JPH09299076A - Soil disease injury controlling agent for solanaceae using bacillus circulans and soil disease injury control and plant growth promoter and plant growth promotion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new strain belonging to Bacillus circulans, viable at a specific high temperature, having activity to control tobacco damping-off and Pseudomonas solanacearum in the field and activity to promote plant growth, thus useful as a soil disease injury controlling agent or plant growth promoter, etc. SOLUTION: This new strain Bacillus circulans A268 (FERM BP-5506) belongs to Bacillus circulans, being viable at 50 deg.C and having activity to control tobacco damping-off and Pseudomonas solanacearum in the field and activity to promote plant growth. Therefore, this new strain is useful as e.g. a soil disease injury controlling agent against the above plant disease in juries or a plant growth promoter. This new strain is obtained as follows: tobacco roots are collected from any tobacco field of the whole of Japan, finely chopped, put into disinfected distilled water, and agitated with a mixer; the resultant suspension is cultured, and bacteria with high controlling effect on tobacco damping-off is selected.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a microorganism belonging to the scientific name Bacillus circulans and its use, more specifically a soil disease control agent for solanaceous plants such as tobacco wilt and solanaceous wilt. And its use as a plant growth promoter.

[0002]

2. Description of the Related Art Tobacco wilt disease caused by the infestation of Pseudomonas so lanacearum , which is one of the plant pathogenic bacteria, or bacterial wilt disease of solanaceous plants (hereinafter abbreviated as "this disease") is tobacco, tomato, eggplant. , Many crops such as bell peppers are often damaged.

This pathogenic bacterium (hereinafter abbreviated to bacterial wilt) is easy to survive in the soil for a long period of time, and once it infects a plant, it grows quickly, so that it is extremely difficult to control it.
It is said to be one of the difficult-to-control diseases among crop diseases.

Currently used control measures against this disease include the use of resistant varieties, application of organic substances, and
Examples include soil tillage and upland drainage, but they often do not show a stable control effect. In addition, soil fumigants such as chloropicrin and methyl bromide are used as chemical control methods. Since the use of these agents causes environmental pollution and destruction of the ozone layer, there is a possibility that the usage amount will be limited in the future. However, the cultivated pest control method is only a complementary means for reducing the damage, and the damage cannot be avoided without using the soil fumigant. Therefore, a safe and highly effective control method has been demanded so far.

In order to produce agricultural products and increase their commercial value, it is necessary to maintain the quality and yield of the harvested products at a certain level. To do so, it is necessary to produce healthy and well-grown seedlings.

To obtain uniform seedlings in tobacco,
We are doing work such as thinning and temporary planting after germination, but it requires a lot of labor and time. Therefore, coated seeds have been developed in order to omit the work of thinning and temporary planting (Japanese Patent Publication No. 47-031122 and Japanese Patent Publication No. 48-013110). However, in this case, problems such as uneven germination and easy uneven growth occur. In addition, some flowers such as eustoma and spinach such as spinach are very difficult to obtain uniform seedlings by normal management. Therefore, it is desired to develop a method for promoting the growth and uniforming of crops.

On the other hand, a wide variety of microorganisms are present in natural soil and form an ecosystem by influencing each other. Some of these microbes include plant growth and
It has been revealed that there are many microorganisms that have a great influence on the occurrence of diseases. Therefore, in order to provide a safe and effective crop cultivation technique, attempts have been made to isolate industrially useful microorganisms from these microorganisms and use them for improving agricultural productivity. There is.

As an example of the control of this disease by microorganisms isolated from such soil, Pseudomonas putida ( Ps
Method using eudomonas putida )
(1990) 56: 404), a method using Pseudomonas fluorescens (Revista
de Microbiologia (1989) Vol. 20: 18-26), and a method using a weakly pathogenic Pseudomonas solanacearum bacterium-producing strain ( Pseudomonas so lanacearum ) (JP-A-1-16579). Since the above-mentioned antagonistic bacteria show antibacterial activity against the wilt bacterium on the medium, it is suggested that the antibacterial substances produced by the antagonistic bacteria are involved as one of the disease suppressive mechanisms.

