JP2018052866A - Plant growth regulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plant growth regulator.SOLUTION: The plant growth regulator comprises a compound represented by general formula 1, or a salt or ester thereof. [In the formula, (A-A-A-A) is (N=CH-CH=CH) or (NH-CH-CH-CH); Rand Rare each independently H, an alkyl group or a halogen atom; and Ris a hydroxyl group or an alkoxy group.]SELECTED DRAWING: None

Description

  The present invention relates to a plant growth regulator.

  In the agricultural field, controlling plant growth is an important technique for improving productivity. Currently, various types of plant growth regulators aimed at controlling plant growth have been put into practical use, and plant growth regulators contribute to the improvement of crop yield and product quality. Plant growth regulators include both those that promote and inhibit the growth of any plant tissue. For this reason, a wide range of materials such as rooting promoters, fruit accelerating agents, fruit enlargement promoters, fruit tree fruiting agents, fruit coloring promoters, drought agents, and herbicides are included as plant growth regulators.

Among plant tissues, roots play a very important role in plant establishment, water absorption, nutrient absorption, and prevention of lodging, so it is important to promote their development.
Plant roots are composed of main roots, lateral roots and adventitious roots, and these are collectively called the root system. The main root has already developed at the seed stage and grows simultaneously with germination. For this reason, if the growth of the main root can be promoted, the absorption of moisture and nutrients in the soil can be promoted from the beginning, the initial growth can be promoted, and the initial drought stress tolerance can be imparted. Lateral roots differentiate and develop from the main roots. For this reason, if the growth of lateral roots can be promoted, the surface area of the roots can be dramatically increased, the absorption of moisture and nutrients in the soil is promoted, the overall growth can be promoted, and resistance to drought stress is imparted. can do. Adventitious roots differentiate and develop from tissues other than roots such as stems and leaves. For this reason, roots generated from cultured cells of plants and roots generated from above-ground tissue sections such as cuttings and leaves are classified as adventitious roots, which promotes the development of adventitious roots in order to promote so-called vegetative propagation efficiently. Has become an important industrial technology. In addition, monocotyledonous plants such as gramineous crops stop the growth of young roots shortly after germination, and most roots except seed roots are adventitious roots generated from stems and are also called crown roots. Promoting the occurrence of these adventitious roots is important in ensuring stable growth of gramineous plants. Adventitious root formation is particularly important for the growth and prevention of lodging of the main crops such as rice, wheat and corn.

A plant growth regulator having an action of promoting the development of these roots is desired. However, there are few plant growth regulators that promote rooting, and the effects are not sufficient. In addition, conventional substances that promote root development often have undesirable effects. For example, auxin compounds that act as plant hormones that are currently widely used as rooting agents are toxic to plants depending on the type and state of the plant and the concentration applied, such as chlorosis and death of stems and leaves. It has been pointed out to have an undesirable effect.
In addition, the following can be illustrated as a prior art.
WO 2011/136285 (Patent Document 1) describes that a compound having a dichlorophenyl group, a difluorophenyl group, or the like generates eucalyptus adventitious roots.
JP-A-5-260869 (Patent Document 2) describes that adventitious roots can be induced in the stem of sweet potato when auxin and α-naphthaleneacetic acid are used in combination.
Further, JP-A-5-49484 (Patent Document 3) describes a technique for inducing adventitious roots by culturing callus of lemon balm in a medium supplemented with auxin.

In addition, as a fruit accelerating and accelerating action of auxin, fruit enlargement, fruit enlargement accelerator, fruit tree fruit extraction and fruit coloring accelerator using auxin's ethylene generation accelerating action, 4-chloro Phenoxyacetic acid, dichloroprop, ethiclozate, etc. have been put into practical use. 2,4-D, 2,4-PA, MCPA, etc. have been put to practical use as herbicides for broad-leaved plants utilizing the endogenous hormone disrupting action of auxin. However, these plant growth regulators are also small in number, are not sufficiently effective, and often have undesirable effects.
As described above, among the plant hormones having rooting promoting action, a chemically synthesized product developed based on auxin is also called super auxin and is mainly used as a herbicide (Non-patent Document 1). For example, quinclorac (Quinclorac, 3,7-dichloro-8-quinolinecarboxylic acid (see Patent Documents 4 and 5)) and quinmerac (Quinmerac, 7-chloro-3-methyl-8-) which are 8-quinolinecarboxylic acid derivatives. There are quinoline carboxylic acids (see Patent Document 6), etc. In addition, 5-chloro-3-methyl-8-quinoline carboxylic acid has been found to have a herbicidal action (see Patent Document 7). -Derivatives of quinolinecarboxylic acid that have a chlorine atom bonded to the 3rd position, or that have a methyl group substituted or that have a chlorine atom bonded to the 7th position show a herbicidal action by exhibiting strong auxin activity However, there was no knowledge that 8-quinolinecarboxylic acid derivatives, which are unsubstituted at the 3-position and the 7-position, have a plant growth-regulating action without growth inhibition.

