JP3113910B2 - Long-term preservation of the phagocytogenic nematode Apherenx avene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phytophagous nematode, Aphelenchus avenae, which is used to reduce plant-borne parasitic fungi and plant-borne nematodes against agricultural and forestry soil diseases and nematode damage.
More specifically, the present invention relates to a method for mass production and long-term storage of a nematode plant in a solid medium consisting of plant industrial waste or a liquid medium consisting of an artificial medium.

[0002]

2. Description of the Related Art It is undeniable that conventional crop production relying on chemical pesticides is the mainstream of agricultural production means, while causing many environmental pollutions. On the other hand, as for sustainable agriculture by biological means, useful viruses, bacteria, fungi, entomopathogenic nematodes, natural enemy insects, and the like have been studied vigorously as issues for the 21st century, and efforts have been made to spread them. However, there is no universal means of biological means, and only entomopathogenic nematodes and BT agents (bacteria) can be controlled in a relatively wide range. There is no biological material or means that is even more difficult against diseases and can control two or more pathogens at the same time.

[0003] nematodes Aferenkusu-Abene according to the present invention (Aphelenchus avenae) [hereinafter referred to as the "main line worms"] is in the temperate regions is a nematode that exists universally, has been living the soil filamentous fungi as bait It has been experimentally reported that it can be cultured with 96 kinds of filamentous fungi (Townshend,
JL (1964) Fungus hosts of Aphelenchus avenae Ba
stian, 1865 and Bursaphelenchus fungivorous Frankl
in and Hooper, 1962and their attractiveness to the
se nematode species.Can.J.Microbiol. 10: 727-737
). Since many of these include filamentous fungi that become soil pathogens, research on biological control of soil diseases by nematodes has been conducted in the last 30 years, mainly in Europe and the United States, and numerous test examples have been reported. ing. Although these tests have demonstrated control effects of 70-80% or more in the literature, the test scale is small and most of the tests use sterile soil, and some of them show damage by nematodes themselves. It has not been put to practical use yet. In addition, there are some test examples in which the application is not performed in a proper period and the control effect is not clear.
The reasons for not being practically used in the past are as follows.

[0004]

[Problems to be Solved by the Invention] The mass production method was not established. Therefore, large-scale field trials have not yet been performed and were unconvincing.

[0005] 2. If subculture is continued with the same filamentous fungus, even if the filamentous fungus is the bacterium that breeds the nematode best, the nematode loses its ability to eat the bacteria after several generations, and almost one year later Maintenance is becoming difficult (Nobuyoshi Ishibashi (ed. 1993))
"Search for useful nematodes and systematization of their mass production and application methods", Grant-in-Aid for Scientific Research A (1) Research Result Report, p.

[0006] 3. If only plant seeds and nematodes are put into sterile soil, depending on the type of plant, the nematodes may enter the seeds, inhibit germination, and be determined as harmful nematodes. There is no sterile soil in the field).

[0007] 4. This nematode is known to survive for a long time in a dry state, but no technology has been developed to bring a large number of nematodes into such a state.

[0008] 5. Although there are some strains that have different bacterial preferences depending on where they are collected, no unified strain has been established worldwide. Therefore, depending on the strain, the test result may be completely opposite depending on the place and the person in charge of the test, and the use of the strain for disease control has been negatively evaluated.

[0009]

In the present invention, of the above-mentioned problems, important problems from a practical viewpoint have been solved as follows. The method for mass production of the nematode proposed in Task 1 is indispensable for practical use in the field. A method for achieving such a mass production method is a solid medium consisting of vegetable industrial wastes or by-products, or an artificial liquid medium consisting of a porous resin support impregnated with a culture solution containing starch and dextrose or sucrose and a phosphate buffer. After heat sterilization, the solid or liquid medium is inoculated with the filamentous fungi of the nematode, and the bacteriophagous nematode whose body surface is sterilized is inoculated into the medium simultaneously with or after the inoculation of the filamentous fungus. It is characterized by culturing.