Nitrogen-fixing bacteria and mycorrhizal fungi are examples of growth promoting techniques that utilize microorganisms isolated from soil. Nitrogen-fixing bacteria fix nitrogen gas in the air to ammonia nitrogen and supply plant nitrogen to promote the growth of plants. In addition, mycorrhizal fungi can promote the growth of plants by symbiotic with the roots of plants, extending hyphae, increasing the utilization efficiency of phosphorus in soil, and supplying phosphorus to plants, which is an essential element of plants. Known (Mycologia (196
5) Vol.57: 562-575).

[0010]

[Problems to be Solved by the Invention] In controlling the present disease,
In the case of using Pseudomonas putida or Pseudomonas fluorescens, these antagonistic bacteria show antibacterial activity against the bacterial wilt on the medium, and the disease suppressing effect has been confirmed in a short-term experiment in a greenhouse. However, in most cases, the control effect is not observed in contaminated fields, or the control effect remarkably decreases in the latter period of cultivation, and the one that shows satisfactory control effect until the latter period when used for solanaceous plants with a long cultivation period is now However, it is not recognized.

Further, in the example using the weakly pathogenic bacterial wilt bacteriocin-producing OM2 strain, it was revealed that a temperature condition of 18 ° C. or higher is required for the roots of the treated strain to settle (Japan. Bulletin of the Japanese Society for Plant Pathology (1989) 55: 511). It was confirmed that the temperature was not satisfied at the time of transplantation of a general tobacco field in March, and thus the treated bacteria were likely to be reduced, and thus the control effect of the disease was low or unstable.

[0012] In promoting growth, nitrogen-fixing bacteria tend to decrease in the number of bacteria in the soil when sprayed on the soil. As a result, the fixed amount of nitrogen decreases, and it is said that there is a problem in comparing the economical efficiency with the case of using a commercially available nitrogen fertilizer. Furthermore, there is a problem that the host is highly specific and the types of plants that can be infected are limited. Also,
Since mycorrhizal fungi are active parasites, they require a plant to be cultivated, and not only is it difficult to industrially cultivate them in large quantities, but in soils with sufficient phosphoric acid, mycorrhizal fungi On the contrary, it is said that the amount used by the bacterium reduces the yield.

[0013] As described above, at present, many roots are stably cultivated in tobacco roots until the latter stage of cultivation, have a high control effect against this disease, and can be easily mass-cultured to cultivate many plants. To the best knowledge of the inventors, no bacteria have been found that combine the two agriculturally useful properties of promoting.

Accordingly, the object of the present invention is to exert no adverse effect on the plant body, to settle on the roots of the plants of the Solanaceae family such as tobacco until the late stage of cultivation, and to have a high effect of controlling the present disease both in greenhouses and outdoors. Soil disease control agent using microorganisms (especially, control agent for tobacco wilt disease and solanaceous plant wilt disease)
Another object of the present invention is to provide a method for controlling soil diseases, and a growth promoting agent and a growth promoting method having a high growth promoting effect on many cultivated plants.

[0015]

[Means for Solving the Problems] The present inventors have further advanced research in this field and have an agriculturally useful property of controlling the disease and promoting the cultivation of plants. Has discovered an unknown bacterium. The bacterium of the present invention, inhabit rhizosphere of the soil or the plants, Bacillus circulans separated from these samples (Baci
llus circulans ), which is 1) does not adversely affect the plant body, 2) has no antibacterial activity against the bacterial wilt disease in vitro, but exhibits control effects in the field until the latter stage of cultivation, and 3) cultivation of the plant It has a preferable biological action such as improving the cultivation efficiency of agricultural crops by promoting the above. In addition to these effects, the bacterium of the present invention is characterized by growing at 50 ° C. Conventionally known Bacillus circulans microorganisms cannot grow at such high temperatures.

[0016] Examples of disease control by the same bacterium belonging to the genus Bacillus, Bacillus Zupuchirusu (Ba cillus subtilis)
Control of Fusarium disease in carnations using
Disease Reporter (1970) 54,5: 446-448), Bacillus subtilis and Bacillus bacteria ( B
Control of bacterial wilt of potato using acillus sp.
rnal of the Indian Potato Association (1993) 20-3,4:
219-222), Bacillus subtili
s) bacterial wilt the control of tomato with (Annals of the Phy
topathological Society of Japan 58-3: 329-339). Also, as a patent for Bacillus circulans, a strain that produces a protease and specifically decomposes soybean meal, and an organic fertilizer produced by the decomposition (Japanese Patent Laid-Open No. 6-237760), a certain substance Manufacturing related (Japanese Patent Laid-Open No. 4-237496, Japanese Patent Laid-Open No. 2-255085,
Japanese Patent Laid-Open No. 4-360685). However, as far as the inventors' knowledge, Bacillus circulans (Bacillus
It has not been reported that the microorganisms belonging to circulans ) are effective in controlling the disease and promoting plant growth.

