Reagent for preventing and treating tobacco black shank disease and its application

Abstract

The present invention discloses the use of potassium nitrosoferricyanide in combating tobacco Phytophthora nicotiana, belonging to the technical field of pesticides. The present invention discovers that potassium nitrosoferricyanide can inhibit the growth of tobacco Phytophthora nicotiana, and that potassium nitrosoferricyanide treatment can improve tobacco's resistance to attack by tobacco Phytophthora nicotiana. Potassium nitrosoferricyanide can be used to prepare formulations for combating tobacco Phytophthora nicotiana and preventing tobacco black shank. The present invention can improve tobacco's resistance to black shank, which is of great significance for preventing and controlling tobacco black shank.

Description

Technical Field

[0001] The present invention relates to tobacco prevention and control technology, and in particular to a reagent for preventing and treating tobacco black shank disease and its application. Background Art

[0002] Tobacco black shank is a soil-borne disease that is extremely destructive to tobacco production. It is caused by Phytophthora parasitica var. nicotianae. This disease is widely distributed globally, particularly in temperate, subtropical, and tropical regions, and has severely impacted tobacco cultivation in nearly 40 countries and regions. In China, with the exception of Heilongjiang Province, where the disease has not been detected, it has occurred in all tobacco-growing provinces and regions, including Taiwan. The disease is particularly prevalent and severe in Henan, Shandong, Anhui, Zhejiang, Hunan, Hubei, Fujian, Guangdong, Guangxi, Yunnan, Guizhou, and Sichuan.

[0003] Tobacco black shank disease is primarily spread through infected soil, manure, and irrigation water. The pathogen is concentrated within 0-5 cm of the soil surface, infecting the base of tobacco stems through wounds or direct invasion. The pathogen can overwinter in diseased residues in soil and manure as chlamydospores and dormant mycelium, surviving for up to three years. The occurrence of the disease is related to a variety of factors, including temperature and humidity, root-knot nematode infestation, tobacco variety resistance, initial pathogen load and pathogenicity, tillage system, and cultivation management.

[0004] The main symptoms are black spots at the base of tobacco plant stems, or they may spread from the bottom leaves upwards to the stems. When humidity is high in the seedbed, the spots may be covered with white hairs and quickly spread to nearby seedlings, causing widespread death. When the disease occurs in the field, the infected area turns black, and the leaves of the affected plants turn yellow and wilt from the bottom up, eventually leading to the death of the entire plant. In severe cases, the leaves may suddenly and permanently wilt and die, a phenomenon farmers refer to as "wearing a coat."

[0005] Currently, the main fungicides used to control tobacco black shank are metalaxyl, fosetyl-aluminum and fosetyl-aluminum mancozeb, dimethomorph, troxymethoxam, dimethoate, oxadixyl-mancozeb, and mancozeb. However, in recent years, these fungicides have been experiencing a decline in efficacy. This may be due to improper use by users, but also to the fact that Phytophthora has developed resistance to most chemical pesticides. Therefore, research on highly effective, low-toxic, low-residue, and environmentally friendly botanical fungicides has become a hot topic.

[0006] Potassium nitrosoferricyanide (SNP) is a chemical agent that can affect the growth and development of plants. It promotes plant protein synthesis and cell division by providing the nitrogen required by plants, thereby promoting plant growth. At the same time, potassium nitrosoferricyanide can promote the growth and development of plant roots, enhance the plant's ability to absorb water and nutrients, and improve the plant's stress resistance. However, there is no research on the prevention and treatment of tobacco black shank disease with potassium nitrosoferricyanide. This application aims to provide a new approach for the prevention and treatment of tobacco black shank disease by exploring the inhibitory effect of potassium nitrosoferricyanide on black shank fungus.

[0007] Therefore, it is of great significance to develop a new and efficient reagent for the prevention and control of tobacco black shank disease and provide a new green and environmentally friendly bio-source pesticide for the prevention and control of tobacco soil-borne disease pathogens. Summary of the Invention

[0008] In order to solve the above problems, the present invention aims to provide an agent for controlling tobacco soil-borne diseases, especially controlling tobacco phytophthora.

[0009] In the present application, in the first aspect, through in vitro experiments in culture dishes, it is confirmed that different concentrations of potassium nitrosoferricyanide have different inhibitory effects on the growth of tobacco blight. When the concentration of potassium nitrosoferricyanide is less than 50mmol / L, its inhibitory effect on the growth of tobacco blight is small. When the concentration of potassium nitrosoferricyanide is greater than 50mmol / L, it has a significant inhibitory effect on the growth of tobacco blight. When the concentration of potassium nitrosoferricyanide is 100mmol / L, its inhibitory effect on the growth of tobacco blight reaches the maximum, which is higher than the inhibitory effect of other concentrations on tobacco blight. When 100mmol / L of potassium nitrosoferricyanide and 20mmol / L of 4-methylcatechol are compounded, its inhibition on the growth of tobacco blight can be further improved.

