Method for improving double-petal flower type of peony

Abstract

The invention relates to a method for improving peony double petal flower types, which belongs to the peony flower type regulation and control technology, indoleacetic acid and a Tween-20 stock solution are used for preparing auxin treatment liquid, the concentration of the indoleacetic acid in the auxin treatment liquid is 25-35 mg.L <-1 >, and the volume concentration of the Tween-20 is 0.04-0.05%; when the flower buds of the peony plants grow to the initial stage of the round peach period, spraying auxin treatment liquid to the whole peony plants by using a pressurized sprinkling can, and performing normal maintenance after spraying; when the flower buds of the peony plants develop to the initial stage of the color exposure period, spraying the auxin treatment liquid to the whole peony plants by using the pressurized sprinkling can again, and maintaining until the peony plants bloom after the auxin treatment liquid is sprayed. By means of the adjusting effect of indoleacetic acid on flower organ development, the growth hormone treatment liquid is quantitatively sprayed in the round peach stage and the initial stage of the color exposure stage, intervention on the petal forming process is achieved on the premise that plant growth and the flowering phase process are not affected, the ornamental characteristic of peonies is effectively enhanced, and the flower quality is improved. The application range of the high-double-petal ornamental variety is expanded, and the commodity value is improved.

Description

Technical Field

[0001] This invention pertains to peony flower shape regulation technology, specifically involving a method for enhancing the double-petal flower shape of peonies. Background Technology

[0002] Peony, belonging to the genus Paeonia in the family Paeoniaceae, is a perennial deciduous subshrub. It is highly valued for its beautiful flower shape and diverse colors, and is a traditional and precious flower in my country, as well as a symbol of its unique culture. Flower shape is one of the core indicators of a peony's ornamental value, mainly including characteristics such as the number of petals, the degree of double petal formation, the size of the flower diameter, and the layered structure. Among these, the degree of double petal formation directly affects its ornamental quality and commercial value.

[0003] Currently, the formation of peony flower shape and double-petal trait mainly depends on the genetic characteristics of the variety. Although traditional hybridization breeding can cultivate varieties with stable double-petal traits, it is time-consuming, inefficient, and limited by germplasm resources and genetic laws, making it difficult to rapidly improve the flower shape of existing varieties. In production practice, some varieties exhibit unstable double-petal traits, are prone to flower shape degeneration during flowering, or experience a decline in ornamental value due to environmental stress, thus hindering their horticultural promotion and industrial utilization.

[0004] In recent years, the role of plant growth regulators in regulating floral organ development has received increasing attention. Studies have shown that exogenous application of hormones such as indoleacetic acid can affect petal differentiation and floral organ transformation. However, hormone application usually affects the overall growth of the plant and the flowering period, making it difficult to precisely control the flowering period simultaneously. Therefore, there is an urgent need to develop a method to optimize the flower shape of existing varieties and improve the double-petal flower shape of peonies without affecting plant growth and the flowering process. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for improving the double-petal flower shape of peonies, which can intervene in the petal formation process without affecting the plant growth and flowering process, thereby enhancing the ornamental characteristics of peonies.

[0006] The technical solution adopted by this invention to solve the above-mentioned technical problems is: a method for improving the double-petal flower shape of peonies, comprising the following steps: (1) Prepare auxin treatment solution using indoleacetic acid and Tween-20 stock solution. The concentration of indoleacetic acid in the auxin treatment solution is 25-35 mg·L. -1 The volume concentration of Tween-20 is 0.04-0.05%.

[0007] (2) When the buds of the peony plant develop to the early stage of the round peach stage, use a pressurized sprayer to spray the whole plant of the peony plant with the growth hormone treatment solution prepared according to the method in step (1), and then carry out normal maintenance.

[0008] (3) When the buds of the peony plant develop to the early stage of the color-revealing period, use a pressurized sprayer to spray the whole plant of the peony plant with the growth hormone treatment solution prepared according to the method in step (1) again, and maintain it until flowering.

[0009] The peony plants mentioned are 5-10 year old, healthy, and planted in the ground.

