Application of nano silicon dioxide in relieving stress of tomato fusarium oxysporum

Abstract

The invention discloses application of nano silicon dioxide in relieving stress of tomato fusarium oxysporum. The invention finds that the nano silicon dioxide can relieve the stress effect of fusarium oxysporum on tomatoes, improve the biomass, photosynthesis capability, sugar content and the like of the tomatoes and promote the growth of the tomatoes. The invention provides the application of nano silicon dioxide in relieving the stress of fusarium oxysporum of tomatoes, and provides a new method for plant prevention and control; the nano silicon dioxide can promote the growth of tomatoes, and theoretical basis and guidance are provided for agricultural production.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and particularly relates to application of nano silicon dioxide in alleviating the stress of Fusarium oxysporum on tomatoes. Background Art

[0002] Tomato wilt is a common and most harmful soil-borne disease of tomatoes caused by the pathogenic fungus Fusarium oxysporuin f.sp.cubense (Foc), which seriously affects tomato production and causes huge economic losses. At present, chemical fungicides are still the main method for preventing and controlling Foc. However, the large-scale use of chemical pesticides will lead to the pollution of soil and water resources, which will eventually seriously endanger human health. At the same time, the long-term use of chemical pesticides will also cause drug resistance in Foc, reducing the control effect. Biological control that uses the interaction between populations to inhibit the growth of pathogens can continuously and effectively control diseases, greatly reduce environmental pollution, and has relatively low costs, so it has been widely promoted and applied.

[0003] Nano-silicon dioxide (SiO 2 NPs) as a kind of nanomaterials, due to its unique structure and physical and chemical properties, are gradually being used in agricultural production. Nano-silicon dioxide has a small particle size, a huge specific surface area, strong stability and adsorption, and is easily absorbed by plants through plant cell walls, so that plants can make full use of silicon to promote their own growth and development. Studies have found that when nano-silicon dioxide is absorbed by plants, it is easier to interact with macromolecules such as sugars and proteins under the action of surface activity, which can improve root vitality and rhizosphere soil enzyme activity, improve the plant's absorption and utilization rate of water, and then promote the plant's absorption and utilization of other nutrients, affecting the growth and development of plants. SiO 2 NPs mainly affect plants in the following two ways: First, SiO 2 NPs can change the original topological structure and hydrophobic properties of plant leaf surfaces, forming a special amphiphilic surface, blocking the highly specific supramolecular recognition process between fungal spores and host surfaces, and inhibiting the early infection process of fungal spores; secondly, as SiO 2 The Si element, the main component of NPs materials, can be absorbed and utilized by plants, and precipitate in different epidermal tissues of plants to form silicified cells, forming mechanical barriers to delay and hinder the invasion of pathogens. Exogenous silicon can significantly increase the activity of SOD, APX and GSH in kidney beans to reduce the harm of anthrax; exogenous silicon can significantly improve the resistance of cowpeas to rust. Suriyaprabha et al. found that nano-silicon dioxide (20-40nm) treatment significantly enhanced the resistance of corn to Fusarium oxysporum and Aspergillus niger, while nano-silicon dioxide (SiO 2The effect of NPs on tomato Fusarium wilt has not been reported. Summary of the invention

[0004] The purpose of the present invention is to provide a method for alleviating the stress damage of Fusarium oxysporum tomato by using nano-silicon dioxide, so as to solve the problems existing in the above-mentioned prior art. The present invention takes tomatoes with less Si accumulation as the research object, and explores the effects of different concentrations of nano-silicon dioxide (SiO 2 The mitigation effect of NPs on tomato seedlings under Fusarium oxysporum stress was studied to guide the correct cultivation techniques to cope with Fusarium oxysporum stress in production. The specific plan is as follows:

[0005] In a first aspect, the present invention provides an application of nano-silicon dioxide in preventing and controlling tomato diseases, wherein the nano-silicon dioxide has an inhibitory effect on tomato wilt caused by the tomato-specific form of Fusarium oxysporum.

