Composition for increasing the yield of leafy vegetables, fruit vegetables, and legumes.

Abstract

To provide a composition for increasing the yield of leafy vegetables, fruit vegetables, and legumes that has a lower environmental impact than conventional compositions. [Solution] A composition for increasing the yield of leafy vegetables, fruit vegetables, and legumes, comprising a cell wall-containing substance of methanol-utilizing bacteria.

Description

Technical Field

[0001] The present invention relates to a composition for increasing the yield of leafy vegetable, fruit vegetable and leguminous plants, a method for increasing the yield of leafy vegetable, fruit vegetable and leguminous plants, and a method for cultivating leafy vegetable, fruit vegetable and leguminous plants.

Background Art

[0002] Currently, due in part to the explosive population growth, producing sufficient supplies of agricultural crops has become a global issue. Application of fertilizers is indispensable for improving productivity and achieving stable production of agricultural crops, but from the perspectives of environmental burden and price instability caused by resource localization, technologies for reducing fertilization amount are in demand.

[0003] Accordingly, in recent years, biostimulant materials that secure crop yield and quality while reducing fertilization amount have attracted attention as a new technology.

[0004] Patent Document 1 discloses a technique for infecting rice with nitrogen-fixing bacteria to obtain the effects of promoting rice growth and increasing seed yield.

Prior Art Literature

Patent Literature

[0005]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0006] As described above, although studies on increasing plant yield using nitrogen-fixing bacteria have been conducted so far, there has been no report on examples of using cell wall components of methanol-assimilating bacteria for leafy vegetable, fruit vegetable and leguminous plants.

Means for Solving the Problem

[0007] As a result of diligent research, the inventors discovered that the yield of leafy vegetables, fruit vegetables, and legumes can be increased by inoculating them with a composition containing the cell wall of methanol-utilizing bacteria, thus completing the present invention.

[0008] In other words, the present invention is as follows. [1] A composition for increasing the yield of leafy vegetables, containing cell wall components of methanol-utilizing bacteria. [2] A composition for increasing the yield of fruit and vegetable plants, containing cell wall components of methanol-utilizing bacteria. [3] A composition for increasing the yield of legume plants, containing cell wall components of methanol-utilizing bacteria. [4] The yield-increasing composition according to any one of the following [1] to [3], wherein the methanol-assimilating bacterium is Methylobacterium sp. Rst strain with accession number NITE P-02628. [5] The composition according to any one of claims [1] to [4], wherein the cell wall-containing material of the methanol-assimilating bacteria comprises at least one of dead cells and bacterial cell walls. [6] A method for increasing the yield of leafy vegetables, comprising the step of inoculating leafy vegetable plants with the cell wall contents of methanol-utilizing bacteria. [7] A method for cultivating leafy vegetables, comprising the step of inoculating leafy vegetables with the cell wall contents of methanol-utilizing bacteria. [8] The method described in [6] or [7], wherein the inoculation is performed during the 4-8 leaf stage of the leafy vegetable plant or 1-3 weeks before harvest. [9] A method for increasing the yield of fruit and vegetable plants, comprising the step of inoculating fruit and vegetable plants with the cell wall contents of methanol-utilizing bacteria.

[10] A method for cultivating fruit and vegetable plants, comprising the step of inoculating fruit and vegetable plants with the cell wall contents of methanol-utilizing bacteria.

[11] The method described in [9] or

[10] , wherein the inoculation is performed between 5 and 10 days before harvest of the fruit and vegetable plants.

[12] A method for increasing the yield of legumes, comprising the step of inoculating legume plants with the cell wall contents of methanol-utilizing bacteria.

[13] A method for cultivating legumes, comprising the step of inoculating legumes with the cell wall contents of methanol-utilizing bacteria.

[14] The method described in

[12] or

[13] , wherein the inoculation is performed between 1 and 50 days after heading of the legume plant.

[15] The method according to any one of the following [6]-

[14] , wherein the methanol-assimilating bacterium is Methylobacterium sp. Rst strain with accession number NITE P-02628.

[16] The method according to any one of [6] to

[15] , wherein the cell wall content of the methanol-assimilating bacteria comprises at least one of dead cells and bacterial cell walls. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a composition for increasing the yield of leafy vegetables, fruit vegetables, and legumes that has a lower environmental impact than conventional methods, a method for increasing the yield of leafy vegetables, fruit vegetables, and legumes, and a method for cultivating leafy vegetables, fruit vegetables, and legumes. [Modes for carrying out the invention]

[0010] The following describes in detail embodiments for carrying out the present invention (hereinafter also referred to as "this embodiment"). It should be noted that the present invention is not limited to this embodiment and can be implemented in various modifications within the scope of its gist.