International Publication No. 2011/136285 Pamphlet JP 05-260869 A JP 05-049484 A U.S. Pat.No. 4,497,651 U.S. Pat.No. 4,632,696 German Patent Application No. 3,233,089 Japanese Examined Patent Publication No. 04-075232

Grossmann 2010. Auxin herbicides: current status of mechanism and mode of action.Pest Maneg. Sci. 66: 113-120.

  An object of the present invention is to provide a plant growth regulator.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have promoted rooting of a specific compound of a quinoline-8-carboxylic acid derivative, which has not previously been found to have a plant growth regulating action, and further improves the root system. It has been found that it has a plant growth regulating action such as promoting the development of the plant, and the present invention has been completed.

That is, the present invention has the following configuration.
1. A plant growth regulator comprising the compound represented by formula 1 or a salt thereof.

However, -A1-A2-A3-A4- and R1 to R3 in the general formula 1 have one of the following structures.
-A1-A2-A3-A4- is -N = CH-CH = CH- or -NH-CH ₂ -CH ₂ -CH _2-
R1 = hydrogen atom, alkyl group, or halogen atom
R2 = hydrogen atom, alkyl group, or halogen atom
1. R3 = hydroxyl group or alkoxy group 2. The plant growth according to 1, wherein —A1-A2-A3-A4- is —N═CH—CH═CH—, wherein R1 is a hydrogen atom, R2 is a hydrogen atom, and R3 is a hydroxyl group or a salt thereof. Regulator.
3. 2. The plant growth according to 1, wherein —A1-A2-A3-A4- is —N═CH—CH═CH—, R1 is a hydrogen atom, R2 is a halogen atom, and R3 is a hydroxyl group, or a salt thereof. Regulator.
4). 4. The plant growth regulator according to 3, wherein R2 is a chlorine atom or a bromine atom.
5. 2. The plant growth according to 1, wherein —A1-A2-A3-A4- is —N═CH—CH═CH—, R1 is a hydrogen atom, R2 is a hydrogen atom, and R3 is an alkoxy group or a salt thereof. Regulator.
6). 6. The plant growth regulator according to 5, wherein R3 is a compound having a methoxy group or a salt thereof.
7). 1. The compound or salt thereof, wherein -A1-A2-A3-A4- is —NH—CH ₂ —CH ₂ —CH ₂ —, R1 is a hydrogen atom, R2 is a hydrogen atom, and R3 is a hydroxyl group Plant growth regulator.
8). Quinoline-8-carboxylic acid, 6-chloroquinoline-8-carboxylic acid, 6-bromoquinoline-8-carboxylic acid (6-Bromo) -quinoline-8-carboxylic acid), Quinoline-8-carboxylic acid methyl ester, 1,2,3,4-tetrahydroquinoline-8-carboxylic acid (1,2,3,4) -Plant growth regulator containing one or more compounds selected from Tetrahydroquinoline-8-carboxylic acid).
A plant rooting agent containing the plant growth regulator according to any one of 9.1 to 8.
10. Fertilizer containing the plant growth regulator in any one of 10.1-8.
11. An agrochemical containing the plant growth regulator according to any one of 1 to 8.

According to the present invention, a novel plant growth regulator is provided. The plant growth regulator of the present invention has high rooting promoting activity.
Further, the plant growth regulator of the present invention has very weak or no side effects as shown by superauxin such as chlorosis of stems and leaves.
The plant growth regulator of the present invention can be used as a rooting promoter at the time of cutting, seedling growing period, and transplanting.
Moreover, in order to promote root system development, the absorption efficiency of a fertilizer component improves, the growth of a plant is accelerated | stimulated, and the crop yield increases.

  The plant growth regulator of the plant of the present invention contains a salt and an ester of the compound represented by the general formula 1 as active ingredients.