[0010] In the second aspect of this application, potted plant experiments were conducted to demonstrate that a combination of potassium nitrosoferricyanide and 4-methylcatechol can improve the growth and development of tobacco seedlings and their ability to resist attack by tobacco blight. Potassium nitrosoferricyanide concentrations promote tobacco plant growth at low concentrations while suppressing growth at high concentrations. When the concentration was less than 100 mmol / L, tobacco agronomic traits showed a trend of gradual increase as the concentration of potassium nitrosoferricyanide increased. Agronomic traits and physiological and biochemical indices performed best at a concentration of 100 mmol / L. When the concentration of 200 mmol / L was used to treat tobacco seedlings, the agronomic traits and physiological and biochemical indices were inferior to those at a concentration of 50 to 100 mmol / L.

[0011] The detailed technical solutions adopted in this application are as follows:

[0012] Application of potassium nitrosoferricyanide in the preparation of preparations against tobacco phytophthora.

[0013] A reagent for preventing and treating tobacco black shank disease, comprising 50-100 mmol / L potassium nitrosoferricyanide.

[0014] In some embodiments, potassium nitroferricyanide is used at a concentration of 100 mmol / L.

[0015] In some embodiments, the reagent includes 50-100 mmol / L potassium nitrosoferricyanide and 10-20 mmol / L 4-methylcatechol.

[0016] In some embodiments, the reagent consists of 100 mmol / L potassium nitrosoferricyanide and 20 mmol / L 4-methylcatechol.

[0017] On the other hand, the present application also provides the use of the above-mentioned reagent in the prevention and control of tobacco soil-borne diseases, in particular for the prevention and control of tobacco blight.

[0018] Beneficial effects of this application:

[0019] This application is the first study to find that potassium nitrosoferricyanide has an inhibitory effect on tobacco blight, especially when potassium nitrosoferricyanide and 4-methylcatechol are combined, it can effectively prevent and control tobacco blight in soil and tobacco, which is of great significance for the prevention and control of tobacco blight (tobacco black shank disease). BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a comparison of the mycelial morphology between the control group and group D in the test of the effect of inhibiting the growth of tobacco Phytophthora nicotianae;

[0021] Figure 2 This is a photo of tobacco seedlings treated in the control group of Example 3;

[0022] Figure 3 This is a photo of the tobacco seedlings processed in the experiment of Example 3. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the examples. Unless otherwise specified, the equipment and reagents used in each example and test example can be obtained from commercial sources. The specific examples described herein are only used to illustrate the present invention and are not intended to limit the present invention.

[0024] Based on the information contained in this application, it will be readily apparent to those skilled in the art that various changes can be made to the precise description of the present invention without departing from the spirit and scope of the appended claims. It should be understood that the scope of the present invention is not limited to the defined processes, properties, or components, as these embodiments and other descriptions are provided merely to illustrate specific aspects of the present invention. In fact, various changes that a person skilled in the art or related fields would clearly be able to make to the embodiments of the present invention are encompassed within the scope of the appended claims.

[0025] In order to better understand the present invention and not to limit the scope of the present invention, all numbers used in this application to express amounts, percentages, and other numerical values should be understood to be modified by the word "approximately" in all cases. Therefore, unless otherwise specified, the numerical parameters listed in the specification and the appended claims are approximate values, which may be changed according to the different ideal properties attempted to be obtained. Each numerical parameter should at least be regarded as obtained based on the reported significant figures and by conventional rounding methods. In the present invention, "about" means within 10% of a given value or range, preferably within 5%.

[0026] In the following embodiments of the present invention, unless otherwise specified, room temperature is used. Room temperature refers to natural room temperature in all seasons without additional cooling or heating, and is generally controlled at 10-30°C, preferably 15-25°C.

[0027] Unless otherwise specified, the reagents and materials used in the examples of the present invention can be purchased from commercial sources.

[0028] Tobacco seedling cultivation involved in the present invention: The flue-cured tobacco variety used for testing was cigar tobacco, with seeds provided by Hubei Provincial Tobacco Company. Sowing: Sow 2 to 3 seeds per hole in a seedling tray. Cultivation conditions: Room temperature was maintained at 28 ± 2°C day and night, and relative humidity was maintained above 80%.

[0029] Test strain: Phytophthora nicotianae was preserved by our research team (Phytophthora nicotianae ACCC39210).

[0030] Potato dextrose medium (PDA): 200 g potatoes, 20 g glucose, 15-20 g agar, 1000 mL distilled water, pH 7.0-7.4.