An example of the bacterium of the present invention is the A268 strain isolated in Example 2 below. A268 strain is 17 April 1996
Deposited with the number of FERM BP-5506 at the Institute of Biotechnology, Institute of Industrial Technology, Japan. Microorganisms mutated from A268 strain,
It is within the scope of the present invention as long as it has the biological effects of 1) to 3) above. In addition, A2 in the rhizosphere of soil or plants
Like the 68 strains, Bacillus circulans, which has the biological effects of 1) to 3) above, is considered to exist. This is especially true for Bacillus circulans, which has the ability to grow at 50 ° C. Separation of such bacteria is carried out by selection according to growth temperature, or for example, in Example 1 described below.
It can be separated by the selection method based on the biological action shown in.

In the Bacillus circulans of the present invention, it is not necessary to prepare a special culture medium when growing,
It grows well in a medium for general bacteria such as King B medium, tryptic soy medium (hereinafter abbreviated as TS medium), M523 medium or meat extract medium. In addition to liquid medium, agar-containing slant medium, plate medium, etc. may be used. The cells can be grown by these cultures to obtain a desired amount of cells.

As the carbon source of the medium, any carbon source that can be assimilated by the microorganism of the present invention can be used. Specifically, in addition to sugars such as glucose, galactose, lactose, arabinose, mannose, and malt extract starch hydrolysates, there are various synthetic or natural carbon sources commonly available to microorganisms. Similarly, as the nitrogen source, various synthetic or natural products generally usable by microorganisms can be used, including organic nitrogen-containing substances such as peptone, meat extract, and yeast extract. Culture conditions are aerobic conditions such as shaking culture and aeration culture. The temperature is 25 to 35 ° C, preferably 25 to 30 ° C, and the pH of the medium is pH 5 to 8, preferably pH.
The culture period of 6 to 7 is 1 to 4 days, preferably 2 to 3 days. It is also possible to use cells grown on a slant or a plate medium containing agar and grown on the medium.

The present invention provides an agent for controlling tobacco wilt disease and solanaceous plant wilt disease, which comprises the above Bacillus circulans and / or a culture thereof as an active ingredient, and a plant growth promoter. It also concerns. Furthermore, the present invention relates to a method for controlling tobacco wilt disease and Solanaceae wilt disease caused by Pseudomonas solanacearum, and a method for promoting plant cultivation, using the above-mentioned control agent or growth promoter. .

The culture of Bacillus circulans in the present invention means a culture suspension of a bacterial strain, viable bacteria, a culture filtrate or an extract of an ingredient effective for promoting germination and growth thereof.

In the present specification, the "root portion" is a portion that absorbs water and nutrients in soil or hydroponic liquid when a plant is cultivated. The introduction into the root can be easily performed by spraying or irrigating the cell culture, or by immersing the root in the cell culture. Alternatively, the purpose can be achieved by mixing the cell culture into the soil and then transplanting the plant.

When used as a control agent for Solanaceae plants or a growth promoter for plants according to the present invention, the viable bacteria are preferably transplanted at a concentration of 10 ⁷ to 10 ⁹ CFU / ml from 7 days before the main field transplant. These are introduced into the root by 1 month after. The number of times of introduction is not limited to once, and may be multiple times. As one method of introduction, in the case of immersion treatment, the immersion time is 30 minutes to 3 hours, preferably 1 to 2 hours. Also, when introducing into the root by irrigation or irrigation treatment,
5-20 ml per seedling before transplant, 50-200 ml after transplant
Is appropriate. Alternatively, the same effect can be obtained by sprinkling the bacterial cell culture solution in the soil.

