JPH0975071A - Microorganism belonging to genus collectorichum and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain Colletotrichum sp.JTA-463 strain exhibiting pathogenicity against a plant belonging to genus Lindernia, capable of selectively killing down or suppressing of growth and controlling Lindernia pyxidaria L. and Lindernia dubia PENN. without affecting to Oryza sativa, etc., and without polluting or destructing the environment. SOLUTION: This microorganism is an aerobic bacterium as Colletotrichum sp.JTA-463 strain having a deposit number of FERM BP-5175, belonging to genus Colletotrichum and exhibits pathogenicity against a plant belonging to genus Lindernia. A control agent against a plant belonging to genus Lindernia is obtained by using the microorganism. Preferably, a plant belonging to genus Lindernia is controlled by using a herbicide containing the microorganism.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel strain belonging to the genus Colletotrichum and a lindernia ( Li
and a control method for a plant belonging to the genus ndernia ).

[0002]

2. Description of the Related Art Azena ( Li , a major weed in paddy fields)
ndernia pyxidaria L.) and American genus A. ( Linde
The main control method for rnia dubia PENN.) is to use chemical herbicides. In recent years, due to the problem of environmental pollution due to heavy use of chemical pesticides, development of a weed controlling agent and a method of using the same that does not rely on chemical pesticides has been desired. In particular, microbial pesticides using plant pathogenic bacteria are highly expected. To date, De Vine (US, target weeds: Stranglervine, Potato family) and Collego (US, target weeds: Northern joi
ntvetch, legume), BioMal (Canada, target weed: Round
-leaved mallow, mallow family) has been registered as a pesticide and commercialized.

However, phytopathogenic fungi that parasitize A. or A. niger have not been known, so no microbial herbicide for these weeds has been developed.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a means for controlling plants belonging to the genus Lindernia with microorganisms.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that microorganisms belonging to the genus Choletotricum parasitize plants belonging to the genus Lindernia and kill them. Heading, completed the present invention. That is, the present invention is a Choletotricum sp. JTA-463 strain that is pathogenic for plants belonging to the genus Lindernia.

The present invention is also a control agent for plants belonging to the genus Lindernia, characterized by containing as an active ingredient a microorganism belonging to the genus Choletotricum and exhibiting pathogenicity to plants belonging to the genus Lindelnia. Furthermore, the present invention is a method for controlling plants belonging to the genus Lindernia using the above-described control agents.

Hereinafter, the present invention will be described in detail. At first,
The novel strain of the present invention, Choletotricum sp. JTA-463
The strain will be described. This strain collects diseased Azena and American Azena from all over Japan, isolates strains having pathogenicity to Azena and American Azena, and cultivates them purely to examine control effects against Azena and American Azena, and also to other crops, especially It was created by a screening method that examines nonpathogenicity to rice. The main bacteriological properties of this strain are listed below.

It is an aerobic bacterium and can grow at a pH of 3-1.
It is in the range of 1, preferably in the range of 5-11. The growth temperature is in the range of 15-30 degrees, and the suitable growth temperature is in the range of 25-30 degrees. Growth on potato dextrose agar is prosperous, colonies form an orange to light brown growth ring that can be seen from the front and back, almost no aerial hyphae are observed, and the surface of the flora is covered with a large number of conidia slime. A viscous clot with bristles. Conidia are colorless, single-celled, and oblong. The size of the conidia is about 15-20 μm × about 3-5 μm. The above-mentioned mycological properties are described in the Plant Fungi Illustration (Kobayashi et al., 1992.P20-52, 408. National Rural Education Association) and Ill.
ustrated Genera of imperfect Fungi, Fourth Edition
(Barnett, HL and Hunter, BB 1987.P6-39, 18
8. Based on a search based on the Macmillan publishing Company), this strain was identified as a microorganism belonging to the genus Choletotricum. Further, as a pathogen for various crops, several microorganisms of the genus Choletotricum are known, but since microorganisms of the genus Choletotricum having pathogenicity to plants of the genus Lindernia are not known, this strain is referred to as a new strain. Certified and Colletotricum sp. JTA-463
The strain was named. Then, this strain was transferred to the Institute of Biotechnology, Institute of Industrial Science and Technology, FERM BP-5175 (deposited on July 7, 1995).
21). For culturing this strain, it is not necessary to use a special method, and the same method as a known strain belonging to the genus Choletotricum can be used. As the medium, both synthetic medium and natural medium can be used as long as they appropriately contain assimilable carbon sources, nitrogen sources, inorganic substances and necessary growth promoting substances. An example of a specific medium is potato dextrose agar medium (PD
A), Czapek agar medium, etc. can be mentioned.
In culturing, the temperature is 15 to 30 ° C., preferably 25.
It is desirable to maintain the pH at -30 degrees and at 3-11, preferably 5-11. When culturing is carried out for about 7-14 days under the above conditions, a sufficient amount of conidia are formed on the surface of the medium. This strain kills Aedena and Aedes aegypti in paddy weeds and does not affect rice. In addition, this strain can be cultured in a large amount, and a large amount of spores can be easily obtained.

