Application of chalcone compounds in preventing and controlling cotton wilt and method for preventing and controlling cotton wilt

Abstract

The invention belongs to the technical field of biological control of cotton wilt, and specifically relates to the application of chalcone compounds in preventing and controlling cotton wilt and a method for preventing and controlling cotton wilt. The invention uses chalcone compounds as the only active ingredient, and plate antibacterial tests and pot tests confirm that chalcone can inhibit the growth of cotton wilt pathogens, reduce the disease index of cotton wilt, and prevent and control cotton wilt.

Description

Technical Field

[0001] The invention belongs to the technical field of biological control of cotton wilt, and particularly relates to application of a chalcone compound in controlling cotton wilt and a control method for cotton wilt. Background Art

[0002] Cotton wilt is one of the two major cotton diseases in the world, which has caused varying degrees of impact on cotton production in cotton-producing countries around the world. Fusarium oxysporum f.sp.Vasinfectum is the pathogen of cotton wilt. It can easily survive under natural conditions, produce conidia, and is mainly spread through soil, seeds and fertilizers. Fusarium oxysporum usually only infects a few plants such as cotton, okra and kenaf. Under greenhouse or disease nursery inoculation conditions, it can infect a variety of plants such as wheat, Solanaceae, Leguminosae, melons and tobacco. Cotton wilt is a typical vascular disease, and cotton can be infected throughout the growth and development period. There are many types of symptoms, including withering type, yellowing type, shrinking type, yellow reticulated type, red leaf type, etc. in the seedling stage; shrinking type, dead spot type, half yellowing type, top dead type, bare stalk type, etc. in the bud stage. This disease often causes a large number of cotton seedlings to die in the early stage, and a large number of leaves and buds to fall off in the later stage, or even die.

[0003] Although cotton wilt has been effectively controlled with the planting of disease-resistant varieties, it has rebounded with the planting of insect-resistant cotton. The main reasons are that large-scale and centralized planting makes crop rotation difficult; disease-resistant breeding takes a long time, the workload is large, and resistance is easily lost; chemical pesticides are effective in treating diseased plants and local soil in sporadic disease areas, but it is difficult to reach the vascular bundle of cotton plants, the effect is poor, and the environment is polluted; and chemical agents are highly toxic, and most of them are volatile, with carcinogenic, teratogenic, and mutagenic properties. Pesticides enter the body of the person applying the pesticides through the mouth, respiratory tract, or direct contact, which can easily cause acute poisoning and seriously endanger the health of humans and animals.

[0004] Chalcone is an α,β-unsaturated ketone, also known as styrylphenyl ketone. It is an important natural product that is widely found in medicinal plants such as licorice, tomorrow leaves, and safflower. The conjugated system composed of double bonds and carbonyl groups is considered to be the pharmacophore of chalcone, because removing this structure will reduce or even eliminate the biological activity. The skeleton of chalcone is composed of two aromatic rings connected by α,β-unsaturated ketone. It has great flexibility and exists in various conjugated forms in nature. It can bind to various receptors and has a wide range of physiological activities, such as anti-tumor, anti-inflammatory and anti-infective. There are no reports on the use of chalcone to prevent and treat cotton wilt. Summary of the invention

[0005] The invention aims to provide an application of a chalcone compound in inhibiting cotton wilt pathogen, thereby inhibiting the mycelium growth of cotton wilt pathogen and preventing and controlling cotton wilt disease.

[0006] In order to achieve the above object, the present invention provides the use of chalcone compounds in inhibiting cotton wilt pathogens.

[0007] Preferably, the inhibiting of cotton wilt pathogen includes inhibiting the growth of mycelium of cotton wilt pathogen.

[0008] Preferably, the cotton wilt pathogen includes Fusarium oxysporum.

[0009] The invention also provides application of the chalcone compound in preventing and treating cotton wilt.

[0010] Preferably, 10 ml of 5-10 mg / mL chalcone solution is applied to the roots of each cotton seedling.

[0011] Preferably, the solvent of the chalcone solution is 50% DMSO solution.

[0012] The invention also provides a method for preventing and controlling cotton wilt, comprising the step of applying a chalcone compound to cotton seedlings.

[0013] Preferably, 10 ml of 5-10 mg / mL chalcone solution is applied to the roots of each cotton seedling.

[0014] Preferably, the solvent of the chalcone solution is 50% DMSO solution.

