Application of potassium iodide in reducing pecan fruit drop rate
By applying potassium iodide solution in the early stage of hickory fruit development, the level of reactive oxygen species was regulated, which solved the problem of high fruit drop rate in hickory in Zhejiang Province, significantly reduced the fruit drop rate, and supported the economic benefits of hickory planting.
Patent Information
- Application Number
- CN202411776996.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2044-12-05
AI Technical Summary
Existing technologies have failed to effectively control the fruit drop rate of hickory nuts, especially in Zhejiang hickory nuts, where the flower and fruit drop rate is as high as 60% or more, affecting yield and economic benefits.
Apply potassium iodide solution at a concentration of 3-10 mmol/L during the early stage of pecan fruit development. Spray the solution at the junction of the fruit and the branch, repeating 2-3 times at 7-10 day intervals. Combine this with Triton X-100 to control reactive oxygen species levels and reduce fruit drop.
Potassium iodide treatment significantly reduced the fruit drop rate of pecans. In particular, the fruit drop rate was significantly lower than that of the control group after treatment with a 3 mmol/L potassium iodide solution, providing a more systematic study of fruit drop patterns and support for planting management.
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Figure CN119234824B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of plant growth regulation technology, and in particular relates to the application of potassium iodide in reducing the fruit drop rate of pecans. Background Technology
[0002] Hickory nuts include Zhejiang hickory nuts ( Carya cathayensis Yunnan hickory ( Carya tonkinensis ), Guizhou hickory ( Carya kweichowensis ), Hunan hickory ( Carya hunanensis ) and Dabie Mountain walnuts ( Carya cathayensis There are several varieties, including Zhejiang hickory. Widely cultivated in Lin'an and Chun'an areas of Zhejiang Province, it is an important economic forest tree in the region. Due to various factors, hickory trees commonly suffer from flower and fruit drop, with a rate exceeding 60% under normal circumstances, negatively impacting yield. Therefore, the mechanism and control techniques for hickory fruit drop have attracted considerable attention from growers and researchers.
[0003] Fruit abscission in plants is closely related to the formation of the abscission layer. After receiving abscission signals, the fruit forms an abscission zone. Subsequently, cells in this zone separate under enzymatic action, forming the abscission layer, which ultimately allows the fruit to fall off under external force. The abscission layer actively removes undesirable fruit, preventing nutrient competition and water loss, while also protecting against pests and diseases. The formation of the abscission layer is often regulated by hormones, enzymes, and fruit abscission genes.
[0004] Reactive oxygen species (ROS) are signaling molecules in plants responding to abiotic stress and play a crucial role in cell senescence and apoptosis. However, excessive ROS can damage plant tissues, affecting plant growth and fruit abscission. Studies have shown a close correlation between ROS and abscission layer formation. In agriculture and industry, ROS have a significant impact on the storage, processing, and transportation of fruits and vegetables. To maintain ROS balance, ROS scavengers are commonly used for preservation and anti-corrosion. Potassium iodide (KI), a non-toxic, reducing inorganic compound, can be used as a ROS scavenger in studies of pecan fruit abscission mechanisms.
[0005] Currently, research on pecans mainly focuses on cultivation techniques, pest and disease control, selection of superior varieties, and nutritional value assessment. Research on the molecular regulatory mechanisms of reactive oxygen species (ROS) in plant growth and development is also gradually improving. However, no research has yet demonstrated how to regulate pecan fruit drop rates through ROS-mediated molecular regulatory mechanisms. Summary of the Invention
[0006] To address the aforementioned technical problems, this invention proposes the application of potassium iodide in reducing the fruit drop rate of hickory nuts. Through statistical analysis, hickory morphology and anatomy, and tissue staining, the role of potassium iodide in controlling fruit drop was analyzed. Its application in reducing the fruit drop rate of hickory nuts slowed down the occurrence of fruit drop in Zhejiang hickory nuts.
[0007] To achieve the above objectives, this invention provides the application of potassium iodide in reducing the fruit drop rate of pecans.
[0008] Preferably, the potassium iodide is applied during the early stage of pecan fruit development.
[0009] The present invention also provides a method for reducing the fruit drop rate of hickory using potassium iodide, comprising the following steps: applying potassium iodide solution to the connection between hickory fruit and branch at the early stage of hickory fruit development, applying 2 to 3 times, with an interval of 7 to 10 days between each application.
[0010] Preferably, the concentration of the potassium iodide solution is 3~10 mmol / L.
[0011] Preferably, the potassium iodide solution is applied by spraying, and the amount of potassium iodide solution applied each time is 1~3 mL.
[0012] Preferably, the potassium iodide solution also includes Triton X-100.
[0013] More preferably, the volume concentration of Triton X-100 in the potassium iodide solution is 0.1%.
