A method for controlling low temperature stress of tomatoes based on nano-copper sulfide

Abstract

The application discloses a method for controlling low-temperature stress of tomatoes based on nano copper sulfide, and belongs to the technical field of novel cold resistance. The application prepares copper sulfide nanoparticles, and uses the copper sulfide nanoparticles to promote the low-temperature stress resistance of tomatoes. The application controls the low-temperature stress of tomatoes by foliar application of CuS NPs, so that the plant height of the tomatoes under low-temperature stress is increased by 14.96%, and the fresh weight of the aboveground part and the fresh weight of the underground part are respectively increased by 32.21% and 64.37%. The prepared copper sulfide nanoparticles are superior to conventional copper-based materials, sulfur-based materials, traditional cold resistance agents and other sulfur-based nanoparticles in effect.

Description

TECHNICAL FIELD

[0001] The application relates to a method for controlling low-temperature stress of tomatoes based on nanometer copper sulfide, and belongs to the technical field of novel cold resistance. BACKGROUND

[0002] With the rapid increase of global population, the demand for crop yield is expected to increase by 50-80% by 2050. How to ensure the realization of this goal is a major challenge facing mankind. In recent years, the frequent occurrence of global extreme climate has brought serious threat to crop growth and yield. Among them, the yield reduction of crops caused by low-temperature freezing disaster accounts for more than 30% of the yield reduction of crops caused by extreme climate, and the trend of increasing frequency and increasing range is increasing.

[0003] With the rapid development of nanotechnology, nanomaterials with high chemical activity and biological effectiveness have shown great application potential in controlling crop cold damage. However, current research on nanomaterials for controlling crop diseases mainly focuses on silver-based nanomaterials. Compared with traditional cold resistance agents, silver-based nanomaterials show better performance in controlling crop cold damage, but the price of silver is high, and the enrichment of silver is harmful to the environment, which is still not suitable for long-term use.

[0004] Therefore, it is of great significance to develop an efficient and safe crop cold resistance agent to cope with the increasingly severe low-temperature stress. SUMMARY

[0005] To solve the above problems, the application prepares copper sulfide nanoparticles, and uses the copper sulfide nanoparticles to promote the low-temperature stress resistance of tomatoes. The application detects the optimal application mode and optimal application concentration of nanometer copper sulfide for controlling low-temperature stress of tomatoes, and compares the effects of different sulfur-based nanomaterials on controlling crop cold damage.

[0006] An object of the application is to provide a method for promoting the low-temperature stress resistance of tomatoes, which uses copper sulfide nanoparticles to treat tomato seeds or uses copper sulfide nanoparticles to treat tomato leaves.

[0007] Preferably, the method for promoting the low-temperature stress resistance of tomatoes uses copper sulfide nanoparticles to treat tomato leaves.

[0008] In one embodiment, in the treatment of tomato seeds with copper sulfide nanoparticles, the concentration of copper sulfide nanoparticles is 20-200 mg / kg of tomato seeds.

[0009] Preferably, the concentration of copper sulfide nanoparticles is 50-100 mg / kg of tomato seeds.

[0010] In one embodiment, the seed treatment of tomato seeds with copper sulfide nanoparticles is that copper sulfide nanoparticles are wetted with water to obtain wetted copper sulfide nanoparticles; the wetted copper sulfide nanoparticles are mixed with tomato seeds, and after shaking to make copper sulfide nanoparticles (NPs) uniformly adhere to each seed, the seeds are sown.

[0011] In one embodiment, the leaf treatment of tomato leaves with copper sulfide nanoparticles is that the concentration of copper sulfide nanoparticles is 20-200 mg / L, the spraying amount is 4-6 mL / plant / day, and the spraying is continuously performed for 4-6 days.

[0012] Preferably, the concentration of copper sulfide nanoparticles is 200 mg / L, the spraying amount is 5 mL / plant / day, and the spraying is continuously performed for 5 days.

[0013] In one embodiment, the preparation method of copper sulfide nanoparticles is as follows:

[0014] (1) Copper chloride ethanol solution is added to thioacetamide ethanol solution, and ultrasonic treatment and standing are performed;

[0015] (2) After standing, the upper supernatant is mixed with water, and stirring reaction is performed; after reaction, cooling, centrifugation, washing, and drying are performed to obtain copper sulfide nanoparticles.