[0006] In a second aspect, the present invention provides an application of nano-silicon dioxide in the preparation of a drug for preventing and controlling tomato diseases, wherein the tomato disease is tomato wilt caused by the tomato-specific type of Fusarium oxysporum.

[0007] In a third aspect, the present invention provides an application of nano-silicon dioxide in alleviating the stress of Fusarium oxysporum on tomatoes, and uses nano-silicon dioxide to treat tomatoes.

[0008] Preferably, the method for treating tomatoes is: spraying the nano-silicon dioxide solution to the front and back of tomato leaves to cover them with nano-silicon dioxide solution droplets, or applying 5-10 ml of the nano-silicon dioxide solution to the roots of tomatoes.

[0009] Preferably, the concentration of the nano-silicon dioxide solution is 50-200 mg / L.

[0010] In a fourth aspect, the present invention provides an application of nano-silica in alleviating the stress of Fusarium oxysporum in tomatoes, wherein the nano-silica prevents and controls tomato wilt through at least one of the following pathways A1) to A7):

[0011] A1) inhibit the growth of Fusarium oxysporum;

[0012] A2) Increase tomato biomass;

[0013] A3) Improve the vitality of tomato roots;

[0014] A4) Improve the photosynthesis capacity of tomatoes;

[0015] A5) Reduce the content of antioxidant substances SOD, POD, and CAT in tomatoes;

[0016] A6) Increase the content of soluble sugar, reducing sugar, fructose, sucrose and starch in tomatoes;

[0017] A7) Improve the resistance of tomatoes to Fusarium oxysporum.

[0018] In a fifth aspect, the present invention provides a method for alleviating the stress of Fusarium oxysporum on tomatoes using nano-silicon dioxide, spraying a nano-silicon dioxide solution to cover the front and back of tomato leaves with nano-silicon dioxide solution droplets, or applying 5-10 ml of the nano-silicon dioxide solution to the roots of tomatoes.

[0019] Beneficial effects:

[0020] 1. The present invention provides the use of nano-silicon dioxide in alleviating the stress of Fusarium oxysporum on tomatoes, providing a new method for plant control;

[0021] 2. Nano-silicon dioxide can promote the growth of tomatoes and provide a theoretical basis and guidance for agricultural production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The concentration of nano-silicon dioxide was screened by the PDA plate confrontation test in Example 2: A is a coarse screening of silicon concentration in the range of 100-500 mg / L, and B is a fine screening of silicon concentration in the range of 50-150 mg / L;

[0023] Figure 2 Statistics of the control index and disease index of tomato seedlings under the stress of Fusarium oxysporum by nano-silicon dioxide in Example 3: A is the control index, and B is the disease index;

[0024] Figure 3 The effect of nano-silicon dioxide on the root activity of tomato seedlings under the stress of Fusarium oxysporum in Example 5;

[0025] Figure 4 The effect of nano-silicon dioxide on soluble protein in tomato seedlings under the stress of Fusarium oxysporum in Example 8;

[0026] Figure 5 The effect of nano-silicon dioxide on the sugar content of tomato seedlings under the stress of Fusarium oxysporum in Example 8, wherein: A is the soluble sugar content, B is the reducing sugar content, C is the fructose content, and D is the sucrose content;

[0027] Figure 6 The effect of nano-silicon dioxide on starch content in tomato seedlings under the stress of Fusarium oxysporum in Example 8;

[0028] Figure 7 This is the effect of nano-silicon dioxide in Example 9 on trypan blue staining of tomatoes under Fusarium oxysporum stress. DETAILED DESCRIPTION

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0031] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0032] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0033] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0034] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0035] Embodiment 1:

[0036] 1. Materials and Methods

[0037] 1.1 Materials

[0038] The tomato variety was 'Zhongza 9', purchased from the Vegetable and Flower Research Institute of the Chinese Academy of Agricultural Sciences.

[0039] The source of Fusarium oxysporum was provided by the College of Plant Protection, Shanxi Agricultural University.

