WO1998017780A1

WO1998017780A1 - Microorganism of the genus ascochyta and use thereof

Info

Publication number: WO1998017780A1
Application number: PCT/JP1997/003511
Authority: WO
Inventors: Masatoshi Gohbara; Michiyo Takabayashi
Original assignee: Japan Tobacco Inc.
Priority date: 1996-10-17
Filing date: 1997-10-01
Publication date: 1998-04-30
Also published as: KR19990072184A; CN1211276A; AU4398397A; JPH10117769A; KR100269417B1; ID18598A

Abstract

Means for effecting selective withering or growth control of weeds of the genus Scirpus of the sedge family without affecting crops, such as rice, by utilizing strains of the genus Ascochyta exhibiting pathogenicity on any of S. juncoides var. ohwianus, S.juncoides var. hotarui, S.wallichii, or S.lineolatus.

Description

Akitoda »Microorganisms belonging to the genus Askokita and uses thereof TECHNICAL FIELD OF THE INVENTION

The present invention relates to a novel strain belonging to the genus Ascochyta, and a method for controlling herbicides and weeds using the strain. BACKGROUND OF THE INVENTION

The main method of controlling weeds of the genus Firefly (Sci rpus), a major weed in paddy fields and uplands, uses chemical herbicides. In recent years, due to the problem of environmental pollution due to the heavy use of chemical pesticides, the development of weed control agents and their uses that do not rely on chemical pesticides has been desired. In particular, there is high hope for microbial pesticides using phytopathogenic bacteria. To date, DeVine (US, target weed: Stranglervine, potato family) and Col lego (US, target weed: Northern jo intvetch, legume), BioMal (Canada, target weed: Round-leaved mal ow, sage family) ) Has been registered as a pesticide and commercialized. However, no microbial herbicide has been developed for the weeds of the genus Firefly. In addition, the main weeds in the paddy field are the firefly (Sci rpus juncoi des var. Ohwianus), the scallop (Sci rpus juncoi des var. No known microorganisms belonging to the genus Askokita which are pathogenic for S. aureus. Problems to be solved by the invention

An object of the present invention is to provide a means for controlling weeds belonging to the genus Firefly in the family Calagidaceae using microorganisms. Disclosure of the invention

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that some strains belonging to the genus Ascokita have extremely excellent controllability against firefly weeds. And completed the present invention.

That is, the present invention is a strain belonging to the genus Ascokita, which is pathogenic to any of the fireflies, fireflies, taiwanhamai, or squirrel fireflies.

Further, the present invention is a herbicide comprising, as an active ingredient, a strain belonging to the genus Ascokita, which is pathogenic to any of the fireflies, fireflies, taiwanhamai, or squirrel fireflies.

Furthermore, the present invention is a method for controlling weeds using the above herbicide.

Hereinafter, the present invention will be described in detail.

First, the novel strain of the present invention, ascokita sp. JT-1006, ascokita sp. JT-1007, ascokita sp. JT-1008, ascokita sp. JT-1009, and ascokita sp. JT-1010 will be described. I do. These strains were collected from diseased weeds of the genus Callarisaceae from all over Japan, isolated from strains having pathogenicity to the genus Firefly of the genus Callarisaceae, and purely cultured. It was created by screening means to examine the control effect and to examine the non-pathogenicity of other crops, especially rice. The main types of mycological properties of the novel strain of the present invention are as follows.

The PH which is an aerobic bacterium and can grow is in the range of 3-13, preferably in the range of 5-7. The growth temperature ranges from 15 to 30 degrees Celsius, and the optimum temperature for growth ranges from 25 to 30 degrees Celsius. The growth on the potato dextrose agar medium is high, and the colony has a large number of orange-brown small grains radially and spirally in gray to olive-colored hyphae, and the number of aerial hyphae is low. The conidia are colorless and similar to the genus Phoma, but have one partition in the center and are divided into two chambers, and are oval. The size of conidia is about 5-1 O imx about 2 _ 5 m.