[0015] Preferably, the cotton seedlings include cotton seedlings with two leaves and one heart.

[0016] Beneficial effects:

[0017] The invention uses chalcone compound as the only active ingredient. Plate antibacterial test and pot test confirm that chalcone can inhibit the growth of cotton wilt pathogen, reduce the disease index of cotton wilt disease, and prevent and treat cotton wilt disease. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0019] Figure 1 The results of the plate antibacterial experiment of chalcone compounds in Example 1; a is the result of the control group, b is the result of the test group 1, and c is the result of the test group 2;

[0020] Figure 2 The results of the flavanone compound plate antibacterial experiment in comparative example 1; a is the result of the control group, b is the result of the test group 1, and c is the result of the test group 2;

[0021] Figure 3 The results of the plate antibacterial experiment (filter paper method) of chalcone compounds in Example 2; a is the result of dropping 20 μL of sterile distilled water, b is the result of dropping 20 μL of 10 mg / ml chalcone solution, c is the result of dropping 20 μL of 50% DMSO, and A is a partial enlarged view of B;

[0022] Figure 4 The results of the plate antibacterial test (filter paper method) of flavanone compounds in comparative example 2 are shown in Figure 2; a is the result of dropping 20 μL of sterile distilled water, b is the result of dropping 20 μL of 30 mg / ml flavanone solution, and c is the result of dropping 20 μL of 50% DMSO;

[0023] Figure 5 These are the results of the potted experiment of chalcone compounds in Example 3; A is 06-146, B is DJ-07-136, C is Xinhai No. 14, and D is NMGB-4. DETAILED DESCRIPTION

[0024] The invention provides application of chalcone compounds in inhibiting cotton wilt pathogens.

[0025] In the present invention, the inhibition of cotton wilt pathogen preferably includes inhibiting the hyphae growth of cotton wilt pathogen; the cotton wilt pathogen preferably includes Fusarium oxysporum.

[0026] The purity of the chalcone compound of the present invention is preferably 97%; the structural formula of the chalcone compound is as follows:

[0027]

[0028] The present invention has no strict requirements on the source of the chalcone compound, and it can be purchased conventionally.

[0029] The present invention conducts a plate antibacterial test. From the results of the plate antibacterial test, it can be seen that a low concentration of the chalcone compound (5 mg / mL) can inhibit the growth of the hyphae of cotton wilt pathogenic bacteria, and a high concentration of the chalcone compound (10 mg / mL) can completely inhibit the growth of the hyphae of cotton wilt pathogenic bacteria.

[0030] The invention also provides application of the chalcone compound in preventing and treating cotton wilt.

[0031] In the present invention, preferably, 10 ml of 5-10 mg / mL chalcone solution is applied to the roots of each cotton seedling; the solvent of the chalcone solution is preferably a 50% DMSO solution. The cotton seedlings of the present invention preferably include cotton seedlings with two leaves and one heart.

[0032] The invention also provides a method for preventing and controlling cotton wilt, comprising the step of applying a chalcone compound to cotton seedlings.

[0033] In the present invention, preferably, 10 ml of 5-10 mg / mL chalcone solution is applied to the roots of each cotton seedling; the solvent of the chalcone solution is preferably a 50% DMSO solution. The cotton seedling preferably includes a cotton seedling with two leaves and one heart.

[0034] The present invention conducts a pot test. From the results of the pot test, it can be seen that when the cotton seedlings have two leaves and one heart, the pathogen is inoculated, chalcone is applied 3 days after the inoculation, and after the treatment for 14 days, the condition of cotton wilt disease is reduced compared with the control group, indicating that chalcone can reduce the occurrence of cotton wilt disease and has great application prospects.

[0035] In order to further illustrate the present invention, the application of the chalcone compound provided by the present invention in preventing and controlling cotton wilt and the method for preventing and controlling cotton wilt are described in detail below in conjunction with the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0036] Materials and reagents involved in the following examples

[0037] The seed materials are Gossypium barbadense L. resource materials: Gossypium barbadense 06-146 (resistant to Fusarium wilt), Xinhai No. 14 (susceptible to Fusarium wilt), Gossypium barbadense DJ-07-136 (resistant to Fusarium wilt) and Gossypium barbadense NMGB-4 (susceptible to Fusarium wilt);

[0038] The wilt pathogen used was Fusarium oxysporum of cotton, physiological race 7 (Feng Jie, Chen Qi. Overview of basic research on cotton wilt in my country [J]. Cotton Science, 1994(02):65-69.);