[0014] Preferably, the potassium iodide solution is applied between 8:00 AM and 11:00 AM, and the temperature at which the potassium iodide solution is applied is 25-30°C.
[0015] Preferably, the potassium iodide solution is applied on a sunny day.
[0016] The present invention also provides a formulation for reducing the fruit drop rate of pecans, the formulation comprising the potassium iodide.
[0017] Compared with the prior art, the present invention has the following advantages and technical effects:
[0018] This invention uses hickory nuts from Lin'an, Zhejiang Province as experimental material to study the key timing and corresponding cytological characteristics of hickory nut fruit drop, determine the patterns of fruit drop and reactive oxygen species changes, statistically analyze the fruit drop rate of hickory nuts, and determine the appropriate concentration of KI to reduce fruit drop in hickory nuts. The aim is to gain a more systematic and comprehensive understanding of the occurrence pattern of hickory nut fruit drop, reduce the occurrence of hickory nut fruit drop by applying exogenous reactive oxygen species scavengers, increase the economic benefits of hickory nut cultivation, and provide support for research on hickory nut fruit preservation technology. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 The abscission layer formed during the shedding of pecan fruits is shown in Figure A, which shows the phenotype of the abscission layer of pecan fruits after 1 month of growth, and Figure B shows the microscopic observation of the abscission layer of pecan fruits after 1 month of growth. The scale bar is 200 μm.
[0021] Figure 2 This is a diagram showing the location where hickory fruits fall off. In the diagram, fr represents the hickory fruit, fs represents the fruit stalk, and br represents the branch.
[0022] Figure 3 These are microscopic images of the abscission layer of pecan fruits. In the image, A is a microscopic image of the abscission layer of a normally growing fruit, with the red arrow indicating the location of the abscission layer and the scale bar being 200 μm. In the image, B is a microscopic image of the abscission layer of a fallen fruit, with the red arrow indicating the location of the abscission layer and the scale bar being 200 μm.
[0023] Figure 4 NBT staining images of underdeveloped hickory fruits are shown. In the image, A represents hickory fruits with relatively better growth, and the red arrows indicate the area where the fruit connects to the branch. The scale bar is 200 μm. In the image, B represents hickory fruits with relatively poor growth, and the red arrows indicate the area where the fruit connects to the branch. The scale bar is 200 μm.
[0024] Figure 5 Images show DAB and NBT staining after KI solution treatment. In A, the image shows DAB staining, with blue arrows indicating the area near the connection between the fruit and the branch. The scale bar is 500 μm. In B, the image shows NBT staining, with blue arrows indicating the area near the connection between the fruit and the branch. The scale bar is 500 μm. Detailed Implementation
[0025] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0026] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0027] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0028] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.
[0029] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0030] Example 1
[0031] 1. Materials and Methods
[0032] 1.1 Experimental Materials and Reagents
[0033] The variety used in this experiment was Zhejiang hickory, and the sampling site was the Zhejiang Agricultural and Forestry University base in Lin'an District, Hangzhou City, Zhejiang Province. The experiment was conducted from April to July 2023 and 2024. Hickory trees with a height of 3-5m and good growth were selected. The fruit drop pattern was observed and statistically analyzed. After pollination was completed and young fruit formation began, the hickory trees were labeled and classified. KI (kidney oxygenate) was sprayed at concentrations of 3 mmol / L, 5 mmol / L, and 10 mmol / L, respectively. Water was sprayed simultaneously as a control group. KI (Xilong Scientific, CAS7681-11-0), DAB (3,3-diaminobenzidine), and NBT (nitrotetrazole blue chloride) are both commonly used colorimetric reagents. DAB reacts with hydrogen peroxide to produce a brown product, while NBT reacts with superoxide anions to form an insoluble blue product.
[0034] 1.2 Experimental Methods
[0035] 1.2.1 Reagent Treatment: Treatment of hickory nuts began in mid-May, with intervals of 7-12 days, for 2-3 treatments. The number of hickory nuts was counted before each treatment. Treatment was conducted between 8-11 AM, at a temperature of 25-30℃, avoiding rainy or hot weather. 0.1 mL of Triton X-100 buffer was added to every 100 mL of KI solution to prevent rapid evaporation of the active ingredients. The reagent was sprayed at the junction of the hickory nut and the branch, stopping treatment when dripping began. The dosage was 2 mL.
[0036] 1.2.2 Fruit drop count: Before spraying KI solution, the experimental groups treated with different reagents were classified to ensure that the number of fruits per branch was about 10-30. One branch was counted as one replicate. There were more than three replicates for each of the three concentration gradients of KI solution. H2O was used as the control group (CK). All samples were randomly distributed.
[0037] Before treatment, the number of hickory fruits was S0. At the same time, the first reagent treatment was performed. After 10 days, the number of hickory fruits after the first reagent treatment was S1. And so on, the number of hickory fruits after the second reagent treatment was S2, and the number of hickory fruits after the third reagent treatment was S3.