[0010] The decrease in fertility due to the subculture of problem 2 is as follows.
The problem is solved by successively subculturing the nematode with a different type of filamentous fungus at each culture stage as a bait, and using a nonpathogenic filamentous fungus as a bait at the final culture stage. That is, this problem is overcome by converting bait molds. For example, Botrytis ciner
From ea) bacteria that started indoor cultivation, next Rhizoctonia solani (Rhizoctonia solani), further next converts food filamentous fungi such as Pythium (Pythium) bacteria or Fusarium (Fusarium) bacteria. Any filamentous fungus capable of reproducing the present nematode may be used, but it is preferable to culture non-pathogenic Botrytis cinerea as a feed when finally entering mass production.

[0011] The problem of germination inhibition in sterile soil of the problem 3 has an important significance mainly in the course of experimental research, and does not reach much of a problem on an actual farm. However, it was confirmed that even this problem can be solved by proper use of the nematode. That is, when a large amount (for example, tens of thousands per cucumber seed) of a main nematode is inoculated to a plant seed in a sterilized state, the germination rate is 20 to
May be reduced by 30%. Alternatively, even when the germination occurs, a scar-like damage caused by the burrowing insect appears on the cotyledon. Some types of plants do not show any damage at all,
Generally, seeds of Cucurbitaceae are easily damaged. However, such damage does not appear at all when inoculated with pathogenic fungi or other nematodes (eg, entomopathogenic nematodes). Even if the clam-like damage appears on the cotyledon, the nematode does not rise to the aerial part, so there is no further damage. In non-sterile soil, no nematode damage appears at all. As a practical matter, sterile soil does not exist in nature, so there is no need to worry about germination inhibition by this nematode.

In addition, when the nematode is applied to the soil in a large amount (similar to the case of entomopathogenic nematodes), a great change occurs in the indigenous nematode fauna. In 1 to 3 months, the fluctuation of the nematode fauna ends, but as a result self-active nematodes increase and plant parasitic nematodes decrease. This is probably because the nematodes are also attracted to the roots of the plants and are densely packed at the tip of the roots, thereby preventing plant parasitic nematodes from approaching and invading the roots. Therefore, if this nematode is applied to prevent deterioration of soil biota due to chemical application, rapid recovery of harmful nematodes can be suppressed. (Ishibashi, N., and Choi, DR. (1991) Biologi
cal control of soilpests by mixed application of e
ntomopathogenic and fungivorous nematodes. J. Nema
tol. 23: 175-181).

The long-term preservation of the nematode of the fourth problem is important for the implementation on an agricultural or commercial scale. Long-term storage of this nematode is much easier than entomopathogenic nematodes (useful nematodes that are already commercially available and used for biological control of pests). That is, the nematodes cultured in a solid medium consisting of vegetable industrial waste or a liquid medium consisting of an artificial medium and mass-produced are collected and formed into a mass, and the relative humidity is 40 to 25% higher than the high humidity in the range of 100 to 97%. Achieved by bringing the nematodes into anhydrobiosis state by maintaining them at aerobic conditions at a temperature of 20-30 ° C. and drying for 8-12 days, gradually tilting to a low humidity range can do. In this way, the nematode which has been put into an anhydrous survival state can survive for a long period of time even at a humidity of 30% or less.

That is, the nematode which has become completely anhydrobiosis in about 10 days in total is shrunk into a substantially coiled form, and can be stored indoors for more than one year. It can be stored for more than 2 years at a low temperature of about 5 ° C. The most viable stage of development is stage 4 larvae,
Clustering the nematode increases viability at other stages. It is only necessary to prevent them from being eaten by ticks during storage. However, if the hermetically sealed state is used to prevent the introduction of mites, there is a possibility that oxygen will be insufficient and the whole will be destroyed. In addition, it is more necessary to pay more attention to watering the nematode than to dehydrate it. When a dry nematode is suddenly put in water, some individuals whose body ruptures appear. There is no problem if the nematode mass is large, but various operations during storage may cause the nematode mass to collapse, so when returning to water, it is better to put it in a 100% humidity container overnight.