[0040] Nano-silicon dioxide (SiO 2 NPs) were purchased from Nanjing Xianfeng Nanomaterials Technology Co., Ltd. (particle size 20 nm, specific surface area 140.21 m 2 / g).

[0041] 1.2 Methods

[0042] The relevant experiments of the present invention were carried out in the Experimental Center and Horticultural Station of the College of Horticulture of Shanxi Agricultural University.

[0043] Select tomato seeds with full seeds and uniform size, sterilize them in 55℃ hot water for 15min, place them in a 28℃ constant temperature incubator and soak them for 6h, germinate them in a culture dish covered with double-layer filter paper, and keep them moist during the period; 48h later, sow the white seeds in a 72-hole seedling tray, water them with distilled water to maintain soil moisture, and when they have two leaves and one heart, plant the tomato seedlings in a 13×14cm nutrient pot, slow down the seedlings for 3 days, water them with distilled water once, and then water them with 1 / 4 times the Japanese Yamazaki tomato formula, gradually increasing to 1 times the nutrient solution. The cultivation medium was purchased from Changchun Zhuangmiao Peat Technology Co., Ltd. (total organic matter + total humic acid ≥50%). Water the seedlings with distilled water to maintain soil moisture during cultivation.

[0044] When the tomato seedlings grow to three leaves and one heart, select the seedlings with the same growth trend for treatment. The tomato seedlings are first pre-treated with silicon, and then inoculated 3 days later. The silicon application method is divided into spraying and root application: spraying to evenly cover the front and back of the tomato leaves with small droplets; root application to the roots of the tomato, 5mL each time. The concentration of Fusarium oxysporum liquid is 1×10 7 CFU / mL, inoculation was carried out by root immersion method: on a sunny afternoon, the roots of tomato seedlings were washed, the stem tips were cut off about 1 cm with scissors, and then immersed in 1×10 7 CFU / mL of Fusarium oxysporum solution for 20 minutes, and then plant the inoculated tomato seedlings in the substrate. Water once with 1x Yamazaki tomato formula nutrient solution (80 ml per plant) 1 day before treatment, and water once every 3 days.

[0045] The treatments of Examples 2-4 and 7 are shown in Table 1, with a total of 12 treatments (CK is a control treatment, Fo is an inoculation treatment, and T1-T10 are treatments with different concentrations of nano-silicon dioxide), and 20 tomato seedlings are repeated in each treatment; the treatments of Examples 5-6 and 8-9 are shown in Table 2, with a total of 4 treatments (CK is a control treatment, Si is a 100 mg / L nano-silicon dioxide treatment, Fo is an inoculation treatment, and Fo+Si is an inoculation + 100 mg / L nano-silicon dioxide treatment), and 20 tomato seedlings are repeated in each treatment.

[0046] Table 1 Experimental treatment of Examples 2-5

[0047]

[0048] Table 2 Experimental treatment of Examples 6-9

[0049]

[0050] 1.3 Cultivation of test materials

[0051] Potato agar medium (PDA): 200g potato (peeled), 20g glucose, 17.5g agar, dilute to 1000ml with water, sterilize at 115℃ for 20 minutes. PDB medium is PDA medium without agar.

[0052] Fusarium oxysporum inoculation: Fusarium oxysporum was activated and cultured on potato glucose medium (PDA medium). After culturing at 26°C for 5 days, 6 bacterial cakes were taken from the edge of the colony using a sterilized cork puncher (6 mm) and added to 200 mL of potato liquid medium. The culture was continued at 26°C and 200 r·min. -1 After the culture was completed, the bacterial solution was concentrated by centrifugation (10000 r / min -1 , 5min), remove the supernatant, and then resuspend the remaining bacterial solution in distilled water and count them using a hemocytometer. 7 CFU spores of Fusarium oxysporum were inoculated by root immersion method.

[0053] 1.4 Data Processing

[0054] The results of the present invention were statistically analyzed using SPSS 24.0 software, and the Duncan's method was used to perform multiple comparisons of the mean values ​​for the significance test of the differences between the data processing, and Microsoft Excel and Prism 9 were used to calculate the membership function, draw tables and plot. When P < 0.05, the difference was considered significant, and the data in the charts were all mean ± standard deviation.