However, -A1-A2-A3-A4- and R1-R3 in general formula 1 have one of the following structures.
-A1-A2-A3-A4-=-N = CH-CH = CH- or -NH-CH ₂ -CH ₂ -CH _2-
R1 = hydrogen atom, alkyl group, or halogen atom
R2 = hydrogen atom, alkyl group, or halogen atom
R3 = hydroxyl group or alkoxy group

The above compound is a compound known as 8-quinolinecarboxylic acid, a derivative thereof, or a salt thereof. In the present invention, the compound represented by the above general formula 1 is used as an active ingredient of a plant growth regulator.
The substituent R1 is any one of a hydrogen atom, a halogen atom, and an alkyl group. As a halogen atom, a chlorine atom, a bromine atom, and an iodine atom are preferable. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, i-propyl group, i-butyl group, i-pentyl group and i-hexyl group. A lower alkyl group having 1 to 6 carbon atoms is preferable, and a methyl group is particularly preferable.

  The substituent R2 is any one of a hydrogen atom, a halogen atom, and an alkyl group. As a halogen atom, a chlorine atom, a bromine atom, and an iodine atom are preferable. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, i-propyl group, i-butyl group, i-pentyl group and i-hexyl group. A lower alkyl group having 1 to 6 carbon atoms is preferable, and a methyl group is particularly preferable.

  The substituent R3 is a hydroxy group or an alkoxy group. Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, i-propoxy group, i-butoxy group, i-pentyloxy group, i An alkoxy group having 1 to 6 carbon atoms such as a hexyloxy group is preferable, and a methoxy group is particularly preferable.

Examples of the salt of the compound represented by the general formula 1 include alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts such as calcium salt and magnesium salt, inorganic base salts such as ammonium salt, triethylamine salt and pyridine. Examples thereof include salts with organic base salts such as salts, picoline salts, ethanolamine salts, triethanolamine salts, dicyclohexylamine salts, or organic amine salts of N, N′-dibenzylethylenediamine salts.
Moreover, salts such as inorganic acid salts such as hydrochloride, sulfate and nitrate, organic acid salts such as formate, acetate, propionate, butyrate and lactate are included.

  The compound represented by the general formula 1 can be synthesized by a known method disclosed in WO2008 / 059513. That is, as a synthesis method of quinoline-8-carboxylic acid having an arbitrary substituent at the 6-position (R2), iodine and glycerol are mixed and stirred using anthranilic acid having an optional substituent at the 5-position as a raw material. It can be synthesized by adding dropwise concentrated sulfuric acid. At this time, it is preferable that the addition amount of iodine is 1 to 5 mol% and the addition amount of glycerol is 100 to 200 mass% with respect to the mass of the anthranilic acid derivative. Although there is no restriction | limiting in particular in the dripping amount of concentrated sulfuric acid, When the ease of operation is considered, it is preferable that it is 0.3-1 times amount of mother liquid. In order to collect a purified product from the reaction solution after completion of the reaction, it can be obtained by adding cold water as appropriate, adjusting the pH to 6 to 7 with aqueous ammonia, and then filtering the solid component. When the purity is insufficient, the obtained solid component can be dissolved in an inert organic solvent such as chloroform, dichloromethane, ethanol, methanol, etc., and activated carbon can be added to remove impurities. The purified product can be further purified by a recrystallization method.

As an example of the substitution reaction, a substitution reaction in which R3 is an alkoxy group is illustrated.
By using quinoline-8-carboxylic acid derivative as a raw material and heating to reflux in an alcohol such as methanol, ethanol, propanol or the like in the presence of an acid catalyst such as sulfuric acid or p-toluenesulfonic acid, R3 is converted to an alkyl group. A substituted compound is obtained. At this time, the quinoline-8-carboxylic acid derivative is preferably 1 to 20% by mass, particularly preferably 5 to 10% by mass.
In addition, a compound in which R3 is substituted with a methyl group can be obtained by reacting in methanol in the presence of a methyl esterifying agent such as trimethylsilyldiazomethane using a quinoline-8-carboxylic acid derivative as a raw material. it can.
To collect the product from the reaction solution after the reaction, the reaction solvent is distilled off, a product-soluble organic solvent that is not mixed with water and water are added, the pH of the aqueous phase is adjusted appropriately, solvent extraction is performed, and the organic solvent is extracted. After recovering the solvent layer, it is dried and the organic solvent is distilled off, and then recrystallized from a single or mixed solvent as necessary. Moreover, what is necessary is just to isolate by separation means, such as a high performance liquid chromatography (HPLC), as needed.
In addition, about substitution reaction other than the above, it can carry out easily by a well-known chemical reaction.

