Application of exogenous progesterone in prevention and treatment of rust disease of loquat fruits
By spraying exogenous progesterone on loquat plants, the problem of preventing and treating rust spots in loquat fruits is solved, the cost of bagging is reduced, and the quality and resistance of the fruit is improved.
Patent Information
- Application Number
- CN202510120099.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-25
- Publication Date
- 2025-05-30
AI Technical Summary
The prior art is difficult to effectively prevent and treat loquat fruit rust spots, and bagging is time-consuming and labor-intensive, reducing fruit quality and economic benefits.
Exogenous progesterone was used to spray the whole plant at a concentration of 3 to 9 mg/L, and sprayed 3 times in total to improve the resistance of the plants to rust spot disease.
It significantly reduces the rust spot rate of loquat fruits, improves fruit quality, reduces labor costs, and is suitable for large-scale promotion and application.
Smart Images
Figure CN120052365A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of agricultural disease control, and particularly relates to the application of exogenous progesterone in controlling rust spot disease of loquat fruits. Background Art
[0002] As one of the main economic tree species, the cultivation area of loquat has expanded rapidly in recent years, and some production problems have attracted more and more attention, especially the fruit quality problem. Some physiological diseases such as purple spot, rust spot, wrinkled skin, sunburn, and fruit cracking that occur during the development and maturity of loquat fruits affect the appearance quality and commercial rate of fruits, causing serious economic losses. In some countries and regions, rust spot disease can cause a 15% - 50% yield loss of loquat.
[0003] In agricultural production, bagging is currently the main effective measure to inhibit rust spot disease of loquat fruits, but bagging is time-consuming and laborious, and bagging will reduce the fruit quality and peel color to a certain extent. Therefore, agricultural producers have always wanted to choose low labor costs or breed loquat varieties with higher resistance to better achieve the economic benefits of agricultural planting.
[0004] Plant growth regulators or other exogenous substances are often used to enhance the stress resistance and disease control of fruits, such as gibberellins (GA), N-(2-chloro-4-pyridyl)phenyl-N'-phenylurea (CPPU), and chlorogenic acid. However, the application of GA shows adverse side effects on crops, such as excessive shoot growth, inhibition of flower bud germination, and the use effects of more chemicals in agricultural production need to be further studied and verified.
[0005] During the process of plant growth and development, a new type of chemical substance - mammalian sex hormones (MSHs) is currently being used and studied. MSHs are lipophilic and low molecular weight complexes, belonging to steroid compounds derived from isoprenoids, including various types of progesterone, estrogen, testosterone, estradiol, androgen, and androsterone. Progesterone (PROG) is a mammalian gonadal hormone and was first identified from apples in 1960.
[0006] In recent decades, extensive research has been conducted on natural PROG in plants, including its distribution sites, contents, and effects on growth and development, and the contents of endogenous progesterone in different plants have been determined by GCMS. For example, the progesterone content in the roots of Arabidopsis thaliana is 160 ng / kg, and the content in flowers reaches 400 ng / kg; the progesterone content in the buds of rice is as high as 1540 ng / kg; the progesterone content in immature fruits of tomatoes is 280 ng / kg, and the progesterone content in mature fruits is 6 ng / kg.
[0007] Multiple studies have confirmed that progesterone plays a crucial role in the abiotic stress response of plants. Progesterone can scavenge excessive reactive oxygen species (ROS), enhancing the environmental tolerance and antioxidant capacity of plants. For example, exogenous progesterone can enhance the cold tolerance of plants such as maize and chickpea; exogenous progesterone significantly alleviates the growth inhibition of maize and wheat seedlings under salt stress; progesterone treatment significantly increases the activities of antioxidant enzymes such as POD, SOD, CAT, and GR in strawberry fruits. In addition, progesterone has also been used in postharvest storage to reduce chilling injury to fruits.
[0008] The above studies indicate that progesterone plays an important role in response to environmental changes and plant development. However, there is currently no research on the effect of progesterone on rust spot disease of loquat fruits. The control measures for fruit rust vary depending on the tree species, especially the occurrence pattern and control measures for rust spot disease of loquat fruits are relatively few.
[0009] Therefore, exploring the effect of exogenous progesterone on controlling physiological diseases of loquat, especially the occurrence of fruit rust, and finding a convenient, low-cost, and green prevention and control measure for fruit rust have become technical problems that need to be solved urgently. Summary of the Invention
[0010] The present invention is to solve the above technical problems, thereby providing an application of exogenous progesterone in controlling rust spot disease of loquat fruits. The technical object of the present invention is to provide a new method for controlling rust spot disease of loquat fruits, so as to reduce the cost of bagging and provide new guiding suggestions for high-quality and high-yield production of loquat.
[0011] To achieve the above technical object, the technical solution adopted by the present invention is as follows:
[0012] The present invention provides an application of exogenous progesterone in controlling rust spot disease of loquat fruits.