[0011] 1. Composition for increasing yield The present embodiment provides a composition for increasing the yield of leafy vegetables, fruit vegetables or leguminous plants, which contains a cell wall-containing material of a methanol-assimilating bacterium. The composition for increasing yield according to the present embodiment may contain the cell wall-containing material of a methanol-assimilating bacterium as an active ingredient.

[0012] 1-1. Cell wall-containing material of methanol-assimilating bacterium It is preferable that the cell wall-containing material of a methanol-assimilating bacterium contains at least one of killed cells of the methanol-assimilating bacterium and bacterial cell walls, because this facilitates formulation and quality control, and reduces risks in terms of environmental safety when used. In this case, the cell wall-containing material of a methanol-assimilating bacterium in the present embodiment may contain both killed cells of the methanol-assimilating bacterium and bacterial cell walls, or may contain only either killed cells of the methanol-assimilating bacterium or bacterial cell walls. The bacterial cell wall of the methanol-assimilating bacterium may be derived from live cells or killed cells of the methanol-assimilating bacterium. The cell wall-containing material of a methanol-assimilating bacterium may contain live cells of the methanol-assimilating bacterium.

[0013] When the cell wall-containing material of a methanol-assimilating bacterium contains killed cells and / or bacterial cell walls, the content of the killed cells and / or bacterial cell walls in the cell wall-containing material of a methanol-assimilating bacterium is not particularly limited, and can be appropriately selected by those skilled in the art according to the purpose. The cell wall-containing material of a methanol-assimilating bacterium may consist only of killed cells and / or bacterial cell walls, or may be obtained by appropriately adding a solvent to killed cells and / or bacterial cell walls to form the cell wall-containing material.

[0014] The content of the cell wall-containing material of a methanol-assimilating bacterium in the composition for increasing yield is not particularly limited, and may be any as long as it exerts a yield-increasing effect, and can be appropriately selected by those skilled in the art according to the purpose.

[0015] 1-2. Methanol-assimilating bacterium Methanol-utilizing bacteria are bacteria belonging to the genus Methylobacterium. They grow on the surface of plants such as perilla and rice, and are known to utilize methanol derived from plants while also supplying vitamins and plant hormones to the plants, thus forming a symbiotic relationship.

[0016] The method for obtaining methanol-assimilating bacteria is not particularly limited, but for example, those isolated from the surface of plant tissue can be used.

[0017] The method for isolating methanol-utilizing bacteria is not particularly limited, but examples include accumulation culture using methanol alone as the carbon source in the culture medium. Specifically, methods include inoculating a washing solution obtained by washing methanol-utilizing bacteria off the surface of a plant into a culture medium, identifying the colonies that have grown, and isolating the methanol-utilizing bacterial colonies, or inoculating a culture solution obtained by culturing a plant in a liquid culture medium into a culture medium, identifying the colonies that have grown, and isolating the methanol-utilizing bacterial colonies.

[0018] The plant tissue used for isolating methanol-utilizing bacteria is not particularly limited as long as it is a part where methanol-utilizing bacteria grow, but can be appropriately selected depending on the purpose. Examples include the stems and hulls of grains. One or more of these tissues may be used.

[0019] The composition of the culture medium and the cultivation conditions for methanol-utilizing bacteria are not particularly limited and can be appropriately selected according to the purpose.

[0020] While methanol-assimilating bacteria are not particularly limited, Methylobacterium sp. Rst strain is preferred. The Rst strain was deposited with the Patent Microorganism Depositary Center of the National Institute of Technology and Evaluation (NITE) (2-5-8 Kazusa-Kamatari, Kisarazu City, Chiba Prefecture 292-0818, Japan) and was accepted as NITE P-02628 on February 7, 2018.

[0021] 1-3. Fungal cell wall There are no particular limitations on the method for preparing the cell walls of methanol-assimilating bacteria, but known methods can be appropriately selected. For example, one method involves culturing and harvesting the bacterial cells, suspending them in an aqueous solution containing 50 mM EDTA and 2% SDS, incubating them at approximately 37°C for about 60 minutes, centrifuging the solution, adding 3 M sodium acetate and ethanol to the supernatant and mixing, then centrifuging again to prepare pellet-shaped bacterial cell walls. There are no particular limitations on the method for confirming the presence or absence of bacterial cell wall components, and a suitable method can be selected depending on the purpose. For example, one method is to use the phenol-sulfuric acid method and confirm the presence using polysaccharides as an indicator.