For the control of this disease, all host plants of this disease, including tobacco, eggplant, tomato and potato, are applicable. Further, the growth promotion can be applied to all plants. Therefore, the plant of which the cultivation is promoted in the present invention is not limited to the type thereof, but is particularly preferably a crop, and the crop means all crops such as cereals, vegetables, flowers, fruit trees and their harvests. To do.

Conventionally, it has been considered that an antibacterial substance is involved in the disease suppressing action of Bacillus bacteria, but this bacterium is characterized in that it has no antibacterial activity against the wilt bacterium in the medium. As a mechanism for suppressing the bacterial wilt caused by this bacterium, it is considered that it is well established in the plant rhizosphere and prevents the invasion of pathogenic bacteria, and that it induces resistance in the plant, but the present invention is bound by this theory. Not a thing.

This bacterial strain is capable of growing at 50 ° C. and is capable of forming spores. The characteristic of this bacterial strain that it is resistant to heat and dryness is a very useful property for formulation. Therefore, the disease controlling agent or the plant growth promoting agent of the present invention can be provided as a liquid preparation or a dry preparation for storage by mixing the microorganism of the present invention with an appropriate medium.

The soil disease controlling agent or the plant growth promoting agent according to the present invention may be combined with a so-called carrier to form an agrochemical composition. Examples of preferable carriers include a water-soluble solvent optionally added with a pH buffer, a protective agent such as skim milk, and a powder agent including an auxiliary agent such as talc after freeze-drying, a granule agent, and a porous body such as vermiculite. Is mentioned.

The soil disease controlling agent or the plant growth promoting agent of the present invention can be in any form such as liquid, powder, tablets and sheets.

The soil disease controlling agent or the plant growth promoting agent of the present invention may be combined with other active ingredients. Other active ingredients are not particularly limited, and examples thereof include insecticides, herbicides, fungicides and the like. The soil disease controlling agent or the plant growth promoting agent of the present invention may be a composition in combination with a soil improving agent, compost, fertilizer, or the like. The amount of the microorganism and the culture thereof when formulated as a soil disease controlling agent, as well as the application time and the application amount, are appropriately determined according to the case of the above-mentioned viable bacteria.

The contents of the present invention will be described below with reference to examples. However, the content of the present invention is not limited to these.

[0031]

【Example】

Example 1 (Separation / Selection Method) Separation / Selection Method of Bacillus circulans The present inventors collected tobacco roots from tobacco fields nationwide. Then, many bacterial strains were isolated from tobacco roots or rhizosphere. Specifically, a healthy tobacco root was dug, the root was cut with scissors, and the attached soil was shaken off. Roots cut to a length of about 1 cm were placed in 10 ml of sterile distilled water, stirred with a mixer, 1 platinum loop of the resulting suspension was removed, and King B medium (Proteose Peptone N
o3 20.0g, dipotassium phosphate 1.5g, magnesium sulfate 1.5g, glycerin 10.0ml, distilled water 1,000ml: J. La
b. Clin. Med (1954) Vol.44: 301-307). Two
After culturing at 8 ℃ for 3 days, each single colony obtained is -80 ℃.
I saved it in the freezer. In this way, a bacterium believed to be well-established on the root surface was obtained.

Then, 1) bacteria themselves do not cause pathogenicity or adverse effects on crops, 2) effectively suppress the occurrence of diseases caused by the wilt fungus in the field until the latter stage of cultivation, and 3) for various cultivated plants. A useful strain having properties such as high growth promoting effect was selected in a greenhouse or field test.

Bacteria having a high control effect against this disease were selected, and among them, bacteria having a plant growth promoting effect were selected. Specifically, as a method for evaluating the effect of controlling the present disease and the effect on the plant, 8 to 9 of tobacco (cultivar: Bright Yellow No. 4) was used.
After testing single seedlings and culturing the selected bacterial strains in King B liquid medium, the roots of tobacco seedlings were irrigated and inoculated with the culture solution, and the seedlings were transplanted into a 4 inch pot containing soil. Furthermore, after the soil irrigation inoculation of the seedling plant with the bacterial wilt solution, the occurrence of the bacterial wilt was regularly investigated in a greenhouse set at 30 ° C, and useful bacterial strains with high control effect were selected.

