Method for preventing and controlling pear ring spot by using tyrosol

Abstract

The invention provides a method for preventing and controlling pear ring rot by using tyrosol. The pear ring rot is prevented and controlled by externally spraying a tyrosol aqueous solution. The concentration of the tyrosol in the tyrosol aqueous solution is 1-5 mg / ml. According to the invention, Dangshan pears are taken as experimental materials, and in-vitro bacteriostasis experiments and botryosphaeria dothidea inoculation experiments prove that tyrosol has a remarkable inhibiting effect on pear botryosphaeria dothidea, and can effectively inhibit the development speed of botryosphaeria dothidea scab and reduce the occurrence and spreading of diseases, so that the damage of botryosphaeria dothidea to plants is reduced. Tyrosol is a natural compound in plants, has low toxicity, and can enhance the defense mechanism of pear when applied to prevention and treatment of pear ring rot, improve the natural resistance of pear to ring rot, reduce or replace the use of chemical pesticides, and reduce the potential risk to the environment and human health.

Description

Technical Field

[0001] The invention belongs to the technical field of fruit tree disease prevention and control, relates to plant natural bactericidal active compounds, and specifically relates to a method for preventing and controlling pear ring rot by utilizing tyrosol. Background Art

[0002] Pear is a deciduous tree plant of the Rosaceae family, belonging to the genus Pyrus. It is the third largest fruit in my country after apples and citrus. Its metabolites such as flavanols, phenolic acids, and arbutin play a vital role in the process of fruit adaptation to the environment, and also provide an indispensable resource for human health. Pear fruit has a fragrant smell, is refreshing and juicy, and is rich in nutrients. The main effective chemical components are phenolic substances, mainly including phenolic acids and flavonoid compounds, such as arbutin, chlorogenic acid, caffeic acid, etc., which have medicinal and edible effects such as moistening the lungs and relieving coughs, scavenging free radicals, and inhibiting bacteria. The planting area of ​​pears in my country is very wide, mainly distributed in Hebei, Shandong, Shaanxi, Gansu and other provinces, but with the increase in planting area, various diseases and pests have also increased. Among them, pear ring rot is the most common disease in my country, which is spread all over my country and seriously hinders the development of the pear industry.

[0003] Pear ring rot is a fungal disease caused by Botryosphaeria dothidea (B.dothidea), which is the main pathogen causing ring rot. It usually invades through wounds or natural openings of plants, causing the disease. This disease not only weakens the growth of pear trees, but in severe cases may also cause fruit rot and even destroy orchards, causing huge economic losses to pear farmers and hindering the sustainable development of the pear industry. The occurrence of pear ring rot is closely related to environmental factors such as temperature, humidity, climatic conditions and the physiological conditions of pear trees themselves. The pathogen mainly invades the wounds or pruning cuts of pear trees and grows rapidly in a humid environment, forming irregular brown spots centered on the lenticels, which eventually lead to fruit rot. Botryosphaeria can attack 312 species of plants in 24 genera, including pome fruits (such as apples, pears, and hawthorns), stone fruits (such as peaches, plums, and apricots), berries (such as kiwis, pomegranates, and grapes), and trees (such as eucalyptus and locusts). Studies have shown that the pathogens that cause pear ring rot are very similar to those that cause apple ring rot. They release a large number of effectors during the infection process, which can weaken the plant's defense mechanism and enhance the pathogen's infectivity.

[0004] At present, the prevention and control measures for pear ring rot are mainly based on chemical control. Combined with the external spraying of pesticides for the prevention and control of other diseases, such as 50% carbendazim, 50% thiophanate-methyl and 70% mancozeb, they are used alternately. However, the use of chemical agents will not only cause irreversible harm to the environment, but also have a direct impact on human health. Long-term contact can easily lead to chronic or acute poisoning and increase the risk of cancer. Moreover, long-term excessive use or continuous use of a pesticide can easily lead to drug resistance. Therefore, a natural, non-toxic and highly effective fungicide is of great significance to resist pear ring rot and improve pear yield and quality.

[0005] As a naturally occurring compound, tyrosol is an environmentally friendly, natural antifungal agent that helps reduce the use of chemical pesticides. Compared with pesticides, tyrosol as a botanical fungicide is less likely to cause drug resistance in pathogens, which is very important for long-term disease management. Tyrosol can be made into different dosage forms, such as aqueous solution, powder, granule, etc., which is convenient for application in different agricultural production scenarios.

