Application of itaconic acid in prevention and treatment of plant root-knot nematode

Abstract

The invention provides application of itaconic acid in prevention and treatment of plant root-knot nematodes, and belongs to the technical field of application of chemical drugs and biopesticides. According to the invention, plant root-knot nematode is taken as a target, and an in-vitro biological test shows that itaconic acid has an excellent poisoning effect on second-stage larvae of meloidogyne incognita; a seed coating test shows that when the concentration of IA is 50-300 mg / L, tomato seeds are soaked for 24 h, and the nematode number and the root knot number of the tomato root meloidogyne incognita in each development stage can be effectively reduced; a pot experiment shows that when the concentration of IA is 50-300mg / L, the root-knot occurrence rate can be reduced and the growth of the tomato seedlings can be promoted by performing root irrigation treatment on the tomato seedlings inoculated with the meloidogyne incognita; greenhouse field tests show that when the concentration of IA is 50-500 mg / L, the root knot index of field tomato meloidogyne incognita can be slowed down, meanwhile, tomato plant growth is promoted, and the optimal use concentration is 250 mg / L.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical medicine and biological pesticide application, and particularly relates to the application of itaconic acid in preventing and controlling plant root-knot nematodes. Background Art

[0002] Plant parasitic nematodes are one of the most difficult to control vegetable and crop pests, with a wide distribution range and serious damage. Among them, root-knot nematodes are internationally recognized destructive pests. They mainly live in the soil or parasitize on the root system of plants. They are hidden and difficult to control. Root-knot nematode disease causes serious reductions in the yield of vegetables, fruits and crops, causing serious economic losses every year worldwide. The disease has now become an important factor restricting the healthy development of facility agriculture, among which the southern root-knot nematode (Meloidogyne incognita) is the most serious. Southern root-knot nematodes are the dominant root-knot nematodes in facility agriculture, with more than 1,700 host plants. Every year, root-knot nematode infection causes a 30% reduction in vegetable yields, resulting in economic losses of more than 3 billion yuan. Nematode-resistant resources have great development prospects, but the progress made in the exploration of nematicidal resources is very limited. It is urgent to accelerate the exploration of effective compounds for controlling plant parasitic nematodes.

[0003] Itaconic acid (IA) is a dicarboxylic acid with a chemical formula of C5H6O4, also known as methylene succinic acid, with a molecular weight of 130.08Da, and exists in nature mainly in the form of white powdery crystals or colorless crystals. Itaconic acid is widely used in light industry, agriculture, medical treatment, energy and other fields. In agricultural applications, the hydrogel made by mixing itaconic acid with urea is mainly used for the cultivation of hydroponic plants. The hydrogel has strong hydrophilicity and can effectively control the release of water-soluble chemicals. In addition, itaconic acid is copolymerized with some water-soluble herbicides to effectively control the release of herbicides. Despite this, the application of itaconic acid's biological activity in agriculture has yet to be explored, especially its role in preventing and controlling plant parasitic nematodes is still in a blank state. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide an application of itaconic acid in preventing and controlling plant root-knot nematodes. The present invention takes plant root-knot nematodes as targets, and through in vitro biological test experiments, it is found that itaconic acid has a significant toxic effect on the active second-instar larvae of southern root-knot nematodes. Through seed coating experiments, potted plant experiments and field experiments, it is found that low-concentration itaconic acid can effectively alleviate the occurrence of root-knot nematode disease and promote the growth of tomato plants.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention provides application of itaconic acid in preventing and controlling plant root-knot nematodes.

[0007] Preferably, the root-knot nematode is Meloidogyne incognita.

[0008] Preferably, the concentration of itaconic acid is 50-1000 mg / L.

[0009] Preferably, the itaconic acid is used as a seed coating agent for controlling root-knot nematodes.

[0010] Preferably, the itaconic acid is used as a seed coating agent at a concentration of 50 to 300 mg / L.

[0011] Preferably, the itaconic acid is used as a root irrigation solution for controlling root-knot nematodes.

[0012] Preferably, the itaconic acid is used as a root irrigation solution at a concentration of 50 to 1000 mg / L.

