JP2021120353A - Plant growth promoting agent - Google Patents

Abstract

To provide a plant growth promoting agent that can safely and effectively promote plant growth, a plant cultivation method, and a plant growth promotion method.SOLUTION: The present invention is characterized by using a viable bacterial cell of Fusarium oxysporum RS-21 strain and/or RS-25 strain. By applying a plant growth promoting agent containing a viable bacterial cell of RS-21 strain and/or RS-25 strain to one or two or more selected from the group consisting of plant seedling soil, plant cultivation soil, plant body and plant seed, the growth of plant can be promoted.SELECTED DRAWING: None

Description

The present invention relates to a plant growth promoter, a plant cultivation method, a plant growth promotion method, and the like.

From the viewpoint of increasing food production and efficient agricultural management, it is desirable to promote the growth of plants and increase the yield of grains, vegetables, fruits, etc. In recent years, plants such as sugar cane (scientific name Saccharum officinarum), corn (scientific name Zea mays), and sorghum (scientific name Sorghum bicolor; also called sorghum or sorghum) have been used as raw materials for bioethanol, so that plant growth It is also desirable from the viewpoint of energy production of biomass raw materials. As described above, since it is desirable to promote the growth of plants, various plant growth promoters have been conventionally developed, and plant growth promoters using microorganisms have also been proposed.

For example, Patent Document 1 discloses that an improved fertilizer containing fertilizer particles, lactic acid bacteria and Bacillus bacteria has an effect of enhancing plant growth, growth or yield. Further, Patent Document 2 discloses that the growth of a plant is promoted by supplying a Bacillus nitrogen-fixing bacterium classified as Bacillus pumilus to the rhizosphere of the plant. Further, Patent Document 3 describes Polaromonas, Barrioborax, Novosphingobium, Nocardioides, Devosia, Mesorhizobium, Sphingobium, Phyllobacterium, Bacillus, Rhizobium or Streptomai. It is disclosed that the growth of a plant is promoted by contacting a microorganism belonging to the genus Phyllobacterium with the seed of the plant or the root of the plant. Further, in Patent Document 4, the growth of plants is promoted by applying Fusarium oxysporum NPF101-2 (FERM P-14236) strain and ES-shi 305 (FERM P-13896) strain to nursery soil. At the same time, it is disclosed that soil diseases are suppressed.

Further, Patent Document 5 describes a step of bringing a non-pathogenic bacterium corresponding to a seed-borne pathogenic bacterium into contact with the flower part of a host plant before and after the flowering period, and a step of contacting the host plant in which the non-pathogenic bacterium obtained after the step is established. A method for producing seeds of a plant resistant to diseases during the seedling raising period, which includes a step of collecting seeds, is disclosed, and examples of the non-pathogenic bacteria include Fusarium spp., Nectria spp., Gibberella spp., Calonectria spp. , Trichoderma spp., Penicillium spp., Talaromyces spp., Acremonium spp., Alternaria spp., Verticillium spp., Bacillus spp., Pseudomonas spp., Xanthomonas spp., Streptomyces spp.

However, it is not known that a specific strain of Fusarium oxysporum exerts an excellent growth promoting effect on plants, and in particular, a specific strain of Fusarium oxysporum has a number of lateral roots of a plant. It was not previously known to increase.

Japanese Patent Publication No. 2008-537531 Japanese Unexamined Patent Publication No. 2014-09696 JP 2015-015933 Japanese Unexamined Patent Publication No. 7-267811 Japanese Patent No. 624001

An object of the present invention is to provide a plant growth promoting agent capable of safely and effectively promoting the growth of a plant, a method for cultivating a plant, a method for promoting the growth of a plant, and the like.

The present inventors conducted diligent research to solve the above problems, selected a tall individual in the field of sorghum bicolor in Ginoza Village, Okinawa Prefecture, and selected an individual with a high plant height, and the microorganisms in the soil of the rhizosphere of the individual. Screening was performed. As a result, the present inventors have found the Fusarium oxysporum RS-21 strain and the RS-25 strain, which have a particularly high plant growth promoting effect, and have completed the present invention.

That is, the present invention
(1) A plant growth promoter containing viable cells of Fusarium oxysporum RS-21 strain, RS-25 strain, or both strains;
(2) A plant lateral root formation promoter containing viable cells of Fusarium oxysporum RS-21 strain;
(3) per agent 1g, agents according to Fusarium oxysporum RS-21 strain and the RS-25 strain of the total number of spores is 10 ⁴ or more above (1) or (2);
(4) The plants are rice family plants, abrana family plants, legume family plants, higanbana family plants, stag beetle family plants, sardine family plants, eggplant family plants, rose family plants, sardine family plants, seri family plants, madder family plants, The agent according to any one of (1) to (3) above, which is a plant selected from Todaiigusa, Aoi, Basho, Hirugao, and Yuri.
(5) The agent according to any one of (1) to (4) above, wherein the plant is a plant belonging to the genus Sorghum of the Gramineae family;
(6) The agent according to any one of (1) to (5) above is applied to one or more selected from the group consisting of plant nursery soil, plant cultivation soil, plant body and plant seed. Plant seedling raising or cultivation method including application steps;
(7) The agent according to any one of (1) to (5) above is applied to one or more selected from the group consisting of plant seedling soil, plant cultivation soil, plant body and plant seed. Plant growth promotion methods, including applicable steps;
(8) Promotion of plant growth exerted by viable cells of RS-21 strain, RS-25 strain, or both strains promotes the rate of increase in weight of the above-ground part, the underground part, or both of the plants. The method for promoting the growth of the plant according to (7) above;
(9) The method for promoting plant growth according to (8) above, wherein the promotion of plant growth exhibited by the RS-21 strain includes an increase in the number of lateral roots of the plant or an increase in auxin-producing sites in the roots;
(10) The method for promoting plant growth according to (9) above, wherein the promotion of plant growth exhibited by the RS-21 strain is due to the secretion of a substance outside the cells;
(11) The plants are rice family plant, abrana family plant, legume family plant, higanbana family plant, stag beetle family plant, sardine family plant, eggplant family plant, rose family plant, uri family plant, seri family plant, madder family plant, The method according to any one of (6) to (10) above, which is a plant selected from Todaiigusa, Aoi, Basho, Hirugao, and Yuri.
(12) Fusarium oxysporum RS-21 strain or Fusarium oxysporum RS-25 strain;
Regarding.

According to the present invention, it is possible to provide a plant growth promoter capable of safely and effectively promoting the growth of a plant, a method for cultivating a plant, a method for promoting the growth of a plant, and the like.

In FIG. 1, 5 types of fungi obtained by screening were inoculated into the rhizosphere soil of sorghum seedlings in an amount of 5 × 10 ⁷ per strain, and after growing for 4 weeks, the above-ground part of each seedling was inoculated. It is a figure which shows the result of having measured the raw weight (g) (n = 6 respectively). The horizontal axis represents the inoculated strain name (RS number) or "Control" (without inoculating the strain). FIG. 2 shows the dry weight (g) of the underground and above-ground parts after inoculating ^{5 × 10 5} RS-21 strains per strain into the rhizosphere soil of the sorghum seedlings and cultivating the sorghum seedlings for one week. It is a figure which shows the result of having measured (n = 6 respectively). The left panel of FIG. 2 shows the dry weight (g) of the above-ground part, and the right panel shows the dry weight (g) of the underground part. The horizontal axis represents the inoculated strain name (RS-21 strain) or "Control" (without inoculation of the strain). FIG. 3 is a diagram showing an outline of a co-culture test for investigating whether the plant growth promoting effect of the strain is due to the volatile organic compound (VOC) produced by the RS-21 strain. FIG. 4 shows the raw weight (g) of the above-ground part of sorghum when the Fusarium oxysporum strain (RS-21 strain or Fo-304 strain) and sorghum were co-cultured for one week in the co-culture device shown in FIG. ) (N = 2 respectively) is a diagram showing the results. The horizontal axis represents the inoculated strain name (RS-21 strain or Fo-304 strain) or "Control" (without inoculating the strain). FIG. 5 shows the raw weight (g) of the underground part of sorghum when the Fusarium oxysporum strain (RS-21 strain or Fo-304 strain) and sorghum were co-cultured for one week in the co-culture apparatus shown in FIG. ) (N = 2 respectively) is a diagram showing the results. The horizontal axis represents the inoculated strain name (RS-21 strain or Fo-304 strain) or "Control" (without inoculating the strain). FIG. 6 measures the raw weight (g) (n = 3 of each) of the above-ground part of Arabidopsis thaliana when Fusarium oxysporum RS-21 strain and Arabidopsis thaliana were co-cultured for one week in the co-culture device shown in FIG. It is a figure which shows the result of this. “PSA” represents the result when the PSA medium was used as the strain culture medium in the co-culture device, and “PDA” represents the result when the PDA medium was used as the strain culture medium in the co-culture device. FIG. 7 measures the raw weight (g) (n = 3 of each) of the underground part of Arabidopsis thaliana when Fusarium oxysporum RS-21 strain and Arabidopsis thaliana were co-cultured for one week in the co-culture device shown in FIG. It is a figure which shows the result of this. “PSA” represents the result when the PSA medium was used as the strain culture medium in the co-culture device, and “PDA” represents the result when the PDA medium was used as the strain culture medium in the co-culture device. FIG. 8 shows the results of observing the state of the roots of Arabidopsis thaliana when Fusarium oxysporum RS-21 strain and Arabidopsis thaliana were co-cultured for one week in the co-culture device shown in FIG. A PDA medium was used as the culture medium for the RS-21 strain. FIG. 9 shows the results of observing the state of roots of Arabidopsis thaliana when the RS-21 strain was not inoculated into the PDA medium in the culture of FIG. FIG. 10 shows the seeds of a transformant in which the auxin-inducible reporter gene DR5 :: GUS was introduced into a wild strain of Arabidopsis thaliana in the co-culture apparatus shown in FIG. 3 (but not inoculated with the RS-21 strain). The result of staining the plant body with GUS stain solution after culturing for 4 days is shown. The arrows in the figure are GUS-stained sites, which represent the expression sites of the auxin-inducible reporter gene. FIG. 11 shows the seeds of a transformant in which the auxin-inducible reporter gene DR5 :: GUS was introduced into a wild strain of Arabidopsis thaliana after co-culturing with the RS-21 strain in the co-culture apparatus shown in FIG. 3 for 4 days. , The result of dyeing the plant body with the GUS stain solution is shown. The arrows in the figure are GUS-stained sites, which represent the expression sites of the auxin-inducible reporter gene. FIG. 12 shows the results of measuring the raw weight (g) (n = 3 of each) of the above-ground part of Arabidopsis thaliana when the RS-21 strain and Arabidopsis thaliana were co-cultured for one week with the co-culture device shown in FIG. It is a figure which shows. The leftmost bar graph shows the results when the RS-21 strain was not inoculated. The horizontal axis represents the type of medium used for the strain culture medium in the co-culture device. "4: 1" or "2: 1" of "+ Sucrose" is a mixture in which the weight ratio of sucrose: glucose is "4: 1" or "2: 1" instead of glucose which is a sugar source of PDA medium. Represents the result when a medium using sucrose: It shows the result when the medium using the mixture which the weight ratio of glucose is "4: 1", "2: 1" or "1: 1" was used. FIG. 13 shows the results of measuring the raw weight (g) (n = 3 of each) of the underground part of Arabidopsis thaliana when the RS-21 strain and Arabidopsis thaliana were co-cultured for one week with the co-culture device shown in FIG. It is a figure which shows. The leftmost bar graph shows the results when the RS-21 strain was not inoculated. The horizontal axis represents the type of medium used for the strain culture medium in the co-culture device. "4: 1" or "2: 1" of "+ Sucrose" is a mixture in which the weight ratio of sucrose: glucose is "4: 1" or "2: 1" instead of glucose which is a sugar source of PDA medium. Represents the result when a medium using sucrose: It shows the result when the medium using the mixture which the weight ratio of glucose is "4: 1", "2: 1" or "1: 1" was used. FIG. 14 shows the raw weight (g) of the above-ground part of Arabidopsis thaliana when co-culturing Arabidopsis thaliana with RS-21 strain or RS-25 strain in the presence of a barium hydroxide aqueous solution group that absorbs carbon dioxide (n, respectively). = 3) is represented. FIG. 15 shows the raw weight (g) (n) of the underground part of Arabidopsis thaliana when Arabidopsis thaliana was co-cultured with RS-21 strain or RS-25 strain in the presence of a barium hydroxide aqueous solution group that absorbs carbon dioxide. = 3) is represented. FIG. 16 shows carbon dioxide generated by the reaction of barium hydroxide and carbon dioxide when co-culturing white inunazuna with RS-21 strain or RS-25 strain in the presence of an aqueous solution group of barium hydroxide that absorbs carbon dioxide. It represents the amount of barium produced (dry weight (g)).