[0055] Embodiment 2:

[0056] This example proves that nano-silicon dioxide can inhibit the growth of Fusarium oxysporum hyphae through a plate confrontation experiment.

[0057] The specific steps are as follows: add 400 μL of SiO 2NPs, spread evenly, wait for air drying, and then inoculate 3mm Fo bacterial cake. Incubate in a 28℃ constant temperature incubator for 6 days, take photos and record with an Olympus camera. Measure the horizontal and vertical diameters with a ruler and calculate the area. The above measurements were performed three times.

[0058] The results are as follows Figure 1 As shown, nano-silicon dioxide with concentrations of 100 mg / L, 200 mg / L, 300 mg / L, 400 mg / L, and 500 mg / L was added to the PDA plate for concentration coarse screening. The results are as follows Figure 1 As shown in A, the mycelial area of ​​Fusarium oxysporum under each concentration treatment was significantly different from that of CK. In the plate confrontation, compared with CK, the mycelial area of ​​100mg / L and 400mg / L nano-silicon dioxide treatments was significantly reduced, and the mycelial area of ​​200mg / L, 300mg / L and 500mg / L nano-silicon dioxide treatments had no significant change. This shows that the concentration of 100mg / L nano-silicon dioxide is a more suitable concentration.

[0059] In order to further evaluate the inhibitory effect of nano-silicon dioxide on Fusarium oxysporum, the present invention finely screened the concentration of nano-silicon dioxide, and the results were as follows: Figure 1 As shown in B. Under different concentrations of nano-silica culture, the mycelial area of ​​Fusarium oxysporum under each concentration treatment was significantly different from that of CK. In the plate confrontation, compared with CK, the mycelial area of ​​75 mg / L, 100 mg / L, 125 mg / L and 150 mg / L nano-silica treatments was significantly reduced, and there was no significant change in the mycelial area of ​​50 mg / L nano-silica treatment.

[0060] The above results show that nano-silica has an inhibitory effect on the growth of Fusarium oxysporum.

[0061] Embodiment 3:

[0062] This example proves that nano-silicon dioxide treatment can reduce the disease index of tomato wilt and improve the prevention and control index by grading the disease of tomatoes.

[0063] The specific steps are as follows: on the 16th day after inoculation with Fusarium oxysporum, when the tomato seedlings grew to 5-6 true leaves, disease index analysis was performed, the growth potential was observed and the incidence of each treatment was recorded, and the disease of tomato Fusarium wilt was graded according to the method of Shang (Shang S H. Micro-ecological mechanism of soil-borne tomato Fusarium wilt in the nitrogen-rich facilities cultivation soil [D]. Shenyang: Shenyang Agricultural University, 2016.). The disease grading standards are shown in Table 3.

[0064] Table 3 Disease classification of tomato plants

[0065]

[0066] The tomato Fusarium oxysporum Fo was inoculated only as the control group, and the tomato Fusarium oxysporum Fo was pretreated with nano-silicon dioxide and then inoculated as the treatment group. The disease index was calculated according to the method of Yang Zhengkun (Yang Zhengkun. Study on the resistance of cucumber to Fusarium wilt induced by exogenous silicon and its physiological mechanism [D]. Luoyang: Henan University of Science and Technology, 2022.). The calculation formulas for the disease index and control effect are as follows:

[0067] Disease index (%) = ∑ (number of plants at each disease level × corresponding disease level) / (total number of plants × highest representative level) * 100;

[0068] Control effect (%) = (control disease index - treatment disease index / control disease index) * 100.

[0069] The statistical results of disease index and control index are as follows: Figure 2 As shown, compared with Fo, the disease index of plants treated with different concentrations of nano-silica was significantly reduced; among them, the T8 treatment had the largest decrease of 41.94%, the lowest disease index, and the best mitigation effect on Fusarium oxysporum; the control index of plants treated with different concentrations of nano-silica had obvious differences, among which the T8 treatment had the highest control index of 41.54%.