[0013] Preferably, the dosage of the root irrigation solution is 100-300 mL / plant.

[0014] Preferably, the plant is tomato.

[0015] Preferably, the tomato variety is L-402.

[0016] Compared with the prior art, the present invention has the following beneficial effects: the present invention provides an application of itaconic acid in preventing and controlling plant root-knot nematodes. The present invention takes plant root-knot nematodes as targets, and through in vitro biological test experiments, it is found that different concentrations of itaconic acid standard products have excellent toxic effects on the second-instar larvae of southern root-knot nematodes; through seed coating experiments, it is found that when the IA concentration is 50-300 mg / L, soaking tomato seeds for 24 hours can effectively reduce the number of nematodes and the number of root knots at various developmental stages of southern root-knot nematodes at the tomato roots; through potted plant experiments, it is found that when the IA concentration is 50-300 mg / L, root irrigation treatment of tomato seedlings infected with southern root-knot nematodes can reduce the incidence of root knots and promote the growth of tomato seedlings; through greenhouse field experiments, it is found that when the IA concentration is 50-500 mg / L, the root knot index of southern root-knot nematodes in field tomatoes can be slowed down and the growth of tomato plants can be promoted, and the optimal concentration is 250 mg / L. The invention studies the use of itaconic acid in preventing and controlling plant root-knot nematodes, and the results show that itaconic acid can effectively prevent and control plant root-knot nematodes, thus providing a new prevention and control approach for the prevention and control of agricultural harmful pathogenic nematodes. DETAILED DESCRIPTION

[0017] The invention provides application of itaconic acid in preventing and controlling plant root-knot nematodes.

[0018] In the present invention, the root-knot nematode is Meloidogyne incognita; the concentration of itaconic acid is 50 to 1000 mg / L, preferably 80 to 900 mg / L, and more preferably 800 mg / mL.

[0019] In the present invention, the itaconic acid is used as a seed coating agent for preventing and controlling root-knot nematodes; the method for using the itaconic acid as a seed coating agent is: soaking the seeds in an itaconic acid solution with a concentration of 50 to 300 mg / L for 22 to 26 hours, the concentration of the itaconic acid solution is preferably 80 to 150 mg / mL, more preferably 100 mg / mL, and the soaking time is preferably 23 to 25 hours, more preferably 24 hours.

[0020] In the present invention, the itaconic acid is used as a root irrigation liquid for preventing and controlling root-knot nematodes; the use concentration of the itaconic acid as a root irrigation liquid is 50-1000 mg / L, preferably 100-500 mg / mL, and more preferably 250-300 mg / mL; the dosage of the root irrigation liquid is 100-300 mL / plant, preferably 150-250 mL / plant, and more preferably 200 mL / plant; the timing for using itaconic acid as a root irrigation liquid to irrigate the roots of plants is the plant seedling stage, preferably when the plant seedlings grow to the four-leaf stage.

[0021] In the present invention, the plant is tomato; the variety of tomato is L-402.

[0022] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0023] Example 1 Bioassay of itaconic acid (IA) against southern root-knot nematode (Meloidogyne incognita)

[0024] The roots of tomato plants infected with southern root-knot nematodes (Meloidogyne incognita) were collected from the greenhouse of the Northern Nematode Research Institute of Shenyang Agricultural University, Shenhe District, Shenyang, Liaoning Province, China. The tomato roots were gently washed with sterile distilled water, and root-knot nematode eggs were picked from the roots and placed in a culture dish. The roots were disinfected with 0.5% sodium hypochlorite solution for 4±1 min in a sterile operating table, rinsed with sterile distilled water for 4±1 times, and 30 mL of sterile distilled water was added. After incubation in a 25°C incubator for 4±1 days, the worm suspension was collected into a 50 mL centrifuge tube for later use.

[0025] The collected second-instar larvae of southern root-knot nematode (Meloidogyne incognita) were used as the target organisms for bioassay. The bioassay was carried out on a commonly used 24-well plate. 400 μL of IA solution of known concentration (specific concentrations are shown in Table 1) was added to 100 μL of worm suspension, about 40 worms. The blank treatment was treated with an equal amount of sterile deionized water (ddH2O). After 24 hours, the number of dead nematodes was counted and the mortality rate was calculated. The test results are shown in Table 1.