As a method of hydrogenating the condensed pyridine ring, quinoline-8-carboxylic acid having an arbitrary substituent is used as a raw material, dissolved in alcohol such as ethanol together with platinum (II) oxide, and reacted in a hydrogen atmosphere. Can be synthesized. At this time, the concentration of the quinoline-8-carboxylic acid derivative with respect to ethanol is preferably 3 to 10%, and the addition amount of platinum (II) oxide is preferably 5 to 10 mol% with respect to the quinoline-8-carboxylic acid derivative. After the synthesis, a purified product can be obtained by using an argon atmosphere and adding a porous adsorbent such as celite to remove impurities. When the degree of purification is insufficient, a purified product can be obtained by elution with a non-hydratable organic solvent such as diethyl ether and distilling off the solvent. The purified product can be further purified by a recrystallization method.
The compound or salt thereof used in the present invention is desirably water-soluble. In the case of a water-insoluble compound, it can be used in the form of being dispersed in water.

  Representative compound names and general formulas useful as plant growth regulators in the present invention are illustrated below. Of course, the present invention is not limited to these compounds.

Compound 1
Quinoline-8-carboxylic acid

Compound 2
6-Chloro-quinoline-8-carboxylic acid

Compound 3
6-Bromo-quinoline-8-carboxylic acid

Compound 4
Quinoline-8-carboxylic acid methyl ester

Compound 5
1,2,3,4-Tetrahydroquinoline-8-carboxylic acid

  The plant growth regulator of the present invention can be used by combining two or more compounds having a plurality of active actions. It can also be used in combination with plant hormones such as auxin.

  The term “plant growth regulation” used in the present invention includes, for example, plant hatching (extension suppression), regulation of flowering time, induction of upright leaves (and improvement of photosynthetic efficiency associated therewith, biomass increasing action), pollen growth Inhibition, flower freshness preservation, plant anti-stress agents (heat, dryness, cold, etc.), weed control by reproductive control, plant aging inhibition, root enlargement, fruit set promotion, fruit enlargement promotion, fruit fall prevention, fruit skin coloring It needs to be interpreted in the broadest sense, including promotion. For example, rooting promoters, plant growth promoters, root system development promoters and the like are typical examples of the plant growth regulator of the present invention, but the plant growth regulator of the present invention is not limited to these. Absent.

  As the plant growth regulator of the present invention, an aqueous solution of a compound can be used as it is as a plant growth regulator, but it can be used in ordinary plant growth regulators such as wettable powders, emulsions, granules, powders, and surfactants. It may be formulated using a carrier. For example, as a solid carrier, mineral powder (kaolin, bentonite, clay, montmorillonite, talc, diatomaceous earth, mica, vermiculite, gypsum, calcium carbonate, phosphorus lime, etc.), vegetable powder (soy flour, wheat flour, wood flour, tobacco) Powder, starch, crystalline cellulose, etc.), polymer compounds (petroleum resin, polyvinyl alcohol resin, polyvinyl acetate resin, polyvinyl chloride, ketone resin, etc.), alumina, waxes and the like can be used. Examples of the liquid carrier include alcohols (methanol, ethanol, propanol, butanol, ethylene glycol, benzyl alcohol, etc.), aromatic hydrocarbons (toluene, benzene, xylene, etc.), chlorinated hydrocarbons (chloroform, Carbon tetrachloride, monochlorobenzene, etc.), ethers (dioxane, tetrahydrofuran, etc.), ketones (acetone, methyl ethyl ketone, etc.), esters (ethyl acetate, butyl acetate, etc.), acid amides (N, N-dimethylacetamide, etc.) , Ether alcohols (such as ethylene glycol ethyl ether), or water can be used.