[0022] 1-4. Dead bacterial cells The method for preparing the dead cells of the methanol-assimilating bacteria is not particularly limited, but a known method can be appropriately selected depending on the purpose. For example, a method of culturing and sterilizing the cultured cells in an autoclave is one example. The dead cells may also be crushed cells that have been subjected to a crushing treatment. The crushing method is not particularly limited, but a known method can be appropriately selected depending on the purpose. The degree of crushing is also not particularly limited, but can be appropriately selected depending on the purpose.

[0023] 1-5. Live bacterial cells The method for preparing viable cells of methanol-assimilating bacteria is not particularly limited, and known methods can be appropriately selected depending on the purpose. For example, methods for recovering cultured cells can be used.

[0024] 1-6. Other ingredients The yield-increasing composition may further contain the cell wall contents of methanol-assimilating bacteria and other components. The other components are not particularly limited and can be appropriately selected depending on the purpose, and may further contain, for example, components that have a yield-increasing effect.

[0025] The yield-increasing composition may contain the cell wall contents of methanol-assimilating bacteria in combination with one or more agriculturally acceptable components. Agriculturally acceptable components are not particularly limited, but examples include solvents, carriers, excipients, binders, solubilizers, thickeners, emulsifiers, dispersants, suspending agents, spreading agents, penetrating agents, stabilizers, swelling agents, lubricants, surfactants, oily liquids, buffers, bactericides, antifreezes, defoaming agents, colorants, antioxidants, preservatives, and further active ingredients. Agriculturally acceptable carriers include agriculturally acceptable liquid carriers such as water, mineral oil fractions like kerosene or diesel oil, plant or animal-derived oils, cyclic or aromatic hydrocarbons (e.g., paraffin, tetrahydronaphthalene, alkylated naphthalenes or their derivatives, or alkylated benzenes or their derivatives), alcohols (e.g., methanol, ethanol, propanol, butanol, or cyclohexanol), ketones (e.g., cyclohexanone), or amines (e.g., N-methylpyrrolidone), or mixtures thereof.

[0026] The content of other components in the cell wall contents of methanol-assimilating bacteria in the yield-increasing composition is not particularly limited and can be appropriately selected depending on the purpose.

[0027] The yield-increasing composition can be used in combination with conventionally known agricultural materials such as pesticides and fertilizers. Examples of agricultural materials include pesticides, fertilizers, soil conditioners, and growing media (potting soil). Specifically, pesticides may include fungicides, insecticides, insecticide-fungicides, acaricides, nematicides, rodenticides, insecticides / repellents, attractants, spreading agents, hormones (growth regulators), herbicides, etc. Fertilizers may include organic fertilizers, chemical fertilizers, liquid fertilizers, solid fertilizers, compound fertilizers, compost, growth promoters, vitality enhancers, calcium supplements, etc. Soil conditioners may be intended for physical, chemical, or biological soil improvement, and may also include oxygen supply agents, etc. Furthermore, pesticides, fertilizers, soil conditioners, and growing media may contain components derived from plants, animals, lime, minerals, or microorganisms. It is preferable that the cell wall components of methanol-assimilating bacteria include at least one of the dead cells and cell walls of methanol-assimilating bacteria, in order to allow the yield-increasing composition to be used in combination with a fungicide.

[0028] The form of the yield-increasing composition is not particularly limited and can be appropriately selected depending on the purpose. For example, it may be a solid (e.g., powder or granules) or a liquid (e.g., solution or suspension), and it is preferable to use it in the form of a liquid such as a solution or suspension. When used as a solution, it may be in liquid form, or it may be used as a liquid prepared at the time of application. The dosage form of the yield-increasing composition is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be formulated in the form of an emulsion, wettable powder, liquid, oil, water-soluble powder, granules, powder, aerosol, paste, or granules.

[0029] Yield-increasing compositions can be used to increase plant yields.

[0030] 2. Methods for increasing yield and cultivation methods This embodiment provides a method for increasing the yield of leafy vegetables, fruit vegetables, or legumes, and a method for cultivating leafy vegetables, fruit vegetables, or legumes.

[0031] 2-1. Process of inoculating plants with the cell wall contents of methanol-utilizing bacteria. The method of this embodiment includes the step of inoculating a plant with a cell wall-containing substance of methanol-utilizing bacteria.