[0016] In one embodiment, in step (1), the mass ratio of copper chloride to thioacetamide is 1-1.5:1-2; the volume ratio of copper chloride ethanol solution to thioacetamide ethanol solution is 120-160:180-210.

[0017] Preferably, the mass ratio of copper chloride to thioacetamide is 1.22:1.60; the volume ratio of copper chloride ethanol solution to thioacetamide ethanol solution is 150:200.

[0018] In one embodiment, in step (1), the copper chloride ethanol solution is added to the thioacetamide ethanol solution at a rate of 1-3 mL / s.

[0019] Preferably, the copper chloride ethanol solution is added to the thioacetamide ethanol solution at a rate of 2 mL / s.

[0020] In one embodiment, in step (2), the volume ratio of the upper supernatant to water is 200-300:200-300.

[0021] Preferably, the volume ratio of the upper supernatant to water is 300:300.

[0022] In one embodiment, in step (2), the stirring reaction is performed at 35-45°C for 0.5-1 h.

[0023] Preferably, the stirring reaction is performed at 40°C for 0.5 h.

[0024] The two objects of the present application are to provide the application of any of the above methods in the field of agriculture.

[0025] The present application also provides zinc sulfide nanoparticles (ZnS NPs) and molybdenum disulfide nanoparticles (MoS2 NPs) in a method for promoting tomato resistance to low temperature stress, comprising the step of: using zinc sulfide nanoparticles (ZnS NPs) or molybdenum disulfide nanoparticles (MoS2 NPs) to treat tomato leaves.

[0026] Advantages of the present application

[0027] The present application promotes tomato resistance to low temperature stress by preparing copper sulfide nanoparticles and using copper sulfide nanoparticles; the optimal application method and optimal application concentration of nano-copper sulfide for controlling tomato low temperature stress are detected, and the effects of different sulfur-based nanomaterials for controlling crop cold damage are compared.

[0028] Specifically,

[0029] (1) The effect of the present application on controlling tomato low temperature stress by foliar application of CuS NPs is better than seed dressing treatment; 200mg / L is the optimal application concentration of CuS NPs for controlling tomato low temperature stress by foliar application;

[0030] (2) The effect of the copper sulfide nanoparticles prepared by the present application is better than that of conventional copper-based materials (CuSO4, CuCl2), sulfur-based materials (Na2SO4), traditional cold-resistant agents and other sulfur-based nanoparticles (ZnS NPs, MoS2 NPs);

[0031] (3) The foliar application of the copper sulfide nanoparticles prepared by the present application (200mg / L) increases the plant height of low temperature stress tomato by 14.96%, and the fresh weight of the aboveground part and the underground part increases by 32.21% and 64.37%, respectively. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 TEM and XRD graphs of different nanoparticles; wherein, A is the TEM picture of CuS NPs; B is the TEM photo of CuS BPs; C is the TEM photo of MoS2 NPs; D is the TEM photo of ZnS NPs; E is the XRD spectrum of CuS NPs, CuS BPs, MoS2 NPs and ZnS NPs.

[0033] Figure 2 The effects of seed dressing treatment and foliar application of different concentrations of CuS NPs on the plant height (A) and aboveground and underground biomass (B) of low temperature stress tomato; wherein, D20, D50, D100, D200 are seed dressing treatments, and S20, S50, S100, S200 are foliar application treatments.

[0034] Figure 3 Effect of foliar application of 200 mg / L CuS NPs, CuS BPs, CuCl2, Na2SO4, CuSO4 and anti-cold agent on the plant height (A) and aboveground and underground biomass (B) of tomato under low temperature stress.

[0035] Figure 4 Effect of foliar application of 200 mg / L CuS NPs, ZnS NPs and MoS2 NPs on the plant height (A) and aboveground and underground biomass (B) of tomato under low temperature stress.

[0036] Figure 5 Photos of the effect of foliar application of 200 mg / L CuS NPs on the aboveground and underground of tomato under low temperature stress. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present application are described below, and it should be understood that the embodiments are used to better explain the present application, and are not used to limit the present application.

