 40-200 μmol / L.

[0045] Example 6: A method for preserving fresh cut lavender flowers

[0046] Based on the description in Example 1, the reduced pressure fumigation preservation method for fresh cut lavender flowers comprises the following parameters: 1-MCP concentration of 1 to 5 μL / L, fumigation pressure of 8 to 10 KPa, and fumigation time of 4 to 6 h.

[0047] Example 7: A method for preserving fresh cut lavender flowers

[0048] Based on the description in Example 1, the method for preserving fresh cut lavender flowers comprises the following parameters: pure decompression treatment, a pressure of 8-10 KPa, and a time of 4-6 hours.

[0049] Example 8: Comparison of preservation effects

[0050] Based on the descriptions in Examples 1 to 7 above, after refrigeration, the lavender was removed and awakened for 6 hours. Immediately afterward, the fumigated lavender was vase-vase-vase-vase-treated. Simultaneously, a batch of unfumigated lavender was vase-vase-vase-vase-treated with sodium hydrosulfide, a H2S donor. The vase-v ...

[0051] The flower awakening treatment includes aseptically trimming the base of the lavender stem by about 2-5 cm to form a 45-degree bevel incision, rehydrating it in clean water, retaining the same number of leaves in good condition, and awakening the flowers for 6 hours; the vase insertion condition includes trimming the base of the lavender stem again by 1-2 cm and immediately inserting it into a transparent glass vase (30 cm high, 5 cm diameter) containing 500 mL of preservative solution; the vase insertion solution for fumigated lavender cut flowers is distilled water, while the vase insertion solution for unfumigated lavender is a sodium hydrosulfide aqueous solution with a concentration of 40-200 μmol / L; 30 lavender plants are inserted into each vase to ensure that the stem base is completely immersed in the vase insertion solution; the cut flower environment temperature is (23±1)°C, the relative humidity is (60±5)%, the light intensity is 1200 lx, and the photoperiod is 12 hours light / 12 hours dark; indicator measurements include: water balance, fresh weight change, flowering rate, flower diameter change rate, and electrical conductivity.

[0052] It should be noted that a control group is also set up in the present invention, and the control group is not treated.

[0053] For the convenience of description, the processing methods corresponding to the above embodiments are summarized in Table 1 below:

[0054] Table 1: Grouping and processing parameters

[0055]

[0056]

[0057] (1) Determination of water balance

[0058] As shown in Tables 2, 3, and 4 below, different effects of H2S vacuum fumigation treatments at different concentrations on the water balance of fresh cut lavender flowers after refrigeration for 1, 2, and 3 days are shown. The results are as follows:

[0059] Table 2: Moisture balance during refrigeration for 1 day

[0060]

[0061] Table 3: Moisture balance during 2 days of refrigeration

[0062]

[0063]

[0064] Table 4: 3-day moisture balance of cold storage

[0065]

[0066] Note: The data in the table are the mean ± standard error of three replicates. Different lowercase letters after the data in the same column indicate significant differences in different concentrations at the same time as tested by Duncan's method (P<0.05).

[0067] It should be noted that starting from the day the flowers are cut, use an electronic balance to measure the total weight G1 of the cut flowers, preservative solution, and jar, and the total weight F1 of the jar and preservative solution. Thereafter, measure the total weight Gn of the preservative solution, jar, and cut flowers, and the total weight Fn of the jar and preservative solution every 24 hours (n is the number of measurement days). Starting from the second day after vase placement, calculate the water absorption and water loss of the cut flowers. Measurements are stopped until the life of the cut flowers ends. Water loss D = G1 - Gn, water absorption A = F1 - Fn, and the cut flower water balance value E (g) = water absorption A - water loss D.