Then, the strain having a high controlling effect in the greenhouse was cultured in King B liquid medium and then centrifuged (× 10,000).
g, 15 minutes), after suspending in sterile water at a concentration of 10 ⁹ CFU / ml,
Tobacco (cultivar: Tsukuba No. 2) was inoculated by irrigating 9 seedling roots and transplanted to a field contaminated with wilt disease fungus. After that, the disease was investigated until the latter stage of tobacco cultivation, and only bacterial strains that were effective until the latter stage were selected.

As a method for evaluating the growth promoting effect and the effect on the plant body, a coated seed of tobacco (variety: Bright Yellow No. 4) was tested, and a vinyl chloride pot containing vermiculite (30 × 30 cm, 36 holes) 5 seeds per well were seeded. Furthermore, after culturing the bacterial strain in King B liquid medium, 100 μl of the culture solution was irrigated and inoculated per seed. Then, it was placed in a greenhouse set at 20 ° C., and two weeks later, the growth of tobacco was investigated, and a useful bacterial strain having a high growth promoting effect was selected.

By the above-mentioned method, the A268 strain isolated from the root surface of tobacco (cultivar: Michinoku No. 1) in Daio-mura, Hiraka-gun, Akita Prefecture using King B medium was selected.

Example 2 (Bacteriological Properties of A268 Strain) Identification results of the A268 strain selected by the above method are shown in Table 1.
Shown in

[0038]

[Table 1] Table 1 Bacteriological properties of A268 strain ------------------------------------ ------------- Test item A268 ---------------------------------- --------------- Morphological bacillus Gram stainability ＋ Spores ＋ Shape Ellipsoidal position Subepithelial sporangia bulge Motility ＋ Attitude toward oxygen Aerobic catalase ＋ Growth under anaerobic condition -VP reaction-pH of VP broth 5.5 Acid generation from glucose + Gas generation from glucose-liquefaction of gelatin + decomposition of starch + use of citrate-use of propionate-yolk reaction- Reduction of nitrate ＋ Growth at pH 6.8 (nutrient broth) ＋ Growth at pH 5.7 －Growth in the presence of 5% NaCl ＋ Growth in the presence of 7% NaCl ＋ Growth at 10 ℃ －30 ℃ Growth ＋ Growth at 50 ℃ ＋ ¹⁾ Growth at 55 ℃ － GC content of intracellular DNA (mol%) ²⁾ 35 -------------------- ----------------------------- Same Result Bacillus circulans ----------------------------------------------- --1: Atypical characteristics. 2: According to the HPLC method.

From the results shown in Table 1, this bacterial strain was tested by Bergey's man.
It was identified as Bacillus circulans from ual of systematic bacteriology Vol.2 (1986). Unlike the typical Bacillus circulans, this bacterial strain is characterized by being able to grow at 50 ° C.

Example 3 (Controlling Effect by Treatment with Bacterial Culture Solution) A268 was cultured in King B liquid medium at 28 ° C. for 2 days with shaking, and then adjusted to 10 ⁹ cfu / ml. Tobacco seedlings (cultivar: Bright Yellow No. 4) are made of vinyl chloride (30 x 30c)
20 9-leaf seedlings cultivated in m, 36 holes) were tested. As for the inoculation of the bacterial culture, 10 ml per strain was irrigated at the origin of the strain. The inoculated tobacco seedlings were cultivated in a greenhouse at 28 ° C for 12 hours, then transplanted using a fertilizer in a clay pot with a diameter of 12 cm, and cultivated in a greenhouse at 30 ° C. Two weeks after transplantation, the bacterial wilt solution (10 ⁶ C
FU / ml) was irrigated at 20 ml per strain. As a control, tobacco was similarly inoculated with King B liquid medium by irrigating the tobacco strain source. Two weeks after the inoculation, the occurrence status of the wilt disease was investigated. As shown in Table 2, the degree of illness was set to 6 levels from 0 to 5, and the illness rate, the average morbidity index and the control rate were calculated by the formulas of Notes 1, 2 and 3. The results are shown in Table 3.

[0041]

(Equation 1)

[0042]

[Table 2] Table 2 ------------------------------------------- ------------------ Disease index symptom ---------------------------- --------------------------------- 0 No disease 1 A part of the leaves wilts and yellows 2 1-3 Leaf wilting / yellowing 3 Withering / yellowing except 2-3 leaves close to the growth point 4 All leaves wilting / yellowing 5 Dead -------------- -----------------------------------------------

[0043]

(Equation 2) However, N is the number of test individuals, and n _{1 to} n ₅ are the numbers of individuals belonging to the disease index 0 to 5.