[0038] Raw materials used in the embodiments:

[0039] CuS BPs, CuCl2, thioacetamide, ZnCl2, Na2Mo04 and glutathione were purchased from Sigma Reagent Co.

[0040] Example 1: Preparation of copper sulfide nanoparticles

[0041] The copper sulfide nanoparticles were prepared by the following steps:

[0042] (1) 1.22 g of CuCl2 was weighed in a beaker, and 150 mL of anhydrous ethanol was added to ultrasonically disperse to obtain a blue and clear copper chloride ethanol solution; 1.60 g of thioacetamide (TAA) was weighed in a beaker, and 200 mL of anhydrous ethanol was added to ultrasonically disperse to obtain a colorless and transparent TAA ethanol solution;

[0043] (2) The copper chloride solution was added to the TAA solution at a speed of 2 mL / s and ultrasonically dispersed for 10 min, and the solution changed from yellow-brown to light yellow emulsion, and was left to stand for 8 h; after standing, the solution was layered, the upper layer was light yellow supernatant, and the lower layer was a large amount of light yellow flocculent;

[0044] (3) Take 300 mL of light yellow supernatant and add it to 300 mL of ultrapure water at a speed of 2 mL / s under stirring conditions. The beaker wall becomes hot and a large number of bubbles are generated in the solution. The solution becomes a brown suspension. Stir the solution at 40°C for 0.5 h. The solution becomes dark green. Centrifuge the dark green solution at 15000 rpm after the solution temperature drops to room temperature. Wash with anhydrous ethanol and ultrapure water several times, and then dry in a vacuum drying oven at 40°C to obtain a black solid, which is copper sulfide nanoparticles (CuS NPs).

[0045] Comparative Example 1: Preparation of zinc sulfide nanoparticles

[0046] Zinc sulfide nanoparticles are prepared as follows:

[0047] (1) Weigh 1.28 g of ZnCl2 in a beaker, add 200 mL of anhydrous ethanol and ultrasonically disperse to obtain a colorless, clear and transparent zinc chloride ethanol solution. Weigh 1.60 g of TAA in a beaker, add 200 mL of anhydrous ethanol and ultrasonically disperse to obtain a colorless and transparent TAA ethanol solution.

[0048] (2) Slowly add the zinc chloride solution to the TAA solution and ultrasonically for 10 min. The solution is a colorless transparent solution. Stand for 8 h to obtain a zinc sulfide precursor solution. A small amount of white precipitate is generated at the bottom of the standing beaker. This precursor can stably exist in the ethanol solution under sealed conditions.

[0049] (3) Take 300 mL of the supernatant of the precursor and slowly add it to 300 mL of secondary water under stirring conditions. The beaker wall becomes hot and bubbles are generated in the solution. Stir at 40°C for 9 h. The clear and transparent solution becomes a white hydrosol. Centrifuge at 15000 rpm, wash with anhydrous ethanol and distilled water, and dry to obtain a white solid, which is zinc sulfide nanoparticles (ZnS NPs).

[0050] Comparative Example 2: Preparation of molybdenum disulfide nanoparticles

[0051] Molybdenum disulfide nanoparticles are prepared as follows:

[0052] Dissolve 0.1 g of Na2Mo04 in 10 mL of ultrapure water, adjust the pH value to 6.5 with HCl (0.1 mol / L, 40 μL), and then add glutathione (0.172 g) and ultrapure water (20 mL) under stirring;

[0053] Mix the mixture for 5 min and transfer it to a reaction kettle. Heat at 200°C for 12 h. After natural cooling to room temperature and centrifugation for 10 min, collect the supernatant. Finally, pass the above supernatant through a 0.22 μM microporous filter membrane. The filtered liquid is dried to obtain a black solid, which is molybdenum disulfide nanoparticles (MoS2 NPs).

[0054] CuS NPs, ZnS NPs, MoS2 NPs prepared from Example 1, Comparative Example 1, Comparative Example 2 and CuS BPs purchased were characterized by transmission electron microscopy and XRD, and the results are shown in Figure 1 .

