KR100753360B1 - Composition for protecting plant diseases comprising chitosan oligosaccharides - Google Patents

Abstract

The present invention relates to a composition for controlling chitosan oligosaccharide-containing plant diseases and a method for controlling plant diseases using the same, wherein the composition of the present invention comprising chitosan oligosaccharides having a molecular weight of 3,000 or less as an active ingredient is directed against plant late blight, rust disease, anthrax or blast disease. It shows an excellent prophylactic and therapeutic effect, and in particular, the composition comprising the aliphatic alcohol ethoxylate-based surfactant together with the chitosan oligosaccharide shows an improved therapeutic effect against anthrax of plants, is harmless to humans and does not cause environmental pollution, It is very useful for producing value-added low pesticide-free and pesticide-free agricultural products.

Description

Composition for plant disease control containing chitosan oligosaccharides {COMPOSITION FOR PROTECTING PLANT DISEASES COMPRISING CHITOSAN OLIGOSACCHARIDES}

The present invention relates to a composition for controlling chitosan oligosaccharide-containing plant diseases having a molecular weight of 3,000 or less and a plant disease control method using the same.

Chitin, a raw material of chitosan, is a high-molecular substance present in shellfish and fungi such as crabs, shrimp, and insects. When the acetyl group in the chitin's molecular structure is removed, it becomes a substance called chitosan. Since it is very difficult to remove 100% of chitin, chitosan is actually D-glucosamine and N-acetyl-D in which 65% to 100% of monomer units are D-glucosamine. It is defined as a polymer of glucosamine.

With the development of chitosan manufacturing technology and solubilization technology, the range of use of chitosan has been gradually expanded. Currently, chitosan-related materials are used in various fields such as agriculture, animal husbandry, textiles, and the environment. In the case of health food, it has been known to have various physiological activities such as immune enhancing effect, cholesterol improving effect, and antibacterial effect.In the agricultural field, not only the growth promoting activity of various plants but also the germination and rooting promoting activity during seed coating treatment are reported. It is.

In relation to the control of plant diseases, it is known that when chitosan is treated with seeds, the biochemical properties of germinated plants are greatly changed. These changes include known biochemical changes associated with plant induction resistance, including increased phytoalexin, increased callose production, increased lignin production, and increased activity of chitinase and glucanase enzymes. In addition to the resistance inducing action of these plants, chitosan has been reported to have direct bactericidal activity against various phytopathogens.

The activity against phytopathogens is known to vary greatly depending on the molecular weight of chitosan, pH in solution, degree of deacetylation, and host plants. U.S. Patent No. 5,374,627 reports that chitosan and acetic acid having a molecular weight of 10,000 to 50,000 are effective in vegetable diseases such as vegetable softwood, brown spreading and brown blight, and bacterial rice blight. When two kinds of different molecular weights, namely, chitosan having a molecular weight of 3,000 to 60,000 and chitosan having a molecular weight of 35,000 to 90,000, the antimicrobial range for phytopathogens is widened, and there is a sufficient improvement in disease resistance and growth. The composition includes organic acids such as lactic acid and succinic acid in addition to chitosan, organic salts, dimethyl sulfoxide, alcohols, and surfactants, and the compositions thus prepared are effective in controlling cucumber gray mold and rice blasting, as well as in potatoes. It is also effective in increasing production. However, the compositions containing chitosan and organic acids are used as plant growth regulators and plant disease preventive agents, but there is a problem that the application range is narrow and the effect is unstable, and there is no therapeutic effect required as a crop protection agent.

Moreover, until now, the case where chitosan oligosaccharide with a molecular weight of 3,000 or less is used for a plant disease control technique is not reported.

Accordingly, the present inventors have found that chitosan oligosaccharides having a molecular weight of 3,000 or less, that is, polymers of D-glucosamine and N-acetyl-D-glucosamine have excellent control effects against plant diseases, and in particular, the composition contains aliphatic alcohol ethoxylate-based surfactants. When included together, the present invention was found to be able to significantly improve the preventive effect as well as the therapeutic effect.

