CN106937645A - Nano magnesia as tobacco Ralstonia solanacearum antiseptic application - Google Patents

Abstract

The invention relates to the application of nano-magnesium oxide as an antibacterial agent for Ralstonia solanacearum (Ralstonia solanacearum), and the nano-magnesium oxide provides a method for preventing and treating tobacco bacterial wilt as an antibacterial agent for Ralstonia solanacearum. The new approach shows a high-efficiency bactericidal effect on Ralstonia solanacearum (Ralstonia solanacearum) in a short period of time in various media. Further, magnesium oxide is a magnesium supplement, which is non-toxic and safe for the environment. At the same time, low-concentration nano-magnesium oxide can quickly cause the death of R. solanacearum, with high precision and quick effect, and it is not easy to cause drug resistance in tobacco and avoid problems such as excessive pesticide residues.

Description

Application of nano-magnesium oxide as an antibacterial agent for Ralstia solanacearum

technical field

The invention belongs to the technical field of fungicide prevention and control, and relates to the application of nano magnesium oxide as an antibacterial agent, in particular to the application of nano magnesium oxide as an antibacterial agent for Ralstonia solanacearum.

Background technique

Tobacco is one of the important economic crops in my country. The planting area and total output both rank first in the world. The development of high-quality tobacco leaves is very important to both tobacco farmers and the cigarette industry. Tobacco leaves are the main harvesting organ. With the extension of continuous cropping years and the change of tobacco varieties, the types of tobacco diseases are increasing day by day. Among them, tobacco bacterial wilt, also known as "smoke plague", is a typical vascular disease that can damage roots, stems, and leaves. In severe cases, it can cause the entire field of tobacco to die, bringing huge economic losses to tobacco farmers.

At present, the main measures for the control of R. solanacearum include physical control, improvement of cultivation management, selection of resistant varieties and chemical control. Among them, the physical control methods such as high border cultivation and soil exposure treatment can reduce the content of pathogenic bacteria in the soil to a certain extent, but the effect is very small. Although crop rotation is the most economical and effective of many agricultural control measures to prevent and control tobacco bacterial wilt, it is difficult to implement with the reduction of arable land. Since the 1970s, experts and scholars engaged in the research of tobacco bacterial wilt have begun to use a large number of tobacco variety resources to select strains with different pathogenicity of bacterial wilt, and to breed resistant varieties through resistance testing. Zhou Qingming et al. A lot of research has been carried out on the selection of resistant varieties of bacterial wilt, and it was found that there are no immune varieties, only a few varieties are disease-resistant, most of them are medium-susceptible and high-susceptible varieties, and most of the high-quality varieties planted in production are not resistant to blue wilt. blight variety. More importantly, bacterial wilt is a soil-borne disease, and its pathogenic bacteria are highly saprophytic, and there are many different physiological races. Relying on complicated and arduous bacterial wilt disease-resistant breeding work cannot solve the existing disease problems in actual planting .

In view of the above reasons, chemical control has gradually become the main method to prevent and control bacterial wilt in production, but there is no medicament with good control effect at present, and the application of medicaments can only delay the peak of bacterial wilt to a certain extent and reduce the incidence That's all. Furthermore, the excessive and unreasonable use of chemical agents has caused irreversible negative pollution to the natural environment. At the same time, the use of a single agent can easily lead to drug resistance of pathogenic bacteria, resulting in a large accumulation of fungicides, resulting in long-term impact on the environment. The pathogenicity variation of pathogenic bacteria and the emergence of new toxic groups have weakened the efficacy of traditional chemical fungicides to a large extent, and the application concentration has to be increased, such a vicious circle. Therefore, it is extremely urgent to find a fungicide that can effectively control plant pathogenic bacteria.

Contents of the invention

In view of this, the object of the present invention is to provide the application of nano magnesium oxide as an antibacterial agent for Ralstonia solanacearum.

To achieve the above object, the present invention provides the following technical solutions:

Application of nano-magnesium oxide as an antibacterial agent for Ralstonia solanacearum.