The present invention
[1] Viable bacteria of Fusarium oxysporum RS-21 strain and / or RS-25 strain (hereinafter, also referred to as "the strain of the present invention" including the case of either of these strains and the case of both strains). A plant growth promoter (hereinafter, also referred to as "plant growth promoter of the present invention") containing the body (preferably contained as an active ingredient);
[2] A plant comprising a step of applying the plant growth promoter of the present invention to one or more selected from the group consisting of plant nursery soil, plant cultivation soil, plant body and plant seed. Seedling raising or cultivation method (hereinafter, also referred to as "plant seedling raising / cultivation method of the present invention");
[3] A plant comprising a step of applying the plant growth promoter of the present invention to one or more selected from the group consisting of plant seedling soil, plant cultivation soil, plant body and plant seed. Growth promotion method (hereinafter, also referred to as "plant growth promotion method of the present invention");
[4] A plant lateral root formation promoter (hereinafter, also referred to as "plant lateral root formation promoter of the present invention") containing a viable cell of Fusarium oxysporum RS-21 strain (preferably contained as an active ingredient). );
[5] The step of applying the lateral root morphogenicity promoter of a plant of the present invention to one or more selected from the group consisting of a plant nursery soil, a plant cultivation soil, a plant body and a plant seed. , Plant lateral root formation promoting method (hereinafter, also referred to as "plant lateral root formation promoting method of the present invention");
Etc. are included.

In the present invention, "promoting the growth of a plant" means promoting the rate of increase in the weight of the above-ground part, the underground part, or both of the plants. By promoting the rate of increase in the weight of the above-ground part of the plant, more specifically, promotion of stem elongation, promotion of stem enlargement, promotion of increase in the number of leaves or total area, and promotion of stem branching. One or more selected from facilitation (eg, facilitation of increasing the number of stem branches). By promoting the rate of increase in the weight of the underground part of the plant, more specifically, promotion of lateral root formation (for example, increase in the number of lateral roots), increase in auxin-producing sites in the root (taproot or lateral root, preferably taproot). One or more selected from the group consisting of promotion of root (preferably taproot) elongation and promotion of root (preferably taproot) enlargement, among which, promotion of taproot formation (eg, taproot). One or more selected from the group consisting of an increase in the number of auxin-producing sites in the root (taproot or lateral root, preferably the main root) and promotion of root (preferably lateral root) elongation. Among them, one or two selected from the group consisting of promotion of lateral root formation (for example, increase in the number of lateral roots) and increase in oxine-producing sites in the root (taproot or lateral root, preferably taproot) is more preferable. Can be mentioned.
In the present invention, "promoting plant growth" and "promoting plant growth" mean promoting plant growth, and "plant growth promoting effect" means an effect of promoting plant growth. do.

The degree of promotion of the "plant growth promoting effect" of the plant growth promoting agent of the present invention is not particularly limited, but a plant cultivated by applying the plant growth promoting agent of the present invention (preferably the following method a or method). Compared with the case where the same kind of plant is cultivated by the same method (control) except that the raw weight or dry weight of the above-ground part or the underground part of the plant cultivated in b) is not applied with the plant growth promoter of the present invention. , 1.1 times or more, preferably 1.3 times or more, more preferably 1.5 times or more, still more preferably 1.7 times or more, still more preferably 2 times or more.
(Method a)
Plants 1 on seedling soil or cultivated soil in which seedling plants (for example, plants with 1 to 10 leaves, preferably plants with 1 to 10 leaves of Morokoshi (Sorghum bicolor)) are growing. ^{A total of 1 × 10 5} spores / mL of RS-21 and RS-25 spores per plant was applied (preferably irrigation into seedling growing soil or cultivated soil), and then artificially set at 27 ° C. under natural light conditions. How to grow for 4 weeks in the meteorological room.
(Method b)
A method of cultivating sorghum seeds after immersing sorghum (Sorghum bicolor) seeds in a total of 1 × 10 ⁵ spores / mL (preferably for 10 hours or more) of RS-21 and RS-25 spores. ..

When the plant growth promoter of the present invention is a plant growth promoter containing viable cells of the RS-21 strain, the degree of increase in the "increase in the number of lateral roots" effect of the plant growth promoter is particularly high. Although not limited, the number of lateral roots of a plant cultivated by applying a plant growth promoter containing a viable cell of RS-21 strain shall not apply a plant growth promoter containing a viable cell of RS-21 strain. Except for the case where the same kind of plant is cultivated by the same method (control), it is preferably 1.1 times or more, preferably 1.2 times or more, and more preferably 1.3 times or more.

(Strain of the present invention)
The microorganism used in the present invention is a viable cell of Fusarium oxysporum RS-21 strain and / or RS-25 strain (strain of the present invention). Examples of such "live cells" include spores, spore-like cells, and mycelium, and among them, spores and spore-like cells are preferably mentioned from the viewpoint of being easier to use and obtaining a higher plant growth promoting effect. .. In the present invention, the entire culture in which the strain of the present invention is cultured may be used as it is as a viable cell of the strain of the present invention, or spores and spores separated from the culture by a method such as filtration or centrifugation. Mycelium may be used, but mycelium may be contained. In addition, the viable cells of the strain of the present invention may contain dead cells.

(Strain information of Fusarium oxysporum RS-21 strain)
Fusarium oxysporum RS-21 strain is a strain isolated from the rhizosphere of a tall sorghum individual selected in the field of sorghum (Sorghum bicolor) in Ginoza Village, Okinawa Prefecture. The RS-21 strain is stored in the Plant Pathology Laboratory (TEL042-367-5691), Faculty of Agriculture, Tokyo University of Agriculture and Technology (3-5-8 Saiwaicho, Fuchu-shi, Tokyo (Zip Code 183-8509)) and is required. Accordingly, it will be sold under certain conditions that ensure the enablement requirements of the present invention. The RS-21 strain was recognized as belonging to Fusarium oxysporum because of its mycological properties described later, but it has been conventionally recognized as having a high colonization ability on plants and a high plant growth promoting effect. Since it can be distinguished from the known Fusarium oxysporum strain, the RS-21 strain was identified as a new strain of Fusarium oxysporum. The RS-21 strain is very characteristic in that it also has an effect of increasing the number of lateral roots, and can be more clearly distinguished from the conventionally known Fusarium oxysporum strain. In addition, the RS-21 strain is non-pathogenic.
(Mycological properties of RS-21 strain)
(I) on the nature PDA medium on medium (potato dextrose agar), PSA medium (potato sucrose agar) and on Czapek medium _{(NaNO 3 2.0g, K 2 HPO} 4 1.0g, MgSO 4 · 7H _{2 O 0.5g, KCl 0.5g, FeSO} 4 · 7H 2 O 0.01g, sucrose 30g, agar 15 g, early hyphal elongation in distilled water 1000ml) over slightly resulting fluffy aerial mycelium , The culture medium is soft. On the PDA medium, pink to purple pigments are produced in the medium.
(Ii) Morphological properties Small conidia are formed in a pseudo-head shape on short septal-free phialides arising from septal-bearing hyphae. The shape is oblong or oval, 0 to 1 septum, and the size is 2 to 4 μm × 6 to 11 μm (average 3.5 μm × 8 μm). Large conidia are formed primarily on the monofialide of the orange-colored Conidia (Sprodochia). It is mainly composed of 3 to 5 septa and 3 diaphragms, the apex is slightly curved in a hook shape, and the base has a heel-like shape. The size is 4 to 6 μm × 40 to 55 μm (average 5 μm × 50 μm). Chlamydospores are formed on hyphae or large conidia and are 7-12 μm in diameter. A large number of spore-like cells (bud cells) are formed by culturing with shaking (about 120 rpm) in PDB medium (potato dextrose liquid) or PSB medium (potato sucrose liquid).
(Iii) Physiological properties The growth temperature is 10 to 35 ° C, and the optimum temperature is 25 to 30 ° C. It can grow between pH 4.0-8.0 and the optimum pH is 6.0-7.0. The RS-21 strain has a growth promoting effect on the above-ground part and the underground part of the plant.