[0039] Chalcone compounds were purchased from Shanghai Yuanye Biotechnology Co., Ltd. (CAS No.: 94-41-7, Product No.: S29931)

[0040] Sea Island Cotton 06-146 is an excellent variety bred by the Institute of Economic Crops of Xinjiang Academy of Agricultural Sciences using composite hybridization technology. Its variety characteristics are: zero branching, high lint percentage, and high resistance to type II wilt. For details, please refer to (Chai Yanjun. Genetic analysis and QTL positioning of yield and wilt resistance of Sea Island Cotton F_(2:5) population [D]. Xinjiang Agricultural University, 2013.).

[0041] Xinhai No. 14 was developed by the Agricultural Science Institute of the First Agricultural Division using the selected line of Xinhai No. 10 × Junhai No. 1. Its variety characteristics are zero-branching, compact plant shape, and S-resistance to wilt disease.

[0042] Sea island cotton DJ-07-136 was provided by the Xinjiang Key Laboratory of Crop Genetic Improvement and Germplasm Innovation of Xinjiang Agricultural University (Han Wanli. Construction of high-density linkage map of sea island cotton resistance to Fusarium wilt and mining of disease resistance genes [D]. Xinjiang Agricultural University, 2021.);

[0043] NMGB-4 was provided by the Xinjiang Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Xinjiang Agricultural University (Zhao Fuxiang. Evaluation of drought resistance of sea island cotton and QTL positioning of drought resistance traits [D]. Xinjiang Agricultural University, 2019.).

[0044] Example 1

[0045] Chalcone plate antibacterial test

[0046] 1. Weigh the chalcone compound and dissolve it in 50% DMSO solution to prepare chalcone solutions with concentrations of 5 mg / ml and 10 mg / ml.

[0047] 2. Mix 5 mg / ml chalcone solution and cotton oxysporum Fusarium oxysporum (spore concentration of 1×10 7 / ml) were mixed at a volume ratio of 1:1. After 24 hours, 20 μL of the mixture was aspirated and dropped in the center of PDA solid culture medium (20 mL), and then inverted and cultured in a 28°C incubator, which was recorded as test group 1;

[0048] 10 mg / ml chalcone solution and Fusarium oxysporum of cotton (spore concentration of 1×10 7 / ml) were mixed at a volume ratio of 1:1. After 24 hours, 20 μL of the mixture was aspirated and dropped in the center of PDA solid culture medium (20 mL), and then inverted and cultured in a 28°C incubator, which was recorded as test group 2;

[0049] Sterile water and Fusarium oxysporum of cotton (spore concentration of 1×10 7 / ml) in a volume ratio of 1:1. After leaving it for 24 hours, 20 μL of the mixture was dropped in the center of PDA solid culture medium (20 mL), and then inverted and cultured in a 28°C incubator, which was recorded as the control group (CK).

[0050] 3. After culturing for 3 days, the growth of Fusarium oxysporum in test group 1, test group 2 and control group was observed, and the mycelium growth inhibition rate was calculated according to the following formula. The results are as follows: Figure 1 And as shown in Table 1.

[0051] Mycelium growth inhibition rate (%) = colony diameter (CK) - colony diameter (treatment) / colony diameter (CK)

[0052] Table 1 Growth of Fusarium oxysporum in cotton in different treatment groups

[0053] Processing Colony diameter (cm) Inhibition rate (%) Test Group 1 7.3 13.10％ Test Group 2 0 100％ Control group (CK) 8.4 /

[0054] according to Figure 1 As can be seen from Table 1, compared with the control group, there was partial bacterial growth in the test group 1, and the mycelial growth inhibition rate was 13.10%, indicating that the 5 mg / ml chalcone solution can inhibit the growth of mycelial fungi of Fusarium oxysporum in cotton; there was no mycelial growth in the test group 2, and the mycelial growth inhibition rate was 100%, indicating that the 10 mg / mL chalcone solution can completely inhibit the mycelial growth of Fusarium oxysporum in cotton.