[0006] Tyrosol belongs to the phenol family and was originally derived from olive oil. Its molecular formula is C8H10O2 and its molecular weight is 138.164. CAS number: 501-94-0. Other names: p-hydroxyphenylethanol; English name: Tyrosol. Molecular structure:

[0007]

[0008] As a natural polyphenol compound, tyrosol has a variety of biological and pharmacological activities. Currently, tyrosol has received extensive attention in the medical field, and has a variety of physiological activities such as anti-oxidation, anti-inflammatory, anti-cancer, prevention of cardiovascular disease and neuroprotection. In the food field, it can be used as a food additive to improve flavor, etc.

[0009] There is currently no research or report on the use of tyrosol in resistance to pear ring rot at home and abroad. Summary of the invention

[0010] In view of the above problems, the present invention provides a method for preventing and controlling pear ring rot using tyrosol.

[0011] In order to achieve the above object, the present invention adopts the following technical solutions:

[0012] In a first aspect, the present invention claims the use of tyrosol in preventing and controlling pear ring rot or in preparing a fungicide for preventing and controlling pear ring rot. Further, the above-mentioned use is to prevent and control pear ring rot by spraying an aqueous solution of tyrosol exogenously.

[0013] In a second aspect, the present invention claims a method for preventing and controlling pear ring rot, using tyrosol to prevent and control pear ring rot. Further, the above method prevents and controls pear ring rot by spraying tyrosol aqueous solution exogenously.

[0014] In the technical solution of the present invention, the concentration of tyrosol in the tyrosol aqueous solution is 1-5 mg / ml, preferably 3-5 mg / ml, and most preferably 5 mg / ml. Further, the tyrosol aqueous solution also contains 0.5%-5% (v / v) Tween 80, preferably 0.5%-2% Tween 80.

[0015] Furthermore, the pear ring rot is a pear disease caused by Botrytis cinerea.

[0016] The invention uses in vitro antibacterial experiments and exogenous spraying of tyrosol solution to prove that tyrosol can inhibit the infection of ring rot bacteria.

[0017] Furthermore, the tyrosol substance required for the experiment was purchased from a biological company, and the B. dothidea strain required for the experiment was provided by the Pear Engineering Technology Research Center of Nanjing Agricultural University, with a conventional strain model of FJ-54.

[0018] During the research, the effective concentration range of the tyrosol aqueous solution was 0-5 mg / ml. The results showed that the inhibition of the mycelial growth of the pathogen of pear ring rot by the tyrosol was dose-dependent. When the concentration of the tyrosol solution was 5 mg / ml, the inhibition rate of the mycelial growth of the pathogen of pear ring rot by tyrosol reached 70.73%.

[0019] A detection method for preventing and controlling pear ring rot using tyrosol was developed. After exogenously spraying 5 mg / ml tyrosol aqueous solution on detached 'Dangshan' pear leaves and inoculating the ring rot pathogen, the diameter of the lesions was observed regularly.

[0020] In a specific embodiment of the present invention, the leaves of 'Dangshan' pear were inoculated with wounds in vitro by puncture method, and two bacterial cakes were attached to each leaf. Finally, the treated leaves were wrapped with cotton and the petioles were placed back on the tray and covered with black plastic bags and placed in a dark incubator with a temperature of 25°C and a humidity of 80%. A 5mm puncher was used to punch holes on the culture medium containing B. dothidea hyphae to obtain the inoculated bacterial cake. 25°C is the optimum temperature for the activity of the ring spot pathogen, and the disease is easy to occur at this temperature and the diameter of the lesions can be observed.

[0021] The present invention uses 'Dangshan' pear as experimental material, and through in vitro antibacterial experiments and ring spot pathogen inoculation experiments, it is proved that tyrosol has a significant inhibitory effect on pear ring spot pathogens, can effectively inhibit the development speed of ring spot pathogen spots, reduce the occurrence and spread of diseases, and thus reduce the infringement of ring spot pathogens on plant bodies. Tyrosol is a natural compound in plants with low toxicity. Applying it to the prevention and treatment of pear ring spot disease can enhance its own defense mechanism, improve its natural resistance to ring spot disease, and reduce or replace the use of chemical pesticides, thereby reducing potential risks to the environment and human health. As a natural plant fungicide, tyrosol pays more attention to green environmental protection and complies with the principles of organic agriculture, so it is expected to be more widely used in this field.