[0044]

(Equation 3)

[0045]

[Table 3] Table 3 ------------------------------------------- -------------- Treatment area Disease rate (%) Average morbidity index Control rate (%) --------------------- ------------------------------------ A268 vaccination 35.0 1.15 64.6 Control 80.0 3.25 − ----- -------------------------------------------------- -

As is clear from Table 3, A2 is larger than that in the control group.
The incidence rate was significantly lower in 68 treatment plots (t test, 1%
level). The average morbidity index was also significantly lower in the treated area (t-test, 1% level), and the control rate after 2 weeks of inoculation was 64.6.
%Met.

Example 4 (Controlling effect of bacterial cell suspension treatment) A268 was cultured in King B liquid medium at 28 ° C. for 2 days with shaking, and then the cells were collected by centrifugation (10,000 × g, 10 minutes) and sterilized in water. (10 ⁹ CFU / ml). Tobacco seedlings (variety: Bright Yellow No. 4) were cultivated by the same method as in Example 3, and the A268 bacterial suspension was similarly inoculated. In the same manner as in Example 3, the bacterial wilt fungus was inoculated, and two weeks later, the onset of disease was investigated. Tobacco inoculated with sterile distilled water was used as a control. The results are shown in Table 4.

[0048]

[Table 4] Table 4 ------------------------------------------- -------------- Treatment area Disease rate (%) Average morbidity index Control rate (%) --------------------- ------------------------------------ A268 vaccination 30.0 0.75 70.0 control 70.0 2.50 − ----- -------------------------------------------------- -

As is clear from Table 4, A2 is larger than that in the control group.
The incidence rate was significantly lower in 68 treatment plots (t test, 5%
level). The average morbidity index was also significantly lower in the treated area (t-test, 1% level), and the control rate after 2 weeks of inoculation was 70.
%Met.

Example 5 (Control Effect by Field Test) A268 was cultured in King B liquid medium at 28 ° C. for 2 days with shaking, and then the cells were collected by centrifugation (10,000 × g, 10 minutes) and suspended in sterile water. (10 ⁹ CFU / ml). The bacterial concentration was confirmed by King B plate medium. Tobacco seedlings (variety: Tsukuba No. 2) were cultivated in a 36-plant vinyl chloride pot (30 × 30 cm, 36 holes), and 9 leaf seedlings were transplanted to the main field at the appropriate time. The bacterial suspension was inoculated by the following treatment.

(1) A268 pre-transplantation treatment: One day before transplantation, a bacterial suspension (10 ⁹ CFU / ml) was pre-irrigated in an amount of 10 ml per strain, and then transplanted to the field. (2) A268 pre-transplantation treatment + soiling treatment: The tobacco strain transplanted as in (1) was cultivated and centrifuged in the same manner as in (1) to suspend the bacterial cells in distilled water (10 ⁸ CFU / ml) and 200 ml of each soil was irrigated at the time of soil donation. (3) Control group: Tobacco seedlings treated with the same method as above before transplanting sterile distilled water were transplanted.

Tobacco seedlings that had been pre-transplanted were treated at 28 ° C for 12 hours.
After being cultivated in the greenhouse, the plant was transplanted to a field contaminated with bacterial wilt disease (10 ³ CFU / 1 g dry soil) on April 14th. The processing at the time of the donation May 2
It was carried out on the 0th day. After the transplantation, the plants were cultivated by the usual cultivation method, and the onset of wilt disease was regularly investigated. The results are shown in Tables 5 and 6.

[0053]

[Table 5] Table 5 ------------------------------------------- -------------------------- August 3 Strain treatment area Number of surveyed strains --------------- -------------------- (Book) Incidence rate (%) Average morbidity index Control rate (%) -------------- -------------------------------------------------- ----- A268 Before transplantation 104 9.3 0.30 63.9 Before transplantation + At Syori 108 13.1 0.30 63.9 Control (water) 106 25.7 0.83 − -------------------- -------------------------------------------------

[0054]

[Table 6] Table 6 ------------------------------------------- -------------------------- August 19 Strain treatment area Number of surveyed strains --------------- ----------------- (Book) Incidence rate (%) Average morbidity index Control rate (%) ----------------- -------------------------------------------------- --A268 Before transplantation 104 16.3 0.72 62.5 Before transplantation + At Syori 108 25.0 1.14 40.6 Control (water) 106 44.3 1.92 − ----------------------- ---------------------------------------------- Note: Number of surveys The difference is due to the removal of strains infected with other diseases.