(Strain information of Fusarium oxysporum RS-25 strain)
Fusarium oxysporum RS-25 strain is stored in the Plant Pathology Laboratory (TEL042-367-5691), Faculty of Agriculture, Tokyo University of Agriculture and Technology (3-5-8 Saiwaicho, Fuchu-shi, Tokyo (postal code 183-8509)). , If necessary, sold under certain conditions that ensure the enablement requirements of the present invention. The RS-25 strain was recognized as belonging to Fusarium oxysporum because of its mycological properties described later, but it has been conventionally recognized as having a high colonization ability on plants and a high plant growth promoting effect. Since it can be distinguished from the known Fusarium oxysporum strain, the RS-25 strain was identified as a new strain of Fusarium oxysporum. The RS-25 strain is non-pathogenic.
(Mycological properties of RS-25 strain)
(I) on the nature PDA medium on medium (potato dextrose agar), PSA medium (potato sucrose agar) and on Czapek medium _{(NaNO 3 2.0g, K 2 HPO} 4 1.0g, MgSO 4 · 7H _{2 O 0.5g, KCl 0.5g, FeSO} 4 · 7H 2 O 0.01g, sucrose 30g, agar 15 g, early hyphal elongation in distilled water 1000ml) over slightly resulting fluffy aerial mycelium , The culture medium is soft. On the PDA medium, pink to purple pigments are produced in the medium.
(Ii) Morphological properties Small conidia are formed in a pseudo-head shape on short septal-free phialides arising from septal-bearing hyphae. The shape is oblong or oval, 0 to 1 septum, and the size is 2 to 4 μm × 6 to 11 μm (average 3.5 μm × 8 μm). Large conidia are formed primarily on the monofialide of the orange-colored Conidia (Sprodochia). It is mainly composed of 3 to 5 septa and 3 diaphragms, the apex is slightly curved in a hook shape, and the base has a heel-like shape. The size is 4 to 6 μm × 40 to 55 μm (average 5 μm × 50 μm). Chlamydospores are formed on hyphae or large conidia and are 7-12 μm in diameter. A large number of spore-like cells (bud cells) are formed by culturing with shaking (about 120 rpm) in PDB medium (potato dextrose liquid) or PSB medium (potato sucrose liquid).
(Iii) Physiological properties The growth temperature is 10 to 35 ° C, and the optimum temperature is 25 to 30 ° C. It can grow between pH 4.0-8.0 and the optimum pH is 6.0-7.0. The RS-25 strain has a growth promoting effect in the underground part of the plant.

(RS-21 strain)
The RS-21 strain has an ability to settle on a plant (preferably a plant of a gramineous plant) and an effect of promoting plant growth. The plant growth promoting effect of the RS-21 strain includes promoting the rate of increase in weight of the above-ground part, the underground part, or both of the plants. By promoting the rate of increase in the weight of the above-ground part of the plant by which the RS-21 strain is applied, more specifically, promotion of stem elongation, promotion of stem enlargement, promotion of increase in the number of leaves or total area, And one or more selected from the promotion of stem branching (for example, promotion of increase in the number of stem branches). In addition, the RS-21 strain promotes the rate of increase in the weight of the underground part of the plant, more specifically, promotion of lateral root formation (for example, increase in the number of lateral roots), roots (taproot or lateral roots, preferably taproot). ), One or more selected from the group consisting of an increase in taproot production sites, promotion of root (preferably side root) elongation, and promotion of root (preferably side root) enlargement, among others. Selected from the group consisting of promotion of lateral root formation (for example, increase in the number of lateral roots), increase in oxine-producing sites in roots (taproot or lateral roots, preferably taproots), and promotion of root (preferably lateral roots) elongation 1 One or two or more are preferably mentioned, and among them, selected from the group consisting of promotion of lateral root formation (for example, increase in the number of lateral roots) and an increase in oxine-producing sites in the root (taproot or lateral root, preferably taproot). One or two are more preferred.

The RS-21 strain secretes a specific substance (preferably a volatile substance) out of the cell, and the substance increases the auxin production site in the root of the plant, and the auxin production in the root is increased, thereby forming lateral roots. Is considered to be promoted.

(RS-25 strain)
The RS-25 strain has an ability to settle on a plant (preferably a gramineous plant) and a plant growth promoting effect. The plant growth promoting effect of the RS-25 strain includes promoting the weight increase rate of the above-ground part, the underground part, or both of the plants, but when the promotion of the weight increase rate of the underground part is not recognized. Therefore, in order to promote the weight increase rate of the above-ground part, it is not essential to promote the weight increase rate of the underground part. By promoting the rate of increase in the weight of the above-ground part of the plant on which the RS-25 strain is applied, more specifically, promotion of stem elongation, promotion of stem enlargement, promotion of increase in the number of leaves or total area, And one or more selected from the promotion of stem branching (for example, promotion of increase in the number of stem branches). The reason why the RS-25 strain accelerates the rate of increase in the weight of the above-ground part of the plant is that the RS-25 strain colonizes the rhizosphere and plant tissues and occupies the field more quickly than the harmful bacteria for the plant. It is thought that it suppresses the growth of harmful bacteria and, as a result, promotes the growth of plants.

As the viable cell of the strain of the present invention, a viable cell obtained by culturing and proliferating the strain of the present invention in a medium can be used. The medium may be a liquid medium or a solid medium as long as the strain of the present invention can be cultured to form spores or spore-like cells. Examples of the medium that can be used for the strain of the present invention include a medium capable of culturing fusalium oxysporum, and more specifically, a potato dextrose medium (potato dextrose agar medium, potato dextrose liquid medium), a potato shoe cloth medium. (Potato shoe cloth agar medium, potato shoe cloth liquid medium), Tourpek-Docs medium (Tupek-Docs agar medium, Tourpek-Docs liquid medium) and the like can be mentioned. After sterilizing these media by a conventional method, the strain of the present invention is inoculated, and the culture is shaken or allowed to stand at 15 to 35 ° C. for 3 to 10 days to obtain a culture having a high spore concentration or spore-like cell concentration. be able to.

The liquid culture containing spores or spore-like cells is mainly composed of pellet-shaped or suspended spores or spore-like cells from which the culture fraction has been removed by dehydration treatment such as filtration and centrifugation. A live spore is obtained. The obtained viable cells may be used as they are in the plant growth promoter of the present invention, or may be used, for example, after freeze-drying, in the plant growth promoter of the present invention. When the viable cells are freeze-dried, it is preferable to add a protective agent such as skim milk, monosodium glutamate, sucrose, trehalose or the like to form a suspension or pellet, and then freeze-dry.

(Plants to which the present invention can be applied)
Examples of plants to which the present invention can be applied include plant seeds, callus, young shoots immediately after germination, growing plants and the like. Such a "growing plant" means that, after that, the height of the above-ground part or the depth of the underground part of the plant increases, or the above-ground part or the underground part of the plant is compared with the current plant. It means a plant whose raw weight of the part increases. Such "growing plant" is based on the height of the above-ground part, the depth of the underground part, the raw weight of the above-ground part or the raw weight of the underground part (that is, "1") at the present time. After that, the height of the above-ground part, the depth of the underground part, the raw weight of the above-ground part or the raw weight of the underground part of the plant body is 1.1 times or more, preferably 1.3 times or more, more preferably 1. Plants having a value of 6 times or more, more preferably 2 times or more, and more preferably 2.5 times or more are preferably included. Specifically, the "growing plant" is preferably a plant that is a seedling (for example, a plant with 1 to 20 leaves), and a plant that is a seedling (for example, 1 to 10 leaves). Plants) are more preferred. In the present invention, the "plant body" refers to organs other than seeds among plant organs such as buds, leaves, stems, flowers, fruits (including fruits), roots, rhizomes, tubers and rhizomes.

As the type of plant to which the present invention can be applied, one or two suitable amounts of the plant growth promoter of the present invention are selected from the group consisting of plant seedling soil, plant cultivation soil, plant body and plant seed. The application is not particularly limited as long as the growth of the plant can be promoted by applying the plant to one or more, but an undergrowth plant and a nude plant are preferably mentioned. The angiosperms may be monocotyledonous plants or dicotyledonous plants.

Specific examples of the types of plants to which the present invention can be applied include rice plants, abrana plants, legumes, higanbana plants, stag beetles, sardines, sardines, roses, and sardines. Plants, Seri family plants, Akane family plants, Todaiigusa family plants, Aoi family plants, Basho family plants, Hirugao family plants, Lily family plants. Plants are preferred. Among the illustrated plants of these families, gramineous plants, Higanbana family plants, Kijikakushi family plants, Basho family plants, and lily family plants are monocotyledonous plants, and other family plants are dicotyledonous plants. ..

Rice plants include Sorghum, Oryza, Saccharum, Zea, Hordeum, Triticum, and Limegi (Sorghum). Secale, Coix, Avena, Panicum, Setaria, Echinochloa, Dactylis, Lolium ) Plants, Festuca plants, Medicago plants, Zoysia plants, Hierochloe plants, Cynodon plants, Eragostis plants, Eremochloa Examples include genus plants, Axonopus genus plants, Paspalum genus plants, Pennisetum genus plants, Stenotaphrum genus plants, etc. Among them, Morokoshi genus plants, rice genus plants, sugar cane genus plants, etc. Corn genus plants, Omugi genus plants, wheat genus plants, limegi genus plants, Juzudama genus plants, crow wheat genus plants, millet genus plants, enokorogusa genus plants, hie genus plants are preferably mentioned, among which Morokoshi genus plants, rice genus plants, More preferably, sugar cane plants, corn plants, barley plants, wheat plants, lime tree plants, juzudama plants, and crow wheat plants are mentioned.
Examples of the above-mentioned plants of the genus Morokoshi include Morokoshi (Sorghum bicolor), examples of the plants of the genus Rice include rice (Oryza sativa) and African rice (Oryza glaberrima), and examples of the plants of the genus Satouki (Saccharum officinarum). Examples of corn plants include corn (Zea mays), examples of corn plants include corn (Hordeum vulgare), and examples of wheat plants include wheat (Triticum aestivum). Examples of the genus plant include Limegi (Secale cereale), examples of the Juzudama genus plant include Hatomugi (Coix lacryma-jobi var. Avena sativa), as a plant of the genus Panicum, a plant of the genus Panicum, a plant of the genus Enocologsa, awa (Setaria italica), and a plant of the genus Echinochloa esculenta. Orchardgrass (Dactylis glomerata L.) can be mentioned as a plant of the genus Camogaya, Italian ryegrass (Lolium multiflorum Lam.), Perenial ryegrass (Lolium perenne) can be mentioned as a plant of the genus Dokumugi, and a plant of the genus Ushinokegusa can be mentioned. Festuca arundinacea is mentioned, as a plant of the genus Egg palm, alfalfa (Medicago sativa) is mentioned, and as a plant of the genus Shiva, there are Shiva (Zoysia japonica), Korai Shiba (Zoysia pacifica), Koshun Shiva (Zoysia matrella). As a plant of the genus Kobo, buffalo grass (Hierochloe odorata) can be mentioned, as a plant of the genus Gyogishiba, Bermudagrass (Cynodon dactylon) can be mentioned, and as a plant of the genus Suzumegaya, weeping grass (Eragrostis curvula) can be mentioned. As a plant of the genus Mukadesiba, centipede grass (Eremoc) hloa ophiuroides), examples of Axonopus genus plants include carpet grass (Axonopusaffinis Chase), examples of Dallis grass genus plants include Dalisgrass (Paspalum dilatatum), and Kikuyu grass (Pennisetum clandestinum). , St. Augustine grass (Stenotaphrum secundatum).