Further, the particle size of the nano magnesium oxide is 20-100nm.

Further, the dosage of the nano magnesium oxide particles is 50-2000 mg/10 ⁸ CFU based on the cell count of Ralstonia solanacearum strain.

Further, the dosage of the nano-sized magnesium oxide particles is 250 mg/10 ⁸ CFU based on the number of Ralstonia solanacearum strain cells.

The beneficial effects of the present invention are: the present invention provides the application of nano-magnesium oxide as an antibacterial agent for Ralstonia solanacearum (Ralstonia solanacearum), and nano-magnesium oxide is used as an antibacterial agent for Ralstonia solanacearum (Ralstonia solanacearum) to prevent and treat tobacco. Ralstonia solanacearum provides a new approach, and it has a high-efficiency bactericidal effect on Ralstonia solanacearum (Ralstonia solanacearum) in a short period of time in various media. Further, magnesium oxide is a magnesium supplement, It is non-toxic and safe for the environment. At the same time, low-concentration nano-magnesium oxide can quickly kill R. solanacearum, with high precision and quick effect. It is not easy to cause drug resistance in tobacco and avoid problems such as excessive pesticide residues.

Description of drawings

In order to make the purpose, technical scheme and beneficial effect of the present invention clearer, the present invention provides the following drawings for illustration:

Fig. 1 is the figure of growth of Ralstonia solanacearum (Ralstonia solanacearum) on the NA solid medium containing nano-magnesium oxide;

Fig. 2 is the growth curve figure of Ralstonia solanacearum (Ralstonia solanacearum) in the B substratum containing nano-magnesium oxide;

Fig. 3 is the scanning electron micrograph of Ralstonia solanacearum (Ralstonia solanacearum) growing in deionized water containing nano-magnesium oxide;

Fig. 4 is the flow cytogram of Ralstonia solanacearum (Ralstonia solanacearum) grown in the PBS damping fluid containing nanometer magnesium oxide;

Fig. 5 is a test chart of the effective time of nano-magnesium oxide on Ralstonia solanacearum (Ralstonia solanacearum).

detailed description

Preferred embodiments of the present invention will be described in detail below.

Example 1

Tobacco Ralstia solanacearum (Ralstonia solanacearum), strain deposit number ACCC01474.

1. Preparation of bacterial suspension: after activating Ralstonia solanacearum (Ralstonia solanacearum), a bacterial suspension was prepared, and the final concentration of bacterial cells in the bacterial suspension was 1.0×10 ¹⁰ CFU/mL.

2. Antibacterial performance test of nano-magnesium oxide against Ralstonia solanacearum in various media

Add 250mg of nano magnesium oxide to the high-temperature sterilized NA medium, and then make it into a solid medium plate, and add 250mg of nano-magnesium oxide to the high-temperature sterilized B medium, deionized water and PBS buffer respectively. Magnesium oxide, four kinds of culture media containing nano-magnesium oxide were prepared.

Take the NA solid medium plate containing nano-magnesium oxide, and set up a control group (NA solid medium plate without nano-magnesium oxide), add 10 μL of bacterial suspension with a concentration of 1.0×10 ¹⁰ CFU/mL, and incubate at 30°C Under culture for 48h. Observe bacterium colony growth situation, as shown in Figure 1, as can be seen from Figure 1, do not appear on the NA solid medium plate containing nano magnesium oxide Ralstia solanacearum (Ralstonia solanacearum) bacterium colony, do not contain nano magnesium oxide A large number of Ralstia solanacearum (Ralstonia solanacearum) colonies appeared in the control group, indicating that nano-magnesium oxide has very good antibacterial properties against Ralstonia solanacearum (Ralstonia solanacearum).