As is clear from Tables 5 and 6, both the disease incidence and the average morbidity of the A268 bacterial suspension treatment group were significantly lower (5% level) than the control group, and the control rate was also up to the latter stage of cultivation. It was stable.

Example 6 (Growth promoting effect of tobacco seedling treatment) A268 strain was cultured in TS liquid medium at 28 ° C. for 3 days with shaking (12
After centrifugation (0 rpm), the cells were collected by centrifugation (10,000 × g, 15 minutes) and separated into bacterial cells and culture supernatant. The cells were suspended in sterile water (3.5 × 10 ⁷ CFU / ml). Vinyl chloride pot (30 x 30
cm, 36 holes) were filled with fertilizing soil for raising seedlings, and tobacco seedlings (cultivar: Bright Yellow No. 4, 5 leaf stage) were temporarily planted one by one, and then the aqueous suspension of the bacterial cells obtained by the above method or The culture supernatant was irrigated with 2 ml of each seedling to the tobacco source. Then, it was placed in a greenhouse at 22 ° C and cultivated by irrigating it so that the soil surface did not dry. After 3 weeks, the tobacco was carefully dug out of the pot, washed with water to remove the fertilizer, and then excess water was removed with a paper towel, and the above-ground portion and the root portion were cut and weighed. In this experiment, 12 tobacco seedlings were tested in each section. As a control, a tobacco irrigated with distilled water or TS liquid medium in the same manner was used. Table 7 shows the results.

[0057]

[Table 7] Table 7 ------------------------------------------- ---------------- Treatment area Number of leaves Weight above ground Weight per root (sheets / piece) (g / piece) (g / piece) ---------- ------------------------------------------------- Fungus Body water suspension 9.08 1.50 0.21 Control (water) 8.50 1.05 0.16 ----------------------------------- ------------------------ Culture supernatant 9.00 1.43 0.22 Control (TS liquid medium) 8.50 1.18 0.15 ---------- -------------------------------------------------

As is clear from Table 7, the number of leaves in the water suspension treated group was 7% and the above-ground weight was 4% compared with the water treated group.
Increased by 3% and root weight by 31%. In addition, the number of leaves was 6% and the above-ground weight was 2% even in the bacterial culture solution-treated area compared to the TS medium-treated area.
Increased by 1% and root weight by 47%.

Example 7 (Promoting effect of tobacco seed treatment) A vinyl chloride pot (30 × 30 cm, 36 holes) was packed with vermiculite, and 12 tobacco-coated seeds (variety: Bright Yellow No. 4) were prepared in each section. After sowing, an aqueous suspension of A268 strain obtained in the same manner as in Example 6 was irrigated with 1 ml per seed. Then, it was placed in a greenhouse at 22 ° C. and cultivated by irrigating the surface so that it would not dry. The number of leaves of the seedlings germinated after 3 weeks was investigated. As a control, distilled water was irrigated in the same manner. Table 8 shows the results. In addition,
There was no difference in the germination rate between the treated plot and the control plot.

[0060]

[Table 8] Table 8 ------------------------------------- Number of leaves in treated area (sheets / Book) ------------------------------------- Cell water suspension 4.00 Control (water ) 3.09 ------------------------------------- Strain culture supernatant 3.92 Control (TS liquid medium ) 3.75 -------------------------------------

As is clear from Table 8, the number of leaves of the aqueous suspension of the bacterial cells and the culture supernatant treated group was 2 each compared to the control group.
It increased by 9.5%.

Example 8 (Growth-promoting effect of cabbage seed treatment) A pot of vinyl chloride (30 x 30 cm, 36 holes) was filled with greenhouse fertilizer, and cabbage seeds (variety: Teresanmaru) were sown in groups of 7 grains each. After that, an aqueous suspension of A268 strain obtained in the same manner as in Example 6 was irrigated with 1 ml per seed. afterwards
It was placed in a greenhouse at 22 ° C and irrigated so that the surface did not dry. 3
After a week, the root length of the seedling was measured, and the above-ground part and the root part were weighed in the same manner as in Example 6. As a control, distilled water was irrigated in the same manner. Table 9 shows the results. There was no difference in the germination rate between the treated group and the control group.