Accordingly, it is an object of the present invention to provide an environment-friendly plant disease control composition derived from natural products that is harmless to the human body and exhibits excellent control effects against various plant diseases without causing environmental pollution.

In accordance with the above object, the present invention provides a composition for controlling plant diseases comprising chitosan oligosaccharides having a molecular weight of 3,000 or less of the following formula (1):

Wherein n is an integer from 2 to 15.

In addition, the present invention provides a composition for controlling plant diseases, wherein the composition further comprises an aliphatic alcohol ethoxylate-based surfactant of the formula (2) as an active ingredient:

Lauryl-O (CH ₂ CH ₂ O) _n H

Wherein n is an integer from 1 to 15.

In addition, the present invention provides a method for controlling plant diseases using the composition.

Hereinafter, the present invention will be described in detail.

The chitosan oligosaccharide of Formula 1 is obtained by converting acetamido group into an amino group by hydrolyzing chitin and deacetylating it, and the degree of polymerization (n = glucosamine bond number) of chitosan oligosaccharide used in the present invention is 2 to 15. . The ratio between the acetamido group and the amino group depends on the degree of hydrolysis, and the number of amino groups / (number of acetamido groups + number of amino groups) × 100 is referred to as the degree of deacetylation (%).

Chitosan oligosaccharides used in the present invention are derived from shrimp shells, and commercially available ones may be used. The molecular weight range is 3,000 or less, preferably 320 to 3,000, more preferably 320 to 2,000, the degree of deacetylation is 65% to 95%, and usually contains 75% to 82% of the residues of D-glucosamine. It is preferable to use it in the quantity of 5-15 weight% with respect to the whole aqueous solution composition.

In order to further improve the physiological treatment effect of the composition of the present invention, an aliphatic alcohol ethoxylate-based surfactant, preferably LA-7 surfactant (heptaoxyethylated lauryl alcohol, Heptaoxyethylated lauryl alcohol) is added to the composition. It is preferable to include as. At this time, the aliphatic alcohol ethoxylate-based surfactant is used in an amount of 0.5 to 5% by weight, preferably 1 to 3% by weight based on the total aqueous solution composition.

In addition, in the present invention, in order to further enhance the preventive and therapeutic effects on plant diseases, organic acids such as lactic acid and succinic acid together with chitosan and surfactants may be further added in an amount of 0.0001 to 5% by weight based on the total aqueous solution composition. Can be.

The composition of the present invention exhibits a prophylactic and therapeutic effect on anthrax such as pepper, watermelon, apple, peach, grass, rust disease such as wheat, barley, leek, late blight such as potato, tomato, and rice blast, especially in anthrax and blast It shows an excellent effect against.

The composition of the present invention may be prepared by dissolving chitosan oligosaccharides in water or a surfactant, optionally with an aliphatic alcohol ethoxylate-based surfactant, in an aqueous solution or in powder form, and a carrier or emulsifier commonly used in the preparation of agrochemical compositions. , Dispersants and the like may be further included.

The composition for controlling the present invention can control the plant diseases by spraying or mixing the plants or areas that need to control such as anthrax, late blight, rust or blast, or mixed with the soil, to the crops to be in direct contact with plant pathogens Direct spraying is most preferred.

For example, when spraying a crop directly, the composition of the present invention may be diluted in water and then sprayed on the plant, the throughput of the plant being 200 per plant based on chitosan oligosaccharides although the throughput may vary depending on the type of plant disease. To 2,000 μg / ml, preferably 333 to 1,000 μg / ml.

Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited by the following examples.