[0038] 1.2.3 DAB and NBT staining: Normally grown and fully abscissed pecan fruits were selected. Fruits treated with 3 mmol / L KI solution and H2O for 1 day and 3 days respectively were stained with DAB and NBT. Tissue approximately 5 mm from the abscission layer of the fruit was excised and immersed in DAB (1 mg·mL⁻¹). -1 The fruit tissue was immersed in NBT (0.1% by mass, pH 7.8) solution under vacuum for 4 hours, then left to stand at room temperature overnight. After staining, the fruit tissue was decolorized with 75% ethanol, changing the decolorization solution 4 times until decolorization was complete. The decolorized fruit tissue samples were then used as anatomical materials.
[0039] 1.2.4 Vibrating Sectioning and Microscopic Observation: The instrument used for sectioning was a Leica VT1200S vibrating microtome. The destained tissue samples were embedded in 5% agarose and fixed on the stage with super glue. Parameters were adjusted to collect 50μm sections, which were then preserved in test tubes with deionized water for subsequent microscopic observation. The instrument used for observation was a Leica DM6B upright fluorescence microscope. Pecan sections were placed on glass slides, and a suitable amount of deionized water was added and slowly covered with the slides. The tissue structure and staining were observed under the microscope, and photographs were taken for recording.
[0040] 1.3 Data Analysis
[0041] The fruit drop rate of pecans after treatment with different concentrations of reagents was calculated. The significant differences between different groups were analyzed by one-way ANOVA. The data were organized using Excel 2016 software, and ANOVA and Duncan's multiple comparisons were performed on the data using SPSS 27.0 software. GraphPad Prism 10.1.2 software was used to create charts, and Microsoft PowerPoint software was used to process the images.
[0042] Total fruit drop rate L = (Number of pecan fruits after final treatment S - Number of pecan fruits before treatment S0) / Number of pecan fruits before treatment S0 × 100%.
[0043] Single fruit drop rate L n =(Number of pecan fruits after the (n+1)th reagent treatment, S) n+1 - Number of pecan fruits S after nth reagent treatment n The number of pecan fruits S after the nth reagent treatment n ×100%.
[0044] 2 Results and Analysis
[0045] 2.1 Pecan fruit drop
[0046] 2.1.1 Abscission layer forms during fruit abscission.
[0047] Observing pecan fruits that have grown for one month, it was found that during their natural shedding process, a distinct abscission layer or abscission zone forms on the fruit and branches (such as...). Figure 1 (As shown in Figure A). Observation revealed that the cells in the abscess layer were smaller and more densely packed than the surrounding cells. DAB staining showed differences in staining between the abscess cells and the surrounding cells (e.g., ...). Figure 1 As shown in Figure B), this illustrates that the shedding process of hickory nuts is related to the formation of the abscission layer.
[0048] 2.1.2 The location of the abscission layer when pecan fruits fall off is different.
[0049] Observations revealed that during the natural shedding of pecan fruits, the abscission layer mainly occurred at the junction of the fruit stalk and branch, and at the junction of the fruit and branch (e.g., Figure 2 As shown in the figure, these two tissues are newly grown structures, with soft texture and poor firmness, indicating that the formation of fruit drop may be related to tissue structure and cell density, affecting the formation of the abscission layer.
[0050] 2.2 Pecan fruit drop rate
[0051] The fruit drop rate of hickory nuts in 2023 and 2024 was statistically analyzed. The initial statistical analysis in Lin'an, Zhejiang Province in 2023 began on May 13th, with each treatment occurring 10 days apart, for a total of 3 treatments. The initial statistical analysis in Lin'an, Zhejiang Province in 2024 began on May 18th, with each treatment occurring 10 days apart, for a total of 3 treatments.
[0052] Table 1. Fruit drop rate of hickory nuts after different reagent treatments
[0053] ;
[0054] Note: Different letters in the same column indicate significant differences at the P≤0.05 level.
[0055] Table 1 shows that under H2O treatment simulating natural fruit drop in hickory, the average fruit drop rate in Lin'an area reached over 80% around June 2023 and 2024. This data is consistent with existing technical records showing a fruit drop rate of 60%–90% in June. Spraying with different concentrations of KI solution generally reduced the fruit drop rate. The 10 mmol / L KI solution treatment showed a higher average fruit drop rate in 2024 than other groups, indicating that fruit drop in hickory is also influenced by other factors. The 3 mmol / L KI solution treatment showed average fruit drop rates of 57.24% and 61.22% in 2023 and 2024, respectively, and its fruit drop rate was significantly lower than the control group in both studies, indicating that 3 mmol / L KI solution is more suitable as a fruit drop inhibitor for hickory. In conclusion, further treatment with 3 mmol / L KI solution was selected for hickory to explore the differences in reactive oxygen species levels within the hickory plant.