[0032] There are no specific restrictions on the timing of vaccination; it can be chosen as appropriate depending on the purpose.

[0033] To increase yield, or when the plant being cultivated is a leafy vegetable, inoculation is preferably carried out, for example, when the leafy vegetable plant has 4 to 8 leaves or 1 to 3 weeks before harvest. Inoculation may also be carried out when the leafy vegetable plant has 4 to 8 leaves and 1 to 3 weeks before harvest. To increase yields, or when cultivating fruit vegetables, it is preferable to inoculate during a period when the plant is under stress due to fruit set, as nutrients are being diverted to the fruit. For example, it is preferable to inoculate fruit vegetables 5 to 10 days before harvest. If the plant is a crop that is harvested continuously, then in the above context, "before harvest" may also mean "before the start of harvest." To increase yields, or when the plant being cultivated is a legume, inoculation is preferably carried out between 1 and 50 days after heading of the legume plant, more preferably between 1 and 30 days after heading, and even more preferably between 5 and 20 days after heading. Performing the inoculation at the preferred time mentioned above is advantageous because it can further increase the yields of leafy vegetables, fruit vegetables, and legumes.

[0034] The number of vaccinations can be one or multiple times. Similarly, if there are multiple vaccination periods, the number of vaccinations at each period can also be one or multiple times.

[0035] The amount of methanol-utilizing bacterial cell wall-containing material inoculated into the aforementioned cereal plants is not particularly limited and can be appropriately selected depending on the purpose. However, the amount of methanol-utilizing bacterial cell wall-containing material inoculated per plant strain, prepared so that the OD is equivalent to 0.5 in OD600 terms, is preferably 1 mL or more, more preferably 2 mL or more, and even more preferably 3 mL or more. The above preferred dosage is advantageous in that it can further increase the yield of grains. The dosage may be the same amount or different amounts at each inoculation.

[0036] The method of inoculation is not particularly limited, as long as the cell wall contents of methanol-utilizing bacteria can be brought into contact with at least a portion of the plant, and can be appropriately selected depending on the purpose. Examples include spraying, coating, and immersion. These may be performed individually or in combination of two or more methods. In particular, it is preferable to spray the plant with a liquid containing the cell wall contents of methanol-utilizing bacteria. Inoculation may be done manually or using machinery. When using machinery, there are no particular limitations, but for example, application (spraying) may be done using a drone.

[0037] The part of the plant to which the cell wall-containing substance of methanol-utilizing bacteria is inoculated is not particularly limited and can be appropriately selected depending on the timing of inoculation. For example, it can be inoculated on seeds, seedlings, or the whole or a part of a mature plant, but inoculation on the leaf surface is preferable. According to the method of this embodiment, even if the inoculation of the cell wall-containing substance of methanol-utilizing bacteria does not reach the rhizosphere, the yield-increasing effect can be obtained by inoculating the above-ground part of the plant. Therefore, it is advantageous because it is simpler than adding it as fertilizer and can be used in combination with pesticides.

[0038] 2-2. Other processes The aforementioned other steps are not particularly limited as long as they do not impair the effects of the present invention, and ordinary steps in the cultivation of grains can be appropriately selected depending on the purpose. Plants can be grown hydroponically or in soil.

[0039] 2-3. Leafy vegetables, fruit vegetables, or legumes and grains The leafy vegetables used are not particularly limited, but examples include spinach, leeks, cabbage, celery, lettuce, Chinese cabbage, broccoli, komatsuna, bok choy, garland chrysanthemum, and mizuna. Among these, the method of this embodiment is preferably used for spinach and leeks.

[0040] 2-4. Fruit and vegetable plants The fruits and vegetables used are not particularly limited, but examples include tomatoes, cucumbers, eggplants, bell peppers, pumpkins, sweet corn, and okra. Among these, the method of this embodiment is preferably used for tomatoes.

[0041] 2-5. Legumes Leguminous plants are not particularly limited, but examples include soybeans, adzuki beans, mung beans, cowpeas, kidney beans, lima beans, peanuts, peas, and broad beans. [Examples]

[0042] The present invention will be described below with reference to manufacturing and testing examples, but the present invention is not limited in any way to these manufacturing and testing examples.