  As the surfactant used for the purpose of emulsification, dispersion, diffusion, etc., any of nonionic, anionic, cationic and zwitterionic can be used. Examples of surfactants that can be used in the present invention include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, oxyethylene polymer , Oxypropylene polymer, polyoxyethylene alkyl phosphate ester, fatty acid salt, alkyl sulfate ester salt, alkyl sulfonate salt, alkyl aryl sulfonate salt, alkyl phosphate salt, alkyl phosphate ester salt, polyoxyethylene alkyl sulfate ester, Quaternary ammonium salts, oxyalkylamines, lecithin, saponins and the like. If necessary, gelatin, casein, sodium alginate, starch, agar, polyvinyl alcohol and the like can be used as an auxiliary agent.

The plant growth regulator of the present invention is not limited in the form of the preparation, and can be formed into various preparation forms such as powders, granules, granules, wettable powders, flowables, emulsions, and pastes. Other components can be produced by mixing, stirring, spray drying and the like according to a conventional method.
When applied to a plant, it can be used as a soil treatment agent, a foliage treatment agent, a seed treatment agent before sowing, a treatment agent for a plant before transplantation, a treatment agent for a plant at the time of transplantation, or the like. In hydroponics, it may be used by mixing with a hydroponic solution, and in tissue culture, it may be suspended or dissolved in a medium.
When the plant growth regulator of the present invention is applied to a target plant, the root mass and root density increase through an increase in the number of roots such as the number of lateral roots and the number of adventitious roots. Effects such as growth, growth promotion, improvement in water absorption, improvement in fertilization capacity, improvement in utilization of fertilizer components, green retention, improvement in photosynthetic capacity, improvement in water stress resistance, prevention of lodging, and increase in yield can be obtained. Moreover, since the heat rise of the grass family plant is improved, the yield of rice and the like can be improved.

When the plant growth regulator of the present invention is used for spraying, the concentration used is preferably 0.01 to 10000 ppm, more preferably 1 to 5000 ppm, and particularly preferably 5 to 1000 ppm. In particular, when used for seedlings in the seedling raising period, it is desirable to spray 50 to 200 mL of the diluted solution having the above concentration per 1 L of the culture soil. In this case, a spreading agent may be used, and the type and amount of the spreading agent to be used are not particularly limited. In addition, the effect is demonstrated even if foliar spraying.
The amount used when directly applied to the soil, including the case of mixing with fertilizer, is preferably 100 to 10,000 g, particularly 500 to 5000 g per hectare. In particular, when used for seedlings at the seedling raising stage, it is desirable to use 0.001 to 10 g per liter of culture soil. In this case, it may be preliminarily mixed in the culture soil before sowing or may be sprayed during the seedling raising period.

When used for seed treatment before sowing, water, alcohols (methanol, ethanol, etc.), ketones (acetone, etc.), aromatic hydrocarbons (toluene, benzene, etc.), chlorinated hydrocarbons (chloroform, chloride) Methylene, etc.), ethers (diethyl ether, etc.), esters (ethyl acetate, etc.) and other liquid carriers diluted to 0.01-100,000 ppm and sprayed on the dried seeds or immersed in the diluent. And can be absorbed by the seeds. Although it does not restrict | limit especially as immersion time, 1 second-120 minutes are preferable. In addition, the liquid carrier may be evaporated from the treated seeds by air drying, reduced pressure drying, heat drying, vacuum drying, or the like. What was formulated using a solid carrier of mineral powder such as clay can be used by adhering to the seed surface. It can also be mixed with a commonly used seed coating agent or seed coating film to coat the seed.
When used in tissue culture or cell culture, the concentration in the medium of a commonly used medium for plant tissue culture (MS medium, white medium, Gamborg B5 medium, etc.) is preferably 0.01 to 10,000 ppm, particularly preferably. It can be dissolved or suspended in the range of 0.1 to 1000 ppm. In this case, as usual, saccharides as a carbon source (sucrose, glucose, etc.), cytokinins (benzyladenine, kinetin, etc.), auxins (indole acetic acid, naphthalene acetic acid, etc.), gibberellins (GA3) as various plant hormones , GA4, etc.), abscisic acid and the like can be added as appropriate.
When it is directly absorbed by a plant before transplantation, the root or whole of the plant can be used by immersing it in a solution diluted or suspended at a use concentration of 0.1 to 1000 ppm. Moreover, if it is a cutting head, cutting bud, cutting, etc., a base part or the whole can be immersed and used. In this case, the immersion time is preferably 1 second to 1 week, particularly 1 minute to 3 days. What was formulated using a solid carrier of mineral powder may be attached to the root, or in the case of cuttings, cuttings, cuttings, cuttings, etc.
The administration time of the plant growth regulator of the present invention can be used at any time during the growth period, but particularly when applied as a plant growth regulator, before sowing, at the time of sowing, at the time of seedling growth, transplanting This is especially effective before and after work involving cultivated rooting, such as when root growth is hindered or a root is damaged by weather factors.