Examples of cruciferous plants include plants of the genus Brassica, plants of the genus Radishes, and plants of the genus Arabidopsis.
Examples of the above Brassica plants include Brassica napus, Brassica rapa var.nippo-oleifera, cabbage (Brassica oleracea var.capitata), broccoli (Brassica oleracea var.italica), and cauliflower (Brassica oleracea var. botrytis), hakusai (Brassica rapa var.pekinensis), komatsuna (Brassica rapa var. Perviridis), chingensai (Brassica rapa var. Chinensis), cub (Brassica rapa L. var. Rapa), kale (Brassica oleracea var. Mizuna (Brassica rapa var. Laciniifolia) is mentioned, and the genus plants include the daikon (Raphanus sativus var. Longipinnatus) and the hatsuka daikon (Raphanus sativus var. Sativus). Can be mentioned.

Leguminous plants include soybean (Glycine), sage (Vigna), lacchis, green bean (Phaseolus), pea (Pisum), solacea (Vicia), and flathead (Vicia). Lens) genus plants can be mentioned.
Examples of the above-mentioned plants of the genus Soybean include soybean (Glycine max), examples of the genus of Sesage plants include Sesage (Vigna unguiculata), Azuki (Vigna angularis), and Ryokuto (Vigna radiata). Examples include Arachis hypogaea, examples of wild bean plants include common beans (Phaseolus vulgaris) and honeybees (Phaseolus coccineus), and examples of pea plants include pea (Pisum sativum L.). Examples of the plant include common bean (Vicia faba), and examples of the plant belonging to the genus Wild bean include lens bean (Lens culinaris).

Allium plants include allium plants, and allium plants include onions (Allium cepa), allium fistulosum, allium chinense, garlic (Allium sativum), and allium (Allium). tuberosum) and Asatsuki (Allium schoenoprasum var. Foliosum).

Examples of the Asparagus family plant include plants of the genus Asparagus, and examples of such plants of the genus Asparagus include asparagus (Asparagus officinalis L.).

Examples of Asteraceae plants include plants of the genus Lactuca, plants of the genus Glebionis, and plants of the genus Chrysanthemum.
Examples of the above-mentioned Lettuces plants include lettuce (Lactuca sativa) and sunny lettuce (Lactuca sativa var. Crispa), examples of Glebionis plants include Glebionis coronaria, and examples of Glebionis coronaria include Jegiku (Glebionis coronaria). Chrysanthemum morifolium).

Examples of Solanaceae plants include plants of the genus Solanam and plants of the genus Capsicum.
Examples of the above-mentioned Solanaceae plants include solanaceous plants (Solanum melongena), tomatoes (Solanum lycopersicum), and potatoes (Solanum tuberosum L.). var. Angulosum), tomato (Capsicum annuum), paprika (Capsicum annuum cv.), Jalapeno (Capsicum annuum), Habanero (Capsicum chinense).

Examples of Rosaceae plants include plants of the genus Fragaria, and examples of such plants of the genus Strawberries include Dutch strawberries (Fragaria ananassa DUCHESNE).

Plants of the family Cucumis include plants of the genus Cucumis, plants of the genus Cucurbita, plants of the genus Citrullus, plants of the genus Bitter melon, plants of the genus Benincasa, plants of the genus Luffa, and Yugao ( Lagenaria) genus plants are mentioned.
Examples of the above-mentioned plants of the genus Cucumber include cucumber (Cucumis sativus) and melon (Cucumis melo), examples of the genus of pumpkin include pumpkin (Cucurbitamoschata) and zucchini (Cucurbita pepo), and examples of the genus of watermelon include watermelon. (Citrullus lanatus), the plant of the genus Turureishi is the bitter gourd (Momordica charantia), the plant of the genus Togan is Benincasa hispida, and the plant of the genus Hechima is Luffa cylindrica. Examples of plants of the genus Yugao include watermelon (Lagenaria siceraria).

Examples of Umbelliferae plants include plants of the genus Daucus, plants of the genus Apium of the Netherlands, plants of the genus Petroselinum, and plants of the genus Oenanthe.
Examples of the above-mentioned leaf celery plant include carrot (Daucus carota subsp. Sativus), and examples of the Dutch leaf celery plant include celery (Apium graveolens var. Dulce) and soup celery (Apium graveolens var.secalinum). Examples of plants of the genus Auction include celery (Petroselinum crispum), and examples of plants of the genus Auction include celery (Oenanthe javanica).

Examples of the Akane family plant include coffee genus (Coffea), and examples of such coffee genus are Arabica coffee (Coffea arabica L.), Robusta coffee (C. canephora var. Robusta), and Riberica coffee (C. liberica Bull). ex Hiern.).

Examples of plants of the family Rushaceae include plants of the genus Manihot and plants of the genus Hevea. Examples of such plants of the genus Manihot include cassava (Manihot esculenta), and examples of plants of the genus Hevea include Hevea brasiliensis.

Examples of Malvaceae plants include plants of the genus Theobroma, and such plants of the genus Theobroma include cacao (Theobroma cacao).

Examples of the Musaceae plants include plants of the genus Musa, and examples of such plants of the genus Musa include bananas (Musa spp.).

Examples of Convolvulaceae plants include bindweed (Calystegia) genus and sweet potato (Ipomoea) genus. Examples of such bindweed plants include bindweed (Calystegia japonica) and bindweed (Calystegia hederacea), and examples of Ipomoea plants include Ipomoea batatas, morning glory (Ipomoea nil), and morning glory (Ipomoea alba).

Examples of Liliaceae plants include plants of the genus Lilium and plants of the genus Tulipa. Such lily genus plants include golden-rayed lily (Lilium auratum), tiger lily (Lilium lancifolium), tiger lily (Lilium leichtlinii), and gardening lily (Asiantic hybrid, Longiflorum hybrid, Maltagon hybrid, trumpet hybrid, oriental). (Hybrid, etc.), and examples of the plant of the genus Lily include various tulips for gardening (Tulipa gesneriana, etc.).

<Plant Growth Promoter of the Present Invention>
The plant growth promoter of the present invention is not particularly limited as long as it contains viable cells of the RS-21 strain and / or the RS-25 strain (the strain of the present invention). The plant growth promoter of the present invention may consist only of viable cells of the strain of the present invention, or may be a carrier, a surfactant, a binder, a bulking agent, a penetrant, a spreading agent, a thickener, or a freeze. It may further contain an optional component such as an inhibitor, an anticaking agent, a disintegrant, an antifoaming agent, an antiseptic, and a decomposition inhibitor. From the viewpoint of obtaining a higher plant growth promoting effect when the RS-21 strain is used in the plant growth promoting agent of the present invention, the plant growth promoting agent of the present invention includes glucose, fructose, which can be assimilated by the RS-21 strain. It preferably contains a carbon source such as sucrose.

When the plant growth promoter of the present invention consists only of the viable cells of the strain of the present invention, such viable cells can be used as the plant growth promoter of the present invention, and the plant growth promoter of the present invention can be used. When is composed of the culture of the strain of the present invention itself, such a culture or a product obtained by diluting the culture with water can be used as the plant growth promoter of the present invention, and the plant growth promoter of the present invention is the present invention. When the viable cell of the strain of the invention and an optional component are contained, for example, the plant growth promoter of the present invention can be obtained by mixing the viable cell with the optional component.

The plant growth promoter of the present invention may consist only of the viable cell of the strain of the present invention itself, but in other cases, the viable cell of the strain of the present invention contained in the plant growth promoter of the present invention. The amount is not particularly limited, and the total amount of viable cells of RS-21 strain and RS-25 strain is, for example, 1 to 99.9% by weight, 1 to 80% by weight, 1 to 1 to the total amount of the plant growth promoter. It may be 60% by weight, 2 to 50% by weight, or the like. The spore concentration of the strain of the present invention contained in the plant growth promoter of the present invention is not particularly limited, but the total number of spores of the RS-21 strain and the RS-25 strain per 1 g of the plant growth promoter is. preferably 10 ⁴ or more, more preferably 10 ⁵ or more, more preferably 10 ⁶ or more, or more preferably is 10 ⁷ or more. The upper limit concentration is not particularly limited, but may be 10 ¹² or less or 10 ¹¹ or less per 1 g of the plant growth promoter. More specifically, the total spore concentration of the strain of the present invention contained in the plant growth promoter of the present invention is in the range of ^{10 4} to 10 ^{12 per 1 g of the plant growth promoter, and 10 5} to ¹¹ It can be said that it is within the range. In the present specification, the phrase "total of viable cells of RS-21 strain and RS-25 strain" refers to the plant growth promoter of the present invention of both RS-21 strain and RS-25 strain. There is no meaning only when it contains viable cells, and the phrase "total number of spores of RS-21 strain and RS-25 strain" also refers to the plant growth promoter of the present invention, RS-21. There is no meaning only when it contains viable cells of both the strain and the RS-25 strain.

The dosage form of the plant growth promoter of the present invention is not particularly limited, and for example, a liquid agent (soluble concentrate), an emulsion (emulsifiable concentrate), a wettable powder (wettable powder), a granule wettable powder (water dispersible granule), and granulated water. Solution (water soluble granule), suspension (suspension concentrate), emulsion (concentrated emulsion), suspoemulsion, microemulsion, dustable powder, microgranule, granules Examples thereof include various liquid preparations and solid preparations such as an agent (granule), an aerosol agent (aerosols), a gel agent (gel), a pellet agent (pellet), and a soil agent (soil). A liquid preparation is preferable from the viewpoint of easy application to plants, and a solid preparation is preferable from the viewpoint of storage stability. When the plant growth promoter of the present invention is diluted and dissolved in water or the like, it is usually desirable to dilute it 1 to 2000 times with water before use.