Illustrated Genera of imperfect Fungi, Fourth Edition (Barnett, HL and Hunter, BB 1987. P6-39) As a result of a search based on Macmillan publishing Company :), the strain was identified as a microorganism belonging to the genus Ascokita. Several pathogenic microorganisms of the genus Ascokita are known as pathogenic fungi such as cucumber and tomato. As microorganisms of the genus, there are two examples: Ascochy ta kurd is tan ica, which is pathogenic to Sci rpus mar it imi s, and Ascochyta l acus tr is, which is scalable to Sc i rpus lacus tr is. However, there is no known compound that exhibits pathogenicity to the firefly, firefly, taiwanhamai, or the firefly in the present invention.

The above strains have been deposited with the National Institute of Advanced Industrial Science and Technology (1-1-3 Higashi, Tsukuba, Ibaraki, Japan) under the following numbers.

Ascokita sp. JT-1006 strain: FERM BP-5692 (deposit date October 3, 1996) Ascokita sp. JT-1007 strain: FERM BP-5693 (deposit date October 3, 1996)

Ascokita _S p. JT-1008 strain: FERM BP-5694 (Deposit date: October 3, 1996)

Ascokita sp. JT-1009 strain: FERM BP-5695 (Deposit date: October 3, 1996)

Ascokita sp. JT-1010 strain: FERM BP-5696 (Deposit date: October 3, 1996)

It is not necessary to use a special method for culturing this strain, and the same method as that of a known strain belonging to the genus Ascokita can be used. As the medium, any of a synthetic medium and a natural medium can be used as long as the medium appropriately contains assimilable carbon sources, nitrogen sources, inorganic substances, and necessary growth promoting substances. Specific examples of the medium include potato dextrose agar medium (PDA) and Czapek agar medium. During culturing, it is desirable to maintain the temperature at 15 to 30 degrees, preferably 25 to 30 degrees, and the pH at 3 to 13, preferably 5 to 7. After culturing for about 7 to 14 days under the above conditions, a sufficient amount of conidia is formed on the medium surface. This strain kills weeds belonging to the genus Callaridaceae in the paddy field or upland field, and does not affect crops such as eggplant, soybean, perilla, and cucumber, in addition to grasses such as rice, wheat, barley, and maize. This strain can be cultivated in large quantities and can easily produce large quantities of spores.

Next, the herbicide and the control method of the present invention will be described.

Microorganisms used in the herbicide of the present invention include Ascokita sp. JT-1006 strain, Ascokita sp. JT-1007 strain, Ascokita sp. JT-1008 strain, Ascokita sp. JT-1009 strain, Ascokita sp. JT- Examples include 1010 strains, and mutants derived from these strains may be used.

The herbicide of the present invention comprises suspending spores obtained by mass-culturing the above strain in water. The method of formulating a drug that can be prepared by the method is not limited to this. In this case, spore concentration, 1 0 ⁶ -1 0 ^'2 / m 1 but is appropriate, but the invention is not restricted to this. When suspending in water, an auxiliary agent such as a surfactant and a spreading agent may be added. Microorganisms, which are the main agents, may be fresh ones immediately after culturing, or ones that have been once stored and reconstituted with water-based ones. As the preservation method, ultra-low-temperature preservation (180 ° C), vacuum freeze-drying and the like, which are widely known as preservation methods of microorganisms, can be used.

The control method of the present invention is carried out by spraying the herbicide on a field. Application rate may be determined depending on the degree of overgrowth weeds, usually field 1 0 ares per spore amount 1 0 'preferably sprayed to 1 0 to be ^fifteen.

The herbicide and the plant to be controlled by the herbicide of the present invention are not particularly limited, but are particularly effective for plants belonging to the genus Firefly. Examples of the firefly species mentioned here are (Scirpus juncoides var. ;), Sang-ri kui (Scirpus triquetula), Kang-ri "(Scirpus triangulatus) ゥ cagara (Scirpus yagara), Kozuki-ya kara (Scirpus planiculmis), and the like, but are not limited thereto. There is no particular limitation on the growth period of the plant to be controlled, and the plant can be widely controlled from a plant shortly after germination to a grown plant.

1) Creation process of the novel strain of the present invention

Collect the weeds and fireflies of the genus Firefly, which grow in the paddy field or in the field and show symptoms, cut off the diseased parts, and cut the leaf pieces from 30 seconds to 60% in 70% ethanol solution. After immersion for 1 second, suspend in 1% sodium hypochlorite solution and an equal volume of 0.1% Tween 80 (Tween 80) solution and immerse for 1 to 3 minutes Then, the surface was sterilized. After washing the leaf pieces once with 0.1% Tween 80 solution and twice with sterile water, place them on PDA medium containing antibiotics and incubate for 2-5 days in a 25 degree incubator, Perimeter of elongated colony The edge was transferred to a fresh PDA medium and cultured to form conidia. In addition, the conidia were stirred and cultured in a new PDA medium to obtain a single colony, and pure microorganisms were isolated.