The plant to which the plant growth regulator of the present invention is applied is not particularly limited. Fresh vegetables such as lettuce, spicy vegetables, leeks such as leek, onion, garlic, beans such as soybeans, peanuts, green beans, peas, azuki bean, other fruit vegetables such as strawberries, radish, turnip, carrots, burdock etc. Roots, taros, cassava, potatoes, sweet potatoes, yams, etc., asparagus, spinach, honeybees, etc., Eustoma, stocks, carnations, chrysanthemum, rice grains, corn, etc., bentgrass , Lawn grasses such as corn borer, oil crops such as rapeseed, sunflower, sugarcane, sugar beet, etc. Sugar crops, fiber crops such as cotton and rush, feed crops such as clover, sorghum and dent corn, deciduous fruit trees such as apples, pears, grapes and peaches, citrus fruits such as Satsuma mandarin, lemon and grapefruit, Woody species such as satsuki, azalea and cedar. Among these, under cultivation such as tomato, pepper, capsicum, eggplant, cucumber, pumpkin, melon, watermelon, celery, parsley, lettuce, leek, onion, asparagus, eustoma, stock, rice, bentgrass, scallop, sugar beet, rush It is particularly effective for plants that are transplanted into plants and plants that grow by rooting from cuts and cuttings such as chrysanthemum, carnation, satsuki, azalea and grape. Examples of the grass family for the purpose of preventing lodging include rice, wheat, barley, rye, corn and the like. Especially when rice and wheat are sprayed at the time of dividing, many adventitious roots are generated, the growth of the whole root system is promoted, and the nutrient absorption efficiency is improved, so that the effect as the plant growth regulator of the present invention is exhibited. preferable.
Application of the plant growth regulator of the present invention to a field or direct application to a plant leads to development of the root system of the cultivated plant, shortening of the growth period, increase in the number of divisions, increase in yield, and the like.

  In addition, for the purpose of improving the effect of the present invention, it can be used in combination with other plant growth regulators (plant hormone agents) as described above, and in some cases, a synergistic effect can be expected. For example, when raising seedlings under conditions such as high planting density, high humidity, lack of sunshine, etc. You may use together with anti- gibberellins (paclobutrazol, uniconazole P, ansimidol, etc.), growth inhibitors (such as daminozide), and ethylene generators (such as ethephon). In cuttings, cuttings, cuttings, and tissue culture, auxin compounds (such as indole acetic acid, indole butyric acid, naphthylacetamide, and naphthalene acetic acid) may be used in combination for the purpose of enhancing rooting promotion effects. You may use together with the gibberellin agent which has a germination promotion effect | action at the time of the seed treatment before sowing.

The plant growth regulator of the present invention can be mixed or used in combination with various insecticides, fungicides, microbial pesticides, fertilizers and the like. In particular, combined use with hydroxyisoxazole, metasulfocarb, metalaxyl and the like, which have been reported to promote rooting in addition to bactericidal action, is effective in combination with bactericides. Mixing with an insecticide that is directly applied to seeds or an insecticide that is used during the seedling stage (thiamethoxam, fludioxonil, metalaxyl, chlorantraniliprole, etc.) is particularly effective.
When used in combination with a fertilizer, the combined use with a seedling fertilizer for the purpose of raising healthy seedlings and the use with a fertilizer applied immediately before transplanting for the purpose of promoting survival are particularly effective. Mixing with a slow-acting fertilizer for the purpose of maintaining the efficacy of the plant growth regulator of the present invention for a long period of time and improving the fertilizer component utilization rate is particularly effective.

  Next, although the manufacture example of a compound 2-the compound 5, the test example of a compound 1-the compound 5 and an Example are shown and this invention is demonstrated further in detail, this invention is not limited to these Examples.