[0068] Tables 2, 3, and 4 show that the water balance values ​​of vase-inserted lavender cut flowers showed an overall downward trend after 1, 2, and 3 days of refrigeration. On the first day, there were no significant differences in water balance values ​​among the treatments. On the second day, the water balance values ​​of all vase-inserted lavender flowers showed a slight increase, with the largest increase in treatment group 3 (5.66±0.24g) and the smallest increase in treatment group CK (2.82±0.10g) after 1 day of refrigeration, indicating that water loss during vase-insertion was less than water absorption. On the third day, the water balance values ​​began to decline, with treatment group CK showing significantly greater water loss than treatment group 2, and treatment group 2 exhibiting the most stable water balance values. On days 4-5, the water balance values ​​of vase-inserted lavender cut flowers stored for 1 and 2 days continued to decline, reaching their lowest values. Treatment groups 4 and CK had the lowest values, indicating that duct blockage was already evident at this point. The water balance values ​​of vase-inserted lavender cut flowers stored for 3 days showed an initial upward and then downward trend. On day 6, the water balance values ​​of the vase-inserted lavender cut flowers increased after 1 and 2 days of refrigeration. However, after 2 days of refrigeration, the water balance value of the CK group increased the least, reaching 2.60 g, but it was still significantly lower than that of treatments 1, 2, 3, and treatments 5 and 6. Overall analysis showed that treatments 1 and 5 had similar results, performing second best, maintaining good water conditions throughout the vase period and significantly outperforming treatments CK, treatments 4, and 6. Treatment 6 performed slightly better than treatment 4, but overall performance remained poor, similar to that of the CK group, with lower water balance values ​​and earlier duct blockage, indicating that the treatments were limited in their effectiveness in delaying water loss in cut lavender flowers.

[0069] The water balance value of the CK group for vase-inserted lavender cut flowers after one day of refrigeration was below 0 on the fourth day. The water balance value of the CK group for vase-inserted lavender cut flowers after two days of refrigeration was below 0 on the third day. The water balance value of the CK group for vase-inserted lavender cut flowers after three days of refrigeration was below 0 on the second day. The negative water balance value indicates that the ducts of the fresh cut flowers in the CK group were blocked at this time. This shows that fresh cut lavender flowers refrigerated for two days still have vase value.

[0070] Throughout the vase life, the water balance values ​​of lavender cut flowers in all six treatment groups shifted negative later than in the control group. Treatment 2 showed the most significant change, with its water balance value turning negative the latest and with the least degree of negativity. Treatments 1 and 5 performed next best. This suggests that H2S vacuum fumigation effectively maintains the water balance of cut flowers, preventing duct blockage and maintaining the water absorption capacity of cut flowers, thereby extending the vase life of cut lavender flowers. Treatment 2 showed the most significant effect, indicating that H2S vacuum fumigation has a significant effect on maintaining water balance in cut flowers, effectively preventing duct blockage and maintaining the water absorption capacity of cut flowers, thus playing a role in extending the life of cut flowers.

[0071] (2) Determination of fresh weight change rate

[0072] As shown in Tables 5, 6, and 7 below, different effects of H2S vacuum fumigation treatments at different concentrations on the fresh weight change rate of lavender fresh cut flowers after refrigeration for 1, 2, and 3 days are shown. The results of the measurements are as follows:

[0073] Table 5: Fresh weight change rate after refrigeration for 1 day

[0074]

[0075] Table 6: Fresh weight change rate after 2-day refrigeration (%)

[0076]

[0077]

[0078] Table 7: Change rate of fresh weight after refrigeration for 3 days (%)

[0079]

[0080] It should be noted that the fresh weight change rate of lavender cut flowers under different treatments was determined gravimetrically. Starting from the day the cut flowers were placed in the vase, the total weight (Gn) of the preservative solution, the jar, and the cut flowers, and the total weight (Fn) of the jar and preservative solution were measured every 24 hours (n being the number of days measured). Cut flower fresh weight (g) = Gn - Fn. Cut flower fresh weight change rate (%) = (cut flower fresh weight on day n - initial cut flower fresh weight) / initial cut flower fresh weight × 100% (n being the number of days measured). When weighing, be sure to seal the container with plastic wrap and ensure that the same lavender cut flowers are weighed each time.

[0081] Tables 5, 6, and 7 show that the fresh weight change rate of vase-inserted lavender cut flowers showed an overall downward trend after 1, 2, and 3 days of refrigeration. Compared with 3 days of refrigeration, the decline in fresh weight change rate after 1 and 2 days of refrigeration was slower. On day 1, there were no significant differences in fresh weight change rate among treatments. On day 2, compared with day 1, the fresh weight change rate of vase-inserted lavender cut flowers after 1 and 2 days of refrigeration increased. Treatment 2 showed the greatest increase after 1 and 2 days of refrigeration, significantly exceeding that of CK, Treatment 4, and Treatment 6. On day 3 of refrigeration, Treatments 2, 1, 3, and 5 maintained positive growth, while CK, Treatment 4, and Treatment 6 began to decline.