[0063]

[Table 9] Table 9 ------------------------------------------- ------------------ Treatment area Root length Above ground weight Root weight (cm / piece) (g / piece) (g / piece) -------- -------------------------------------------------- --- Cell suspension 1.94 1.34 0.18 Control (water) 1.77 0.94 0.07 ------------------------------- ------------------------------

As is clear from Table 9, the cells treated with the water suspension had a root length of 10% and an aerial weight of 43 as compared with the control group.
%, And root weight increased by 157%.

Example 9 (Growth promoting effect of cucumber seed treatment) A pot (30 x 30 cm, 36 holes) made of vinyl chloride was filled with greenhouse fertilizer, and 8 cucumber seeds (cultivar: Akimidori) were sown. An aqueous suspension of A268 strain obtained in the same manner as in Example 5 was irrigated with 1 ml per seed. Then 22 ℃
, And irrigated the surface so that it would not dry. After 3 weeks, the root length of the seedling was measured, and the above-ground part and the root part were weighed in the same manner as in Example 5. As a control, distilled water was irrigated in the same manner. The results are shown in Table 10. There was no difference in the germination rate between the treated group and the control group.

[0066]

[Table 10] Table 10 ------------------------------------------- ------------ Treatment area Root length Above ground weight Root weight (cm / piece) (g / piece) (g / piece) -------------- ----------------------------------------- Bacterial water suspension 10.9 1.17 0.31 Control (water) 7.1 0.92 0.19 ------------------------------------------------ ------------

As is clear from Table 10, the cells treated with the water suspension had a root length of 90% and an aerial weight of 90%, as compared with the control group.
27% and root weight increased 63%.

Example 10 (Growth-promoting effect of spinach seed treatment) A pot of vinyl chloride (30 x 30 cm, 36 holes) was filled with greenhouse fertilizer, and 14 spinach seeds (variety: Sentaro) were sown. After that, A268 obtained in the same manner as in Example 6
An aqueous suspension of the strain was irrigated with 1 ml per seed. Then, it was placed in a greenhouse at 22 ° C. and irrigated so that the surface did not dry. After 3 weeks, the root length of the seedling was measured and the fresh weight of the plant was measured. As a control, distilled water was irrigated in the same manner. The results are shown in Table 11. There was no difference in the germination rate between the treated group and the control group.

[0069]

[Table 11] Table 11 ------------------------------------------- ------ Treatment area Root length fresh weight (cm / piece) (g / piece) ---------------------------- --------------------- Cell suspension in water 5.46 0.35 Control (water) 4.58 0.31 --------------- ----------------------------------

As is clear from Table 11, the cells treated with the water suspension had a root length of 19% and a fresh weight of 13% as compared with the control group.
Increased.

Claims (7)

[Claims] Claim: 1. Bacillus cir
culans ) and grows at 50 ° C. 2. A Bacillus cirlance
culans ), which has the action of controlling tobacco wilt and wilt of Solanaceae plants in the field and of promoting the growth of crops. 3. A strain of A268, which has been deposited at the Institute of Biotechnology, Institute of Biotechnology, with the accession number of FERM BP-5506, or its progeny, mutant or variant. Characterized in that it comprises a wherein microorganisms and / or their culture according to any one of claims 1 to 3 as an active ingredient, Pseudomonas solanacearum (Pseu domonas solanacearum) is a plant that occurs due An agent for controlling diseases, especially tobacco wilt and wilt of solanaceae. 5. A seed of Solanaceae the controlling agent according to claim 4, roots, due to the presence in plantations or soil, Pseudomonas solanacearum (Pseudomonas
a method for controlling plant diseases caused by Sola nacearum ), particularly tobacco wilt disease and solanaceous plant wilt disease. 6. A plant growth promoter comprising the microorganism according to any one of claims 1 to 3 and / or a culture thereof as an active ingredient. 7. A method for promoting plant growth, which comprises allowing the growth promoting agent according to claim 6 to be present in seeds, roots, cultivated areas of plants, or soil thereof.