Production Example 1 (Compound 2: Synthesis of 6-chloroquinoline-8-carboxylic acid)
A mixture of 1.01 g of 5-chloroanthranilic acid and 26.6 mg of iodine in 0.76 g of glycerol is vigorously stirred, and 0.44 ml of concentrated sulfuric acid is added dropwise at 65 ° C. to 70 ° C. over 30 minutes at 140 ° C. The reaction was performed for 6 hours. The mixture was brought to room temperature, 17 mL of water at 0 ° C. was added, the pH was adjusted to 6.5 with 28% aqueous ammonia, the solid was washed with cold water, and dried. The obtained residue was dissolved in chloroform, insoluble matters were removed by filtration, activated carbon was added to adsorb impurities, and activated carbon was removed by filtration. The residue obtained by evaporating the solvent was recrystallized under a mixed solution of chloroform and ethyl acetate, and the obtained crystal was washed with ethyl acetate. The solvent was distilled off to obtain 96.2 mg (yield 7.9%) of a compound. NMR, mass spectrum and melting point of this compound were measured to confirm that it was compound 2 (6-chloroquinoline-8-carboxylic acid) having the structure of general formula 3.

Production Example 2 (Compound 3: Synthesis of 6-bromoquinoline-8-carboxylic acid)
A mixture of 1.26 g of 5-bromoanthranilic acid and 23.3 mg of iodine in 0.76 g of glycerol is vigorously stirred, and 0.44 ml of concentrated sulfuric acid is added dropwise at 65 ° C. to 70 ° C. over 30 minutes at 140 ° C. The reaction was performed for 6 hours. The mixture was brought to room temperature, 17 mL of water at 0 ° C. was added, the pH was adjusted to 6.5 with 28% aqueous ammonia, the solid was washed with cold water, and dried. The residue obtained was dissolved in ethanol, filtered, and dried. The residue obtained was dissolved in chloroform, activated carbon was added to adsorb impurities, and the activated carbon was removed by filtration. The residue obtained by distilling off the solvent was recrystallized under a mixed solution of chloroform and ethyl acetate, and the solvent was distilled off to obtain 28.7 mg (yield 2.0%) of the compound. NMR, mass spectrum and melting point of this compound were measured, and it was confirmed that it was compound 3 (6-bromoquinoline-8-carboxylic acid) having the structure of general formula 4.

Production Example 3 (Compound 4: Synthesis of methyl quinoline-8-carboxylate)
85.6 mg of quinoline-8-carboxylic acid was placed under an argon atmosphere and dissolved in 2.5 ml of methanol and 2.5 ml of dichloromethane. After adding 0.8 ml of trimethylsilyldiazomethane and reacting for 30 minutes, the solvent was distilled off. The residue was purified by silica gel column chromatography using a mixed solution of 40% ethyl acetate and 60% hexane as a developing solvent, and the solvent was distilled off to obtain 69.4 mg (yield 77%) of the compound. NMR, mass spectrum and melting point of this compound were measured, and it was confirmed that this compound was compound 4 (methyl quinoline-8-carboxylate) having the structure of general formula 5.

Production Example 4 (Compound 5: Synthesis of 1,2,3,4-tetrahydroquinoline-8-carboxylic acid)
174 mg of quinoline-8-carboxylic acid and 15.3 mg of platinum (II) oxide were dissolved in 3 ml of ethanol, allowed to react under a hydrogen atmosphere and allowed to react for 5 hours, and then under an argon atmosphere. Celite was added to adsorb impurities and removed by filtration. The material obtained by distilling off the solvent was washed with warm diethyl ether, and the solvent was distilled off to obtain 140.8 mg (yield 79%) of the compound. NMR, mass spectrum and melting point of this compound were measured, and it was confirmed that it was compound 5 (1,2,3,4-tetrahydroquinoline-8-carboxylic acid) having the structure of general formula 6.
The NMR measurement results and melting point measurement results of Compounds 2 to 5 are shown in Table 1 below.

Test example <Confirmation test of adventitious root generation induction effect by dipping treatment of azuki bean>
Compounds 1 to 5 were diluted with distilled water to prepare aqueous solutions with concentrations of 0.03 mM and 0.1 mM, adjusted to pH 7 with dilute hydrochloric acid and aqueous sodium hydroxide, and azuki bean root promotion assay (Itagaki et al. 2003. Biological activities and structure-activity relationship of substitution compounds of N- [2- (3-indolyl) ethyl] succinamic acid and N- [2- (1-naphthyl) ethyl] succinamic acid, derived from a new category of root-promoting substance, N- (phenethyl) succinamic acid analogs. Plant Soil 255: 67-75.). Note that the test using only 0.03 mM solution of Compound 3 was not performed.
Azuki bean slices were immersed in 0.03 mM and 0.1 mM test solutions for 72 hours, and the number of adventitious roots generated after 7 days was counted. The number of repetitions was 5. Moreover, when measuring the activity of each compound, what was treated with distilled water as a control was cultured, and the number of adventitious roots was similarly measured. For this reason, the control group showed the total average value measured several times.
The test results are shown in Table 2 below.