For each isolated strain, the pathogenicity of the fireflies of the genus Callarisaceae to the weeds was reviewed again, and the effects on rice, wheat, corn, tomatoes, and cucumber were examined. New strain of Ascokita sp. JT-1006, Ascokita sp, JT-1007, Ascokita sp. JT-1008, Ascokita sp. JT-1009 strain and Ascokita sp. JT-1010 strain were isolated.

2) Identification of created strain

The strain of the present invention was identified mainly by observing the conidial morphology. As a result, as described above, this strain was identified as a microorganism belonging to the genus Ascokita.

3) Mass culture and formulation method

Sterile water is added to the microorganism belonging to the genus Ascokita grown on the PDA medium, and the mixture is stirred to prepare a high-concentration spore suspension. About 100 μΛ of N-8 juice agar is added. By dropping it on the medium and diffusing it with a sterile L-shaped glass rod, it became possible to inoculate microorganisms on a large amount of petri dishes (9 cm in diameter) at one time. As a result, spore production volume, Petri dish one per about 6 X 1 0 ⁷ spores production is recognized we were.

Thus, the microorganism of the present invention can easily and in large quantities obtain spores by culturing on a plate medium.

Furthermore, the obtained spores can be suspended in 10% skim milk and dried under vacuum to obtain a wettable powder. This wettable powder can be suspended in water, added with a surfactant such as Tween 80, and applied.

4) Pathogenicity test for firefly

Sugar beetle seeds are suspended in a solution obtained by adding an equal volume of 1% Tween 80 (Tween 80) solution to sodium hypochlorite solution (Sodium um hypochlor oride), and immersed for 1 to 3 minutes. Sterilized. Surface-sterilized seeds were sown on a medium in a test tube for plant growth which had been sterilized in advance and grown from the first to second leaf stage as test materials. For the microorganism of the present invention, mycelia obtained by culturing on a potato agar medium were punched out of two pieces of discs with a cork borer and inoculated into the above-mentioned test tubes. After 10 days in a constant temperature room at 25 degrees Celsius, the control rate of Pinus thunbergii was investigated. The results are shown in Table 1. The fungus mortality rate of this bacterium was 100%, and the control effect was 100%.

Table 1 Efficacy of control of each strain against firefly Strain No. Death rate Control rate (%)

JT-1006 100 100

JT-1007 100 100

JT-1008 100 100

JT-1009 100 100

JT-1010 100 100

JTKA-644 0 0

JTH-102 0 0

JTSS-001 0 0

* Death rate: Number of dead strains Z Number of inoculated strains X 100

* Control rate: reduction rate of the whole plant

* JTKA-644: Ascochyta sp. Obtained from plants of the genus Cyperus

* JTH-102: Exserohi lum monoceras obtained from 7 millet

* JTSS-001: Fusar i um sp.

As is clear from Table 1, the microorganism of the present invention exhibited an excellent control effect on the firefly (Sci rpus j unco i des var. Ohwi anus).

5) Pathogenicity test for fireflies against weeds

Tests on firefly weeds were performed in the same manner as in the virulence test on firefly, and two discs were used.

Firefly, Thai Wanmai, Japanese firefly and Shiji were used as test plants. Table 2 shows the test results. Table 1 Control effect of firefly on weeds by JT-108

Neimse Nuyun Plant Effect

Mozuki Holau

Hotaruiita Mouth Nuri (Scirpus juncoides var.

Taiwanjar π Mai (Scirpus wallichii) +

Japanese squirrel V (Scirpus 1 ineolatus) +

Sissy (Scirpus nipponicus +

+: Withering or growth suppression

-: No effect As is clear from Table 12, the microorganism of the present invention exhibited an excellent control effect on weeds of the genus Firefly in the genus Calaridaceae. Similar results were obtained with other strains.