[0043] Production Example 1: Isolation of methanol-utilizing bacteria Rice stems were used as samples, and accumulation culture was performed in NMS medium (Whittenbury, R., KC Phillips, and JF Wilkinson. 1970. Enrichment, isolation and some properties of methane-utilizing bacteria. J. Gen. Microbiol. 61:205-218.) supplemented with 0.01% yeast extract and 0.5% methanol. The culture solution after accumulation culture was streaked onto a plate medium of the same composition, and the resulting colonies were isolated to obtain Methylobacterium sp. Rst strain.

[0044] The aforementioned Methylobacterium sp. Rst strain was deposited with the Patent Microorganism Depositary Center of the National Institute of Technology and Evaluation (NITE) (2-5-8 Kazusa-Kamatari, Kisarazu City, Chiba Prefecture 292-0818, Japan) and was accepted as NITE P-02628 on February 7, 2018.

[0045] Preparation Example 2: Preparation of Cell Wall Contents of Methanol-Assimilated Bacteria <Preculture> The Methylobacterium SP Rst strain obtained in Production Example 1 was cultured in 5 mL of Hypho minimal medium (Delaney NF, Kaczmarek ME, Ward LM, Swanson PK, Lee MC & Marx CJ Development of an optimized medium, strain and high-throughput culturing methods for Methylobacterium extorquens. PLoS One 8, e62957 (2013)) with 0.2% sodium succinate added, in a test tube at 28°C for 48 hours.

[0046] <Main culture> To 100 mL of Hypho Minimum Medium with 0.5% methanol added, the previously cultured culture solution was added to achieve an OD600 of 0.002. The cultures were then incubated in two 500 mL baffled Erlenmeyer flasks at 28°C and 180 rpm for 72 hours. The OD600 at the time of bacterial collection was 2.9-3.3.

[0047] <Preparation of cell wall-containing substances> After the above-described culture, the cultured cells were collected by centrifugation. They were then washed twice with sterile water. The washed cells were sterilized in an autoclave at 121°C for 20 minutes. The sterilized pellet was diluted with a spreading agent of the following composition to obtain a cell wall-containing solution, with the OD equivalent to 0.5 based on the OD600 of the bacterial suspension. Note that while a spreading agent was used here, its use is optional. -Spreading agent- • Polyoxyethylene (9) nonylphenyl ether: 0.2 g / L • Sodium carboxymethylcellulose: 1g / L * Prepared with ultrapure water

[0048] Spinach and green onions were used as examples of leafy vegetables, and the following methods were used to test the ability to increase the yield of leafy vegetables.

[0049] Test Example 1: Spinach <Sampling> In a greenhouse located in Fukaya City, Saitama Prefecture, the sample was sprayed onto 54 spinach plants in each test plot (see below). The first spraying was carried out on November 29th, and the second spraying on December 8th. The spraying rate was approximately 500 mL per 0.2 ares, and it was applied to the leaves using a sprayer. The first and second sprayings were carried out when the spinach plants had 4 and 8 leaves, respectively, and the spinach was harvested on December 16th. -Test Section- • Control group: Sprayed with only a spreading agent. • Test plot: The cell wall-containing solution prepared in Production Example 2 was sprayed.

[0050] <Analysis of each test plot> The total weight of spinach (54 plants) harvested on December 16th was calculated. The result was 32.6 kg in the control group and 38.7 kg in the experimental group. Furthermore, the plant height and leaf color (SPAD value) of spinach harvested on December 16th were analyzed. As a result, the average plant height was 29.4 cm in the control group, compared to 30.5 cm in the experimental group. The average SPAD value was 59.2 in the control group, compared to 61.2 in the experimental group. The study suggested that substances contained in the cell walls of methanol-utilizing bacteria may be involved in increasing the yield of leafy vegetables.

[0051] Test example 2: Green onions <Sampling> In a greenhouse in Fukaya City, Saitama Prefecture, the sample was sprayed onto 265 scallion plants in each test plot (see below). The first spraying was carried out on November 11th, the second on November 30th, and the third on December 10th. The spraying rate was approximately 1000 mL per 0.2 ares, and it was applied to the leaves using a sprayer. The first and second sprayings were carried out when the scallions had 4 and 8 leaves, respectively, and the scallions were harvested on December 17th. -Test Section- • Control group: Sprayed with only a spreading agent. • Test plot: The cell wall-containing solution prepared in Production Example 2 was sprayed.

[0052] <Analysis of each test plot> The total weight of the scallions (265 plants) harvested on December 17th was calculated. The result was 6.6 kg in the control group, compared to 8.2 kg in the experimental group. Furthermore, the height of the green onions after the third application was analyzed. The results showed that the average height in the control group was 44.7 cm, while in the experimental group it was 52.0 cm. The study suggested that substances contained in the cell walls of methanol-utilizing bacteria may be involved in increasing the yield of leafy vegetables.