[0056] 2.3 Investigation into the differences in reactive oxygen species in fallen pecan fruits
[0057] Because an abscission layer is formed during the fruit's shedding process, DAB staining was performed on sections of normally growing, unshed, and shed pecan fruits, and the differences in coloring were observed under a microscope.
[0058] The results are as follows Figure 3 China A and Figure 3 As shown in Figure B, there was no significant difference in the staining of reactive oxygen species in normally growing fruits. However, the abscission layer of fallen fruits showed a deeper color, indicating that the reactive oxygen species level was higher in the abscission layer after the fruit fell off.
[0059] To investigate the reactive oxygen species (ROS) in pecan fruits before they have completely fallen off, weak, dark yellow, and poorly grown fruits were collected and NBT-stained sections were prepared. The results are as follows: Figure 4 China A and Figure 4As shown in Figure B, observations revealed significant color differences in the area where the fruit connects to the branch, indicating that an increase in reactive oxygen species (ROS) levels may be one of the chemical signals for the formation of the abscission layer. This means that an increase in ROS levels within the fruit leads to the death of abscission layer cells, resulting in the formation of an abscission zone between the fruit and the branch until the fruit completely falls off.
[0060] 2.4 KI treatment reduces reactive oxygen species levels in pecans
[0061] By statistically analyzing the fruit drop rate of hickory nuts, normally growing hickory nuts were treated with 3 mmol / L KI solution for 1 day and 3 days respectively. After collection at the same time, DAB and NBT staining were performed, and the color differences were observed by sectioning.
[0062] The results are as follows Figure 5 China A and Figure 5 As shown in Figure B, comparing the staining of the area near the connection between the fruit and the branch, it can be seen from the 1d and 3d treatments that the KI treatment showed a lighter color and a lower level of reactive oxygen species in the body than the H2O treatment. The scavenging effect of KI on reactive oxygen species was further verified by DAB and NBT staining.
[0063] 3. Conclusion
[0064] KI, a reducing compound, possesses reactive oxygen species (ROS) scavenging capabilities and is frequently used in chemical engineering research to detect ROS levels; however, its application in fruit development is less studied. This study involved spraying different concentrations of KI onto pecan fruits, regularly tracking fruit drop, and subsequently selecting an appropriate concentration. Statistical analysis of data from Lin'an, Zhejiang Province, in 2023 and 2024 showed that the average fruit drop rate of pecans exceeded 80% in May and June, and treatment with 3 mmol / L KI significantly reduced the fruit drop rate.
[0065] The fruit drop phenomenon in Zhejiang pecans is influenced by both external environmental factors and internal factors. This invention statistically shows that the natural fruit drop rate from May to June is 72.22% to 95.00%. Other pecan varieties, such as thin-shelled pecans, also have high fruit drop rates, indicating that pecan fruit drop mainly occurs in the early stages of young fruit formation. Poor pollination and nutrient competition are the main causes of fruit drop. The location of the fruit's connective tissue and its supporting morphology may also affect fruit drop. The accumulation of reactive oxygen species can damage plants, leading to cell death and causing flower, leaf, and fruit drop. The level of reactive oxygen species at the abscission layer is higher in pecans during fruit drop compared to normally growing fruits, and spraying with 3 mmol / L KI reduces the fruit drop rate. This invention screens out agents and suitable concentrations for controlling fruit drop, laying the foundation for research on the fruit drop patterns of Zhejiang pecans and having significant implications for pecan cultivation and management.
[0066] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. The application of potassium iodide in reducing the fruit drop rate of pecans, characterized by: A potassium iodide solution with a concentration of 3 mmol / L was applied to the junction of the pecan fruit and the branch. The potassium iodide solution also contained Triton X-100. The potassium iodide was applied at the early stage of pecan fruit development.
2. A method for reducing the fruit drop rate of pecans using potassium iodide, characterized in that, Includes the following steps: Potassium iodide solution was applied to the junction of the pecan fruit and the branch during the early stage of pecan fruit development, 2-3 times, with an interval of 7-10 days between each application. The concentration of potassium iodide solution was 3 mmol / L, and the potassium iodide solution also contained Triton X-100. The potassium iodide solution was applied between 8:00 AM and 11:00 AM, and the application temperature was 25-30°C.
3. The method for reducing the fruit drop rate of hickory nuts according to claim 2, characterized in that, The potassium iodide solution is applied by spraying, and the amount of potassium iodide solution applied each time is 1~3 mL.
4. The method for reducing the fruit drop rate of hickory nuts according to claim 2, characterized in that, The volume concentration of Triton X-100 in the potassium iodide solution is 0.1%.
5. The method for reducing the fruit drop rate of hickory nuts according to claim 2, characterized in that, The potassium iodide solution was applied on a sunny day.