[0055] The results show that the particle size of CuS NPs, ZnS and MoS2 NPs is about 10 nm, and the particle size of CuS BPs is about 1 μm; the XRD results show that CuS NPs and CuS BPs both have CuS characteristic peaks, ZnS NPs have ZnS characteristic peaks, and MoS2 NPs have MoS2 characteristic peaks.

[0056] Example 2: Copper sulfide nanoparticles control low temperature stress of tomato

[0057] 1. Detect the effects of different concentrations and ways of copper sulfide on the resistance of tomato to low temperature stress.

[0058] The experimental groups are as follows: healthy control group (Healthy control), low temperature control group (Cold control), seed dressing treatment group, including: 20, 50, 100 and 200 mg / kg seed CuS NPs, leaf application treatment group, including: 20, 50, 100 and 200 mg / L CuS NPs aqueous solution.

[0059] The healthy control is not subjected to low temperature treatment, but the same amount of ultrapure water is applied to the leaf and CuS NPs treatment; the low temperature control group is subjected to low temperature treatment, and the same amount of ultrapure water is applied to the leaf and CuS NPs treatment.

[0060] Seed dressing treatment group: tomato seeds (Hezuo 903) were soaked in warm water for 4 h, then dried in the dark; NPs were weighed according to a certain mass ratio (NPs / seed), and 20 μL of water was used to wet the NPs; then the wet NPs powder was mixed with the tomato seeds and placed in a 170 rpm shaker for 30 min, until the NPs were evenly attached to each seed, and then the seeds were sown.

[0061] Leaf application treatment group: after the tomato was sown for 6 weeks, the first leaf application was started, i.e. the NPs solution of the corresponding concentration was ultrasonically dispersed for 30 min, and then uniformly sprayed on the tomato leaves, 5 mL per plant per day, and continuously sprayed for 5 days; then the plants were moved to a low temperature environment (10°C) for one week, and then moved to a normal environment temperature for one week before harvesting.

[0062] The results are shown in Figure 2As shown in Fig. 2, the results showed that, compared with the healthy control group, the plant height, aboveground fresh weight and underground fresh weight of the low temperature exposure control group were significantly decreased. Seed dressing treatment and foliar application treatment could increase the plant height, aboveground fresh weight and underground fresh weight of the low temperature stressed tomato to a certain extent, among which, the seed dressing treatment D100 (100 mg / L CuS NPs) was better, and the seed dressing treatment D200 (200 mg / L CuS NPs) was worse; the foliar application treatment S200 (200 mg / L CuS NPs) showed the best effect, which was significantly better than the low temperature exposure control group.

[0063] Therefore, the foliar application treatment was the optimal application mode of CuS NPs for enhancing the resistance of tomato to low temperature stress, and 200 mg / L was the optimal application concentration of CuS NPs for controlling the low temperature stress of tomato.

[0064] 2. Detection of the effect of different copper-based materials on the resistance of tomato to low temperature stress

[0065] The 200 mg / L CuS NPs, the same amount of CuS BPs, the same amount of CuCl2, the same amount of Na2SO4, the same amount of CuSO4 and the agricultural guidance concentration of traditional cold-resistant agent in the foliar application treatment were applied to the tomato by foliar spraying, and the experimental process was consistent with that of Example 1.

[0066] The results are shown in Fig. 3. Figure 3 As shown in Fig. 3, the results showed that, among the plant height, the foliar application of 200 mg / L CuS NPs significantly increased the plant height of the low temperature stressed tomato by 11.05%; among the aboveground fresh weight, the foliar application of CuS NPs, CuS BPs, Na2SO4 and the cold-resistant agent all significantly increased the biomass of the low temperature stressed tomato, and CuS NPs showed the best effect, which significantly increased the aboveground fresh weight of the low temperature stressed tomato by 32.33%; and among the underground fresh weight, the foliar application of CuS NPs also showed the best effect, which significantly increased the underground fresh weight of the low temperature stressed tomato by 63.01%.

[0067] In summary, the foliar application of 200 mg / L CuS NPs showed the best effect in relieving the low temperature stress of tomato, and was significantly better than the control effect of other copper-based materials and traditional cold-resistant agents.