Regarding the difference in fungal preference proposed in Task 5, nematodes are classified according to descriptive taxonomy, so that they are the same species if they have the same morphology. There are many nematodes that differ from each other, and this tendency is particularly strong in nematodes that exist universally in the world. This nematode is also ubiquitous around the world, and its preference for bait filamentous fungi varies greatly depending on where it is collected. For example, the main nematode from Kyushu reproduces best on Rhizoctonia solani, but the main nematode in the Tohoku region prefers Pythium. in this way,
Nematodes with different preferences are isolated.
Is treated as. Further isolation of such an isolate would provide a nematode exploitation particularly suitable for certain diseases. The classification at the DNA level is expected to be a national or global arrangement of isolates (Nobuyoshi Ishibashi (ed.
93) "Search for useful nematodes and systematization of their mass production and application method" Scientific Research Grant A, 1994
(1) Research result report p.172). The present invention is to grasp the preference of this nematode, or to use bait fungi according to it,
Alternatively, it is needless to say that it is most preferable to apply a main nematode suitable for the bait filamentous fungi that live in the soil.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION (Method for mass production of this nematode) Culture using vegetable industrial waste or by-products Juice scum (bagasse), fruit juice squeezed during the production of fruit juices such as mandarin orange (juice scum), shochu production process squeezed scum (shochu squeezed), beer scum (brewers grain) , Beet pulp, potato chip refuse, medium after cultivation of sea urchin fly, green tea, oolong tea husks, slag from instant coffee production (coffee slag), etc. are also used as livestock feed or fuel, but most Has been discarded,
Many companies are confused about the process. These plant cultures can cultivate filamentous fungi if the temperature and humidity are favorable, and if the filamentous fungus is the bait filamentous fungus of the nematode, the cultivation of the nematode becomes possible.

Filamentous fungi grow on all of the above plant cultures, that is, solid media, but there is a great difference in the growth of filamentous fungi in one kind of culture. As a result, the reproduction of nematodes also has a large difference. Even a medium after breeding beet pulp or sea flies that can satisfactorily proliferate both filamentous fungi and nematodes in one kind of culture can be further improved by adding a small amount of other cultures. This is because by mixing a plurality of types of cultures, the culture medium has a buffering action, and the pH of the culture medium does not increase during the culture period of fungi or nematodes. In particular, the tea stock has the effect of adsorbing the generated ammonia and suppressing the rise in pH. So no matter what medium you make,
It is better to mix tea stock with 2-3 types of cultures.

Basically, since it is necessary to provide a void in the entire solid medium, a plant culture having a large amount of voids is used as a basal medium. Currently available plant-based industrial wastes that serve as basal media include bagasse, beet pulp, chaff,
For example, when bagasse is used as a basal medium, a preferable composition is bagasse 1: juice residue 1: green tea dashi 1, in a dry weight ratio.
Or bagasse 1: trash 1: green tea or oolong tea duck shell 1. When the beet pulp is a basal medium, the preferred composition is beet pulp: beer scum 1 or juice pomace 1: brown soup husk 1. A suitable formulation for rice hulls may be rice husk 1: juice slag 1: brown soybean husk 1.
In the case of trash, it may be used alone, but it is better to mix it with the above-mentioned tea stock. The water content of each prepared medium is preferably 50 to 60%. The pH is best maintained in the range of 5-6 during the culture.

After the solid medium is sterilized in an autoclave, a filamentous fungus serving as a feed for the nematode is inoculated. In Rhizoctonia solani, which has a rapid hypha elongation, it is preferable to inoculate the mycelium suspension and the nematode simultaneously. . Botrytis cinerea, which elongates slightly more slowly than Rhizoctonia solani, is inoculated with the nematode approximately three days after inoculation of the filamentous fungus. The nematode to be inoculated must be sterilized in advance on the body surface. For example, immersion in streptomycin 1000 ppm solution for 30 minutes, sterile water
After centrifugal washing twice, 20 g of medium (60% moisture, about 7
g) is inoculated with about 70 nematodes.

The medium in which the nematode bred most was a medium of beet pulp 1: beer slag 1, and about 4 million main nematodes were obtained three weeks after feeding on Botrytis cinerea.
The most readily available juice pomace, scum, and bagasse combination produce 1 to 1.5 million heads. By this calculation, about 150 to 200 million main nematodes can normally be produced per kg of the dry weight of the culture medium (Choi, Dong-Ro, a
nd Ishibashi, Nobuyoshi (1989) Propagation of five
Aphelenchus avenae isolates on six species of fun
gi and five substrates. Jpn. J. Nematol. 19: 13-17
).

However, a medium of 3 kg in wet weight containing 60% of water requires a 10-liter container and occupies that space for mass production. Therefore, nematode production on a solid medium is not always efficient. I can not say. It is also required to prevent the infestation of mites during the culture period. Therefore, as a more efficient mass culture method, there is a method using an artificial liquid medium.