[0026] Mortality rate (%) = number of dead nematodes / total number of nematodes × 100.

[0027] Table 1IA Bioassay against Meloidogyne incognita

[0028]

[0029]

[0030] The results of bioassay showed that itaconic acid had a good toxic effect on the second-instar larvae of the southern root-knot nematode (Meloidogyne incognita).

[0031] Example 2 Itaconic acid (IA) seed coating treatment test

[0032] Tomato seeds were surface disinfected by soaking in 1% (V / V) sodium hypochlorite solution for 5 min and washed 3 times with distilled water. The seeds were soaked in IA solution (50 mg / L, 100 mg / L and 300 mg / L) for 24 h for coating, and sterile distilled water was used as a blank control (ddH2O). 30 seeds were treated in each treatment group. The coated seeds were sown in a seedling tray with a matrix (purchased from Pinstop Horticulture (Shanghai) Co., Ltd.), vermiculite and sand in a mass ratio of 2:1:1. The seedling tray was placed in an artificial climate chamber with a temperature of 28±2°C and a relative humidity of 60%. When the seeds germinated and grew to the four-leaf stage, they were transplanted into 13 cm × 12 cm plastic pots filled with substrate, vermiculite, and sand in a mass ratio of 2:1:1 and placed in a greenhouse at a temperature of 28 ± 2 °C and a relative humidity of about 60%. After 3 days of planting, each seedling was inoculated with 1 mL of nematode suspension (about 500 active second-instar larvae of southern root-knot nematodes).

[0033] After 14 days of cultivation of seedlings inoculated with nematodes, the number of root knots in each treatment root was counted, and then the root samples were bleached with 5% (V / V) sodium hypochlorite solution for 4 minutes, rinsed with running water for 1 minute, and soaked in distilled water for 15 minutes to remove the residual sodium hypochlorite solution. The root samples were then heated and boiled in acid fuchsin solution for 3 minutes, rinsed with running water to remove the surface dye, and then heated in acidified glycerol solution (containing 50mL glycerol and 5 drops of concentrated hydrochloric acid solution with a concentration of 5mol / L) for 1.5 minutes and cooled for use. The number of nematodes at different developmental stages in tomato roots was counted using a stereomicroscope. The test results are shown in Table 2.

[0034] Table 2 Effects of IA seed coating on the development of southern root-knot nematodes

[0035]

[0036] Note: Data are expressed as mean ± standard deviation. Different letters in the same column indicate significant differences at P < 0.05 level as tested by Duncan's method.

[0037] The results of the experiment showed that the use of IA as a seed coating agent could significantly reduce the number of root knots and total nematode numbers, while inhibiting the development of southern root-knot nematodes in tomato roots.

[0038] Example 3 Effect test of itaconic acid (IA) root irrigation on controlling southern root-knot nematode in potted plants

[0039] The potted effect test of itaconic acid (IA) against southern root-knot nematodes was conducted in the greenhouse of the Northern Nematode Research Institute of Shenyang Agricultural University, using tomatoes (L-402) sensitive to Meloidogyne incognita as the test material. Tomato seeds were surface disinfected in 1% (V / V) sodium hypochlorite solution for 5 minutes, rinsed with sterile distilled water 5 times, and sown in a seedling pot with a matrix (purchased from Pinstop Horticulture (Shanghai) Co., Ltd.), vermiculite and sand in a mass ratio of 2:1:1. When the tomato seedlings grew to the four-leaf stage, they were transplanted into 12×12 cm pots. After 1 to 2 days of planting, 2 mL of nematode suspension (about 2000 second-instar larvae of southern root-knot nematodes) was inoculated in each pot, and 200 mL of IA solution of different concentrations was irrigated to the roots at the same time. The same volume of sterile distilled water was irrigated to the roots as a blank control (specific concentrations are shown in Table 3). Treatment modes: ddH2O (irrigation with sterile distilled water, no nematode inoculation), IA (irrigation with IA solution, no nematode inoculation), IA+RKN (irrigation with IA solution, nematode inoculation), ddH2O+RKN (irrigation with sterile distilled water, nematode inoculation). An investigation was conducted 30 days after root irrigation, and the test results are shown in Table 3.