[0055] Comparative Example 1

[0056] With embodiment 1, the difference is:

[0057] Weigh a flavanone compound (CAS No.: 487-26-3, Product No.: B29177, purity HPLC ≥ 98%), dissolve it in 50% DMSO solution, and prepare flavanone solutions with concentrations of 15 mg / ml and 30 mg / ml;

[0058] Test group 1: 15 mg / ml flavanone solution and cotton oxysporum Fusarium oxysporum (spore concentration of 1×10 7 / ml) in a volume ratio of 1:1, and after standing for 24 hours, 20 μL of the mixture was aspirated and dropped in the center of PDA solid culture medium (20 mL), and then inverted and cultured in a 28°C incubator;

[0059] Test 2: 30 mg / ml flavanone solution and cotton oxysporum Fusarium oxysporum (spore concentration of 1×10 7 / ml) were mixed at a volume ratio of 1:1, and after standing for 24 hours, 20 μL of the mixture was pipetted and dropped onto PDA solid culture medium (20 mL);

[0060] Control group (CK): sterile water and cotton oxysporum Fusarium oxysporum (spore concentration of 1×10 7 After 24 hours of standing, 20 μL of the mixture was dropped in the center of PDA solid culture medium (20 mL), and then inverted and cultured in a 28°C incubator.

[0061] After 3 days of cultivation, the growth of Fusarium oxysporum in the experimental group 1, experimental group 2 and control group was as follows: Figure 2 And as shown in Table 2.

[0062] Table 2 Growth of Fusarium oxysporum in cotton in different treatment groups

[0063]

[0064]

[0065] According to Table 2 and Figure 2 It can be seen that compared with the control group, the mycelium growth of the test group 1 was consistent with that of the control group, and the mycelium growth inhibition rate was 0.133%. The 15 mg / ml flavanone solution could not inhibit the growth of the mycelium of Fusarium oxysporum in cotton; compared with the control group, the mycelium growth of the test group 2 was consistent with that of the control group, and the mycelium growth inhibition rate was 0.400%. The 30 mg / mL flavanone solution could not inhibit the growth of the mycelium of Fusarium oxysporum in cotton.

[0066] Example 2

[0067] Chalcone plate antibacterial test (filter paper method)

[0068] 1. Prepare pathogen plates: 100 μl of Fusarium oxysporum (spore concentration of 1×10 7 The spore suspension (0.174 g / ml) was dropped onto a PDA solid medium (20 ml), and the spore suspension was evenly spread on the PDA solid medium (20 ml) using a spreading rod until the PDA solid medium (20 ml) completely absorbed the spore suspension and no liquid flowed, indicating that the pathogen plate preparation was completed.

[0069] 2. After the plate was dried, three sterile filter papers with a diameter of 10 mm were randomly placed. 20 μL of sterile distilled water was added to one filter paper, 20 μL of 50% DMSO was added to another filter paper, and 20 μL of the 10 mg / ml chalcone solution in Example 1 was added to another filter paper. The plate was inverted and cultured in a 28°C incubator. After 3 days, the results were observed. Figure 3 shown.

[0070] according to Figure 3 It can be seen that the sterile filter paper with drops of sterile distilled water and 50% DMSO is full of bacteria, while the sterile filter paper with drops of 10 mg / ml chalcone solution is not full of bacteria, indicating that chalcone can inhibit the mycelial growth of cotton wilt pathogen.

[0071] Comparative Example 2

[0072] With embodiment 1, the difference is:

[0073] After the plate was dried, three sterile filter papers with a diameter of 10 mm were randomly placed on it. 20 μL of sterile distilled water was added to one filter paper, 20 μL of 50% DMSO was added to another filter paper, and 30 μL of the 30 mg / ml flavanone solution in Comparative Example 2 was added to another filter paper. The plate was inverted and cultured in a 28°C incubator. After 3 days, the results were observed. Figure 4 shown.

[0074] according to Figure 4It can be seen that the sterile filter paper with drops of sterile distilled water and 50% DMSO is full of bacteria, while the sterile filter paper with drops of 30 mg / ml flavanone solution is also full of bacteria, indicating that flavanone cannot inhibit the growth of cotton wilt bacteria.

[0075] Example 3

[0076] Experiment on the efficacy of chalcone in potted plants

[0077] The cotton seeds of Sea Island Cotton 06-146 (resistant to wilt), Sea Island Cotton DJ-07-136 (resistant to wilt), Xinhai No. 14 (susceptible to wilt) and NMGB-4 (susceptible to wilt) were sterilized, wrapped in black plastic bags, and placed in a constant temperature incubator at 26°C. The next day, the white cotton seeds were picked out and planted in plastic small pots (with a diameter of 10 cm). The soil ratio was 2 parts by mass of sterile soil + 1 part by mass of vermiculite. Five cotton seeds were planted in each small pot. The cotton was cultured in a cotton culture room with a photoperiod of 16h (light) / 8h (darkness), a temperature of 25°C, and a relative humidity of 60% to 70%.