[0031] Example 1 Test on the effect of inhibiting tobacco phytophthora growth

[0032] According to Table 1, a certain amount of potassium nitrosoferricyanide and 4-methylcatechol were added to potato glucose medium to prepare a drug-containing medium. The activated tobacco phytophthora was punched at the edge of the tobacco phytophthora colony with a sterile puncher with a diameter of 7 mm, and the cake was inoculated upside down in the center of the treated PDA medium plate. Three replicates were set for each treatment, and the plates were placed in a 37°C incubator for culture.

[0033] Table 1

[0034]

[0035] Observe and record the diameter of tobacco Phytophthora colonies at the same time every day and take photos. The records are shown in Table 2.

[0036] Table 2

[0037]

[0038]

[0039] As shown in Table 2, due to the rapid growth of P. nicotianae, the control group's P. nicotianae colonies covered the entire plate on the potato culture medium after 3 days. At a potassium nitrosoferricyanide concentration of 10 mmol / L, while the colony diameter did not decrease significantly, the growth rate was significantly reduced. At a potassium nitrosoferricyanide concentration of 50 mmol / L, the colony diameter decreased significantly. As the potassium nitrosoferricyanide concentration increased, the colony diameter of P. nicotianae decreased. At 100 mmol / L, the growth of P. nicotianae was completely inhibited.

[0040] On the 5th day, a small amount of hyphae from the control group and group D was diluted with sterile water, placed on a slide, and the hyphae morphology was observed under a microscope. Figure 1 As shown, compared with the control, after treatment with potassium nitrosoferricyanide, the grown hyphae were deformed in morphology and the cell diameter and length were shortened.

[0041] Studies have found that potassium nitrosoferricyanide can significantly inhibit the growth of tobacco blight mycelium and destroy the integrity of the mycelial cell wall. This may be because potassium nitrosoferricyanide affects the activity of some key enzymes in the mycelial cells, causing changes in the structure and function of the mycelial cells, thereby affecting their normal growth.

[0042] Example 2 Effect of Potassium Nitroferrocyanide on Tobacco Plant Growth

[0043] Tobacco seeds were sown in double seed sowing methods in plug trays for seedling cultivation. After the seeds germinated, they were watered twice a week with 0.5 L of water each time. When the tobacco seedlings grew to the four-leaf and one-heart stage, they were transplanted into flower pots (10 cm high and 10 cm in diameter at the top). One week later, they were transplanted into large flower pots (20 cm high and 20 cm in diameter at the top) for potted experiments.

[0044] The following five treatment groups were set up for tobacco:

[0045] Group 1: 50 mmol / L potassium nitrosoferricyanide;

[0046] Group 2: 70 mmol / L potassium nitrosoferricyanide;

[0047] Group 3: 100 mmol / L potassium nitrosoferricyanide;

[0048] Group 4: 150 mmol / L potassium nitrosoferricyanide;

[0049] Group 5: 100 mmol / L potassium nitrosoferricyanide, 20 mmol / L 4-methylcatechol;

[0050] Control group: sterile water.

[0051] Seven days after transplanting the tobacco seedlings of each treatment, the above reagents were sprayed on the tobacco seedlings every three days. After the tobacco had grown for five weeks, its growth indexes were measured.

[0052] Experimental results and analysis

[0053] As shown in Table 3, a high concentration of 150 mmol / L potassium nitrosoferricyanide has a certain inhibitory effect on the growth of tobacco seedlings, while a combination of 100 mmol / L potassium nitrosoferricyanide and 20 mmol / L 4-methylcatechol can promote the growth of tobacco seedlings.

[0054] Table 3

[0055]

[0056] Example 3 Potted plant experiment testing tobacco black shank resistance

[0057] When the tobacco plants grew to 4-5 leaves, the experimental group was sprayed with Group 5 reagent for 3 consecutive times, once every three days. After 9 days, the soil was inoculated with tobacco phytophthora fermentation liquid. 50 tobacco plants were treated, and clean water was used as the control. After 2 weeks, the incidence of disease was counted. The incidence of disease in the experimental group was 4%, while the incidence of disease in the control group was 100%. And from Figure 2 and Figure 3In the figure, it can be seen that the tobacco seedlings in the control group are obviously wilting, the leaves are yellowing and whitening, and there are lesions; while the disease resistance of tobacco plants in the experimental group is significantly enhanced, no lesions appear, and the tobacco seedlings grow well.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An agent for preventing and treating tobacco black shank, characterized in that: The reagent consists of 100 mmol / L potassium nitrosoferricyanide and 20 mmol / L 4-methylcatechol.

2. Use of the agent of claim 1 in the prevention and treatment of soil-borne diseases of tobacco, characterized in that: The tobacco soil-borne disease control refers to the control of tobacco black shank-causing Phytophthora tobacco.

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