[0070] The above results show that nano-silica treatment can reduce the disease index of tomato Fusarium wilt and improve the control index.

[0071] Embodiment 4:

[0072] This example treats tomatoes under Fusarium oxysporum stress by using nano-silicon dioxide at different concentrations, proving that nano-silicon dioxide can increase tomato biomass.

[0073] The specific steps are as follows: on the 16th day after the inoculation of Fusarium oxysporum, 5 tomato seedlings with uniform growth were randomly selected for each treatment, the plant height and stem diameter of the tomato were measured, each plant was separated from the stem base, divided into the aboveground part and the underground part, and the fresh weight was weighed respectively, and the seeds were dried in an oven at 105℃ for 15min, then adjusted to 60℃ and dried to constant weight, and the dry weight was weighed. The above measurements were biologically repeated 3 times.

[0074] The statistical results are shown in Table 4. Compared with CK, the plant height, stem diameter, fresh weight and dry weight of the aboveground part, and fresh weight and dry weight of the underground part of Fo tomato seedlings were significantly reduced by 35.74%, 4.27%, 37.63% and 42.73%, 42.5% and 50%, respectively. Compared with Fo, the growth potential of T8 tomato seedlings was significantly improved, among which the plant height, stem diameter, fresh weight and dry weight of the aboveground part, and fresh weight and dry weight of the underground part were significantly increased by 65.17%, 18.07%, 110.41%, 95.65%, 66.67% and 88.89%, respectively.

[0075] Table 4 Effects of different concentrations of nano-silica on the biomass of tomato seedlings under Fusarium oxysporum stress

[0076]

[0077] The above results show that under the stress of Fusarium oxysporum, the biomass of tomatoes is significantly reduced, and nano-silica can increase the biomass of tomatoes.

[0078] Embodiment 5:

[0079] When plants are under stress, the content of substances related to oxidation reactions will increase, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). This example provides the detection of antioxidant substances in tomatoes under the stress of Fusarium oxysporum.

[0080] The specific steps are as follows: malondialdehyde (MDA) content was determined by 2-thiobarbituric acid method (Shi Yu. Study on the mitigating effect and mechanism of exogenous silicon on water stress injury of tomato seedlings [D]. Xianyang: Northwest Agriculture and Forestry University, 2014.); superoxide anion was determined by hydroxylamine oxidation method (Shi Yu. Study on the mitigating effect and mechanism of exogenous silicon on water stress injury of tomato seedlings [D]. Xianyang: Northwest Agriculture and Forestry University, 2014.); enzyme solution extraction was performed according to the method of Gong et al. (Gong HJ, Zhu XY, Chen KM, et al. Silicon alleviates oxidative damage of wheat plants in pots underdrought [J]. Plant Science, 2005, 169 (2): 313-321.): 0.3 g of frozen sample was taken and 3 mL of pre-cooled sodium phosphate buffer (PBS, 0.05 mol·L -1 , pH 7.8), grind into a homogenate, transfer to a 10 mL centrifuge tube, and centrifuge at 4°C 9661×g for 20 min. The supernatant was used to determine the activities of SOD, POD, and CAT, where SOD activity was determined by NBT photoreduction method, POD activity was determined by guaiacol method, and CAT activity was determined by UV absorption method. All the above determinations were repeated three times.

[0081] The statistical results are shown in Table 5. Compared with CK, the root SOD activity of Fo treatment increased significantly by 114.40%. Compared with Fo, the root SOD activity of T1 and T5 treatments did not change significantly; T2-T4 and T8 treatments decreased significantly by 35.34%, 48.67%, 19.44% and 15.69%, respectively; T6, T7, T9 and T10 treatments increased significantly by 19.15%, 84.35%, 33.09% and 57.18%, respectively.

