Method for improving bacterial wilt resistance of cassava through sucrose treatment

Abstract

The invention discloses a method for improving bacterial wilt resistance of cassava through cane sugar treatment, and belongs to the field of vegetable cultivation, and the method comprises the following steps: raising seedlings to obtain cassava growing to 45 days old, and soaking cassava seedling raising bags in a cane sugar aqueous solution with the concentration of 1-3% (w / v) for 3-5 days, the cane sugar aqueous solution being 1-2.5 cm higher than the cassava seedling raising bags; the sucrose used in the invention is a common food additive, is pollution-free and edible, can be used for treating the cassava seedlings without causing pollution and chemical residues, has no negative influence on the normal growth of the cassava seedlings, and can improve the disease resistance of the cassava. By optimizing the concentration of the sucrose aqueous solution, the disease resistance effect of the sucrose aqueous solution with the concentration of 3% is optimal. The method is simple and easy to implement, quick in effect and high in efficiency, and has important significance on healthy development of the cassava industry.

Description

Technical Field

[0001] The present invention belongs to the technical field of vegetable cultivation, and particularly relates to a method for improving the resistance of cassava to bacterial blight by sucrose treatment. Background Art

[0002] Cassava can be both a food crop and an energy crop. Therefore, there is a huge demand for cassava in domestic and foreign markets. However, the yield of cassava is frequently restricted by diseases. Among them, cassava bacterial blight is a bacterial disease that seriously endangers the cassava yield in the world. Its pathogenic bacterium is Xanthomonas axonopodis pv. manihotis ( Xanthomonas axonopodis pv. Manihotis, Xam ), Xam which can colonize in the xylem vessels of cassava stems and spread over long distances with the reproduction of the stems. High temperature and high humidity are the most suitable conditions for the outbreak of bacterial blight. Especially during the typhoon and rainy seasons, the disease can spread rapidly in the field with air, rain and insects, causing serious harm. Moreover, the incidence and severity of bacterial blight are variable in time and space and difficult to predict, which brings great trouble to disease control.

[0003] Sugar is a key substance reflecting the energy level of plants. The continuous perception of sugar levels and the control of energy supply by plants are important conditions for their survival. Research shows that sucrose can regulate the expression of defense-related genes in plants, thereby affecting the disease resistance of plants. However, whether sucrose can regulate the disease resistance of cassava has not been reported. Summary of the Invention

[0004] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present invention, to avoid obscuring the purpose of this part, the abstract and the title. However, such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] In view of the above and / or problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for improving the resistance of cassava to bacterial blight by sucrose treatment.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: Cassava seedlings are grown to 45 days old, and the cassava seedling bags are soaked in a sucrose aqueous solution with a concentration of 1-3% (w / v), wherein the sucrose aqueous solution submerges the cassava seedling bags by 1-2.5 cm.

[0008] As a preferred scheme of the method for improving the resistance of cassava to bacterial blight by sucrose treatment according to the present invention, wherein: the soaking time is 3-5 days.

[0009] As a preferred embodiment of the method for improving the resistance of cassava to bacterial blight by sucrose treatment according to the present invention, wherein: the concentration of the sucrose aqueous solution is 3% (w / v).

[0010] As a preferred embodiment of the method for improving the resistance of cassava to bacterial blight by sucrose treatment according to the present invention, wherein: the seedling raising includes, Filling the seedling raising bags with the substrate obtained by mixing nutrient soil and vermiculite, cutting the lignified cassava stems into cassava segments, inserting the cassava segments into the substrate of the seedling raising bags with the bud eyes facing upwards, watering the substrate thoroughly with water, placing it in a greenhouse at 25 - 30 °C for growth, with 12 - 14 h of light and 10 - 12 h of darkness, and watering and fertilizing to make the cassava grow to 45 days old.

[0011] As a preferred embodiment of the method for improving the resistance of cassava to bacterial blight by sucrose treatment according to the present invention, wherein: when cutting the lignified cassava stems into cassava segments, the cassava segments are 8 - 12 cm.

[0012] As a preferred embodiment of the method for improving the resistance of cassava to bacterial blight by sucrose treatment according to the present invention, wherein: the watering is to water 100 - 200 mL of water every 3 days.

[0013] As a preferred embodiment of the method for improving the resistance of cassava to bacterial blight by sucrose treatment according to the present invention, wherein: the fertilizing is to water 50 - 100 mL of Huawuque aqueous solution every 10 days.