[0040] The root knot index grading standard is as follows: level 0, index value is 2, no root knots; level 1, index value is 1, there are some small root knots on the fibrous roots; level 2, index value is 5, there are some obvious small root knots on the fibrous roots, and no root knots on the taproot; level 3, index value is 10, there are some obvious large root knots on the fibrous roots, and no root knots on the taproot; level 4, index value is 25, most of the fibrous roots are large root knots, and there are no root knots on the taproot; level 5, index value is 50, half of the root system has root knots, and there are also root knots on the taproot; level 6, index value is 75, a large number of root knots appear on the taproot; level 7, index value is 90, most of the taproots have root knots; level 8, index value is 100, all taproots have roots.

[0041] Root knot index (%) = Σ[(number of diseased plants at each level × relative level value) / (total number of plants surveyed × highest level value)] × 100

[0042] Control effect (%) = [(control root knot index value - treatment root knot index value) / control root knot index value] × 100.

[0043] Table 3 Effects of IA root irrigation on the growth of tomato seedlings and its control effect on southern root-knot nematodes

[0044]

[0045]

[0046] Note: Data are expressed as mean ± standard deviation. Different letters in the same column indicate significant differences at P < 0.05 level as tested by Duncan's method.

[0047] Pot experiments showed that root irrigation with the experimental concentration of IA solution could effectively improve the control effect against southern root-knot nematodes and promote the growth of tomato seedlings.

[0048] Example 4 Field test on the effect of itaconic acid (IA) root irrigation on the control of southern root-knot nematodes

[0049] The field test of itaconic acid (IA) against southern root-knot nematodes was conducted in a field seriously infected with southern root-knot nematodes (Meloidogyne incognita) in Liaozhong County, Liaoning Province. Tomato (L-402) sensitive to Meloidogyne incognita was used as the test material. Tomato seeds were surface disinfected in 1% (V / V) sodium hypochlorite solution for 5 minutes, rinsed with sterile distilled water 5 times, and sown into a sterile substrate, vermiculite and sand in a mass ratio of 2:1:1 seedling pots. When the tomato seedlings grew to the four-leaf stage, they were transplanted and irrigated with 200mL of IA solution of different concentrations (specific concentrations and treatment modes are shown in Table 4). Abamectin (Abamentic) with an equal volume concentration of 100mg / L was used as a drug control. Abamectin was purchased from Beijing Solebow Technology Co., Ltd., and tap water (Water) with an equal volume of irrigated roots was used as a blank control. An investigation was conducted 30 days after root irrigation. The test results are shown in Table 4.

[0050] Table 4IA root irrigation control effect of southern root-knot nematode potted plants

[0051]

[0052] Note: Different uppercase and lowercase letters indicate significant differences at P<0.05 and P<0.01 levels as tested by Duncan's method.

[0053] Field trials showed that when the experimental IA concentration was between 50 and 500 mg / L, IA could effectively reduce the root knot index of tomatoes in the field and effectively prevent the occurrence of tomato root knot nematode disease.

[0054] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Application of itaconic acid in controlling plant root-knot nematodes.

2. The use according to claim 1, characterized in that: The root-knot nematode is the southern root-knot nematode.

3. The use according to claim 1, characterized in that: The concentration of itaconic acid is 50-1000 mg / L.

4. The use according to claim 1, characterized in that: The itaconic acid is used as a seed coating agent for preventing and controlling root-knot nematodes.

5. The use according to claim 4, characterized in that: The concentration of itaconic acid used as a seed coating agent is 50-300 mg / L.

6. The use according to claim 1, characterized in that: The itaconic acid is used as a root irrigation solution for preventing and controlling root-knot nematodes.

7. The use according to claim 6, characterized in that: The concentration of itaconic acid used as root irrigation solution is 50-1000 mg / L.

8. The use according to claim 7, characterized in that: The dosage of the root irrigation solution is 100-300 mL / plant.

9. The use according to claim 1, characterized in that: The plant is tomato.

10. The use according to claim 9, characterized in that: The tomato variety is L-402.

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