[0082] Compared with CK, the POD activity of the roots in the Fo treatment increased significantly by 56.86%. Compared with Fo, the POD activity of the T1-T10 treatments decreased significantly by 23.08%, 13.04%, 25.59%, 22.71%, 21.92%, 18.19%, 17.22%, 30.98%, 11.21% and 18.99%, respectively.

[0083] Compared with CK, the root CAT activity of Fo treatment did not change significantly. Compared with Fo, the CAT activity of T1-T10 treatments increased significantly by 33.36%, 30.71%, 21.92%, 25.66%, 37.14%, 28.49%, 57.78%, 36.77%, 23.58% and 125.82%, respectively.

[0084] Table 5 Effects of different concentrations of nano-silica on SOD, POD and CAT of tomato seedlings under Fusarium oxysporum stress

[0085]

[0086] The above results show that under the stress of Fusarium oxysporum, the activities of SOD, POD and CAT of tomatoes were significantly increased, while nano-silicon dioxide could reduce the activities of SOD, POD and CAT.

[0087] Embodiment 6:

[0088] This example demonstrates that nano-silicon dioxide can improve the root activity of tomato seedlings under Fusarium oxysporum stress.

[0089] The specific steps are as follows: Root activity was determined using the TTC staining method (Li Hesheng, Sun Qun, Zhao Shijie. Principles and Techniques of Plant Physiological and Biochemical Experiments [M]. Beijing: Higher Education Press. 2000), and the above measurements were performed with three biological replicates.

[0090] The results are as follows Figure 3 As shown in the figure, compared with CK, the root activity of tomato seedlings treated with Fo was significantly reduced by 24.53%. Compared with Fo, the root activity of tomato seedlings treated with Fo+Si was significantly increased by 33.88%. This indicates that the infection of Fusarium oxysporum will lead to a decrease in the root activity of tomato seedlings. After being alleviated by nano-silicon dioxide, the root activity of tomato seedlings was significantly improved.

[0091] The above results show that nano-silica can alleviate the stress of Fusarium oxysporum on tomatoes and improve the root activity of tomatoes.

[0092] Embodiment 7:

[0093] Plant diseases mainly weaken the photosynthetic capacity of plants by reducing the net photosynthetic rate and stomatal conductance of leaves. This example provides the detection of photosynthetic fluorescence characteristics of tomato seedlings under the stress of Fusarium oxysporum.

[0094] The specific steps are as follows: on the 16th day after the inoculation of Fusarium oxysporum, the second and third fully expanded functional leaves were taken and the chlorophyll content was determined using the 95% ethanol extraction method. After 2 hours of dark treatment at night on the 16th day of treatment, the chlorophyll fluorescence parameters of the second and third fully expanded functional leaves were measured using a portable photosynthetic meter (Li-6800, Beijing Ligaotai Technology Co., Ltd.). After the measurement was completed, the photosynthetic parameters were measured after 30 minutes of light activation. The parameters of the photosynthetic meter were set as follows: the light intensity was set to 350 μmol·m -2 ·s -1 , the flow rate was set to 500 μmol·s -1 , the relative humidity of the air was set to 50%, CO 2The concentration is 400 μmol·mol -1 The above measurements were performed with 5 biological replicates.

[0095] The test results are shown in Table 6. Compared with CK, Si has a lower net photosynthetic rate, transpiration rate, and intercellular CO 2 The concentration and stomatal limitation value of Fo increased significantly, by 3.69%, 12.07%, 1.33% and 5.13% respectively; the net photosynthetic rate, transpiration rate, stomatal conductance, instantaneous water use efficiency and stomatal limitation value of Fo decreased significantly, by 49.23%, 29.06%, 39.13%, 28.43% and 10.26% respectively. 2 Compared with Fo, the net photosynthetic rate, transpiration rate, stomatal conductance, instantaneous water use efficiency and stomatal limitation value of Fo+Si were significantly increased by 72.85%, 30.90%, 35.71%, 32.06% and 8.57%, respectively. 2 The concentration decreased by 8.56%.

