JPH11187866A - Strain having antimicrobial property against pathogenic filamentous fungus of plant and control of filamentous fungus of plant using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a Pseudomonas sp. CGF 878 strain having antimicrobial activity against pathogenic filamentous fungi of plant, capable of safely and effectively controlling disease damage of plant caused by Fusarium, which is disease damage, without phytotoxicity. SOLUTION: This strain has antimicrobial activity against pathogenic filamentous fungi of plant such as filamentous fungi belonging to the genus Fusarium, etc., and is deposited as FERM P-16,561. Preferably an agrochemical of microorganism is prepared by using a Pseudomonas sp. CGF 878 strain belonging to the genus Pseudomonas as an active ingredient. Preferably soil and/or a plant is treated with the strain to control filamentous fungi of plant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention scientific name has antibacterial properties against phytopathogenic fungi Pseudomonas (PSEUD
The present invention relates to a new strain belonging to the genus omonas ) and a method for controlling a fungal disease of a plant by spraying this strain alive on soil and / or a plant.

[0002]

It has been known that some filamentous fungi belonging to the genus Fusarium and the like include those that cause enormous disease on various crops. For example, Fusarium oxysporum causes tomato wilt, eggplant semi-wilt, cucumber vine, sweet potato vine and the like.

[0003] Diseases caused by Fusarium spp. Are known as soil diseases, and at present, there are not so many effective control methods even though they cause great damage to many crops. Conventional methods for controlling soil diseases include, for example, soil disinfection using chloropicrin and methyl bromide.However, this method involves environmental problems such as killing useful microorganisms and insects in the soil. There is a problem that there is an odor, and therefore, the use is restricted near a house. In addition, there is also a concern that if pathogens invade after sterilization, the disease may progress.

[0004] Several methods for controlling plant diseases using Pseudomonas bacteria have been found and patent applications have been filed. For example, bacterial wilt of a solanaceous plant (Japanese Unexamined Patent Publication No.
No. 325, Japanese Unexamined Patent Publication No. Hei 6-86668,
-17291), rice seedling blight (Japanese Unexamined Patent Publication No.
No. 4783), plant diseases caused by phytopathogenic bacteria of the genus Potrichtis and Penicillium (Japanese Patent Laid-Open No. Hei 4-7740).
No. 5), plant diseases caused by Gram-positive bacteria (Japanese Unexamined Patent Publication No.
It has been reported that Pseudomonas bacteria can control plant diseases caused by Fusarium bacteria (Japanese Patent Publication No. 6-6523). However, the control effect is not yet satisfactory.

The present invention provides a bacterium having high antagonism to Fusarium disease, a microbial pesticide containing the bacterium as an active ingredient, and a plant obtained by treating soil and / or plants with the bacterium. It is intended to provide a method for controlling a fungal disease.

[0006]

Means for Solving the Problems The present inventors have proposed Pseudomonas sp. CG belonging to the genus Pseudomonas.
F878 strain ( Pseudomonas spp. C
GF878) was found to effectively control plant fungal disease caused by Fusarium spp. And the like, leading to the present invention.

[0007] That is, the present invention provides a Pseudomonas sp. CGF878 strain ( Pseudo) belonging to the genus Pseudomonas having antibacterial properties against phytopathogenic fungi.
omonas spp. CGF878), a Pseudomonas sp. CGF878 strain belonging to the genus Pseudomonas having antibacterial properties against phytopathogenic fungi ( P
pseudomonas spp. CGF878) as an active ingredient, and Pseudomonas sp. CGF878 strain ( Pseudomon) belonging to Pseudomonas genus bacteria having antibacterial properties against phytopathogenic fungi.
as spp. CGF878), a method for controlling a plant filamentous fungus characterized by treating soil and / or a plant, and a Pseudomonas sp. CGF878 strain belonging to a Pseudomonas sp.
p. A method for controlling plant fungal disease, comprising treating soil and / or plants with a microbial pesticide containing CGF878) as an active ingredient.

Hereinafter, the present invention will be described in detail. Among the plant fungal diseases, the following diseases are important in agriculture as diseases caused by Fusarium spp. For example, cabbage chlorosis (pathogen; Fusarium oxysporum)
f. sp. conglutinans ), cucumber vine wilt (pathogen; Fusarium oxyspor)
um f. sp. cucumeinum ), tomato wilt (pathogen; Fusarium oxysporum)
f. sp. lycopersici ), eggplant semi-blight (pathogen; Fusarium oxysporum)
f. sp. melongenea ), sweet potato vine disease (pathogen; Fusarium oxysporum)
f. sp. batatas ) and the like. The present invention provides a method for effectively controlling these plant diseases.