[0022] Beneficial effects of the present invention:

[0023] The present invention provides the use of tyrosol in preparing a fungicide for preventing and treating pear ring rot. In vitro antibacterial experiments and exogenous tyrosol spraying experiments prove that tyrosol has obvious resistance to ring rot fungi and can play an obvious role in a wide concentration range, so it is suitable for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 These are the results of the inhibition experiment on the mycelial growth of the ring rot pathogen with different concentrations of tyrosol on PDA medium.

[0025] Figure 2 The diameter measurement results of the inhibition experiment of different concentrations of tyrosol on the mycelium growth of ring rot fungus on PDA culture medium.

[0026] Figure 3 The figure shows the inhibitory effect of exogenous spraying of 5 mg / ml tyrosol on the ring rot lesions on the leaves of 'Dangshan' pear.

[0027] Figure 4 The results are the measurement results of the diameter of the ring rot spots on the leaves of 'Dangshan' pear after exogenous spraying of 5 mg / ml tyrosol.

[0028] Figure 5 SOD enzyme activity in 'Dangshan' pear leaves inoculated with ring rot for 6 days after tyrosol treatment.

[0029] Figure 6 POD enzyme activity in 'Dangshan' pear leaves inoculated with ring rot 6 days after tyrosol treatment.

[0030] Figure 7 CAT enzyme activity in 'Dangshan' pear leaves inoculated with ring rot for 6 days after tyrosol treatment.

[0031] Figure 8 OFR content of leaves of 'Dangshan' pear inoculated with ring rot 6 days after tyrosol treatment.

[0032] Fig. 9 These are the effects of tyrosol treatment on H2O2 content in 'Dangshan' pear leaves inoculated with ring rot 6 days ago. DETAILED DESCRIPTION

[0033] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods.

[0034] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0035] The tyrosol substance required for the experiment was purchased from a biological company, and the B. dothidea strain required for the experiment was a conventional strain provided by the Pear Engineering Technology Research Center of Nanjing Agricultural University, model FJ-54.

[0036] Set up eight concentrations of 0, 0.1, 0.5, 1, 2, 3, 4, and 5 mg / ml of tyrosol aqueous solution. Dissolve tyrosol in water and sterilize it with a 0.22 μm water filter in a clean bench. Add it to PDA medium to prepare PDA medium of different concentrations. Use a 5mm puncher to punch holes in the medium containing B. dothidea hyphae to obtain inoculated bacterial cakes. Cultivate in a dark incubator at 25°C and 80% humidity, and observe the growth of the colonies later.

[0037] Example 1 In vitro antibacterial experiment of tyrosol at different concentrations on ring rot pathogen.

[0038] The preparation method of potato dextrose agar (PDA) medium used for the culture and propagation of P. truncatula is as follows: 200 g peeled potato, 20 g glucose, 15 g agar, pH 5.8, distilled water to 1000 ml, sterilized at 121°C for 20 min, and set aside after cooling.

[0039] When the plate without tyrosol is almost full, take pictures and measure the growth diameter of mycelium to calculate the inhibition rate.

[0040] Inhibition rate (%) = (control new growth hyphae diameter - treatment new growth hyphae diameter) / control new growth hyphae diameter × 100. Each treatment was repeated five times.

[0041] The inhibitory effect of tyrosol on the mycelial growth of pear ring rot pathogen Figure 1 and Figure 2 As shown, when tyrosol is at 5 mg / ml, it can significantly inhibit the growth of pathogenic fungi. Table 1 summarizes the inhibition rate of tyrosol on the growth of plant pathogenic fungi. As shown in Table 1, when the concentration of tyrosol is 5 mg / ml, the inhibition rate of the growth of Botrytis cinerea mycelium reaches 70.73%, indicating that tyrosol has a significant inhibitory effect on Botrytis cinerea growing on PDA complete nutrient medium.