[0096] The above results show that when there is no Fusarium oxysporum stress, nano-silica can improve the photosynthesis capacity of tomatoes, and when there is Fusarium oxysporum stress, nano-silica can restore the photosynthesis capacity of tomatoes.

[0097] Table 6 Effects of nano-silicon dioxide on photosynthetic parameters of tomato seedlings under Fusarium oxysporum stress

[0098]

[0099] The above results show that under the stress of Fusarium oxysporum, the photosynthetic capacity of tomatoes is significantly reduced, and nano-silica can restore the photosynthetic capacity of tomatoes.

[0100] Embodiment 8:

[0101] When plants are under stress, the hydrolytic enzymes with enhanced activity hydrolyze starch into sucrose, soluble sugars and other substances that have the function of regulating cell osmotic potential. This example provides the detection of soluble protein and non-structural carbohydrate content.

[0102] The specific steps are: testing the roots, new leaves (the 2nd and 3rd fully expanded functional leaves), and old leaves (the 2nd and 3rd fully expanded functional leaves from the bottom) of tomatoes. The soluble protein content was determined by Coomassie Brilliant Blue G-250 (Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding [J]. Analytical biochemistry, 1976, 72 (1-2): 248-254.), the soluble sugar content was determined by anthrone colorimetry (Zhang Yuanbo. Effects of exogenous silicon on resistance, yield and quality of tomato plants under low temperature stress at seedling stage [D]. Jinzhong: Shanxi Agricultural University, 2022.), the fructose and sucrose contents were determined by resorcinol method (Chen Xiuyu. Study on the effect of exogenous trehalose on sugar metabolism of tomatoes under salt stress [D]. Tianjin: Tianjin University, 2019.), and the starch content was determined by perchloric acid method (Chen Xiuyu. Study on the effect of exogenous trehalose on sugar metabolism of tomatoes under salt stress [D]. Tianjin: Tianjin University, 2019.). All the above determinations were repeated three times.

[0103] Effects of nano-silica on soluble protein in tomato seedlings under Fusarium oxysporum stress Figure 4 As shown in the figure, compared with CK, the soluble protein content of old leaves in Si treatment decreased significantly by 20.56%, and the soluble protein content of old leaves in Fo treatment decreased significantly by 19.94%. Compared with Fo, the soluble protein content of old leaves in Fo+Si treatment increased significantly by 12.78%.

[0104] Effects of nano-silicon dioxide on sugar content in tomato seedlings under Fusarium oxysporum stress Figure 5 shown. Figure 5 A is the soluble sugar test result. Compared with CK, the soluble sugar content of new leaves and old leaves in Fo treatment decreased significantly, by 12.72% and 22.32%, respectively. Compared with Fo, the soluble sugar content of new leaves, old leaves and roots in Fo+Si treatment increased significantly, by 57.04%, 95.55% and 10.40%, respectively. Figure 5 B is the reducing sugar test result. Compared with CK, the reducing sugar content of new leaves and old leaves treated with Fo decreased significantly, by 67.96% and 51.51%, respectively. Compared with Fo, the reducing sugar content of new leaves, old leaves and roots treated with Fo+Si increased significantly, by 131.46%, 152.82% and 29.15%, respectively. Figure 5C is the fructose detection result. Compared with CK, the fructose content of new and old leaves in Fo treatment decreased significantly, by 18.91% and 64.14%, respectively. Compared with Fo, the fructose content of new and old leaves in Fo+Si treatment increased significantly, by 48.88% and 155.77%, respectively. Figure 5 D is the sucrose test result. Compared with CK, the sucrose content of new leaves and roots in Si treatment increased significantly by 9.40% and 15.31%, respectively; the sucrose content of new leaves and old leaves in Fo treatment decreased significantly by 6.49% and 24.05%, respectively. Compared with Fo, the sucrose content of new leaves and old leaves in Fo+Si treatment increased significantly by 33.98% and 47.69%, respectively.