[0082] Starting on the third day, the fresh weight change rate began to decline in all treatments, but Treatment 2 had the lowest rate of decline. It maintained a high growth rate of 10.94±0.33% on the first day of refrigeration, significantly exceeding that of the other treatments. It reached 5.04±0.77% on the second day of refrigeration, also significantly exceeding that of the other treatments. Although it turned negative on the third day of refrigeration, it remained significantly higher than the other treatments. From the fourth to fifth day, the fresh weight change rate of all treatments continued to decline, but Treatment 2 maintained the highest level. Treatment 6 performed between Treatments 5 and 4. After the first day of refrigeration, it maintained only a slight positive growth rate of 0.20±0.65% on the fourth day. After the second day of refrigeration, it turned negative on the third day, significantly lower than Treatments 1, 2, 3, and Treatment 5, but better than the CK and Treatment 4. By the sixth day, the fresh weight loss in Treatment 6 was significantly higher than that in Treatments 1, 2, and 3, similar to that in Treatment 5, but still better than the CK and Treatment 4.

[0083] It can be seen that H2S reduced pressure fumigation treatment has a more obvious effect on maintaining the fresh weight change rate of lavender fresh cut flowers, and effectively delays the rate of decrease in fresh weight of cut flowers. Among them, treatment group 2 has the best effect on delaying cut flower aging, and its fresh weight change rate has been at the highest state.

[0084] (3) Determination of flowering rate

[0085] As shown in Tables 8, 9, and 10 below, different effects of H2S vacuum fumigation treatments at different concentrations on the flowering rate of lavender fresh cut flowers after refrigeration for 1, 2, and 3 days are shown. The results of the measurements are as follows:

[0086] Table 8: Flowering rate after refrigeration for 1 day

[0087]

[0088] Table 9: Flowering rate (%) after 2 days of cold storage

[0089]

[0090] Table 10: Flowering rate (%) after 3 days of cold storage

[0091]

[0092]

[0093] It should be noted that starting from the day of vase insertion, the number of initial buds for each group of 10 cut flowers was recorded, and the number of blooms for each group of 10 cut flowers was recorded daily. Recording was stopped until the cut flowers reached the end of their lifespan. Each treatment was repeated three times.

[0094] Flowering rate = number of flowers / initial number of buds × 100%

[0095] Tables 8, 9, and 10 show that the flowering rates of the three batches of lavender cut flowers showed an overall trend of first increasing and then decreasing. The flowering rates of the vase-inserted lavender cut flowers stored for one and two days reached a peak on the third day and then gradually declined. However, the flowering rate of the vase-inserted lavender cut flowers stored for three days peaked earlier, on the second day, and then rapidly declined.

[0096] Treatment 2 consistently demonstrated the best results under all cold storage conditions. Among cut flowers stored for one day, the flowering rate in Treatment 2 reached 18.30 ± 0.16% on day 3, significantly higher than that in Treatments 5, 1, 3, 4, 6, and the CK group. For the following 4-6 days, the flowering rate in Treatment 2 remained significantly higher than that in the other treatments, demonstrating strong persistence. Treatment group 3 performed well on the 4th day, but on the 5th and 6th days (there was no significant difference from treatment group 1). The flowering rate of treatment group 6 on the 3rd day was 14.30±0.68%, which was significantly lower than that of treatment groups 1, 2, 3 and treatment group 5, but higher than that of the CK group. In the later period, the performance was similar to that of treatment groups 4 and 5, and the flowering rate dropped rapidly. Among the cut flowers stored for 2 days, the flowering rates of treatment groups 2, 5 and treatment group 1 on the 3rd day were significantly higher than those of treatment groups 3, treatment group 6, treatment group 4 and CK group, but the overall peak flowering rate was slightly lower than that of treatment group 1 day. Among the cut flowers stored for 3 days, the peak flowering rate appeared earlier on the 2nd day, with treatment groups 2 and treatment group 3 performing best. Treatment group 6 was similar to treatment group 4 and significantly lower than treatment groups 1, 2, 3 and treatment group 5.