2. Cultivation of fungi and fungiphagous nematodes in an artificial liquid medium This method is intended for mass production of this nematode by using a fermenter. In order for this nematode to eat filamentous fungi,
Since the needle must be inserted at right angles to the hypha, a support is needed to support the nematode body. Therefore, not all of the support medium can be liquid. Therefore, first, a solid support necessary for propagating a filamentous fungus is impregnated with a culture solution for propagating the fungus.

As described above, since a proper space is required in the medium for mass propagation of the nematode, what is used as the support is important. Since no agar is used, the culture solution to be impregnated on the support must be slightly richer than when agar is used. The culture solution is adjusted with a phosphate buffer so that the pH can be maintained in the range of 5 to 6 during the culture period. An example of a support and a culture solution adjusted in consideration of such requirements is as follows.

Support: Sponge, for example, a porous resin such as foamed polyurethane or porous (continuous pore) polyvinyl formal resin, or an organic or inorganic fiber waste, a fiber aggregate such as a woven or nonwoven fabric, a sponge, or the like. A solid material having water absorption and water retention such as a porous substance is applicable. These are cut, cut or assembled into appropriate dimensions, sufficiently washed with water and dried before use.

Culture solution: Agar was removed from PDA or PSA medium, and phosphate buffer was used instead of distilled water.
Dextrose or sucrose is as prescribed. The pH of the culture solution is preferably in the range of 5.2 to 5.5.

The above-mentioned support, for example, a sponge, is impregnated with the above-mentioned culture solution, poured into a fermenter container, and after removing the excess solution, sterilization is performed in an autoclave at about 120 ° C. for about 60 minutes. Next, the bait mold and the nematode are inoculated into the culture medium in the fermenter. The inoculation is carried out with the filamentous fungus and the nematode simultaneously or with an appropriate delay after the filamentous fungus inoculation. For example, when the filamentous fungus is Rhizoctonia solani, it is preferable to inject the bacteria simultaneously with the nematode, and when feeding on Botrytis cinerea, about two days before the inoculation of the nematode. When a large amount of the nematode to be inoculated is held on an agar medium or the like, the agar medium cut into 4 to 5 cm squares in a clean bench may be directly placed on a sponge medium in a fermenter container.

It is necessary to sterilize the body surface of the nematode prior to inoculating the medium. Sterilization is performed by centrifugally washing and concentrating an appropriate number of nematodes with sterile water, and then using a streptomycin aqueous solution by a conventional method.

The cultivation is performed at a temperature of 25 ° C. under aerobic conditions through sterilized air. The ventilation amount may be the minimum amount of the container used, and the ventilation may be stopped occasionally. In particular,
It is better not to ventilate for 3 days after inoculation of bacteria and nematodes. p
H was measured every other week, and if it became pH 6 or higher, the pH of the culture solution was slightly lowered (pH: 5.0 to 5.0.
2) Adjust. When the nematode starts to adhere to the glass wall in a coil shape, the inside of the container is washed and sieved with a 400 mesh sieve. The sponge is placed on a 100 mesh sieve and 400 mesh is placed underneath, and the nematodes are collected to 400 mesh. The collected nematodes are stored by the storage method according to the present invention.

Next, the agricultural application of the nematode mass-produced by this method will be described. The nematode can be widely applied to soil disease control of plants such as crops, inhibition of plant parasitic harmful nematodes or comprehensive control of soil pests.

[Soil disease control] For example, cucumber withering
Rhizoctonia solani, a soil-causing fungus of the diseaseRhiz
octonia solani) AG-4, Fusarium oxyspor
Mu f. sp. Lagenary (Fusarium oxysporum f. S
p. lagenariae), Pitium sp (Pythiumsp.)
And / or Phytophthora nicotiana var. Parasi
Tika (Phytophthora nicotiana var.parasitica)
Cucumbers do not germinate in the containing soil at all,
Preferably, at most 400,000 per liter of this soil
Head, more preferably at most 200,000 main nematodes and inoculate about 1
After culturing for a week, the germination rate of cucumber seeds
Germination rate of 7 (including neither soil pathogens nor nematodes)
It reaches 0-85%, and the effect of soil disease control is great. Main nematode
Germination when the number of inoculated birds exceeds 400,000 / liter soil
The rate drops rather. Apply the nematode alone to sterile soil
Germination rate in the presence of soil pathogens
It is just surprising that there is little decline.
You.