[0068] 3. Detection of the effect of different sulfur-based nanomaterials on the resistance of tomato to low temperature stress

[0069] The CuS NPs, ZnS NPs and MoS2 NPs prepared in Example 1, Comparative Example 1 and Comparative Example 2 were detected for their effects on the resistance of tomato to low temperature stress.

[0070] The 200 mg / L CuS NPs, ZnS NPs and MoS2 NPs in the foliar application treatment were applied to the tomato by foliar spraying, and the experimental process was consistent with that of Example 1.

[0071] Plant height, fresh weight and results are as follows Figure 4 The tomato plant photo is shown in Figure 5 As shown, the results showed that in terms of plant height, foliar application of 200 mg / L CuS NPs, ZnS NPs and MoS2 NPs increased the plant height of low-temperature tomatoes by 14.96%, 3.67% and 6.58%, respectively, among which CuS NPs performed the best; in terms of aboveground fresh weight, foliar application of CuS NPs, ZnS NPs and MoS2 NPs significantly increased the aboveground fresh weight of low-temperature tomatoes by 32.21%, 25.17% and 27.23%; in terms of underground fresh weight, foliar application of CuS NPs and MoS2 NPs significantly increased the underground fresh weight of low-temperature tomatoes by 64.37% and 43.68%.

[0072] The above results showed that compared with other sulfur-based nanomaterials, foliar application of 200 mg / L CuS NPs had the best effect in alleviating low temperature stress in tomatoes.

[0073] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method of promoting tolerance to low temperature stress in tomato, characterized in that, Tomato seeds are treated with copper sulfide nanoparticles by seed dressing, or tomato leaves are treated with copper sulfide nanoparticles by foliar spraying; In the seed dressing of tomato seeds with copper sulfide nanoparticles, the concentration of copper sulfide nanoparticles is 50-100 mg / kg of tomato seeds. In the foliar spraying of tomato leaves with copper sulfide nanoparticles, the concentration of copper sulfide nanoparticles is 200 mg / L, the spraying amount is 4-6 mL / plant / day, and the spraying is continuous for 4-6 days. The preparation method of the copper sulfide nanoparticles is as follows: (1) adding copper chloride ethanol solution into thioacetamide ethanol solution, ultrasonic treatment, and standing; (2) mixing the supernatant with water after standing, stirring and reacting; and cooling, centrifuging, washing, and drying after the reaction to obtain copper sulfide nanoparticles.

2. The method of claim 1, wherein, In the seed dressing of tomato seeds with copper sulfide nanoparticles, the wet copper sulfide nanoparticles are obtained by wetting copper sulfide nanoparticles with water; the wet copper sulfide nanoparticles are mixed with tomato seeds, and after oscillation until the copper sulfide nanoparticles are uniformly attached to each seed, the seeds are sowed.

3. The method of claim 1, wherein, In the foliar spraying of tomato leaves with copper sulfide nanoparticles, the concentration of copper sulfide nanoparticles is 200 mg / L, the spraying amount is 5 mL / plant / day, and the spraying is continuous for 5 days.

4. The method of claim 1, wherein, In step (1), the mass ratio of copper chloride to thioacetamide is 1-1.5:1-2; and the volume ratio of copper chloride ethanol solution to thioacetamide ethanol solution is 120-160:180-210.

5. The method of claim 4, wherein, The mass ratio of copper chloride to thioacetamide is 1.22:1.60; and the volume ratio of copper chloride ethanol solution to thioacetamide ethanol solution is 150:

200.

6. The method of claim 1, wherein, In step (1), the copper chloride ethanol solution is added into the thioacetamide ethanol solution at a rate of 1-3 mL / s.

7. The method of claim 6, wherein, The copper chloride ethanol solution is added into the thioacetamide ethanol solution at a rate of 2 mL / s.

8. The method of claim 1, wherein, In step (2), the volume ratio of the supernatant to water is 200-300:200-300.

9. The method of claim 8, wherein, The volume ratio of the supernatant to water is 300:

300.

10. The method of claim 1, wherein, In step (2), the stirring and reaction is carried out at 35-45 ℃ for 0.5-1 h.

11. The method of claim 10, wherein, The stirring and reaction is carried out at 40 ℃ for 0.5 h.

12. Use of the method of any one of claims 1-11 in the field of agriculture.

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