[0014] As a preferred embodiment of the method for improving the resistance of cassava to bacterial blight by sucrose treatment according to the present invention, wherein: the concentration of the Huawuque aqueous solution is 1 - 2 g / L.

[0015] Advantages of the present invention: (1) The sucrose in the present invention is a commonly used food additive, which is pollution-free and edible. Treating cassava seedlings with it will not cause pollution and chemical residues, has no negative impact on the normal growth of cassava seedlings, and can improve the disease resistance of cassava.

[0016] (2) The method for improving the disease resistance of cassava by sucrose treatment provided by the present invention is simple, easy to implement, has quick results and high efficiency, can quickly improve the resistance of cassava to bacterial blight, and has important significance for the healthy development of the cassava industry. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 The number of bacteria in cassava against bacterial wilt after treatment with sucrose aqueous solutions of different concentrations for 0 days, 2 days, and 5 days in Example 1 and Comparative Examples 1 to 2 of the present invention. Detailed implementation manners

[0019] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention in conjunction with the embodiments of the specification.

[0020] Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar promotions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0021] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments.

[0022] The main components of the flower non-water-deficient aqueous solution used in the present invention are: by mass fraction, nitrate nitrogen 5.97%, ammonium nitrogen 3.92%, urea nitrogen 10.11%, water-soluble phosphorus 20%, water-soluble potassium 20%, magnesium 0.07%, EDTA-copper 0.05%, EDTA-iron 0.1%, EDTA-manganese 0.1%, EDTA-zinc 0.1%, boron 0.15%, molybdenum 0.002%, EDTA-cobalt 0.0005%.

[0023] The components of the LB solid medium used in the present invention are: yeast extract 5 g / L, tryptone 10 g / L, sodium chloride 10 g / L, agar powder 20 g / L, and it is obtained by high-temperature sterilization at 121 °C for 20 min.

[0024] The preparation method of the bacterial suspension used in the present invention is: taking the Xanthomonas axonopodis pv. cynodontis strain preserved in the laboratory, inoculating it onto the LB solid medium, culturing it at 28 °C for 18 h, rinsing the bacteria in the medium with 1 mM MgCl2 solution, and diluting to OD 600 = 0.6 to obtain the bacterial suspension.

[0025] Example 1. This example provides a method for improving the resistance of cassava to bacterial wilt by sucrose treatment, specifically as follows: Seedling raising: Fill the seedling-raising bags with a diameter of 10 cm with a substrate obtained by mixing nutrient soil and vermiculite in a mass ratio of 1:1. Cut the lignified cassava stems into cassava segments about 10 cm long, insert them into the substrate of the seedling-raising bags with the bud eyes facing up. After thoroughly watering the substrate with water, place it at 30 °C for growth, with 12 hours of light and 12 hours of darkness. Water 100 mL every 3 days and pour 50 mL of the Hua Wu Que Shui solution every 10 days, where the concentration of the Hua Wu Que Shui solution is 1 g / L; Sucrose treatment: Raise seedlings to obtain 45-day-old cassava. Immerse the cassava seedling-raising bags in sucrose aqueous solutions with concentrations of 1%, 2%, and 3% (w / v) for 5 days respectively. Among them, the sucrose aqueous solution submerges the seedling-raising bags by about 1 cm to obtain the cassava with resistance to bacterial wilt in this example.

[0026] Comparative Example 1. The difference between this comparative example and Example 1 is that the concentration of the sucrose aqueous solution is adjusted to 0% (w / v), and the rest of the treatment methods are the same as those in Example 1.

[0027] For the cassava treated in Example 1 and Comparative Example 1, each lobe has 2 inoculation points. Inject 0.1 mL of the bacterial suspension into each inoculation point. After the inoculation is completed, place it in the dark at 30 °C for 12 h and then in the light for cultivation. Statistically analyze the lesion area on the cassava leaves 8 days after inoculation. The results are shown in Table 1.

[0028] Table 1 Effects of sucrose aqueous solution treatment concentration on the resistance of cassava to bacterial wilt , It can be clearly seen from Table 1 that 8 days after inoculating the cassava treated only with deionized water with bacteria, the lesion area on the leaves is significantly larger than that of the cassava leaves treated with the sucrose aqueous solution. Moreover, the lesion area on the leaves treated with the 3% concentration of the sucrose aqueous solution is reduced by 75% compared with that of the 0% concentration. Thus, it can be seen that the treatment with a 3% sucrose aqueous solution can significantly improve the resistance of cassava to bacterial wilt.