As shown in Table 2, the solution containing compounds 1 to 5 showed higher adventitious root generation inducing action and rooting promoting action as compared with the number of adventitious root rooting in the control group.
In particular, Compound 1 showed a rooting rate of 300% or more at a concentration of 0.03 mM and 500% or more at a concentration of 0.1 mM. Further, the compound 2 having a concentration of 0.03 mM and the compounds 4 and 5 having a concentration of 0.03 mM and 0.1 mM showed a rooting rate of 200% or more. In addition, signs such as chlorosis of stems and leaves were not observed.

<Effect in the field>
Compounds 1-5 were mixed in fertilizer and sprayed on corn during field cultivation. Each compound was found to have significant root system development, growth promotion, and increased yield compared to the fertilizer-only field. In addition, chlorosis generation of stems and leaves by spraying was not observed.

<Corn support root increase effect test>
For feed corn (variety LG3215; Snow Brand Seedling Co., Ltd.), 1/1000 amount of spreading agent in 1 mM quinoline-8-carboxylic acid solution (Approach BI: Polyoxyethylene hexitan fatty acid ester: Maruwa Biochemical Co., Ltd.) The plant was added four times every two weeks from the third week after sowing.
Supporting roots were counted for 20 plants 4 months after sowing, and an average value was calculated.
The test results are shown in Table 3 below.

  As shown in Table 3, the solution containing 1 mM quinoline-8-carboxylic acid of the present invention exhibits a strong support rooting effect as compared with the control group, and the compound of the present invention exhibits a strong rooting effect even in soil cultivation. It was clear to do.

Claims (11)

A plant growth regulator comprising the compound represented by formula 1 or a salt thereof.

However, -A1-A2-A3-A4- and R1-R3 in the general formula 1 have any one of the following structures.
-A1-A2-A3-A4- is -N = CH-CH = CH- or -NH-CH ₂ -CH ₂ -CH _2-
R1 = hydrogen atom, alkyl group, or halogen atom
R2 = hydrogen atom, alkyl group, or halogen atom
R3 = hydroxyl group or alkoxy group   The compound according to claim 1, wherein -A1-A2-A3-A4- is -N = CH-CH = CH-, R1 is a hydrogen atom, R2 is a hydrogen atom, and R3 is a hydroxyl group, or a salt thereof. Plant growth regulator.   The compound or a salt thereof according to claim 1, wherein -A1-A2-A3-A4- is -N = CH-CH = CH-, R1 is a hydrogen atom, R2 is a halogen atom, and R3 is a hydroxyl group. Plant growth regulator.   The plant growth regulator according to claim 3, wherein R2 is a chlorine atom or a bromine atom.   The compound or a salt thereof according to claim 1, wherein -A1-A2-A3-A4- is -N = CH-CH = CH-, R1 is a hydrogen atom, R2 is a hydrogen atom, and R3 is an alkoxy group. Plant growth regulator.   The plant growth regulator according to claim 5, which is a compound or a salt thereof in which R3 is a methoxy group. _2. A compound or a salt thereof, wherein —A1-A2-A3-A4- is —NH—CH ₂ —CH ₂ —CH ₂ —, R1 is a hydrogen atom, R2 is a hydrogen atom, and R3 is a hydroxyl group. The plant growth regulator described in 1.   Quinoline-8-carboxylic acid, 6-chloroquinoline-8-carboxylic acid, 6-bromoquinoline-8-carboxylic acid (6-Bromo) -quinoline-8-carboxylic acid), Quinoline-8-carboxylic acid methyl ester, 1,2,3,4-tetrahydroquinoline-8-carboxylic acid (1,2,3,4) -Plant growth regulator containing one or more compounds selected from Tetrahydroquinoline-8-carboxylic acid).   The plant rooting agent containing the plant growth regulator in any one of Claims 1-8.   The fertilizer containing the plant growth regulator in any one of Claims 1-8.   The agrochemical containing the plant growth regulator in any one of Claims 1-8.