The method for collecting the strain of the present invention will be described below. To search for bacteria that are antagonistic to phytopathogenic fungi such as tomato wilt fungi from soil and plants, first, the cultivation of antitobacterial fungi is carried out by confronting tomato wilt fungus on potato dextrose agar medium. Was done. As a result of examining many collected bacteria, bacteria having strong antibacterial activity against a plurality of phytopathogenic fungi could be obtained. The bacteriological properties of the obtained bacteria are as follows. (1) Morphological properties Shape: rod-shaped Gram stain: negative Motility: + sporulation:-(2) Colony shape Smooth round colonies in broth agar plate culture (3) Physiological properties Nitrate reduction: + hydrogen sulfide generation :-Gelatin liquefaction: + Urease:-Oxidase: + Decomposition of arginine: + Decomposition of acetamide:-Attitude to oxygen: Aerobic Growth at 25 ° C: + Growth at 37 ° C: + Growth at +42 ° C:- Indole degradation:-Esculin degradation:-β-galactosidase activity:-assimilation of sugars and organic acids D-glucose: + D-maltose:-D-fructose:-arabinose: + L-rhamnose:-D-mannose :-D-xylose: + D-mannitol:-Sucrose:-Malonic acid: + Use of citric acid: + The strain having a property, "Bar Jays Manual of systematic tee poke Bact (bergey's Manual of Syste
mechanical Bacteriology), Volume 1, 1
When the search on the basis of 984 years ", it is a gram-negative bacilli, to grow aerobically, than properties such that oxidase activity is positive, the strain, which belongs to Pseudomonas (Pseudomonas) genus, In addition, Pseudomonas Mendocina ( Pseudomo)
nas mendocina ). On the other hand, it is different from typical Pseudomonas mendocina in that it cannot grow at 42 ° C., has gelatin hydrolyzability, and assimilates arabinose and sucrose. It also produces a non-fluorescent, water-soluble reddish brown pigment.

[0010] Accordingly, the present strain, it is considered to be classified to the genus Pseudomonas, which Pseudomonas sp. CGF878 strains (Pseudomo
nas spp. CGF878), and deposited on December 17, 1997, with the Research Institute of Biotechnology and Industrial Technology, FERM P-16561.
561).

Next, Pseudomonas sp. Of the present invention
CGF878 strain ( Pseudomonas spp.
A method for preparing a microbial pesticide containing CGF878) as an active ingredient will be described. First, the Pseudomonas sp. CGF878 strain of the present invention ( Pseudomonas
spp. CGF878) in an appropriate medium. The medium used here is not particularly limited as long as the strain grows, and a commonly used medium may be used. After culturing and growing the strain, the cells are collected by centrifugation, mixed with a protective agent, and lyophilized.
It can be prepared as a powdery or granular microbial pesticide containing the present strain. As the protective agent, one or a mixture of saccharides such as glucose, fructose, sucrose, and trehalose can be used.

On the other hand, the Pseudomonas sp. CGF878 strain ( Pseudomonas sp.
p. Similarly, after culturing CGF878), the mixture can be mixed with an appropriate carrier to give a powder or granules. The carrier in this case, talc, clay, calcium carbonate, mineral powder such as diatomaceous earth, peat moss,
There are polymer compounds such as polyvinyl alcohol and natural polymer compounds such as xanthan gum and alginic acid.

Next, Pseudomonas sp. Of the present invention
CGF878 strain ( Pseudomonas spp.
A method of using a microbial pesticide containing CGF878) as an active ingredient will be described. Pseudomonas sp. CG of the present invention
F878 strain ( Pseudomonas spp. C
GF878) is present in the roots and stems of crops that are subject to plant fungal disease such as tomatoes and Chinese cabbage,
Shows antibacterial effect Thus, this objective is achieved by seed germination, i.e. by coating the seeds with the strain, spreading the seedling soil and mixing the strain on the seedlings by mixing. The powders and granules created can be coated on the seeds as they are, and when the seeds germinate, the coated bacterial strain can be established on the roots, or mixed with the seedling soil to establish them on the roots and stems. It is. Furthermore, it can be suspended in water and sprayed on the entire seedling, or the root can be immersed in the fungus solution, so that the root can be fixed on the plant, and various plant fungal diseases can be controlled. Thus, various plant diseases caused by filamentous fungi can be controlled by a simple treatment method using a microorganism pesticide containing the present strain as an active ingredient.

The mechanism of the effect of controlling plant filamentous fungal diseases may be inhibition of hyphal growth of fungi, inhibition of sclerotium formation, or inhibition of germination by antibacterial substances. In this strain, an inhibitory effect on hyphal growth against tomato wilt fungus was observed on the agar medium.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

[0016]

EXAMPLES Example 1 Pseudomonas sp. CGF878 strain ( Pse
udomonas spp. CGF878) was measured for its antibacterial activity against phytopathogenic fungi. The antibacterial activity was examined by a confronting culture method on a potato dextrose agar medium (potato 200 g extract, glucose 20 g, agar 15 g, water 1 L). Table 1 shows the results.

[0017]

[Table 1] ++: Strong antibacterial activity +: Positive antibacterial activity-: No antibacterial activity Example 2 Pseudomonas sp. C
GF878 strain ( Pseudomonas spp.
CGF878, bacterial density 1 × 10 ⁸ cfu / ml)
After soaking for 0 minutes, the plants were planted in nursery pots. After planting, 7
On the day, Fusarium oxysporum (Tomato wilt fungus;
Fusarium oxysporum IFO-312
13, a bacterial density of 1 × 10 ⁶ cfu / ml) was applied to 10 ml of the entire soil surface. Then, on the 49th day, a disease investigation was conducted. Table 2 shows the results. The control value was 100.0%.