[0042] Table 1 Inhibition rate of tyrosol on the growth of mycelium of ring rot pathogen on solid culture medium

[0043]

[0044] Example 2: Exogenous spraying of tyrosol was used to detect the inhibitory effect of tyrosol on the pathogen of pear ring rot.

[0045] The leaves of Dangshan pear (Dang shan su li) were used as research materials, and leaves with uniform size, smooth surface and no damage were selected. First, the leaves were washed with distilled water, and the petioles that were too long were cut short to prevent the formation of gas emboli and affect the normal function of the duct. Then, the leaves were soaked in 0.1% sodium hypochlorite solution for 3 to 5 minutes to disinfect and remove microorganisms on the surface of the leaves. After disinfection, they were repeatedly rinsed with distilled water 3 to 5 times to ensure that the residual disinfectant was completely removed. After processing, the base of the leaves was covered with wet cotton and placed on a tray covered with wet gauze to keep the leaves moist.

[0046] Tyrosol was prepared into a 5 mg / ml aqueous solution, and 1% (v / v) Tween 80 was added and sprayed on the leaf surface. The spraying of water was used as the control group. The above leaves were inoculated with bacteria in vitro using the puncture method, and 2 bacterial cakes were attached to each leaf. Finally, the treated leaves were returned to the tray and covered with a black plastic bag and placed in a dark incubator with a temperature of 25°C and a humidity of 80%. The diameter of the lesions was measured at 0, 2, 4, 6, and 8 days.

[0047] After the leaves of Dangshan pear were treated with 5 mg / ml tyrosol aqueous solution and inoculated with the pathogen of ring rot, Figure 3 and Figure 4 As shown by the diameter of lesions, the lesions were significantly smaller than those in CK treatment.

[0048] The inhibition rate of exogenous spraying of 5 mg / ml tyrosol on the pathogen of pear ring rot was 23.35% on the eighth day.

[0049] A series of biochemical indices were measured on pear leaves inoculated with the pathogen of ring rot, including the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and the levels of hydrogen peroxide (H2O2) and superoxide anion (OFR). Figure 5-9 According to the data, 6 days after the leaves of the 'Dangshan' pear were inoculated with the ring rot pathogen, the activities of SOD, POD, and CAT increased significantly compared with the control group (CK), with increases of 31.98%, 59.79%, and 38.49%, respectively. At the same time, the levels of H2O2 and OFR decreased significantly compared with the control group, with decreases of 22.27% and 32.86%, respectively.

[0050] In summary, tyrosol improves the scavenging efficiency of hydrogen peroxide (H2O2) and superoxide anion (OFR) in pear trees when attacked by ring rot pathogens by enhancing the activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). This effect enhances the resistance of pear trees to ring rot pathogens and slows down the infection process of pathogens. Therefore, tyrosol has a significant effect on inhibiting the development of pear ring rot and can be used as an effective means to prevent and control pear ring rot.

Claims

1. Application of tyrosol in preventing and controlling pear ring rot or in preparing a fungicide for preventing and controlling pear ring rot.

2. The use according to claim 1, characterized in that: Pear ring rot was controlled by spraying tyrosol aqueous solution exogenously.

3. The use according to claim 2, characterized in that: The concentration of tyrosol in the tyrosol aqueous solution is 1-5 mg / ml; preferably, 3-5 mg / ml; most preferably, 5 mg / ml.

4. The use according to claim 3, characterized in that: The tyrosol aqueous solution also contains 0.5%-5% Tween80.

5. The use according to claim 1 or 2, characterized in that: The pear ring rot is a pear disease caused by Botrytis cinerea.

6. A method for preventing and controlling pear ring rot, characterized in that: Use tyrosol to control pear ring rot.

7. The method according to claim 6, characterized in that Pear ring rot was controlled by spraying tyrosol aqueous solution exogenously.

8. The method according to claim 7, characterized in that The concentration of tyrosol in the tyrosol aqueous solution is 1-5 mg / ml; preferably, 3-5 mg / ml; most preferably, 5 mg / ml.

9. The method according to claim 8, characterized in that The tyrosol aqueous solution also contains 0.5%-5% Tween80.

10. The method according to claim 6 or 7, characterized in that: The pear ring rot is a pear disease caused by Botrytis cinerea.

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