[0029] Comparative Example 2. The difference between this comparative example and Example 1 is that the concentration of the sucrose aqueous solution is adjusted to 5%, 8%, and 10% (w / v) respectively, and the rest of the treatment methods are the same as those in Example 1.

[0030] For the cassava treated in Example 1 and Comparative Examples 1 - 2, each lobe has 2 inoculation points. Inject 0.1 mL of the bacterial suspension into each inoculation point. After the inoculation is completed, place it in the dark at 30 °C for 12 h and then in the light for cultivation. Statistically analyze the number of bacteria in the cassava at 0 days, 2 days, and 5 days after inoculation. The results are as Figure 1 shown.

[0031] Comparison Figure 1 After treatment with sucrose aqueous solutions of different concentrations, on the cassava at 0 days, 2 days, and 5 days XamBacterial count. It can be seen that the bacterial count on the leaves per unit area of cassava treated with 5% and 8% (w / v) sucrose aqueous solutions showed no significant difference from that treated with 0% (w / v) sucrose aqueous solution 2 days after inoculation, but was lower than that treated with 0% (w / v) sucrose aqueous solution 5 days after inoculation, yet higher than that treated with 1%, 2%, and 3% (w / v) sucrose aqueous solutions. The bacterial count on the leaves per unit area of cassava treated with 10% (w / v) sucrose solution was significantly higher than that of the control group. This indicates that treatment with an overly high sucrose solution cannot improve the resistance of cassava to Xam and that a 1 - 3% (w / v) sucrose aqueous solution is the optimal treatment range for enhancing the resistance of cassava to Xam .

[0032] In summary, the present invention provides a method for improving the disease resistance of cassava by sucrose treatment. Among them, sucrose is a commonly used food additive, pollution - free and edible. Treating cassava seedlings with it will not cause pollution and chemical residues, has no negative impact on the normal growth of cassava seedlings, and can improve the disease resistance of cassava. In addition, through the optimization of the concentration of the sucrose aqueous solution, it is found that a 1 - 3% concentration of the sucrose aqueous solution can rapidly improve the resistance of cassava to bacterial wilt.

[0033] It should be noted that the above 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 with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for improving the resistance of cassava to bacterial blight by sucrose treatment, characterized in that: Including, Cassava seedlings are grown until they reach 45 days old. The cassava seedling bags are soaked in a sucrose aqueous solution with a concentration of 1-3% (w / v), where the sucrose aqueous solution submerges the cassava seedling bags by 1-2.5 cm.

2. The method for improving the resistance of cassava to bacterial blight by sucrose treatment according to claim 1, characterized in that: The soaking time is 3-5 days.

3. The method for improving the resistance of cassava to bacterial blight by sucrose treatment according to claim 1, characterized in that: The concentration of the sucrose aqueous solution is 3% (w / v).

4. The method for improving the resistance of cassava to bacterial blight by sucrose treatment according to claim 1, characterized in that: The seeding includes, Filling the seedling bags with a substrate made by mixing nutrient soil and vermiculite. Cutting the lignified cassava stems into cassava segments, inserting them into the substrate of the seedling bags with the bud eyes facing upwards. After thoroughly watering the substrate, placing it in a growth environment at 25-30 °C, with 12-14 hours of light and 10-12 hours of darkness, and watering and fertilizing to grow the cassava until it reaches 45 days old.

5. The method for improving the resistance of cassava to bacterial blight by sucrose treatment according to claim 4, characterized in that: When cutting the lignified cassava stems into cassava segments, the cassava segments are 8-12 cm long.

6. The method for improving the resistance of cassava to bacterial blight by sucrose treatment according to claim 4, characterized in that: The watering is to pour 100-200 mL of water every 3 days.

7. The method for improving the resistance of cassava to bacterial blight by sucrose treatment according to claim 4, characterized in that: The fertilizing is to pour 50-100 mL of Huawuque aqueous solution every 10 days.

8. The method for improving the resistance of cassava to bacterial blight by sucrose treatment according to claim 7, characterized in that: The concentration of the Huawuque aqueous solution is 1-2 g / L.

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