[0010] The selected peony varieties are 'Zhao Fen' and 'Jing Yu'.

[0011] In step (1), indoleacetic acid is first dissolved in ethanol, and then diluted with distilled water to a final volume of 1.0 mg·mL. -1 Indoleacetic acid stock solution; before spraying, take indoleacetic acid stock solution and Tween-20 stock solution, dilute with distilled water to prepare auxin treatment solution.

[0012] When preparing to spray in steps (2) and (3), prepare the auxin treatment solution according to the method in step (1), and prepare the auxin treatment solution in the dark.

[0013] In steps (2) and (3), the amount of auxin treatment solution sprayed is 100-200 mL per plant. When spraying the auxin treatment solution, spray until the plant surface is moist and no droplets run off.

[0014] In steps (2) and (3), the auxin treatment solution is sprayed onto the peony plants half an hour before sunset.

[0015] The criteria for determining the early stage of the round peach stage are: half of the flower buds swell into a spherical shape with a horizontal diameter of about 2.5 cm, and the petals are tightly closed; the criteria for determining the early stage of the color-revealing stage are: half of the flower buds change from a tightly wrapped state to a loose state with a horizontal diameter of about 4 cm, the sepals gradually open, and the edges of the petals are slightly higher than the sepals.

[0016] The beneficial effects of this invention are: 1. This invention provides a technical approach for regulating peony flower shape through the application of exogenous indoleacetic acid (IAA). By leveraging the regulatory effect of IAA on the development of floral organs, quantitative application of auxin solution during the early stages of the full bloom and color development stages allows for intervention in the petal formation process without affecting plant growth or the flowering process. This effectively enhances the ornamental characteristics of peonies, helps expand the application range of high-double-petal ornamental varieties, and increases their commercial value.

[0017] 2. Compared to traditional methods that rely on genetic breeding to alter flower shape, this invention utilizes hormone regulation to achieve controllable regulation of peony flower shape development without altering the plant's genetic background. This method breaks the dependence of flower shape trait improvement on germplasm resources at the technical level, providing a more flexible, shorter-cycle, and more efficient regulatory approach, demonstrating strong technological innovation and physiological regulation research value.

[0018] 3. The treatment solution used has simple components; indoleacetic acid and Tween-20 are both common plant physiological reagents, resulting in low preparation costs and readily available materials. The spraying process is environmentally friendly, non-toxic to plants, and leaves no residue, aligning with the concept of green agriculture and possessing good universality and feasibility. The overall treatment process requires no special equipment or high energy consumption, is simple to operate, economically applicable, and suitable for both scientific research experiments and field cultivation, demonstrating promising prospects for sustainable promotion and industrial application. Attached Figure Description

[0019] Figure 1 The difference in double petal rate of 'Zhao Fen' peony after spraying with auxin treatment solutions of different indoleacetic acid concentrations.

[0020] Figure 2 The difference in double petal rate of 'Jingyu' peony after spraying with auxin treatment solutions of different indoleacetic acid concentrations.

[0021] Figure 3 The flowering conditions of 'Zhao Fen' and 'Jing Yu' peonies during their peak bloom period after being sprayed with auxin treatment solutions of different concentrations of indoleacetic acid. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. The specific contents listed in the following embodiments are not limited to the technical features necessary to solve the technical problem of the present invention. Furthermore, the listed embodiments are merely a part of the present invention, and not all embodiments.

[0023] The method for improving the double-petal flower shape of peonies according to the present invention includes the following steps: Step 1: Plant Selection This invention selected 5-10 year old, vigorous, ground-planted peony plants as the treatment subjects. The experimental peony varieties were 'Zhao Fen' and 'Jing Yu', both of which have a mixed single-petal, semi-double, and double-petal flower type. In nature, the double-petal rate of flowers is about 40%. The experimental site was located in Luoyang, Henan (34°35'48N; 112°24'50E).