Next, the control agent and control method of the present invention will be described. The microorganism used for the control agent of the present invention,
Choletotricum sp. JTA-463 strain can be mentioned, but other than this strain belongs to the genus Choletotricum,
Any microorganism may be used as long as it is a microorganism showing pathogenicity to plants belonging to the genus Lindernia. The control agent of the present invention is
The spores obtained by culturing a large amount of microorganisms belonging to the genus Choletotricum can be suspended in water to prepare a formulation, but the formulation method is not limited thereto.
In this case, the spore concentration is suitably 10 ⁵ to 10 ⁸ cells / ml, but is not limited to this. When suspending in water, auxiliary agents such as a surfactant and a spreading agent may be added. In addition to fresh microorganisms immediately after culturing, microorganisms as the main agent may be those that have been preserved and then reconstituted with water as the main component. As a storage method, ultra-low temperature storage (-80 ° C), vacuum freeze-drying, etc., which are widely known as storage methods for microorganisms, can be used.

The control method of the present invention is carried out by applying the above-mentioned control agent to a field. The amount to be applied may be determined according to the degree of overgrowth of weeds, but it is preferable to apply the amount so that the spore amount is usually 10 ¹¹ to 10 ¹² per 10 ares in the field. The plant targeted by the control agent and the control method of the present invention is not particularly limited as long as it is a plant belonging to the genus Lindernia. Further, there is no particular limitation on the growth period of the plant to be controlled, and it is possible to widely control the plant from a plant just after germination to a grown plant.

[0011]

【Example】

1) Creation process of the novel strain of the present invention Azena and A. agena, which grow in a paddy field or a field and show symptoms, are collected, and the diseased part is cut off,
The leaf pieces were placed in a 70% ethanol solution for 30 seconds to 60 seconds.
After soaking for 2 seconds, 1% sodium hypochlorite solution (Sodi
um hypochloride) 0.1% Tween 80 (Twe
en 80) solution was suspended in the added solution and immersed for 1 to 3 minutes to sterilize the surface. The leaf pieces were washed once with a 0.1% Tween 80 solution and twice with sterilized water, then placed on an antibiotic-containing PDA medium and cultured in a thermostat at 25 ° C. for 2-5 days to extend. The periphery of the colony was transferred to a new PDA medium and cultured to form conidia. Newer PD
The conidia were stirred and cultured in the A medium to obtain a single colony, whereby pure separation of the microorganism was performed.

[0012] With respect to each of the isolated strains, the pathogenicity against Azena and American Azena was examined again, and the effect on rice was examined to show an excellent herbicidal effect on Azena and American Azena, which did not affect rice. , A novel strain Choletotricum sp. JTA-46
Three strains were isolated. 2) Identification of the created strain The strain of the present invention was identified by observing the morphology of conidia. As a result, as described above, this strain was identified as a microorganism belonging to the genus Choletotricum. 3) Mass culture and formulation method Sterile suspension of high concentration is prepared by adding sterilized water to a microorganism belonging to the genus Choletotricum grown on PDA medium and stirring the mixture, and about 100 μl of the medium is added to a new medium. Dropping onto the top and diffusing this with a sterile L-shaped glass rod made it possible to inoculate a large amount of petri dishes (9 cm in diameter) with microorganisms at once. As a result, the spore production is
About 2.5 × 10 ⁸ spores were produced per Petri dish.

As described above, the microorganism of the present invention can easily obtain a large amount of spores by culturing in the plate medium. Further, the obtained spores can be suspended in 10% skim milk and vacuum dried to obtain a wettable powder. This wettable powder can be applied by suspending it in water and adding a surfactant such as Tween 80. 4) Pathogenicity test for Azena and American Azena Azena and American Azena were grown in commercially available pots, and those from the 2 to 5 leaf stage were used as test materials.