[0013] Specifically, the loquat is white-fleshed loquat.
[0014] Specifically, the white-fleshed loquat variety is 'Snow White'.
[0015] Specifically, 90 days after full bloom of 'Snow White' loquat, the whole plant is sprayed with progesterone, and then sprayed once every 15 days for a total of 3 times.
[0016] Specifically, the spraying concentration of progesterone is 3 - 9 mg / L, preferably 6 mg / L.
[0017] Specifically, the spraying amount of progesterone is until water droplets appear on the front and back of the leaves and the surface of the fruit clusters.
[0018] The beneficial effects of the present invention are as follows:
[0019] The present invention provides an application of exogenous progesterone in preventing and controlling the rust spot disease of loquat fruits, and discloses its specific spraying method and spraying concentration. It is found through the experiments of the present invention that the method provided by the present invention can reduce the rust spot rate of loquat fruits, improve the quality of loquat fruits to a certain extent, and at the same time, compared with bagging, the operation is simpler and the labor cost is lower, which is suitable for large-scale popularization and application. Description of the Drawings
[0020] Figure 1 It shows the influence of exogenous progesterone treatment on the phenotypic characteristics of loquat fruits.
[0021] Figure 2 It shows the influence of exogenous progesterone treatment on the single fruit weight of loquat fruits.
[0022] Figure 3 It shows the influence of exogenous progesterone treatment on the longitudinal diameter and transverse diameter of loquat fruits.
[0023] Figure 4 It shows the influence of exogenous progesterone treatment on the color difference of the peel of loquat fruits.
[0024] Figure 5 It shows the influence of exogenous progesterone treatment on the soluble solid content of loquat fruits.
[0025] Figure 6 It shows the influence of exogenous progesterone treatment on the soluble sugar and titratable acid contents of loquat fruits. Detailed Embodiments
[0026] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be specifically described below in conjunction with embodiments. It is necessary to point out that the following embodiments are only used to explain and illustrate the present invention, and are not used to limit the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above-mentioned inventive content still fall within the protection scope of the present invention.
[0027] Example 1
[0028] I. Test Materials
[0029] The test samples were collected from the "New Loquat Variety R & D Base" in Sanxing Village, Fengle Township, Shimian County, Ya'an City, Sichuan Province (29°18′55″N - 29°18′56″N, 102°32′16″E). The base belongs to the subtropical monsoon climate with mild climate. The altitude is 867 - 877 m. The test materials were 7-year-old grafted white-fleshed loquat variety 'Snow White' (the base rootstock is 'Big Five Stars', the middle is "6-6-6", and the "6-6-6" material is the seedling offspring of 'Big Five Stars'), and the plant spacing is 4 m × 4 m.
[0030] The test reagent was progesterone (Progesterone, PROG), and its molecular formula is C21 H 30 O 2 , with a molecular weight of 314.46, is a white crystal, of analytical purity, and is purchased from Shanghai Yuanye Bio-Technology Co., Ltd. PROG is insoluble in water and soluble in ethanol, and is stored under normal temperature and in the dark.
[0031] II. Experimental Treatments
[0032] According to the growth and development habits of 'Snow White' fruits, fruits were thinned at the early stage of fruit enlargement of the second batch of flowers in early February 2024 (about 80 days after flowering), leaving 3 fruits per fruit cluster. After fruit thinning, a bactericide and insecticide were sprayed once. The fruits were not bagged and were managed conventionally.
[0033] Exogenous progesterone spraying experiment: 90 days after full bloom of 'Snow White' loquats, 15 plants with consistent growth vigor were selected for the exogenous progesterone experiment. Five treatments were set up, with single-plant plots and repeated 3 times. The concentrations of progesterone sprayed on the whole plant were 0 (clear water, control, CK), 3, 6, 9, and 12 mg / L (using 0.01% Tween 20 as a surfactant), sprayed once every 15 days, for a total of 3 times. If it rained, it was sprayed again. Each treatment was sprayed on the whole plant until water dripped from the front and back of the leaves and the surface of the fruit clusters (about 10 L of progesterone solution was sprayed per plant); the spraying was meticulous and uniform, and each treatment was kept from interfering with each other (separated by a thin film). After the third spraying, the leaves and the surface of the fruits were naturally dried. The fruits were not bagged and were managed conventionally. At 165 days after full bloom (maturity stage), physiological diseases were counted and samples were collected, and all measurement indexes were repeated 3 times.
[0034] III. Statistical Analysis of Physiological Diseases
[0035] The resistance grading standard for loquat rust spot disease refers to 'Descriptive Specifications and Data Standards for Loquat Germplasm Resources' compiled by Zheng Shaoquan.
[0036] Rust spot rate = (total number of rust spot fruits at all levels N / total number of fruits) × 100%.