In addition, the inhibition of germination of cucumber seeds in soil containing plant soil pathogens, such as cucumber damping off, and plant parasitic nematodes, such as root-knot nematode ( Meloidogyne spp. ) And negusal nematode ( Pratylenchus spp. ) . It can be prevented by insects. In other words, the germination rate of cucumber is 0 in the inoculated soil of the wilt fungus alone or the mixed inoculum of the wilt fungus and root-knot nematode or the root-knot nematode, whereas about 200,000 to 500,000 heads / liter are contained in the soil containing the wilt fungus. When the seeds of the plant are sown after admixing the soil, preferably about 400,000 heads / liter soil, with the nematodes, no germination inhibition is observed. In addition, about 500,000 to 1.5 million heads / liter soil, preferably about 1 million heads / liter soil, is used in the amount of entomopathogenic nematodes Steinernema carpocapse ( Steinern).
ema carpocapsae ) does not cause any germination inhibition. Examples of the soil pathogens include Rhizoctonia solani AG-4, Fusarium oxysporum f. sp. Lagenerie ( Fusarium o
xysporum f. sp. lagenariae ), pitium sp ( Py
thium sp. ), Phytophthora nicotiana var. parasitica
At least one of them.

Furthermore, for example, root-knot nematode ( Melo)
idogyne spp. ) and Negusaresenchu ( Pratylench)
us spp. ) and adding at least one plant parasitic nematode to the above tripartite coexistence system of the take-all fungus, the main nematode and the entomopathogenic nematode in an amount of about 200 heads / liter soil. , The germination rate drops from 100% to 80%,
The plant height of the growing plant does not change, and the effect of eliminating the pest damage by using the present nematode in combination with the useful nematode is remarkable.

In addition, a test inoculum treated or not treated with a fumigant and treated with a disease-inhibiting agent treated with the fungus Rhizoctonia solani AG-4 alone and a large amount of nematodes (for example, about 200 million heads) were mixed. For example, when germinated seeds of spinach are sowed in the applied mixed inoculation group, respectively, the germination rate after 20 days is higher in the single inoculation group in the non-fumigant-untreated group, significantly reduced in the treated group and about one week thereafter. Within 100% died within. In other words, in the fumigant treatment, soil treatment with chemicals results in dramatic poverty of the biota, which leads to rapid recovery of pests. On the other hand, in the mixed inoculation group, the germination rate is higher in the fumigant-treated group and lower in the untreated group.
This is presumably because untreated soil has abundant biota and has a large interference effect between organisms. If the nematode is applied to such chemically treated soil, the preventive effect against soil diseases can be enhanced.

[Inhibition of Plant Parasitic Nematode Proliferation] The growth of the plant parasitic harmful nematode can be suppressed by applying the main nematode cultivated in large quantities to soil containing the plant parasitic harmful nematode. The object of the present invention can be achieved by applying the present nematode 50 to 100 times the amount of the above-mentioned plant parasitic harmful nematode. Examples of plant parasitic nematodes include root-knot nematodes ( Meloidogyne spp. ) And root-knot nematodes ( Pr.
atylenchus spp.)
Including seeds.

[Comprehensive control of soil pests] In soils containing both pathogenic fungi and pests in the soil, comprehensive control of soil pests can be carried out by mixing and applying entomopathogenic nematodes (Steinner nematodes) and main nematodes. it can. In addition, as for the soil pest, the remarkable effect of the present invention was confirmed for Spodoptera litura and / or Kaburayaga, but is not limited thereto.

When the above-mentioned soil pest is Spodoptera litura, it is preferable to mix an equal amount or more of this nematode with Steinernema carpocapsae, and when the soil pest is Kabulayaga, the present nematode is substantially mixed with Steinernema. It is preferable to mix them in equal amounts.

EXAMPLES The method of the present invention and a method for culturing the nematode are described below.
The method of use will be described in detail in Examples, culture examples, and application examples.