(Carrier)
As described above, the plant growth promoter of the present invention includes carriers, surfactants, binders, bulking agents, penetrants, spreading agents, thickeners, antifreeze agents, anticaking agents, disintegrants, and defoamers. It may further contain an optional component such as a foaming agent, a preservative, and a decomposition inhibitor. Examples of the carrier as an optional component include a solid carrier and a liquid carrier. Examples of solid carriers include natural minerals such as quartz, kaolinite, pyrophyllite, sericite, starch, bentonite, acidic white clay, attapulsite, zeolite, and diatomaceous soil; calcium carbonate, ammonium sulfate, sodium sulfate, and chloride. Inorganic salts such as potassium; synthetic silica and synthetic silicates; natural polymers such as wheat flour, starch, crystalline cellulose, carboxymethyl cellulose, and gelatin; sugars such as glucose, fructose, mantose, lactose, and sucrose; and urea; And so on. Examples of the liquid carrier include alcohols such as ethylene glycol, propylene glycol, and isopropanol; aromatic hydrocarbons such as xylene, alkylbenzene, and alkylnaphthalene; ethers such as butyl cellosolve; ketones such as cyclohexanone; γ- Esters such as butyrolactone; acid amides such as N-methylpyrrolidone and N-octylpyrrolidone; vegetable oils such as soybean oil, rapeseed oil, cottonseed oil, and castor oil; and water; These solid carriers and liquid carriers may be used alone or in combination of two or more.

(Surfactant)
Examples of the surfactant as an optional component include the following (A), (B), (C), (D) and (E). In addition, the surfactant may be used alone or in combination of two or more.

(A) Nonionic surfactant:
(A-1) Polyethylene glycol type surfactant:
For example, polyoxyethylene alkyl (C ₁₂ ~ ₁₈₎ ether, ethylene oxide adducts of alkyl naphthol, polyoxyethylene (mono or di) alkyl (C ₈ ~ ₁₂₎ phenyl ether, polyoxyethylene (mono- or di-) alkyl ( C ₈ ~ ₁₂₎ formalin condensates of phenyl ether, polyoxyethylene (mono-, di- or tri-) phenyl phenyl ether, polyoxyethylene (mono-, di- or tri-) benzyl phenyl ether, polyoxypropylene (mono-, di- or tri) Polymers of benzylphenyl ether, polyoxyethylene (mono, di or tri) styrylphenyl ether, polyoxypropylene (mono, di or tri) styrylphenyl ether, polyoxyethylene (mono, di or tri) styrylphenyl ether, polyoxy polyoxypropylene block polymer, alkyl (C ₁₂ ~ ₁₈₎ polyoxyethylene polyoxypropylene block polymer ethers, alkyl (C ₈ ~ ₁₂₎ phenyl polyoxyethylene polyoxypropylene pro Pile emissions block polymer ether, polyoxyethylene bisphenyl ether , polyoxyethylene resin acid esters, polyoxyethylene fatty acid (C ₁₂ ~ ₁₈₎ monoesters, polyoxyethylene fatty acid (C ₁₂ ~ ₁₈₎ diesters, polyoxyethylene sorbitan fatty acid (C ₁₂ ~ ₁₈₎ esters, glycerol fatty acid ester ethylene oxide adducts, castor oil ethylene oxide adduct, hydrogenated castor oil ethylene oxide adduct, alkyl (C ₁₂ ~ ₁₈₎ amine ethylene oxide adduct, and include fatty acids (C ₁₂ ~ ₁₈₎ amide ethylene oxide adducts ..
(A-2) Multivalent alcohol-type surfactant:
For example, glycerol fatty acid esters, polyglycerol fatty acid esters, pentaerythritol fatty acid esters, sorbitol fatty acid (C ₁₂ ~ ₁₈₎ esters, sorbitan fatty acid (C ₁₂ ~ ₁₈₎ esters, sucrose fatty acid esters, polyhydric alcohol alkyl ethers, and fatty acid Examples thereof include alkanolamide.
(A-3) Acetylene-based surfactant:
For example, acetylene glycol, acetylene alcohol, ethylene oxide adduct of acetylene glycol, ethylene oxide adduct of acetylene alcohol and the like can be mentioned.
(A-4) Other surfactants:
For example, alkyl glycosides and the like can be mentioned.

(B) Anionic surfactant:
(B-1) Carboxylic acid type surfactant:
For example, polyacrylic acid, polymethacrylic acid, polymaleic acid, copolymer of maleic acid and olefin (for example, isobutylene and diisobutylene), copolymer of acrylic acid and itaconic acid, co-polymer of methacrylic acid and itaconic acid. Polymers, maleic acid and styrene copolymers, acrylic acid and methacrylic acid copolymers, acrylic acid and acrylic acid methyl ester copolymers, acrylic acid and vinyl acetate copolymers, acrylic acid and copolymer of maleic acid, N- methyl - fatty (C ₁₂ ~ ₁₈₎ sarcosinates, resin acids and fatty acids (C ₁₂ ~ ₁₈₎ carboxylic acids such as, as well as their salts carboxylic acids.
(B-2) Sulfuric acid ester type surfactant:
For example, alkyl (C ₁₂ ~ ₁₈₎ sulfates, polyoxyethylene alkyl (C ₁₂ ~ ₁₈₎ ether sulfuric acid ester, polyoxyethylene (mono or di) alkyl (C ₈ ~ ₁₂₎ off phenyl ether sulfates, polyoxyethylene (mono or di) alkyl (C ₈ ~ ₁₂₎ sulfuric acid ester of a polymer of phenyl ether, polyoxyethylene (mono-, di- or tri-) phenyl phenyl ether sulfuric acid esters, polyoxyethylene (mono-, di- or tri-) benzyl phenyl ether sulfate Estel, Polyoxyethylene (mono, di or tri) styrylphenyl ether sulfate ester, polyoxyethylene (mono, di or tri) styrylphenyl ether polymer sulfate, polyoxyethylene polyoxypropylene block polymer sulfate, sulfuric acid Examples thereof include sulfated oils, sulfated fatty acid esters, sulfated fatty acids, and sulfated esters such as sulfated olefins, and salts of these sulfated esters.
(B-3) Sulfonic acid type surfactant:
For example, paraffin (C ₁₂ ~ ₂₂₎ sulfonic acid, alkyl (C ₈ ~ ₁₂₎ benzenesulfonic acid, alkyl (C ₈ ~ ₁₂₎ formalin condensates of benzenesulfonic acid, formalin condensate of cresol sulfonic acid, alpha-olefin ( C ₁₄ ~ ₁₆ ) Sulfonic acid, Dialkyl (C ₈ ~ ₁₂ ) Sulfosuccinic acid, Lignin sulfonic acid, Polyoxyethylene (mono or di) alkyl (C ₈ ~ ₁₂ ) Phenyl ether sulfonic acid, Polyoxyethylene alkyl (C ₁₂ ~ ₁₈ ) Ether sulfosuccinic acid half ester, naphthalene sulfonic acid (mono or di) alkyl (C ₁ to ₆ ) naphthalene sulfonic acid, formalin condensate of naphthalene sulfonic acid, (mono or di) alkyl (C ₁ to ₆ ) naphthalene sulfonic acid formalin condensate, formalin condensate of creosote oil sulfonic acid, alkyl (C ₈ ~ ₁₂₎ ether disulfonic acid, Igepon T (trade name), polystyrene sulfonic acid, and, copolymer of styrene sulfonic acid and methacrylic acid Sulfonic acids such as, and salts of those sulfonic acids can be mentioned.
(B-4) Phosphate ester type surfactant:
For example, alkyl (C ₈ ~ ₁₂₎ phosphates, polyoxyethylene alkyl (C ₁₂ ~ ₁₈₎ ether phosphate ester, a polyoxyethylene (mono or di) alkyl (C ₈ ~ ₁₂₎ phenyl ether phosphate ester, a polyoxyethylene ( mono-, phosphate esters of di or tri) alkyl (C ₈ ~ ₁₂₎ phenyl ether polymer, polyoxyethylene (mono-, di- or tri-) phenyl phenyl ether phosphoric acid ester, polyoxyethylene (mono-, di- or tri-) benzyl phenyl ether Phosphoric acid ester, polyoxyethylene (mono, di or tri) styrylphenyl ether phosphoric acid ester, polyoxyethylene (mono, di or tri) styrylphenyl ether polymer phosphoric acid ester, polyoxyethylene polyoxypropylene block polymer phosphoric acid ester, Examples thereof include phosphoric acid esters such as phosphatidylcholine, phosphatidylethanolimine, and condensed phosphoric acid (for example, tripolyphosphoric acid), and salts of these phosphoric acid esters.
Examples of the salts in (B-1) to (B-4) above include alkali metals (lithium, sodium, potassium, etc.), alkaline earth metals (calcium, magnesium, etc.), ammonium, and various amines (for example, alkylamines). , Cycloalkylamine, alkanolamine, etc.) and the like.

(C) Cationic surfactant:
For example, an alkylamine salt, an alkyl quaternary ammonium salt and the like can be mentioned.

(D) Amphoteric surfactant:
Examples thereof include betaine-type surfactants and amino acid-type surfactants.

(E) Other surfactants:
For example, a silicone-based surfactant, a fluorine-based surfactant, and the like can be mentioned.

(Binder)
Examples of the binder as an optional component include a water-soluble binder and a water-insoluble binder. Examples of the water-soluble binder include dextrin (roasted dextrin and enzyme-modified dextrin, etc.), acid-decomposed starch, oxidized starch, pregelatinized starch, etherified starch (carboxymethyl starch, hydroxyalkyl starch, cationic starch, etc.), and esterification. Processed starches such as starch (acetate starch and phosphoric acid starch, etc.), crosslinked starch, and grafted starch; natural substances such as sodium alginate, Arabic gum, gelatin, tragant gum, locust bean gum, and casein; eg carboxymethyl cellulose. Cellulous derivatives such as sodium salts, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, ethyl cellulose, and acetyl cellulose; for example, polyvinyl methyl ether, polyethylene glycol, polypropylene glycol, polyethylene polypropylene block copolymer, polyvinyl alcohol, partially saponified. Examples thereof include copolymers of vinyl acetate and vinyl ether, polyvinylpyrrolidone, copolymers of polyvinylpyrrolidone and vinyl acetate, and other polymers such as polyacrylamide. Examples of the water-insoluble binder include polyvinyl acetate, a copolymer of vinyl acetate and ethylene, a copolymer of vinyl acetate and vinyl versaticate, a copolymer of vinyl acetate, ethylene and vinyl chloride, and a polyacrylic acid ester. Acrylic acid ester and styrene copolymer, acrylic acid ester and silicone copolymer, acrylic acid ester and ethylene copolymer, polyurethane, styrene and butadiene copolymer, acrylonitrile and butadiene copolymer, etc. Water-insoluble thermoplastic resin; for example, amino resin (urea resin, melamine resin, etc.), phenol resin (resole resin, novolak resin, etc.), resorcinol formaldehyde resin, xylene resin, furan resin, epoxy resin, polyisocyanate adhesive, non- Examples thereof include saturated polyesters and thermosetting resins such as thermosetting acrylic resins. Examples of the epoxy resin used as a water-insoluble binder include bisphenol A type epoxy compound, bisphenol F type epoxy compound, novolak type epoxy compound, aliphatic epoxy compound, alicyclic group epoxy compound, and glycidylamine type epoxy compound. , And glycidyl ester type epoxy compounds and the like. Examples of the curing agent for the epoxy resin include polyamide-based, aliphatic polyamine-based, alicyclic polyamine-based, aromatic polyamine-based, and heterocyclic amine-based.