Take the B medium containing nano-magnesia, and set up a control group (B medium without nano-magnesia), add 10 μL of bacterial suspension with a concentration of 1.0×10 ¹⁰ CFU/mL, and then rotate at 200 rpm at 30°C cultured in a shaker for 48 hours. During the cultivation process, the absorbance of the culture solution of the experimental group and the control group at a wavelength of 600nm was measured with a UV spectrophotometer every 2h, and the concentration of Ralstonia solanacearum (Ralstonia solanacearum) in the experimental group and the control group was drawn according to the absorbance. Growth curve, as shown in Figure 2, as can be seen from Figure 2, Ralstonia solanacearum (Ralstonia solanacearum) does not grow in the B medium containing nano-magnesium oxide, but does not contain nano-magnesia in the matched group The growth is logarithmic, indicating that the nano-magnesium oxide has very good antibacterial properties against Ralstonia solanacearum.

Take deionized water containing nano-magnesia, and set up a control group (deionized water without nano-magnesia), add 10 μL of bacterial suspension with a concentration of 1.0×10 ¹⁰ CFU/mL, and then rotate at 200 rpm at 30°C cultured in a shaker for 48 hours. Get the culture fluid in the experimental group and the control group and observe under the scanning electron microscope, as shown in Figure 3, as can be seen from Figure 3, after nano-magnesium oxide treatment, tobacco Ralstia solanacearum (Ralstonia solanacearum) cell morphology was destroyed In the control group, Ralstia solanacearum (Ralstonia solanacearum) cell morphology was still smooth and smooth, and the cell membrane was intact. Following disruption of the cell membrane, cytoplasmic leakage can lead to cell death.

Take the PBS buffer containing nano-magnesia, and set up a control group (PBS buffer without nano-magnesia), add 10 μL of bacterial suspension with a concentration of 1.0×10 ¹⁰ CFU/mL, and then rotate at 200 rpm at 30°C cultured in a shaker for 48 hours. Ralstia solanacearum (Ralstonia solanacearum) in the culture solution in the experimental group and the control group was carried out PI staining, observed by flow cytometry, as shown in Figure 4, as can be seen from Figure 4, the apoptosis rate of the control group The apoptosis rate was 4.3%, while the apoptosis rate was as high as 86.1% after being treated with nano-magnesium oxide, indicating that nano-magnesia has very good antibacterial properties against Ralstonia solanacearum.

Example 2

Add 0 mg, 50 mg, 100 mg, 200 mg, 400 mg, 800 mg, 1600 mg, and 2000 mg of nano-magnesium oxide to the NA medium after high-temperature sterilization to make solid medium plates, and then add 10 μL to each solid medium plate The bacterial suspension with a concentration of 1.0×10 ¹⁰ CFU/mL was cultured at 30°C for 48 hours. Observe the colony growth, 0mg, 50mg, 100mg, 200mg are inhibited in different degrees compared with the control, and the inhibitory effect is strengthened as the concentration increases; 400mg, 800mg, 1600mg, 2000mg treatments have no bacterial growth.

Example 3

Determination of the Effective Time of Nano Magnesium Oxide on Ralstonia solanacearum

Cultivate Ralstonia solanacearum overnight to the logarithmic phase, remove the medium, add nano-magnesium oxide to a final concentration of 250 mg/10 ⁸ CFU of nano-magnesia, and act for 0h, 2h, 4h, 8h, and 12h respectively After using the LIVE/DEAD kit for staining, the bactericidal effect of nano-magnesia on Ralstonia solanacearum was observed by laser confocal. The results are shown in Figure 5. ) for 2 hours, the cell permeability of Ralstonia solanacearum (Ralstonia solanacearum) changed, and a small part died, until 12 hours, almost all of them died.

Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that it can be described in terms of form and Various changes may be made in the details without departing from the scope of the invention defined by the claims.

Claims (4)

1. Application of nano-magnesium oxide as an antibacterial agent for Ralstonia solanacearum. 2. The application according to claim 1, characterized in that the particle size of the nano magnesium oxide is 20-100nm. 3 . The application according to claim 1 , wherein the dosage of the nano-magnesia particles is 50-2000 mg/10 ⁸ CFU based on the cell count of the Ralstonia solanacearum strain. 4 . The application according to claim 1 , wherein the dosage of the nano-magnesia particles is 250 mg/10 ⁸ CFU based on the cell count of the Ralstonia solanacearum strain.