[0053] Test Example 3: Soybeans As an example of a legume, soybeans were used to test increased yields of fruit and vegetable crops as follows.

[0054] <Sampling> In a field in Kutchan-cho, Abuta-gun, Hokkaido, the sample was applied to 1200 soybean plants in each test plot (see below). The application was carried out once, approximately 10 days after heading. The amount applied per plant was approximately 8 mL, and it was sprayed onto the leaves using a sprayer. -Test Section- • Control group: Sprayed with only a spreading agent. • Test plot: The cell wall-containing solution prepared in Production Example 2 was sprayed.

[0055] <Analysis of each test plot> The dry grain weight per plant was calculated for the harvested soybeans (1200 plants). The results showed that the control group yielded 17.6 kg, while the experimental group yielded 19.8 kg. This suggests that the cell wall components of methanol-utilizing bacteria may be involved in the increased yield of legumes.

[0056] Test Example 4: Tomato Tomatoes were used as an example of a fruit vegetable, and the following methods were used to test increased yields of fruit vegetables.

[0057] <Sampling> In a greenhouse in Mukawa-cho, Yufutsu-gun, Hokkaido, the sample was sprayed on approximately 80 tomato plants in each test plot (see below). The first spraying was done in early July, one week after the start of harvesting, the second spraying was done two weeks after the first, and the third spraying was done two weeks after the second. The amount sprayed per plant was approximately 8 mL, and it was applied to the leaves using a sprayer. Tomato harvesting took place from mid-July to late September. -Test Section- • Control group: Sprayed with only a spreading agent. • Test plot: The cell wall-containing solution prepared in Production Example 2 was sprayed.

[0058] <Analysis of each test plot> The total weight of tomatoes (80 plants) harvested over seven consecutive days in late September was calculated. The control group yielded 16.52 kg, while the experimental group yielded 23.8 kg. This suggests that the cell wall components of methanol-utilizing bacteria may be involved in the increased yield of fruit and vegetable crops. [Accession Number]

[0059] NITE P-02628

Claims

1. A composition for increasing the yield of leafy vegetables, containing cell wall components of methanol-utilizing bacteria.

2. A composition for increasing the yield of fruit and vegetable plants, containing cell wall components of methanol-utilizing bacteria.

3. A composition for increasing the yield of legume plants, containing cell wall components of methanol-utilizing bacteria.

4. The yield-increasing composition according to any one of claims 1 to 3, wherein the methanol-assimilating bacterium is Methylobacterium sp. Rst strain with accession number NITE P-02628.

5. The composition according to any one of claims 1 to 3, wherein the cell wall-containing material of the methanol-assimilating bacteria comprises at least one of dead cells and bacterial cell walls.

6. A method for increasing the yield of leafy vegetables, comprising the step of inoculating leafy vegetables with the cell wall contents of methanol-utilizing bacteria.

7. A method for cultivating leafy vegetables, comprising the step of inoculating leafy vegetables with the cell wall contents of methanol-utilizing bacteria.

8. The method according to claim 6 or 7, wherein the inoculation is performed during the 4-8 leaf stage of the leafy vegetable plant or during the 1-3 week period before harvest.

9. A method for increasing the yield of fruit and vegetable plants, comprising the step of inoculating fruit and vegetable plants with the cell wall contents of methanol-utilizing bacteria.

10. A method for cultivating fruit and vegetable plants, comprising the step of inoculating fruit and vegetable plants with the cell wall contents of methanol-utilizing bacteria.

11. The method according to claim 9 or 10, wherein the inoculation is performed between 5 and 10 days before harvesting the fruit and vegetable plants.

12. A method for increasing the yield of legume plants, comprising the step of inoculating legume plants with the cell wall contents of methanol-utilizing bacteria.

13. A method for cultivating legumes, comprising the step of inoculating legumes with the cell wall contents of methanol-utilizing bacteria.

14. The method according to claim 12 or 13, wherein the inoculation is performed between 1 and 50 days after heading of the legume plant.

15. The method according to claim 6, 7, 9, 10, 12, or 13, wherein the methanol-assimilating bacterium is Methylobacterium sp. Rst strain with accession number NITE P-02628.

16. The method according to claim 6, 7, 9, 10, 12, or 13, wherein the cell wall-containing material of the methanol-assimilating bacteria comprises at least one of dead cells and bacterial cell walls.