[0024] Step 2: Preparation of auxin treatment solution The auxin treatment solution contains 5-85 mg·L -1Indoleacetic acid and 0.04-0.05% Tween-20. Preparation requires first preparing 1.0 mg / mL of the solution. -1 The method for preparing the indoleacetic acid (IAA) stock solution is as follows: First, weigh 100 mg of IAA reagent, dissolve it in a small amount of 95% anhydrous ethanol, and then dilute to 100 mL with distilled water. Next, prepare the required amount of auxin treatment solution to obtain an IAA concentration of 5 mg / L per 1 L. -1 Taking a auxin treatment solution with a Tween-20 content of 0.05% as an example, the preparation first requires taking 5 mL of 1.0 mg·mL⁻¹ auxin solution. -1 Add 0.5 mL of Tween-20 stock solution to the indoleacetic acid stock solution, and then add distilled water to a final volume of 1 L.

[0025] Indoleacetic acid solution is chemically unstable; therefore, it should be stored away from light and at low temperatures when preparing and using auxin treatment solutions. It is best to prepare the solution just before spraying.

[0026] Step 3: Spraying treatment When the peony buds have developed to the early stage of the "round peach" stage, spray the entire peony plant with a growth hormone treatment solution once. When the peony buds have developed to the early stage of the "showing color" stage, spray the entire peony plant with the growth hormone treatment solution again. After spraying, maintain normal care. When spraying, use a pressurized sprayer equipped with a misting nozzle to spray the entire peony plant, avoiding excessive spraying intensity that could damage the buds. Each time you spray, use 100-200 mL of growth hormone treatment solution per plant, and spray until the plant surface is moist but not dripping. Spraying time should be controlled half an hour before sunset to prevent indoleacetic acid from becoming ineffective.

[0027] The criteria for determining the early stage of the "Zhao Fen" peony's "round peach" stage are as follows: when half of the flower buds have swollen into a spherical shape with a horizontal diameter of about 2.5 cm, the petals are tightly closed, and the petal color has not yet developed, appearing as a bluish-white or off-white, it is considered to have entered the early stage of the "round peach" stage. The criteria for determining the early stage of the "revealing color" stage are as follows: when the edges of the petals of half of the flower buds show color, and the flower buds have changed from a tightly wrapped state to a looser state, with a horizontal diameter of about 4 cm, the sepals gradually unfold, and the edges of the petals are slightly higher than the sepals, it is considered to have entered the early stage of the "revealing color" stage.

[0028] The criteria for determining the early stage of the "Jingyu" peony's "round peach" stage are: when half of the flower buds swell into a spherical shape with a horizontal diameter of about 2.5 cm, and the petals are tightly closed, it is considered to have entered the early stage of the "round peach" stage. The criteria for determining the early stage of the "showing color" stage are: when half of the flower buds change from a tightly wrapped state to a looser state with a horizontal diameter of about 4 cm, the sepals gradually open, and the edges of the petals are slightly higher than the sepals, it is considered to have entered the early stage of the "showing color" stage.

[0029] Step 4: Results Statistics After the second application of growth hormone treatment, the plants were cared for normally until flowering. During peak bloom, the flower types were observed and recorded. The criteria for determining single, semi-double, and double flowers for the 'Zhao Fen' peony were as follows: fewer than 15 petals with complete stamens and pistils; 15-70 petals with partially petalized stamens; and at least 70 petals with mostly or completely petalized stamens. The criteria for determining single, semi-double, and double flowers for the 'Jing Yu' peony were as follows: fewer than 15 petals with complete stamens and pistils; 15-60 petals with partially petalized stamens; and at least 60 petals with mostly or completely petalized stamens.

[0030] Test measurement To investigate the effect of indoleacetic acid (IAA) content in different auxin treatment solutions on the double-petal rate of peony flowers, the IAA content in the auxin treatment solutions was adjusted for the 'Zhao Fen' and 'Jing Yu' peony varieties, and cultivation experiments were conducted according to the above method. Each experimental group consisted of 10 peony plants. The peony varieties and IAA content used in each experimental group are shown in Table 1. After the peonies bloom, the percentage of double-petaled peonies is calculated, and the experimental results are as follows: Figure 1 , 2 As shown in Figure 3, a comparison revealed that the indoleacetic acid content was 5-15 mg·L⁻¹. -1 and 25-35 mg·L -1 Compared to the experimental group without indoleacetic acid, the experimental groups showed a significant increase in the rate of double petals, and the concentration of indoleacetic acid in the 25-35 mg·L⁻¹ group was also significantly higher. -1 The experimental group had the highest rate of double-petaled flowers. With increasing indoleacetic acid content (45-55 mg·L⁻¹), the rate increased. -1 The rate of double petals in the experimental group decreased significantly, 75-85 mg·L -1 The experimental group had the lowest rate of double-petaled flowers. This indicates that an appropriate amount of indoleacetic acid (IAA) helps increase the rate of double-petaled flowers, while excessive IAA has a negative effect.