Example 1:  Plant Disease Control Effects of Chitosan Oligosaccharides

To investigate the plant disease control effects of lactate chitosan oligosaccharides (molecular weight: 320 to 2,000; Mirae Biotech Co., Ltd.) with a total glucosamine content of 62%, the representative plant diseases are rice blast, rice leaf blight, tomato blight, tomato gray mold The following experiments were carried out on wheat rust, barley flour and pepper anthrax.

First, chitosan oligosaccharides were dissolved in 250 μg / ml Tween 20 aqueous solution to prepare final concentrations of 1,000 μg / ml and 500 μg / ml. Distilled water containing 250 μg / ml of Tween 20 was used as a control. Each of the plants used in the experiment was prepared by filling a pot of about 70% of water or horticultural soil in a plastic pot of 4.5 cm in diameter, and then seeding the seeds and growing them in a greenhouse at 25 ± 5 ° C. for 1 to 4 weeks. The chitosan oligosaccharide sample and the control sample were spray-sprayed at each concentration, and then air-dried for 24 hours, and each pathogen was inoculated by the following method.

(1) rice blast

3-4 leaves of rice seedlings were spray-inoculated with a spore suspension (5 × 10 ⁵ spores / ml) of B. aureus ( Magnaporthe grisea, Korea Research Institute of Chemical Research), and then wet-treated in a room at 25 ° C. for one day. Then, incubated for 5 days in a constant temperature room at 25 ℃.

(2) rice leaf blight

After incubating for 7 days in a medium (90 g of wheat bran, 15 g of chaff, 100 ml of distilled water) , the leaf blight bacteria ( Tantanporus cucumeris, Korea Research Institute of Chemical Technology) were inoculated into 5 leaf rice seedlings. After wet treatment for 4 days in a 25 ℃ humid room, and incubated for 4 days in a constant temperature room at 25 ℃.

(3) tomato plague

Of Plague Bacteria ( Phytophthora infestans, Phytophthora infestans, Gangneung University) After spray-inoculating the saponist suspension extracted from the safflower sac (1 × 10 ⁵ sac sac / ml), it was wet-treated at 25 ° C. for 2 days and incubated at 25 ° C. for 2 days.

(4) tomato gray mold

After treating 3-4 leaf tomato seedlings with spore suspension (1 × 10 ⁶ spores / ml) of ash fungus ( Botrytis cinerea, Korea Research Institute of Chemical Technology), incubated for 3 days in 20 ℃ It was.

(5) Wheat Red Rust

Spores of Pseudomonas aeruginosa ( Puccinia recondita, Incheon University) spores in one-leaf wheat seedlings were sprayed with a suspension of 0.67 g spores / l in a 250 µg / ml Tween 20 solution at 20 ° C. After a day of treatment in a humid room of 20 ℃ was transferred to a constant temperature room and incubated for 6 days.

(6) wheat flour

Inoculate spores of powdery mildew bacteria ( Erysiphe graminis f. Sp. Hordei, Korea Research Institute of Chemical Research) that were passage-cultured on host plants to seedling barley seedlings. Incubated for days.

(7) pepper anthrax

5-6 leaf pepper seedlings were sprayed with a spore suspension (1 × 10 ⁶ spores / ml) of pepper anthrax pathogens ( colletotrichum coccodes , Chungbuk National University) for 2 days in a wet room and The cells were incubated for 2 days in a constant temperature room.

Rice blast, wheat rust and barley powdery mild disease were 7 days after inoculation, rice leaf blight blight was 8 days after inoculation, tomato ash fungus 3 days after inoculation, and tomato blight and pepper anthrax 4 days after inoculation. Lesion area ratio was investigated. The control value was calculated according to the following Equation 1 from the investigated lesion area ratio to confirm the preventive effect on each plant disease, and the results are shown in Table 1 below.

As shown in Table 1, chitosan oligosaccharides showed a high preventive effect against pepper anthrax, rice blast, tomato late blight and wheat red rust. However, the effect was very low or little on rice leaf blight, tomato gray mold and barley powdery mildew.