[0037] Sunburn index = Σ (number of fruits at all levels × level number) / (total number of fruits × highest level number) × 100%.
[0038] Shrunken fruit rate: The percentage of shrunken fruits in the total number of inspected fruits was counted to calculate the shrunken fruit rate.
[0039] Fruit cracking grading standard: The percentage of cracked fruits in the total number of inspected fruits was counted to calculate the fruit cracking rate.
[0040] IV. Determination of Fruit Quality
[0041] The total soluble solids (TSS) were determined using a WYT-1 handheld refractometer; the soluble sugar content was determined by the anthrone colorimetric method; and the titratable acid (calculated as malic acid) content was determined by sodium hydroxide titration.
[0042] The method for determining lignin content was as follows: The loquat fruit tissue was dried to a constant weight at 80 °C and then ground into powder, which was passed through a 40-mesh sieve. Approximately 3 g of the powder was added to a test tube, and 5 mL of washing solution (100 mol / L K 2 HPO 4 , 0.5% Triton X-100, 0.5% PVP, pH = 7.8) was added, and the mixture was shaken (300 r / min) at room temperature for 30 min, then centrifuged (6000 r / min, 10 min). The supernatant was removed, and the washing procedure was repeated once. Then the precipitate was suspended in 5 mL of 100% methanol and washed four times. The precipitate was dried in an oven at 65 °C for 12 h, 0.1 mL of mercaptoacetic acid and 1 mL of 2 mol / L HCl were added, and the mixture was heated in a water bath (98 °C) for 8 h, cooled on ice for 5 min, and centrifuged at 8000 r / min for 10 min at 4 °C. The supernatant was removed. The precipitate was washed three times with distilled water and dried in an oven at 65 °C overnight. The dried precipitate was resuspended in 1 mL of 1 mol / L NaOH and gently shaken at 25 °C for 18 h, then centrifuged at 10000 r / min for 20 min. 0.5 mL of the supernatant was taken and added to a 2-mL centrifuge tube, and 0.1 mL of concentrated hydrochloric acid was added. The mixture was allowed to stand at 4 °C for 4 h to allow lignin to bind with mercaptoacetic acid. Finally, it was centrifuged at 10000 r / min for 20 min at 4 °C, the supernatant was removed, and the precipitate was dissolved in 1 mL of 1 mol / L NaOH. Using 1 mol / L NaOH as the blank, the absorbance was measured at a wavelength of 280 nm using a microplate reader (Synergy H1, BioTek, Vermont, USA).
[0043] (V) Data analysis
[0044] Correlation analysis was performed using Pearson's correlation coefficient analysis and visualized using SPSS 22.0 (SPSS, Inc., Chicago, IL, USA). The significance of the data was analyzed by Duncan's multiple range test, and different letters were used to indicate significant differences (p < 0.05).
[0045] V. Results and analysis
[0046] (1) Effects of exogenous progesterone treatment on the phenotypic characteristics of loquat fruits
[0047] From Figure 1It can be observed that the treatment with exogenous progesterone at different concentrations has a significant impact on the phenotypic characteristics of mature loquat fruits. The fruit rust on the surface of the fruits in the control group (CK) and the group treated with 3 mg / L progesterone was relatively obvious, and the appearance quality was poor; the fruit skin of the fruits in the 6 mg / L treatment group was relatively smooth, the fruit rust was significantly reduced, and the overall appearance quality was significantly improved; however, as the concentration further increased to 9 mg / L and 12 mg / L, the fruit rust phenomenon became more serious, and the smoothness of the fruit surface decreased. This indicates that under the experimental conditions, 6 mg / L is the optimal concentration for improving the phenotypic characteristics of loquat fruits.
[0048] 2. Effects of exogenous progesterone treatment on physiological diseases of loquats
[0049] Exogenous progesterone treatment has a certain impact on the physiological diseases of loquat fruits at the mature stage (Table 1). The fruit rust rate showed significant differences with the change of progesterone concentration. Among them, the 6 mg / L treatment significantly reduced the fruit rust rate, which was only 25.19%, a reduction of about 73.4% compared with 94.81% in the control group. For the sunburn rate, there was little difference between each treatment group and the control group, and they were all maintained between 9.63% and 12.96%, indicating that the improvement effect of progesterone treatment on the sunburn rate was not obvious. In terms of the fruit shrinkage rate, the 6 mg / L treatment also showed a significant improvement effect, which was only 1.85%, a decrease of 64.3% compared with 5.19% in the control group. In addition, the 6 mg / L treatment also had the most significant effect on reducing the fruit cracking rate, which was only 3.70%, while the fruit cracking rate in the control group was 8.52%. In summary, the 6 mg / L progesterone treatment showed the best effect in reducing the fruit rust rate, fruit shrinkage rate and fruit cracking rate, and higher or lower concentrations did not show the same improvement effect.