[0097] Data from the three cold storage conditions show that the different treatments significantly affected the flowering rate of lavender cut flowers. Treatment 2 performed best under all cold storage conditions, achieving the highest flowering rate at peak flowering and maintaining a high flowering rate throughout the remaining period, significantly extending the viewing period of the cut flowers.

[0098] Furthermore, cold storage duration significantly impacted flowering rate. Cut flowers stored for one day had the highest peak flowering rate, followed by those stored for two days, and lowest after three days. Furthermore, the longer the cold storage period, the earlier the peak flowering occurred and the shorter the duration of flowering. Cut flowers stored for one and two days reached peak flowering on the third day, while those stored for three days peaked on the second day and then declined rapidly. This suggests that excessive cold storage may shorten the duration of flowering and reduce the ornamental value of cut flowers.

[0099] These results indicate that appropriate H2S vacuum fumigation treatment (treatment group 2) combined with appropriate refrigeration time (1-2 days) can effectively increase the flowering rate of lavender cut flowers and prolong their viewing period, providing an effective preservation solution for the commercial application of lavender cut flowers.

[0100] (4) Determination of flower stem change rate

[0101] As shown in Tables 11, 12, and 13 below, different effects of H2S vacuum fumigation treatments at different concentrations on the change rate of flower diameter of fresh cut lavender flowers after refrigeration for 1, 2, and 3 days are shown. The results of the measurements are as follows:

[0102] Table 11: Change rate of flower stems after refrigeration for 1 day (%)

[0103]

[0104]

[0105] Table 12: Change rate of flower stems after 2 days of cold storage (%)

[0106]

[0107] Table 13: Change rate of flower stems after 3-day cold storage (%)

[0108]

[0109] It should be noted that a vernier caliper was used as a measuring tool to determine the changes in flower diameter of fresh cut lavender flowers under different treatments. Starting from the day of vase placement, the diameters of the six largest flowers in a vertical direction on five branches were measured daily with a vernier caliper. The average value, Rn (n is the number of measurement days), was calculated as the cut flower diameter. Measurements were continued until the end of the cut flower's lifespan. Flower diameter change rate = (Rn - R1) / R1 × 100%

[0110] As shown in Tables 11, 12, and 13, the diameter change rate of vase-arranged lavender cut flowers after refrigeration for one, two, and three days initially increased and then decreased with increasing storage days. Among the groups, the diameter change rate of treatment 2 was significantly higher than that of the CK group, and the downward trend was less pronounced than in the other treatments.

[0111] On the first day, there was no significant difference in the diameter change rate of the vase-inserted lavender cut flowers stored for 1, 2, and 3 days; on the second day, the diameter change rate of the vase-inserted lavender cut flowers stored for 1, 2, and 3 days began to increase, and the diameter change rate of the vase-inserted lavender cut flowers stored for 3 days increased the most; on the third day, the diameter change rate of the vase-inserted lavender cut flowers stored for 1 and 2 days continued to increase, and on the third day, the diameter change rate of treatment groups 2, 3, 1, and 5 was significantly higher than that of treatment group 6, treatment group 4, and CK group; but the diameter change rate of the vase-inserted lavender cut flowers stored for 3 days began to decrease, and the downward trend of the diameter change rate of treatment group 2 was significantly lower than that of the CK group; on the fourth day, the diameter change rate of the CK group was lower than that of treatment groups 1, 2, 3, 5, and 6, and there were significant differences between these treatment groups and CK; on the fifth and sixth days, the diameter change rate of the three batches of lavender cut flowers showed a clear downward trend.

[0112] Overall, the different treatments had varying degrees of positive effects on the rate of flower diameter change of lavender cut flowers, effectively increasing flower diameter, improving ornamental value, and, to a certain extent, delaying the time it takes to reach maximum flower diameter. The order of effect of the treatments on the rate of flower diameter change was: Treatment 2 > Treatment 3 > Treatment 5 > Treatment 1 > Treatment 6 > Treatment 4 > CK.

[0113] In addition, the refrigeration time also has a significant effect on the rate of change of flower diameter. The cut flowers refrigerated for 3 days began to show a decrease in flower diameter on the third day, while the cut flowers refrigerated for 1 day and 2 days began to decline significantly on the fourth day, indicating that the longer the refrigeration time, the shorter the flower diameter growth period and the shorter the viewing period.