[0031] Experiments showed that for the same peony variety, there was no significant difference in flowering period among the experimental groups, indicating that spraying auxin solution at the early stages of the rounding peach stage and the early stages of the color-revealing stage does not affect plant growth or the flowering process. The peony flower shape control method of this invention does not affect the control of peony flowering period, which is beneficial for the industrial application of peony cultivation.

[0032] The above description of specific embodiments is only for the purpose of helping to understand the technical concept and core idea of ​​the present invention. Although specific preferred embodiments have been used to describe and illustrate the technical solutions, they should not be construed as limiting the present invention itself. Those skilled in the art can make various changes in form and detail without departing from the technical concept of the present invention. These easily conceived changes or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A method for improving the double-petal flower shape of peonies, characterized in that: Includes the following steps: (1) Prepare auxin treatment solution using indoleacetic acid and Tween-20 stock solution. The concentration of indoleacetic acid in the auxin treatment solution is 25-35 mg·L. -1 The volume concentration of Tween-20 is 0.04-0.05%; (2) When the buds of the peony plant develop to the early stage of the round peach stage, use a pressurized sprayer to spray the whole plant of the peony plant with the growth hormone treatment solution prepared according to the method in step (1), and then carry out normal maintenance. (3) When the buds of the peony plant develop to the early stage of the color-revealing period, use a pressurized sprayer to spray the whole plant of the peony plant with the growth hormone treatment solution prepared according to the method in step (1) again, and maintain it until flowering.

2. The method for improving the double-petal flower shape of peony as described in claim 1, characterized in that: The peony plants mentioned are 5-10 year old, healthy, and planted in the ground.

3. The method for improving the double-petal flower shape of peony as described in claim 1, characterized in that: The selected peony varieties are 'Zhao Fen' and 'Jing Yu'.

4. The method for improving the double-petal flower shape of peony as described in claim 1, characterized in that: In step (1), indoleacetic acid is first dissolved in ethanol, and then diluted with distilled water to a final volume of 1.0 mg·mL. -1 The indoleacetic acid stock solution was prepared; then, the indoleacetic acid stock solution and Tween-20 stock solution were diluted with distilled water to prepare the auxin treatment solution.

5. The method for improving the double-petal flower shape of peony as described in claim 4, characterized in that: When preparing to spray in steps (2) and (3), prepare the auxin treatment solution according to the method in step (1), and prepare the auxin treatment solution in the dark.

6. The method for improving the double-petal flower shape of peony as described in claim 1, characterized in that: In steps (2) and (3), the amount of auxin treatment solution sprayed is 100-200 mL per plant.

7. The method for improving the double-petal flower shape of peony as described in claim 6, characterized in that: When spraying the auxin treatment solution, spray until the plant surface is moist but no liquid droplets are running.

8. The method for improving the double-petal flower shape of peony as described in claim 1, characterized in that: In steps (2) and (3), the auxin treatment solution is sprayed onto the peony plants half an hour before sunset.

9. The method for improving the double-petal flower shape of peony as described in claim 1, characterized in that: The criteria for determining the early stage of the round peach stage are: half of the flower buds swell into a spherical shape with a horizontal diameter of about 2.5 cm, and the petals are tightly closed; the criteria for determining the early stage of the color-revealing stage are: half of the flower buds change from a tightly wrapped state to a loose state with a horizontal diameter of about 4 cm, the sepals gradually open, and the edges of the petals are slightly higher than the sepals.

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