Example 2:  Long-lasting Effects of Chitosan Oligosaccharides on Plant Disease

In order to investigate the sustained effect on plant diseases, among the four plant diseases showing a high preventive effect in Example 1, except that the samples were treated three days before the inoculation for tomato late blight, wheat red rust and pepper anthrax The experiment was conducted in the same manner as in Example 1, and the results are shown in Table 2 below.

As shown in Table 2, the three days before the inoculation of chitosan oligosaccharide against tomato late blight, wheat red rust and pepper anthrax showed a relatively lower prophylactic effect than the one day before inoculation, indicating that the chitosan oligosaccharide was plant surface. Even in more than 3 days it can be seen that the drug is stable.

Example 3:  Effects of Chitosan Oligosaccharides on Plant Disease

In order to investigate the therapeutic effect of chitosan oligosaccharides on plant diseases, experiments were conducted in the same manner as in Example 2 except that the samples were treated about 16 hours after inoculation of pathogens, and the results are shown in Table 3 below. It was.

As shown in Table 3, chitosan oligosaccharides showed a certain therapeutic effect against pepper anthrax, but little treatment effect against tomato late blight and wheat red rust.

Example 4:  Selection of Surfactants with Excellent Treatment Effect against Red Pepper Anthrax

In order to investigate the surfactant for enhancing the therapeutic effect of chitosan oligosaccharides against red pepper anthrax, the experiment was carried out in the same manner as in Example 3 except for treating each of the eight surfactants shown in Table 4 instead of Tween 20. The results are shown in Table 4 below.

As shown in Table 4, it can be seen that LA-7 has the strongest therapeutic effect against pepper anthrax.

Example 5:  Effects of Chitosan Oligosaccharides and LA-7 on Plant Disease

Prevention of 1 day before inoculation of pepper anthracnose of LA-7 and chitosan oligosaccharide mixtures using a solution of 500 μg / ml of chitosan oligosaccharide in 250 μg / ml Tween 20 or LA-7 aqueous solution The therapeutic effect was investigated in the same manner as in Example 1 and Example 3, compared with the case of using only chitosan oligosaccharides and the results are shown in Table 5 below.

As shown in Table 5, when the chitosan oligosaccharides and LA-7 at the same time when the prevention effect is similar to the case of using only chitosan oligosaccharides, it can be seen that the treatment effect is much better.

The composition comprising the chitosan oligosaccharide according to the present invention exhibits an excellent preventive effect against plant late blight, rust and rice blast, exhibits a therapeutic effect against anthrax, and when used with an aliphatic alcohol ethoxylate-based surfactant against anthrax In addition to the improved therapeutic effect, there is little risk of toxicity or environmental pollution to humans or livestock, it can be useful for the production of high value-added low pesticide-free and pesticide-free agricultural products.

Claims (7)

A method for controlling a plant disease selected from the group consisting of anthrax, late blight, rust, and blasting, comprising directly treating a plant composition comprising a chitosan oligosaccharide having a molecular weight of 320 to 3,000 as an active ingredient to a plant. The method of claim 1, The chitosan oligosaccharide has a degree of deacetylation of 65% to 95%. The method of claim 1, A method for controlling plant diseases, characterized in that the chitosan oligosaccharides comprise 5 to 15% by weight of the total composition. The method of claim 1, A method for controlling plant diseases, characterized in that it further comprises an aliphatic alcohol ethoxylate surfactant. The method of claim 4, wherein Wherein the aliphatic alcohol ethoxylate-based surfactant is LA-7 (heptaoxyethylated lauryl alcohol). The method of claim 4, wherein Aliphatic alcohol ethoxylate surfactant is included in an amount of 0.5 to 5% by weight based on the total composition. The method of claim 1, A method for controlling plant diseases, characterized in that the treatment of 200 to 2,000 μg / ml based on chitosan oligosaccharides.