[0105] Effects of nano-silicon dioxide on starch content in tomato seedlings under Fusarium oxysporum stress Figure 6 As shown in the figure, compared with CK, the starch content of new leaves, old leaves and roots in Si treatment increased significantly by 9.62%, 23.24% and 26.14%, respectively; the starch content of new leaves, old leaves and roots in Fo treatment decreased significantly by 29.90%, 25.96% and 25.82%, respectively. Compared with Fo, the starch content of new leaves, old leaves and roots in Fo+Si treatment increased significantly by 41.72%, 20.43% and 96.99%, respectively.

[0106] The above results show that Fusarium oxysporum stress significantly reduced the soluble sugar, reducing sugar, fructose, sucrose and starch content of tomatoes, and nano-silicon dioxide can increase the soluble sugar, reducing sugar, fructose, sucrose and starch content of tomatoes.

[0107] Embodiment 9:

[0108] Leaves play a vital role in the growth and reproduction of plants. They are responsible for not only carrying water, but also completing the transport of substances and photosynthesis, and are also involved in cell metabolism and internal regulation. This example provides a trypan blue staining test for tomato leaves.

[0109] The specific steps are: put the leaves to be stained into a beaker, add the freshly prepared trypan blue dye solution, and dye for 3-5 minutes at room temperature; take out the leaves for observation, the living cells of the leaves are not colored and maintain normal shape, and the dead cells of the leaves are light blue and swollen.

[0110] Effects of nano-silicon dioxide on trypan blue staining of tomato seedlings under Fusarium oxysporum stress Figure 7As shown in the figure, there was no significant difference in tomato seedlings after trypan blue staining between Si and CK; there were more black spots on the leaves of tomato seedlings treated with Fo after trypan blue staining, which were the infection sites of Fusarium oxysporum, indicating that Fo caused greater damage to tomato leaves. Compared with Fo, the number of black spots on the leaves of tomato seedlings treated with Fo+Si after trypan blue staining was significantly reduced, indicating that Si reduced the damage of Fo to tomato leaves.

[0111] The above results show that nano-silica can improve the resistance of tomatoes to Fusarium oxysporum and alleviate the stress of Fusarium oxysporum on tomatoes.

[0112] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. The application of nano-silicon dioxide in preventing and controlling tomato diseases is characterized by: The nano silicon dioxide has an inhibitory effect on tomato wilt caused by the tomato-specific type of Fusarium oxysporum.

2. The application of nano-silicon dioxide in the preparation of drugs for preventing and controlling tomato diseases is characterized in that: The tomato disease is tomato wilt caused by the tomato-specific type of Fusarium oxysporum.

3. The application of nano-silicon dioxide in alleviating the stress of Fusarium oxysporum on tomatoes is characterized in that: Treating tomatoes with nanosilica.

4. The use according to claim 3, characterized in that: The method for treating tomatoes comprises: spraying the nano-silicon dioxide solution to the front and back sides of tomato leaves to cover the nano-silicon dioxide solution droplets, or applying 5-10 ml of the nano-silicon dioxide solution to the roots of tomatoes.

5. The use according to claim 4, characterized in that: The concentration of the nano silicon dioxide solution is 50-200 mg / L.

6. Application of nano-silicon dioxide in alleviating the stress of Fusarium oxysporum on tomatoes, characterized in that: The nano silicon dioxide prevents and controls tomato wilt by at least one of the following pathways A1) to A7): A1) inhibit the growth of Fusarium oxysporum; A2) Increase tomato biomass; A3) Improve the vitality of tomato roots; A4) Improve the photosynthesis capacity of tomatoes; A5) Reduce the content of antioxidant substances SOD, POD, and CAT in tomatoes; A6) Increase the content of soluble sugar, reducing sugar, fructose, sucrose and starch in tomatoes; A7) Improve the resistance of tomatoes to Fusarium oxysporum.

7. A method for alleviating tomato Fusarium oxysporum stress using nano-silicon dioxide, characterized in that: Spray the nano-silica solution until the front and back of the tomato leaves are covered with nano-silica solution droplets, or apply 5-10 ml of nano-silica solution to the roots of the tomatoes.

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