(Volume thicker)
Optional bulking agents include, for example, quartz, sulphate, sea sulphate, dolomite, choke, kaolinite, pyrophyllite, sericite, halosite, metahalosite, cypress clay, diatomaceous earth, pottery stone, etc. Natural minerals such as Siegrite, Alofen, Silas, Kira, Tarku, Bentonite, Palestone, Attapulsite, Zeolite, and Diatomaceous Earth; Baked natural minerals; for example, inorganic salts such as magnesium carbonate, calcium carbonate, sodium carbonate, sodium hydrogen carbonate, ammonium sulfate, sodium sulfate, magnesium sulfate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, and potassium chloride; Sugars such as glucose, fructose, sucrose, and lactose; polysaccharides such as clay, powdered cellulose, and dextrin; organic substances such as urea, urea derivatives, benzoic acid, and salts of benzoic acid; eg wood. Plants such as flour, corn stalks, walnut shells, and tobacco stalks; fly ash, white carbon, fertilizer, and the like.

(Other pharmacological components)
The plant growth-promoting agent of the present invention is other than other components having a plant growth-promoting effect (for example, fertilizer) and / or a plant growth-promoting effect as long as it does not interfere with the plant-promoting effect of the viable cells of the strain of the present invention. It may further contain a component having a pharmacological action (for example, a herbicidal component, a bactericidal component, an insecticidal component).

(Plant lateral root formation promoter of the present invention)
Among the plant growth promoters of the present invention, the agent containing Fusarium oxysporum RS-21 strain can also be used as a plant lateral root formation promoter (preferably, a plant lateral root number increasing agent).

<Plant cultivation method of the present invention, plant growth promotion method of the present invention>
As the plant cultivation method of the present invention and the plant growth promotion method of the present invention, the plant growth promoter of the present invention is selected from the group consisting of plant seedling raising soil, plant cultivation soil, plant body and plant seed. It is not particularly limited as long as it includes a step applied to one or more of the plants, and a normal cultivation method for the plant species can be used except that the step is included. Such a normal cultivation method usually includes giving the plant an environment (water, light, air, moderate temperature) in which the plant can grow, and a more detailed cultivation method for each plant species is known cultivation. The method can be used. The number of times the plant growth promoting agent of the present invention is applied is not particularly limited as long as the plant growth promoting effect of the present invention can be obtained, and may be once or twice or more. In the present specification, the "plant cultivation soil" means the soil for cultivating the plant, and the "plant seedling raising soil" means that the plant seedlings are grown and then replanted in another soil. It means the soil for growing seedlings on the premise of.

(Application of plant growth promoter to plant seedling soil or cultivated soil)
In the present invention, the method of applying the plant growth promoter of the present invention to the seedling soil or cultivated soil of a plant is particularly limited only by the method of applying the plant growth promoter of the present invention to the seedling soil or cultivated soil of a plant. For example, the plant growth promoter of the present invention may be irrigated or sprayed on the seedling soil or cultivated soil of the plant, or the plant growth promoter of the present invention may be mixed with the culture soil or the like. , The mixture may be applied to a plant and used as at least a part of the seedling soil or cultivated soil of the plant. From the viewpoint of obtaining more plant growth promoting effect of the plant growth promoting agent of the present invention (particularly, a plant growing promoting agent containing viable cells of RS-21 strain), the plant growing promoting agent of the present invention is used for plant roots. It is preferable to apply it to seedling raising soil or cultivated soil so that it is contained more in the sphere soil (root sphere soil) or the soil that will become the root sphere soil of the plant in the future, and more specifically, the plant growth promotion of the present invention. It is preferable to irrigate the seedling growing soil or the cultivated soil with the agent. The rhizosphere soil means the soil of the portion around the root of the plant, and more specifically, the rhizosphere soil includes the soil of the portion within 5 mm from the surface of the root of the plant. The plant growth promoter of the present invention may be applied to either soil for raising seedlings of plants or soil for cultivating plants, or may be applied to both soils. Further, the plant growth promoter of the present invention may be applied to the seedling raising soil or the cultivated soil as it is, or the plant growth promoting agent of the present invention may be diluted with water or the like and then applied to the seedling raising soil or the cultivated soil. good.

The timing of applying the plant growth promoter of the present invention to the seedling raising soil or cultivated soil of a plant is not particularly limited as long as the plant growth promoter of the present invention is applied to the seedling raising soil or cultivated soil of a plant, but the seeds of a plant. Seedling soil or cultivated soil before sowing, seedling raising soil or cultivated soil after sowing and before sprouting of plant seeds, plant after sprouting [preferably a plant that is a seedling (for example, a plant with 1 to 20 leaves) ), More preferably a seedling raising soil or a cultivated soil of a plant body (for example, a plant body having 1 to 10 leaves)]. When the plant growth promoter of the present invention is applied to the seedling growing soil or cultivated soil of the plant after germination, the plant growth promoter of the present invention is applied to the seedling raising soil or cultivated soil in which the plant is growing at that time. It may be applied to the seedling raising soil or the cultivation soil of the plant replanting destination, and the application to the seedling raising soil or the cultivation soil of the plant replanting destination is to plant the plant seedlings. It is preferably applied to the above soil. When the plant growth promoter of the present invention is applied to the seedling raising soil or the cultivation soil of the plant replanting destination, the present invention is applied after or while applying the plant growth promoter of the present invention to the seedling raising soil or the cultivation soil. It is preferable to mix the plant growth promoter of the above with the seedling raising soil or the cultivated soil.
When the plant growth promoter of the present invention is applied to seedling raising soil or cultivated soil before sowing, the plant growth promoter of the present invention is applied, for example, within one month before sowing, preferably within one week. It is preferable to apply it to the seedling raising soil or the cultivated soil within 3 days before, and when the plant growth promoting agent of the present invention is applied to the seedling raising soil or the cultivated soil of the plant replanting destination, the plant growth promotion of the present invention is carried out. For example, the agent may be applied to the seedling raising soil or the cultivation soil of the replanting destination within 1 month before replanting, preferably within 1 week, and more preferably within 3 days before replanting.

The position of the plant growth promoter of the present invention to be applied to the seedling soil or the cultivated soil of the plant is not particularly limited, but the linear distance from the position of the seed to be sown or sown is preferably within 35 cm, more preferably. Cultivated soil within 25 cm, more preferably within 15 cm can be mentioned. At that time, as described above, it is preferable to apply the plant growth promoter of the present invention to the seedling raising soil or the cultivated soil so that the plant root zone soil or the soil that will become the root zone soil in the future contains more.

The amount of the plant growth promoter of the present invention applied to the seedling growing soil or the cultivated soil of a plant is not particularly limited as long as the plant growth promoting effect can be obtained, but for example, per plant body or plant seed 1 The total number of spores of RS-21 and RS-25 to be administered per plant is 1 × 10 ⁴ or more, preferably 1 × 10 ⁵ or more, and more preferably 1 × 10 ⁶ or more. The upper limit thereof is not particularly limited, but from the viewpoint of cost effectiveness, for example, 1 × 10 ⁹ or less and 1 × 10 ⁸ or less can be mentioned. Further, as an application amount when the plant growth promoter of the present invention is applied to the seedling growing soil or the cultivated soil of the plant, the number of spores of the RS-21 strain and the RS-25 strain to be administered per ^{1 m 2 of the seedling growing soil or the cultivated soil.} The total number is 1 × 10 ¹¹ or more, preferably 1 × 10 ¹² or more, more preferably 1 × 10 ¹³ or more, and the upper limit is not particularly limited, but from the viewpoint of cost effectiveness, for example. 1 × 10 ¹⁶ pieces or less, 1 × 10 ¹⁵ pieces or less can be mentioned.

(Application of plant growth promoter to plants)
In the present invention, the method of applying the plant growth promoter of the present invention to the seedling soil or cultivated soil of a plant is particularly limited as long as the method of applying the plant growth promoter of the present invention to the seedling soil or cultivated soil of a plant. However, for example, a method of applying to the roots of plants (preferably radicles) or the flower part before and after the flowering period can be mentioned. The method of applying the plant growth promoter of the present invention to the roots (radicles) of a plant can be preferably used for the RS-21 strain, and the method of applying it to the flower part before and after the flowering period is applied to the RS-25 strain. It can be preferably used.

As a method of applying the plant growth promoter of the present invention to the roots (radicles) of a plant, specifically, a method of spraying, spraying or applying the plant growth promoter of the present invention to the roots of a plant, or Examples thereof include a method of immersing the radicle in the plant growth promoter of the present invention.

As a method of applying the plant growth promoter of the present invention to the flower part before and after the flowering period, specifically, a method of spraying, spraying or applying the plant growth promoter of the present invention to the flower part before and after the flowering period of the plant body. Alternatively, a method of immersing the flower part in the plant growth promoter of the present invention can be mentioned. The strain of the present invention in the plant growth promoter of the present invention applied to the flower part before and after the flowering period usually colonizes the flower organ, the seed coat, the seed coat and the ovule tissue, and the strain of the present invention colonizes the plant body after pollination. Can develop pollinated seeds. Seeds that have matured sufficiently to have germination ability and have the strain of the present invention established can be recovered by a method known in the art. After collecting such seeds, the seeds may be dried as needed to improve storage stability. The drying method may be any method as long as it retains the germination ability of the seed and appropriately reduces the water content in the seed as long as the established strain of the present invention is not killed. Examples thereof include a natural drying method in which the air is exposed to the outside air, a dehumidifying drying method in which a dehumidifying agent is placed in a closed container, an air drying method in which hot air or cold air is blown and dried using a blower or the like, or a combination thereof. Subsequent seed storage methods may follow methods well known in the art.
In the present invention, the "flowering period" means a period during which the plant to which the plant growth promoter of the present invention is applied is in bloom. "Before and after the flowering period" means a period including before the flowering of the plant begins and after the flowering ends. This period is 2 weeks before and after the flowering period, preferably 10 days before and after, and more preferably 1 week before and after or 5 days before and after. For example, when the plant is rice and two weeks before and after the flowering period, the period from the ear development period in which the young ears grow rapidly in the rice to the completion of the flowering period in the strain and before the seeds mature is applicable. ..