Judgment of disease onset (Disease index) 0: External health 1: Some leaves die 2: More than 50 leaves die 3: Stems die

[0019]

(Equation 1)

[0020]

(Equation 2)

[0021]

[Table 2] Example 3 Eggplant seedlings at the 3-4 leaf stage were subjected to Pseudomonas sp.
F878 strain ( Pseudomonas spp. C
GF878, bacterial density 1 × 10 ⁸ cfu / ml)
After soaking for a minute, the seedlings were planted in pots. On the 7th day after planting, Fusarium oxysporum (Eggplant semi-blight fungus; Fu)
sarium oxysporum , bacterial density 1 × 10 ⁶
cfu / ml) was drenched over the entire surface of 10 ml of the soil. Then, on the 30th day, a disease investigation was performed. Table 3 shows the results.
The control value was 75.0%.

[0022]

[Table 3] Judgment of disease onset (Disease index) 0: External health 1: Some leaves die 2: More than 50 leaves die 3: Stalk die

[0023]

(Equation 3)

[0024]

(Equation 4) Example 4 Cucumber seedlings at the 3-4 leaf stage were subjected to Pseudomonas sp.
CGF878 strain ( Pseudomonas spp.
CGF878, a cell density of 1 × 10 ⁸ cfu / ml) was immersed in the solution for 20 minutes, and then planted in a nursery pot. After planting,
On the 7th day, Fusarium oxysporum (Cucumber vine disease; Fusarium oxysporum IFO)
-31224, bacterial density of 1 × 10 ⁶ cfu / ml)
Irrigation was performed over the entire surface of the soil. Then, on the 49th day, a disease investigation was conducted. Table 4 shows the results. The control value was 50.0%.

[0025]

[Table 4] Judgment of disease onset (Disease index) 0: External health 1: Some leaves die 2: More than 50 leaves die 3: Stalk die

[0026]

(Equation 5)

[0027]

(Equation 6) Example 5 Pseudomonas sp. C
GF878 strain ( Pseudomonas spp.
CGF878, bacterial density 1 × 10 ⁸ cfu / ml)
After soaking for 0 minutes, the plants were planted in the field. Fusarium oxysporum ( Fusarium ox)
ysporum IFO-31213, bacterial density 1 × 10
⁶ cfu / ml) was drenched over the entire surface soil of the field. The concentration of the tomato wilt fungus immediately before planting in the field is about 5 × 10 ³ c
fu / g-soil. Then, three months later, a disease investigation was conducted. Table 5 shows the results. The control value was 54.3%.

[0028]

[Table 5] The calculation of disease incidence, disease severity and control value is the same as in Example 2.

[0029]

Industrial Applicability According to the present invention, it has become possible to effectively control plant fungal disease. In particular, it is possible to effectively control the disease caused by Fusarium spp., Which is a soil disease that has been difficult to control conventionally. The present invention provides a method for using a living bacterium as a so-called biological control measure, and provides a safe method for controlling plant diseases without chemical injury.

Claims (8)

[Claims] 1. A Pseudomonas sp. CGF878 strain ( Pseudom) belonging to the genus Pseudomonas, which has antibacterial properties against phytopathogenic fungi.
onas spp. CGF878). 2. A Pseudomonas sp. CGF belonging to the genus Pseudomonas according to claim 1, wherein the phytopathogenic fungus is a filamentous fungus belonging to the genus Fusarium.
878 strain ( Pseudomonas spp. CG
F878). 3. A Pseudomonas sp. CGF878 strain ( Pseudomonas sp.) Belonging to the genus Pseudomonas having antibacterial properties against phytopathogenic fungi.
p. A microbial pesticide comprising CGF878) as an active ingredient. 4. The microorganism pesticide according to claim 3, wherein the phytopathogenic filamentous fungus is a filamentous fungus belonging to the genus Fusarium. 5. A Pseudomonas sp. CGF878 strain ( Pseudomonas sp.) Belonging to the genus Pseudomonas having antibacterial properties against phytopathogenic fungi.
p. (CGF878), a method for controlling a fungal disease of a plant, which comprises treating a soil and / or a plant. 6. The method for controlling a plant filamentous fungus according to claim 5, wherein the plant filamentous fungus is a filamentous fungus caused by a filamentous fungus belonging to the genus Fusarium. 7. A Pseudomonas sp. CGF878 strain ( Pseudomonas sp.) Belonging to the genus Pseudomonas having antibacterial properties against phytopathogenic fungi.
p. A method for controlling plant fungal disease, comprising treating soil and / or a plant with a microbial pesticide containing CGF878) as an active ingredient. 8. The method according to claim 7, wherein the fungal disease is a fungal disease caused by a fungus belonging to the genus Fusarium.