6) Effects on crops

Test for crop performed in the same manner as virulence tests for Inuhotarui, spore concentration of inoculum used was 1 0 ⁷ / ml. Test plants were rice, wheat, corn, eggplant, soybean, perilla, and cucumber. Table 13 shows the test results.

Table 1 3 Effects on crops

Plants

+

+: Withering or growth suppression

1: No effect As is clear from Table 1, the microorganism of the present invention did not affect the growth of rice, wheat, corn, eggplant, cucumber, perilla, and soybean. [Formulation Example 1] (Liquid)

Conidia (10 '°) of Ascokita sp. JT-1008 strain and Twenty 80 (lg) were added to 1 L of water and mixed to prepare a liquid preparation.

[Formulation Example 2] (Wettable powder)

Maltodextrin Ichisu 9% Clay 1% Water 90% of the mixture 1 m conidia per minute (JT-100 7 strains) 1 0 were suspended ^eight. After air-drying, the dried product was mixed and pulverized to prepare a wettable powder.

[Formulation Example 3] (Wettable powder)

Skim milk 1 0% water 90% of the mixture 1 m conidia per minute (JT-1006 strain) 1 0 were suspended ^eight. After vacuum drying, the dried product was mixed and pulverized to prepare a wettable powder.

[Formulation Example 4] (Powder)

Hydroxycarboxylic propyl one 5-cyclodextrin 1 4%, white solved one Bonn 1 2% clay 7 4% of the mixture 1 g per conidia (JT-1009 strain) 1 0 ⁸ were mixed. After drying, the powder was uniformly ground to prepare a powder.

[Formulation Example 5] (Granules)

^ - cyclodextrin 5%, starch 2% bentonite sheet 1 8% carbonate force Rushiumu 3 6%, water 2 9% of the mixture 1 g per conidia (JT-1010 strain) 1 0 ⁸ was added kneading After that, granules were prepared by granulating with a granulator and drying.

[Formulation Example 6] (Emulsion)

Conidia per 1 g of a mixture of 18% of polyoxyethylene nonylphenyl ether ammonium phosphate, 6% of polyoxyethylene nonylphenyl ether, 29% of triethyl phosphate and 47% of tributyl phosphate (JT-1008 strain ) 1 0 ⁸ was added Hitoshi - it was suspended in and adjusted emulsion.

[Formulation Example 7] (Oil)

Spindle oil 95%, castor oil 4%, conidia in mixture 1 m 1 1% silicone oil (JT-1008 strain) 1 0 suspended ⁸ were adjusted oil.

[Formulation Example 8] (Dry flowable agent)

Sodium alkylbenzene sulfonate 12%, polyethylene glycol Ether 8 8% of the composition in 1 m 1 was suspended conidia (JT-1006 strain) 1 0 ⁸ was adjusted Doraifu Roaburu agent.

[Formulation Example 9] (Capsule)

Sodium alginate 7% kaolin 5% Glycerin 1 5%, water 7 9.3% of conidia in mixture 1 m 1 (JT-1007 strain) 1 0 were suspended ^eight, 0.2 mole acetic acid It was dropped into the calcium solution to obtain a capsule-like product. After chopping this, it was sieved and air-dried to prepare a capsule. The invention's effect

The herbicide of the present invention can selectively kill weeds of the genus Fireflies of the family Calagidaceae and control their growth without affecting crops such as rice. In addition, it does not destroy the environment that pollutes the environment like chemical pesticides.

Claims

Scope of word blue

1. A strain belonging to the genus Ascokita, which is pathogenic to any of the fireflies, fireflies, taiwanhamai, or phoenix.

2. The strain belonging to the genus Ascokita is Ascokita sp. JT-1006, Askokita sp. JT-1007, Askokita sp. JT-1008, Askokita sp. The strain according to claim 1, wherein the strain is present.

3. A herbicide characterized by containing, as an active ingredient, a strain belonging to the genus Ascokita, which is pathogenic to any of the fireflies, fireflies, taiwanhamai, or swordfish.

4. The strain belonging to the genus Ascokita is Ascakita sp. JT-1006, Askokita sp. JT-1007, Askokita sp. JT-1008, Askokita sp. JT-1009, or Askokita sp., JT-1010. 4. The herbicide according to claim 3, wherein the herbicide is present.

5. A method for controlling weeds using the herbicide according to claim 3 or 4.