(Application of plant growth promoter to plant seeds)
In the present invention, the method of applying the plant growth promoter of the present invention to plant seeds is not particularly limited as long as the method of applying the plant growth promoter of the present invention to plant seeds, for example, plant seeds. Examples thereof include a method of spraying, spraying or applying the plant growth promoter of the present invention, and a method of immersing the seed in the plant growth promoter of the present invention. Such seeds may be dried, if necessary, as described above, in order to improve storage stability.

(Preferable application method of plant growth promoter containing RS-21 strain)
Preferable application methods of the plant growth promoter of the present invention containing the RS-21 strain include a method of applying the plant growth promoter of the present invention to seedling growing soil or cultivated soil of a plant. Specifically, the plant growth promoter of the present invention is applied to a plant. A method of irrigating seedling growing soil or cultivated soil, a method of spraying on soil or a plant body, or a method of spraying the plant growth promoter of the present invention as it is or by mixing it with culture soil, etc. Examples thereof include a method of using at least a part of seedling raising soil or cultivating soil, or a method of combining them. It is also preferable to use the plant growth promoter of the present invention as it is or mix it with potting soil or the like, sow or transplant seedlings, establish the RS-21 strain in the rhizosphere of the seedling plant, and then plant it in the field. Further, it is more preferable to carry out additional treatment as appropriate during the cultivation period.

(Preferable application method of plant growth promoter containing RS-25 strain)
Preferable application methods of the plant growth promoter of the present invention containing the RS-25 strain include a method of applying the plant growth promoter of the present invention to seedling growing soil or cultivated soil of a plant. Specifically, the plant growth promoter of the present invention is applied to a plant. A method of irrigating seedling growing soil or cultivated soil, a method of spraying on soil or a plant body, or a method of spraying the plant growth promoter of the present invention as it is or by mixing it with culture soil, etc. Examples thereof include a method of using at least a part of seedling raising soil or cultivating soil, or a method of combining them. It is also preferable to use the plant growth promoter of the present invention as it is or mix it with potting soil or the like, sow or transplant seedlings, establish the RS-25 strain in the rhizosphere of the seedling plant, and then plant it in the field. Further, it is more preferable to carry out additional treatment as appropriate during the cultivation period.

(Method of promoting lateral root formation of a plant of the present invention)
In the plant cultivation method of the present invention or the plant growth promoting method of the present invention, when the side root formation promoting agent of the plant of the present invention (preferably, the side root number increasing agent of the plant) is used as the plant growth promoting agent of the present invention. , It is possible to promote the formation of lateral roots of a plant (preferably to increase the number of lateral roots of a plant). As a method for promoting the formation of lateral roots of a plant of the present invention, one or more of the lateral root formation promoting agents of the present invention are selected from the group consisting of plant seedling soil, plant cultivation soil, plant body and plant seed. As long as the step applied to the above is included, the usual cultivation method for the plant species can be used except that the step is included.

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to these examples.

[Selection of strains with high plant growth promoting effect]
In the field of sorghum (Sorghum bicolor) in Ginoza Village, Okinawa Prefecture, individuals with tall sorghum were selected and screened for microorganisms in the soil of the rhizosphere of the individuals. Five types of fungal strains (RS-10, RS-16, RS-17, RS-21, RS-24) were isolated, and spore-like bacterial cells 1 of each strain were isolated in the soil of the rhizosphere of sorghum seedlings. × 10 ⁷ pieces / mL was inoculated with 5 mL / strain and cultivated for 4 weeks. The result of measuring the raw weight (g) of the above-ground part of sorghum is shown in FIG. The control graph shows the raw weight (g) (n = 6 of each) of the above-ground part of the sorghum that was not inoculated with any of the strains, and the graph with the strain name is the above-ground part of the sorghum that was inoculated with the strain. Represents raw weight (g) (n = 6 respectively).

As can be seen from the results in FIG. 1, the sorghum inoculated with the RS-21 strain in the soil of the rhizosphere had the highest raw weight in the above-ground part as compared with the case of control and the case of inoculating other strains. .. Therefore, RS-21 strain was selected as a strain having a high plant growth promoting effect.

As a result of analyzing the mycological properties and gene sequence of the RS-21 strain, Fusarium oxysporum (Fusarium oxysporum) whose mycological properties have already been reported as described in the above section (Mycological properties of the RS-21 strain). Since it was consistent with Fusarium oxysporum) and the base sequence of the rDNA-ITS region was also consistent with Fusarium oxysporum (accession No. KF718226.1) on the database, the RS-21 strain was Fusarium oxysporum. It was identified as Fusarium oxysporum. In addition, in order to investigate the pathogenicity of the RS-21 strain, when plants such as sorghum, tomato, and cabbage were inoculated by irrigation with a spore-like bacterial cell suspension, control water (simple water not containing the RS-21 strain) was used. No difference in growth was observed from the irrigated plot, confirming that the RS-21 strain was non-pathogenic.

The RS-25 strain was found in the same manner as the RS-21 strain was found. As a result of analyzing the RS-25 strain, it was identified as Fusarium oxysporum for the same reason as in the case of the RS-21 strain. The RS-25 strain was also confirmed to be non-pathogenic.

[Confirmation test of plant growth promoting effect of F. oxysporum RS-21 strain 1]
In order to confirm the plant growth promoting effect of RS-21 strain in more detail, the following experiment was carried out.

The RS-21 strain was cultured, and the spore-like cells were collected and suspended in water to prepare a plant growth promoter. ^{This plant growth promoter contains 1 × 10 5} spores / mL of the RS-21 strain.

On the other hand, 40 g of sterile potting soil was placed in a 50 mL plastic pot and irrigated, and then sorghum seeds were sown in the culture soil, and 5 g of sterilized potting soil was covered with soil and irrigated again. After sowing, sorghum seedlings were obtained by cultivating for one week in an artificial weather room set at 27 ° C. under natural light conditions.

Next, a new 200 mL plastic pot was prepared, and 200 g of sterile potting soil was placed in the plastic pot and irrigated. The above-mentioned sorghum seedlings were transplanted into the plastic pot, and 5 mL of the above-mentioned plant growth promoter was inoculated into the soil in the rhizosphere of the seedlings. After continuing the cultivation of sorghum for one week, the dry weight (g) of the above-ground part and the dry weight (g) of the underground part were measured. As a control, sorghum was cultivated by the same method except that it was not inoculated with a plant growth promoter, and the dry weight of the above-ground part and the underground part of the sorghum was measured.

The results of measuring the dry weight (g) (n = 6 respectively) of the above-ground part are shown in the left panel of FIG. 2, and the results of measuring the dry weight (g) (n = 6 of each) of the underground part are shown on the right of FIG. Shown on the panel. As can be seen from FIG. 2, when the plant growth promoter containing the RS-21 strain was used, both the dry weight of the above-ground part and the dry weight of the underground part were significantly increased as compared with the control. More specifically, when a plant growth promoter containing the RS-21 strain was used, the dry weight of the above-ground part was 1.4 times that of the control, and the dry weight of the underground part was 1.2 times that of the control. As described above, it was shown that the plant growth promoting agent containing the RS-21 strain has a plant growth promoting effect on both the above-ground part and the underground part of sorghum.

[Confirmation test of plant growth promoting effect of F. oxysporum RS-21 strain 2]
The following experiments were conducted to investigate the effect of the inoculation amount of RS-21 strain on the growth promoting effect of sorghum.

Suspend the spores of the RS-21 strain in water to prepare plant growth promoters with ^three spore concentrations (1 x 10 3 spores / mL, 1 x 10 ⁵ spores / mL, 1 x 10 ^{7 spores / mL).} bottom. A confirmation test of the plant growth promoting effect was carried out by the same method as described in Example 2 with or without using these plant growth promoting agents (control).

As a result, it was shown that the higher the spore concentration of the RS-21 strain in the plant growth promoter used, the higher the growth promoting effect on sorghum. From this, it was shown that the density or concentration of RS-21 strain in the soil of the rhizosphere of sorghum is important for obtaining more growth promoting effect of sorghum.

[Confirmation test of plant growth promoting effect of volatile organic compounds produced by F. oxysporum RS-21 strain]
It has been reported that among the volatile organic compounds (VOCs) released by bacteria, there are substances that promote the growth of plants and substances that inhibit the growth of plants. Therefore, in order to investigate whether or not the volatile organic compound produced by the RS-21 strain has a plant growth promoting effect, the method described in (Fiers et al., PLoS ONE 2013, 8 (6), e66805.) The following experiments were conducted with reference to.

A co-culture device as shown in FIG. 3 was produced by the following method. A plastic circular petri dish with a diameter of 9 cm without a lid was placed in a plastic square petri dish measuring 14 cm in length and 10 cm in width (Fig. 3). A sterilized 25 mL potato dextrose agar medium (PDA medium) was dispensed into a circular petri dish and left at room temperature until the PDA medium solidified. Then, the RS-21 strain was inoculated on the PDA medium (Fig. 3). Next, in a square petri dish, 45 mL of sterilized 1/2 Murashige and Skoog medium (MS medium) was dispensed around the circular petri dish and left at room temperature until the MS medium solidified. The upper MS medium in the square petri dish was removed, and two sterilized and germinated sorghum seeds were sown on the upper end of the remaining MS medium. In addition, a hole was made in the circular dish so that only the gas in the circular dish could move into the square dish (Fig. 3). As shown in the lower right of FIG. 3, such a co-culture device was allowed to stand perpendicular to the ground and grew for one week (FIG. 3). The raw weight (g) of the above-ground part of the sorghum (n = 2 respectively) is shown in FIG. 4, and the raw weight (g) of the underground part is shown in FIG. 5 (n = 2 respectively). As a non-pathogenic Fusarium oxysporum strain having a growth promoting effect on sorghum, there is a Fo-304 strain. The results of growing sorghum using the Fo-304 strain instead of the RS-21 strain are also shown in FIGS. 4 and 5. Further, as a control, the results of growing sorghum in the same manner except that none of the strains are used are shown in FIGS. 4 and 5.

From the results of FIGS. 4 and 5, it was shown that the plant growth promoting effect of the RS-21 strain was due to VOC.