[0050] Table 1 Effects of exogenous progesterone on physiological diseases of loquat fruits at the mature stage (unit: %)
[0051]
[0052] 3. Effects of exogenous progesterone treatment on the appearance quality of loquat fruits
[0053] (1) Single fruit weight
[0054] As Figure 2 can be seen, exogenous progesterone treatment has no significant effect on the single fruit weight of loquat fruits. The single fruit weight of the control fruits was 59.79 g, and the single fruit weights of the fruits treated with different concentrations of progesterone were 57.02 g, 58.82 g, 60.21 g and 56.84 g respectively.
[0055] (2) Longitudinal and transverse diameters of the fruits
[0056] Exogenous progesterone treatment can affect the longitudinal and transverse diameters of loquat fruits ( Figure 3) Among them, the treatments with 3 and 12 mg / L progesterone significantly reduced the longitudinal diameter of the fruits, which were 45.11 and 47.86 mm respectively, significantly decreasing by 9.45% and 4.62% compared with the control. The transverse diameter of the control fruits was 50.08 mm, and the transverse diameters of the fruits treated with different concentrations of progesterone were 45.69, 48.11, 49.47, and 47.09 mm respectively. The exogenous progesterone at 3, 6, and 12 mg / L significantly decreased by 8.77%, 3.93%, and 5.97% compared with the control.
[0057] (3) Peel color index of the fruits
[0058] The coloring of the fruits is an important factor affecting the commercial quality of the fruits. The L* value reflects the lightness and darkness of the color, the a* value reflects the red-green chromaticity, and the b* value reflects the yellow-blue degree.
[0059] It can be seen from Figure 4 that the exogenous progesterone treatment can significantly increase the L* value of the fruits. The L* value of the control fruits was 63.74, and the L* values of the fruits treated with progesterone were 70.72, 72.96, 71.53, and 70.00 respectively, significantly increasing by 9.86%, 12.63%, 10.89%, and 8.93% compared with the control. Different concentrations of progesterone treatment affected the a* value of loquat fruits. Among them, the treatments with 6, 9, and 12 mg / L progesterone significantly reduced the a* value of the fruits, and there was no significant difference between the treatment with 3 mg / L progesterone and the control. The progesterone treatment can significantly increase the b* value of the fruits. The b* value of the control fruits was 49.46, and the b* values of the fruits treated with progesterone were 52.61, 52.16, 52.94, and 51.96 respectively, significantly increasing by 5.98%, 5.18%, 6.57%, and 4.81% compared with the control.
[0060] 4. Effects of exogenous progesterone treatment on the internal quality of loquat fruits
[0061] (1) Soluble solid content of the fruits
[0062] The exogenous progesterone treatment can affect the soluble solid content of the fruits ( Figure 5 ). Treating the fruits with an appropriate concentration of progesterone can increase the soluble solid content of the fruits. Among them, the soluble solid contents of the fruits treated with 6, 9, and 12 mg / L exogenous progesterone were significantly higher than those of the control, which were 14.67%, 14.73%, and 14.63% respectively, increasing by 1.17, 1.23, and 1.13 percentage points compared with the control respectively.
[0063] (2) Soluble sugar and titratable acid contents of the fruits
[0064] The exogenous progesterone also has an impact on the soluble sugar and titratable acid contents of loquat fruits ( Figure 6) Among them, the soluble solid content of fruits treated with 6, 9, and 12 mg / L progesterone was significantly higher than that of the control, being 11.45%, 11.29%, and 11.86% respectively, which were increased by 1.22, 1.06, and 1.63 percentage points compared with the control. Treatments with different concentrations of progesterone could affect the titratable acid content of fruits. Among them, the titratable acid content of fruits treated with 3, 6, and 12 mg / L progesterone was significantly lower than that of the control, being 0.47%, 0.33%, and 0.38% respectively, which were significantly decreased by 0.03 percentage points, 0.17 percentage points, and 0.12 percentage points compared with the control.
Claims
1. Application of exogenous progesterone in preventing and controlling loquat fruit rust disease.
2. The use according to claim 1, characterized in that: The loquat is white-fleshed loquat.
3. The use according to claim 1 or 2, characterized in that: The loquat variety is 'Snow White'.
4. The use according to claim 3, characterized in that: 90 days after the 'Snow White Princess' loquat bloomed, the whole plant was sprayed with progesterone, and then sprayed once every 15 days, for a total of 3 times.
5. The use according to claim 4, characterized in that: The spraying concentration of the progesterone is 3-9 mg / L.
6. The use according to claim 5, characterized in that: The spraying concentration of the progesterone is 6 mg / L.
7. The use according to any one of claims 4 to 6, characterized in that: The spraying amount of the progesterone is such that water drops appear on the front and back sides of leaves and the surface of the ear.