[0078] When the cotton seedlings grew to two leaves and one heart, the root cutting and fungus dipping method was used to use the cotton oxysporum Fusarium suspension (spore concentration 10 7 Each pot was inoculated with 50 ml of 10 mg / ml chalcone solution. After 3 days, the roots were irrigated with 50 ml of 10 mg / ml chalcone solution in Example 1. Sterile water treatment was used as a control. In the pot test, each treatment was repeated 3 times, with 30 plants in each repeat. The investigation was carried out 14 days after the treatment. The investigation was carried out according to GBT 22101.4-2009 Technical Specifications for Evaluation of Cotton Disease and Insect Resistance Part 4: Fusarium wilt. The investigation grading standards are as follows:

[0079] The main symptoms of cotton wilt in the greenhouse seedling stage are green wilt type and yellow net pattern type. The true leaves and cotyledons wilt, the leaves become soft and droop, the leaf edges begin to wither, the leaf veins turn yellow, and the leaves wilt and the cotton plants die. The classification standards for each disease level are as follows:

[0080] Level 0: The cotton plants are healthy, have no diseased leaves, and grow normally.

[0081] Level 1: 1-2 cotyledons of the cotton plant turn yellow and wilt.

[0082] Level 2: Two cotyledons and one true leaf of the cotton plant turn yellow and wilt, and the leaf veins become yellow reticular.

[0083] Level 3: Two cotyledons and two or more true leaves of the cotton plant turn yellow and wilt, and the leaf veins become yellow reticular or withered; the cotton plant becomes dwarfed or wilted.

[0084] Level 4: All leaves of the cotton plant are infected and the cotton plant dies.

[0085] Statistics of survey results: Calculate the disease index of each variety based on the survey results.

[0086] The disease index is measured as "DI" and is calculated as follows:

[0087] Disease index (DI) = [Σ(d c ×n c ) / (n t ×4)]×100, where d c is the corresponding disease grade, n c is the number of diseased plants at each disease level, n t The total number of plants.

[0088] The calculation results are accurate to two decimal places, as shown in Table 3 and Figure 5 shown.

[0089] Table 3 Effect of chalcone solution root irrigation on cotton wilt disease index

[0090]

[0091]

[0092] According to Table 3 and Figure 5 It can be seen that the cotton seedlings irrigated with chalcone solution showed slower and lighter symptoms of leaf yellowing, wilting and leaf falling than the cotton seedlings irrigated with sterile water as a control, indicating that chalcone has a certain preventive and therapeutic effect on cotton wilt.

[0093] According to the above content, it can be seen that chalcone compounds can inhibit the growth of cotton wilt pathogens, reduce the disease index of cotton wilt disease, and prevent and control cotton wilt disease.

[0094] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. Application of chalcone compounds in inhibiting cotton wilt pathogen; The cotton wilt pathogen is physiological race 7 of Fusarium oxysporum.

2. The use according to claim 1, characterized in that: The inhibiting of cotton wilt pathogen includes inhibiting the growth of mycelium of cotton wilt pathogen.

3. Application of chalcone compounds in the prevention and treatment of cotton wilt; The pathogen of cotton wilt is physiological race 7 of Fusarium oxysporum (F. oxysporum).

4. The use according to claim 3, characterized in that: 10 mL of 5-10 mg / mL chalcone solution was applied to the roots of each cotton seedling.

5. The use according to claim 4, characterized in that: The solvent of the chalcone solution is 50% DMSO solution.

6. A method for preventing and treating cotton wilt, characterized in that: The method comprises the steps of applying a chalcone compound to cotton seedlings; The pathogen of cotton wilt is physiological race 7 of Fusarium oxysporum (F. oxysporum).

7. The method according to claim 6, characterized in that 10 mL of 5-10 mg / mL chalcone solution was applied to the roots of each cotton seedling.

8. The method according to claim 7, characterized in that The solvent of the chalcone solution is 50% DMSO solution.

9. The method according to claim 6, characterized in that The cotton seedlings include cotton seedlings with two leaves and one heart.

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