[Effect of medium composition of F. oxysporum RS-21 strain on plant growth promoting effect 1]
It is known that the amount and type of VOCs released by Trichoderma spp., Fusarium spp., Cochliobolus spp., Etc., depending on the growth conditions (nutrition conditions, culture days, fungal condition, etc.) (Bruce et al., Holzforschung 2000, 54, 481-486; Fiers et al., PLoS ONE 2013, 8 (6), e66805; Lee et al., Arch Microbiol. 2015, 197 (5), 723-727 Nemcovic et al., FEMS Microbiol Lett. 2008, 284 (2), 231-6; Wheatley et al., Int Biodete. Biodegrad. 1997, 39, Issues 2-3, 199-205). To investigate whether the composition of the medium of the RS-21 strain affects the plant growth promoting effect, and whether the RS-21 strain also exerts a growth promoting effect on plants other than sorghum. The following experiments were carried out to investigate.

A plastic circular petri dish with a diameter of 9 cm without a lid was placed in a plastic square petri dish measuring 14 cm in length and 10 cm in width. In a circular petri dish, 25 mL of sterilized potato dextrose agar medium (PDA medium) or potato sucrose agar medium (PSA medium) was dispensed and left at room temperature until the PDA medium or PSA medium solidified. Then, RS-21 strain was inoculated on PDA medium or PSA medium. Next, in a square petri dish, 45 mL of sterilized 1/2 Murashige and Skoog medium (MS medium) was dispensed around the circular petri dish and left at room temperature until the MS medium solidified. Three sterilized and germinated Arabidopsisthaliana seeds were sown on MS medium in a square petri dish. In addition, a hole was made in the circular dish so that only the gas in the circular dish could move into the square dish. The co-culture device was allowed to stand perpendicular to the ground, and Arabidopsis thaliana was grown for one week. In addition, as a control, Arabidopsis thaliana was grown in the same manner except that the RS-21 strain was not used. The results of measuring the raw weight (g) (n = 3 respectively) of the above-ground part and the raw weight (g) (n = 3 each) of the underground part of these Arabidopsis thaliana are shown in Table 1 below.

Among the results in Table 1, the result of the raw weight (g) of the above-ground part of Arabidopsis thaliana is shown in FIG. 6, and the result of the raw weight (g) of the underground part is shown in FIG. From the results of FIGS. 6 and 7, the RS-21 strain increased the raw weight of both the above-ground part and the underground part as compared with the case of the control when cultured in either the PDA medium or the PSA medium, and had a plant growth promoting effect. It was shown to exert. In addition, when the RS-21 strain was cultured in PDA medium, the raw weights of the above-ground and underground parts increased significantly (with a significant difference) compared to the control case, and especially when the RS-21 strain was cultured in PDA medium. It was shown to exert a high plant growth promoting effect. From this, it was shown that glucose is preferable to sucrose as the sugar source of the medium for culturing the RS-21 strain from the viewpoint of obtaining a higher plant growth promoting effect.

Further, for each Arabidopsis thaliana listed in Table 1 above, the root length (cm) and the number of lateral roots (lines) were measured, and the lateral root density (number of lateral roots (lines) / main root length (cm)) was calculated. The results are shown in Table 2 below.

Further, FIG. 8 shows the state of Arabidopsis roots when the RS-21 strain was cultured in PDA medium, and FIG. 9 shows the state of Arabidopsis roots in the case of the control.

From the results of Table 2, FIG. 8 and FIG. 9, the VOC produced by the RS-21 strain has almost no effect on the taproot length of Arabidopsis thaliana, but the number of lateral roots is significantly increased and the lateral root density is significantly increased. Shown (with significant difference). Since it is known that auxin is involved in the increase in the number of lateral roots of plants, it is suggested that the VOC produced by the RS-21 strain may induce the expression of auxin in plants.

[Effect of VOC produced by F. oxysporum RS-21 strain on auxin expression in plants]
The following experiments were conducted to investigate how the VOC produced by the RS-21 strain affects the expression of auxin in plants.

Seeds of transformants in which the auxin-inducible reporter gene DR5 :: GUS was introduced into a wild strain of Arabidopsis thaliana were prepared. The seeds of Arabidopsis thaliana were grown for 4 days by the method described in Example 5 above, and then stained with a GUS stain. The observation result of Arabidopsis thaliana in the case of the control to which the RS-21 strain was not applied is shown in FIG. 10, and the observation result of Arabidopsis thaliana in the case of applying the RS-21 strain is shown in FIG. The stage of 4 days from the start of growth is a stage in which no difference in the degree of growth is observed yet, and the expression site of the auxin-inducible reporter gene at this stage indicates the formation site of the lateral root primordium.

In FIGS. 10 and 11, the site indicated by the arrow is a GUS-stained site, and the site is an expression site of the auxin-inducible reporter gene. As can be seen from FIGS. 10 and 11, it was shown that the number of lateral root primordia in the middle of the taproot increased when the RS-21 strain was applied. From this, it was considered that the VOC produced by the RS-21 strain increased the number of lateral roots through auxin induction in the plant, which led to the promotion of the growth of the underground and above-ground parts of the plant.

[Effect of medium composition of F. oxysporum RS-21 strain on plant growth promoting effect 2]
In Example 5 above, the RS-21 strain has a higher plant growth promoting effect when cultured in PDA medium (sugar source is glucose) than when cultured in PSA medium (sugar source is sucrose). I understood. The following experiments were conducted in order to investigate in more detail how the composition of the sugar source when culturing the RS-21 strain affects the plant growth promoting effect.

The PDA medium contains 2% by weight glucose. Instead of glucose, which is the sugar source, a medium using a mixture having a sucrose: glucose weight ratio of 4: 1 or 2: 1 and a fructose: glucose weight ratio of 4: 1, 2: 1 or 1. Each medium was prepared with a mixture of 1: 1. Using these media, Arabidopsis thaliana was grown for one week in the same manner as in Example 5 above, and the raw weight (g) of the above-ground part and the raw weight (g) of the underground part of the Arabidopsis thaliana were used. Each n = 3) was measured. The result of the raw weight (g) of the above-ground part is shown in FIG. 12, and the result of the raw weight (g) of the underground part is shown in FIG. From the results shown in FIGS. 12 and 13, the RS-21 strain exerted the highest plant growth promoting effect when cultured in PDA medium, and was cultured in PDA medium when cultured in a medium containing fructose and glucose at a ratio of 1: 1. It was shown that the plant growth promoting effect was almost the same as that in the case of. From the results of FIGS. 12 and 13, it was shown that fructose is preferable to sucrose and glucose is preferable to fructose as the sugar source of the medium of the RS-21 strain.

_{[Effect of CO 2} released by F. oxysporum RS-21 strain on plant growth]
The following experiment was conducted to confirm that the plant growth promoting effect of the RS-21 strain was _{not due to the CO 2 released by the RS-21 strain.}

It is known that the _{barium hydroxide aqueous solution absorbs CO 2} in the air, and the barium hydroxide _{reacts with CO 2 to form barium carbonate.} In the co-culture apparatus used in the method described in Example 5 above, a barium hydroxide aqueous solution section was installed in the square petri dish so as to absorb _{CO 2 in the square petri dish.} A PDA medium was used as the medium for the RS-21 strain, and Arabidopsis thaliana was grown for one week by the method described in Example 5 above. In addition, as a control, Arabidopsis thaliana was grown in the same manner except that the RS-21 strain was not used. In addition, Arabidopsis thaliana was grown in the same manner using the F. oxysporum RS-25 strain instead of the RS-21 strain. The raw weight (g) (n = 3 each) of the above-ground part and the raw weight (g) (n = 3 each) of the underground part of these Arabidopsis thaliana were measured. The result of the raw weight (g) of the above-ground part is shown in FIG. 14, and the result of the raw weight (g) of the underground part is shown in FIG. In addition, in order to confirm that the _{barium hydroxide aqueous solution actually absorbs the CO 2} released by the RS-21 strain or the RS-25 strain, the drying of barium carbonate generated by the reaction _{between barium hydroxide and CO 2 is performed.} The weight was measured. The result is shown in FIG. From the results of FIG. 16, it was confirmed that the _{barium hydroxide aqueous solution actually absorbed CO 2.} From the results of FIGS. 14 and 15, when CO ₂ released by the RS-21 strain was absorbed, plant growth was promoted at the same level or higher as compared with the cases of FIGS. 4 and 5 which did not absorb _{CO 2.} It was shown to be effective. From this, _{it was shown that the CO 2} released by the RS-21 strain is not related to the plant growth promoting effect of the RS-21 strain.

Moreover, from the results of FIGS. 14 and 15, it was shown that the F. oxysporum RS-25 strain also has a plant growth promoting effect.

According to the present invention, it is possible to provide a plant growth promoter capable of safely and effectively promoting the growth of a plant, a method for cultivating a plant, a method for promoting the growth of a plant, and the like.

Claims (12)

A plant growth promoter containing viable cells of Fusarium oxysporum RS-21 strain, RS-25 strain, or both strains. A plant lateral root formation promoter containing viable cells of Fusarium oxysporum RS-21 strain. Agent per 1g, agent according to claim 1 or 2 The total spore number of Fusarium oxysporum RS-21 strain and the RS-25 strain is 10 ⁴ or more. The plants are rice plants, abrana plants, legumes, higanbana plants, stag beetles, sardines, eggplants, roses, sardines, seri, sardines, sardines, and sardines. The agent according to any one of claims 1 to 3, which is a plant selected from plants, Aoi family plants, Basho family plants, Hirugao family plants, and Yuri family plants. The agent according to any one of claims 1 to 4, wherein the plant is a plant belonging to the genus Sorghum of the Gramineae family. The step of applying the agent according to any one of claims 1 to 5 to one or more selected from the group consisting of plant nursery soil, plant cultivation soil, plant body and plant seed. Plant raising or cultivation method. The step of applying the agent according to any one of claims 1 to 5 to one or more selected from the group consisting of plant seedling soil, plant cultivation soil, plant body and plant seed. How to promote plant growth. The promotion of plant growth exerted by the viable cells of the RS-21 strain, the RS-25 strain, or both strains promotes the rate of increase in the weight of the above-ground part, the underground part, or both of the plants. The method for promoting the growth of a plant according to claim 7. The method for promoting plant growth according to claim 8, wherein the promotion of plant growth exhibited by the RS-21 strain includes an increase in the number of lateral roots of the plant or an increase in auxin-producing sites in the roots. The method for promoting the growth of a plant according to claim 9, wherein the promotion of the growth of the plant exhibited by the RS-21 strain is due to the secretion of a substance outside the cells. The plants are rice plants, abrana plants, legumes, higanbana plants, stag beetles, sardines, eggplants, roses, sardines, seri, sardines, sardines, and sardines. The method according to any one of claims 6 to 10, which is a plant selected from a plant, a plant of the family Aoi, a plant of the family Basho, a plant of the family Hirugao, and a plant of the family Yuri. Fusarium oxysporum RS-21 strain or Fusarium oxysporum RS-25 strain.

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