[0114] (5) Determination of relative conductivity

[0115] As shown in Tables 14, 15, and 16 below, different effects of H2S vacuum fumigation treatments at different concentrations on the electrical conductivity of fresh cut lavender flowers after refrigeration for 1, 2, and 3 days are shown. The results are as follows:

[0116] Table 14: Relative conductivity after refrigeration for 1 day (%)

[0117]

[0118] Table 15: Relative conductivity after 2 days of refrigeration (%)

[0119]

[0120] Table 16: Relative conductivity (%) after refrigeration for 3 days

[0121]

[0122]

[0123] It should be noted that the permeability of the plasma membrane of the petals of fresh cut lavender flowers under different treatments was measured using a conductivity meter. 0.2 g of petals were weighed and placed in a 50 mL centrifuge tube, followed by the addition of 20 mL of distilled water. The mixture was shaken on an oscillator at 200 rpm for 1 hour at 28 ° C. The conductivity meter was used immediately. To measure the final conductivity (E2), the centrifuge tube was heated at 95 ° C for 10 minutes and then cooled to ambient temperature. Calculated using the following formula. Relative conductivity: E = E1 / E2 × 100%

[0124] As shown in Tables 14, 15, and 16, the relative electrical conductivity of vase-inserted lavender cut flowers after refrigeration for 1, 2, and 3 days showed an overall upward trend. On the first day, no significant differences were observed among the treatment groups. Starting from the second day, differences between the treatment groups gradually emerged. The relative electrical conductivity of the vase-inserted lavender cut flowers stored for 1 and 2 days increased the most on the fourth day in the CK group, while the relative electrical conductivity of Treatment 2 was the lowest at this time, reaching 25.75±0.47% and 38.17±1.83%, respectively. The relative electrical conductivity of the vase-inserted lavender cut flowers stored for 3 days increased the most on the third day in the CK group, reaching 58.80±0.65%, significantly higher than that of the other treatment groups. The greatest difference between the two groups was 20.25%. The relative electrical conductivity of the vase-inserted lavender cut flowers stored for 3 days was consistently higher than that of the vase-inserted lavender cut flowers stored for 1 and 2 days.

[0125] It should be noted that one of the basic properties of plant aging in the early stage is exactly the integrity and loss of function of membrane. Along with the aging of cut flowers, the permeability of cell membrane can increase thereupon, causing the ion of cytoplasm to penetrate into the external environment, causing the increase of electrical conductivity. Therefore, the plasma membrane permeability of petals can be embodied according to the electrical conductivity size. In the present invention, H2S decompression fumigation all has a certain impact on the petal plasma membrane permeability of lavender fresh cut flowers, wherein the control effect of the plasma membrane permeability of treatment group 2 pairs of lavender fresh cut flowers is best, and its electrical conductivity numerical value is always in the lowest level, more effectively plays a protective role to the integrity and functionality of cell membrane, effectively delays the aging process of cut flowers.

[0126] In summary, this study compared the effects of four different treatment methods on the preservation of cut lavender flowers. The results showed that H2S vacuum fumigation, 1-MCP vacuum fumigation, simple vacuum treatment, and H2S donor sodium hydrosulfide treatment all delayed senescence in cut lavender flowers to varying degrees, but the effects varied significantly.

[0127] Among the H2S vacuum fumigation treatments, Treatment 2 (H2S concentration 100-150 μL / L, fumigation pressure 8-10 kPa, fumigation time 4-6 hours) was the most effective, significantly outperforming all other treatments. This treatment effectively delayed the decline in fresh weight of cut flowers, maintained water balance, controlled the increase in petal conductivity, and maintained the highest flowering rate and largest flower diameter under all cold storage conditions, resulting in the best overall performance. Treatment 3 was second most effective, while Treatment 1 was less effective, indicating that the appropriate H2S concentration, fumigation pressure, and duration are crucial for optimal preservation.

[0128] The 1-MCP vacuum fumigation treatment performed well in terms of flowering rate, particularly on the third day under 1- and 2-day cold storage conditions, second only to Treatment 2. However, its freshness retention was inferior to that of the H2S vacuum fumigation treatment, with a rapid decline in flowering rate in the later stages. Its effectiveness in delaying fresh weight loss and maintaining water balance was intermediate between Treatments 1 and 4.