Of the present invention obtained by culturing on PDA medium
Suspend microbial spores in 0.1% Tween 80 solution, 1
0^Five10 / ml / ml⁸Adjust to 1 / ml and use air spray
, And inoculated A. sect. You
After putting it in a humid room at 25 degrees for 48 hours, put it in a greenhouse at 25 degrees.
2 weeks after the transfer, the number of infected Azena and American Azena
The body rate and control rate were investigated. The results are shown in Table-1.
Was. Both Azena and American Azena plants are 10^FiveIndividual/
The spore concentration of 100 ml causes 100% of the disease, and the control effect of this bacterium is
It was 100%. Table-1 Control effect of JTA-463 bacteria ──────────────────────────── Spore concentration Azena americana (Anatum / ml) Incidence rate Control Incidence rate Control rate (%) ──────────────────────────── 0 0 0 0 0 10^Five 100 100 100 100 10⁶ 100 100 100 100 10⁷ 100 100 100 100 10⁸ 100 100 100 100 ───────────────────────────── * Infection rate: Number of diseased strains / Number of inoculated strains × 100 * Control rate: Whole plant Reduction rate (attainment) As is clear from Table 1, the microorganisms of the present invention are
It showed an excellent control effect against A. genus. 5) Effects on rice The rice test was conducted on Azena and American Azena.
Inoculation source cells used in the same manner as
Child concentration is 10⁸The number was set to 1 / ml. The test results are shown in Table-2.
Was. Table-2 Effects on crops ───────────────── Plant presence ───────────────── Rice-Wheat-Azena + American Azena + ───────────────── ＋: Death or growth inhibition −: No effect As can be seen from Table 2, the microorganism of the present invention is the growth of rice.
Did not affect. [Formulation Example 1] (Liquid formulation) Conidia (10) of Choletotricum sp.
⁹Pieces) and Tween 80 (1 g) are added to 1 L of water and mixed.
Then, the liquid agent was adjusted. [Formulation Example 2] (Wettable powder) 1 ml of a mixed solution of maltose 9%, clay 1% and water 90%
Conidia per hit (JTA-463 strain) 10⁸Suspend the pieces
Was. After air-drying this, the dried product is mixed and crushed, and a wettable powder is added.
It was adjusted. [Formulation Example 3] (Wettable powder) Per 1 ml of mixed solution of skim milk 10% and water 90%
Ikiko (JTA-463 strain) 10⁸The pieces were suspended. this
After vacuum drying, mix and pulverize the dried product to adjust the wettable powder.
Was. [Formulation Example 4] (Dust) Hydroxypropyl-β-cyclodextrin 14%,
1g of a mixture of 12% white carbon and 74% clay
Conidia (JTA-463 strain) 10⁸The pieces were mixed.
This was dried and then uniformly pulverized to prepare a powder. [Formulation Example 5] (Granule) β-cyclodextrin 15%, starch 2%, bent
18% Night, 36% Calcium Carbonate, 29% Water
Conidia per 1 g of product (JTA-463 strain) 10 ⁸Add pieces
After kneading and kneading, granulate with a granulator and dry
Granules were adjusted. [Formulation Example 6] (Emulsion) Polyoxyethylene nonylphenyl ether phosphate
18% monium, polyoxyethylene nonylphenyl ether
Ether 6%, Triethyl phosphate 29%, Tributyrate phosphate
Conidia per gram of 47% mixture (JTA-463
Co., Ltd. 10⁸An emulsion was prepared by adding individual pieces and suspending uniformly. [Formulation Example 7] (Oil) Spindle oil 95%, castor oil 4%, silicone oil
Conidia (JTA-463) in 1 ml of 1%
Co., Ltd. 10⁸The individual was suspended and the oil solution was adjusted. [Formulation Example 8] (Dry flowable agent) Sodium alkylbenzene sulfonate 12%, Polyester
Mineral content in 1 ml of 88% ethylene glycol ether composition
Ikiko (JTA-463 strain) 10⁸And dry dry
Able agent was adjusted. [Formulation Example 9] (Capsule) Sodium alginate 0.7%, Kaolin 5%, Glyce
Conidia in 1 ml of a mixture of 15% phosphorus and 79.3% water
(JTA-463 strain) 10⁸Suspend pieces and 0.2 mol vinegar
Dropping into calcium acid solution to obtain a capsule-like product
Was. After shredding this, it is sieved and air-dried to give capsules.
It was adjusted.

[0015]

INDUSTRIAL APPLICABILITY The control agent of the present invention selectively kills or suppresses the growth of Azalea and Astragalus arena and can control them without affecting rice. It does not pollute or destroy the environment like chemical pesticides.

Claims (5)

[Claims] 1. A strain of Choletotricum sp. JTA-463 which is pathogenic for plants belonging to the genus Lindernia. 2. A control agent for a plant belonging to the genus Lindernia, which comprises a microorganism belonging to the genus Choletotricum and showing pathogenicity to a plant belonging to the genus Lindelnia as an active ingredient. 3. The agent for controlling a plant belonging to the genus Lindernia according to claim 2, wherein the microorganism belonging to the genus Choletotricum is a strain Choletotricum sp. JTA-463. 4. The control agent for plants belonging to the genus Lindernia according to claim 2 or 3, wherein the plant belonging to the genus Lindernia is Azena or Physcomitrella patens. 5. A method for controlling a plant belonging to the genus Lindernia using the control agent according to claim 2.