[0129] The pure decompression treatment was more effective than the control treatment, but less effective than the H2S decompression fumigation treatment. The relative conductivity of this treatment was significantly lower than that of the CK treatment on the sixth day after one day of refrigeration, and it also effectively slowed the increase in conductivity after two and three days of refrigeration. This suggests that decompression treatment alone has some effect on delaying senescence in cut lavender flowers, but the effect is weaker than that of decompression fumigation with H2S gas, indicating that H2S gas plays a key role in the preservation process.

[0130] The H2S donor, sodium hydrosulfide, had the weakest effect. While superior to the control group, it was significantly lower than the H2S and 1-MCP vacuum fumigation treatments on all indicators. Flowering rates were low under all cold storage conditions, fresh weight decreased rapidly, and water balance maintenance was poor, indicating that direct H2S gas vacuum fumigation is more effective than treatment with H2S donor solution.

[0131] Comprehensive comparison shows that H2S reduced pressure fumigation treatment is the best choice for preserving fresh cut lavender flowers. It can significantly extend the vase life of cut flowers and improve their ornamental value.

[0132] The above embodiments are only for illustrating the technical concept and features of the present invention in a specific scenario. Its purpose is to enable people who need this technology to understand the content of the present invention and implement it. It does not limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preserving fresh cut lavender flowers, characterized in that: The following steps are involved: (1) Select fresh lavender in the budding stage with consistent specifications for harvesting, and select lavender with a stem length of about 45 cm, a stem diameter of about 0.3-0.5 cm, full buds but not yet open, and no pests or mechanical damage; the harvesting time is selected between 6:00 and 8:00 in the morning on a clear day, when the temperature is about 15-18°C; after harvesting, immediately transfer the lavender to a turnover box equipped with a moisturizing sponge, and place the sample in a refrigerated truck preset at 4±0.5°C and a relative humidity of 90±5% for transportation back for subsequent processing; (2) The harvested lavender was grouped into 80 plants / bunch, and the bottom of each bundle was properly tied with a rubber band and subjected to reduced pressure fumigation treatment; After processing, take out the lavender, dry the surface moisture, and place it in a polypropylene turnover frame (50cm×35cm×20cm) disinfected with 75% alcohol according to the original grouping. Place 5 to 6 bunches in each frame, with the base of the stems arranged neatly in the same direction. A layer of sterile absorbent paper is laid on the bottom and top of the frame to absorb moisture. (3) After the water is dried, the lavender is placed in a turnover basket and covered with plastic wrap. The thickness of the plastic wrap is 15-20 μm, the specification is 35 cm × 50 cm, and the material is low-density polyethylene (LDPE) plastic wrap; the cold storage conditions are a temperature of 4 ° C, a humidity of 90%, and a cold storage time of 24h-72h. It is then refrigerated in a cold storage.

2. A method for preserving lavender cut flowers as claimed in claim 1, characterized in that, The lavender used is "New Lavender No. 4" British blue lavender.

3. A method for preserving lavender cut flowers as claimed in claim 1, characterized in that, In step (1), the flower buds are full but not yet opened, which means that about 80% of the flower buds are purple but have not yet opened.

4. A method for preserving lavender cut flowers as claimed in claim 1, characterized in that, The reduced pressure fumigation treatment in step (2) is selected from any one of H2S reduced pressure fumigation treatment, 1-MCP reduced pressure fumigation treatment, and pure reduced pressure treatment.

5. A method for preserving lavender cut flowers as claimed in claim 4, characterized in that, The H2S reduced pressure fumigation treatment is 50-200 μL / L H2S, the fumigation pressure is 6-12 KPa, and the fumigation time is 2-8 hours.

6. A method for preserving lavender cut flowers as claimed in claim 4, characterized in that: The 1-MCP reduced pressure fumigation treatment is as follows: the 1-MCP concentration is 1-5 μL / L, the fumigation pressure is 8-10 KPa, and the fumigation time is 4-6 hours.

7. A method for preserving lavender cut flowers as claimed in claim 4, characterized in that: The pure decompression treatment is performed at a pressure of 8-10 KPa and for a time of 4-6 hours.

8. A method for preserving lavender cut flowers as claimed in claim 1, characterized in that, The air permeability of the fresh-keeping film in step (2) is 8000-10000 mL / m 2 ·24h·atm, transparency ≥92%.

9. Use of the method for preserving lavender cut flowers according to any one of claims 1 to 8 in preserving lavender cut flowers.

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