[0037] (culture example 1) [bacteria-eating nematodes Aferenkusu-Abene (Aphelenchus av
Enae ) Mass production method using solid medium] Beet pulp 1
0.0 g (wet weight) and 10.0 g (wet weight) of beer residue
The mixture was mixed in a 00 ml glass container, charged in an autoclave, and sterilized by heating at 120 ° C. for 30 minutes. After cooling, a solid medium of pH 5.2 was obtained. The water content of the medium is 58
% By weight. And cultured for 3 days at a temperature 25 ° C. ± 1 ° C. To this medium was inoculated separately pure cultured filamentous fungus Botrytis cinerea (Botrytis cinerea). Separately, 50 nematodes were immersed in a streptomycin 1000 ppm solution for 30 minutes.
The body surface was sterilized by centrifugal washing three times with sterile water. The medium in which the above filamentous fungi proliferated for 3 days was inoculated with the nematode of which the body surface was sterilized, and cultured for 3 weeks under the above constant temperature condition. Cover the container enough to let air in and out, but keep out mites. After 3 weeks of culture, about 4 million main nematodes were obtained. After 3 weeks, the pH was 6.
5 by this method.
It is possible to produce about 4 million main nematodes per 4 g, that is, 480 million main nematodes in terms of 1 kg of the dry weight of the medium.

(Culture Example 2) [Large-scale production of fungiphagous nematode Apherenx avene using artificial liquid medium] A commercially available porous resin sponge [Everlight Peace (trade name)] used for pillows or cushions is used. The support was cut into strips each having a size of about 5 cm, a width of about 1 cm and a length of about 20 cm, washed well with water, and dried. 600 g potato, dextrose or sucrose 60
g, and 3,000 ml of Zeelensen phosphate buffer (pH: in the range of 5.2 to 5.5) to prepare a culture solution. The prepared culture solution is sucked into the sponge, put into a 5 L fermenter container for about the 7th minute, excess liquid is removed, sterilized in an autoclave at 120 ° C. for 60 minutes, and naturally cooled to form an artificial liquid medium. I got

Next, 100 to 120 main nematodes were collected.
Washed three times with sterile water at 500 rpm centrifugation and collected in 50 ml cylinders to 5 ml. A total of 30 ml was added with 0.001% arethane or hibitan, and the mixture was allowed to stand for 2 hours. During this time, ventilation was performed using a Pasteur pipette or the like. Thereafter, the mixture was centrifugally washed three times with sterile water, concentrated to 1 ml, and 9 ml of sterile water containing 10 mg streptomycin was added to make the total volume 10 ml. The mixture was immediately centrifuged for 2 minutes and the supernatant was discarded. After performing this operation twice, it was centrifugally washed three times with sterile water, and concentrated to 0.5 ml or less to obtain an inoculated nematode whose body surface was sterilized.

The filamentous fungus Rhizoctonia solani and the nematode were simultaneously injected from the inoculation port of the fermenter flange and cultured. The culture temperature was set at 25 ° C., and three days after inoculation of the fungus and the nematode, sterilized air was passed. The amount of ventilation was set to the minimum amount of the container used (0.5 L / min for this container), and ventilation was stopped occasionally. pH is 1
If the pH was measured every week and the pH became 6 or more, the pH of the culture solution was adjusted slightly lower (pH: 5.0 to 5.2) with Zeerenzen buffer.

When the nematode began to adhere to the glass wall in a coil shape, the inside of the container was washed and sieved with a 400 mesh. Put the sponge on a 100 mesh sieve,
400 mesh was placed underneath, and the nematodes were collected to 400 mesh, and about 200 million collected nematodes were stored by the preservation method according to the present invention.

(Culture Example 3) All of the above Production Example 2 except that Botrytis cinerea was used as a filamentous fungus to feed on the nematode, and the filamentous fungus was inoculated into an artificial liquid medium and injected two days later. In the same manner as described above, 200 to 300 million main nematodes were obtained.

(Example 1) [Long-term preservation method of the nematodes] The nematodes obtained in the above culture example 1 were collected, agglomerated and placed in a glass desiccator (10 L) container, at a temperature of about 25 ° C. and a relative humidity of 97%. For 2 days. As the humidity control solution, any solution that does not generate harmful gas may be used, and in this embodiment, a glycerin solution or a saturated saline solution was used. When the humidity was gradually reduced to 86%, 76%, 50%, and 30% for two consecutive days, the body shrunk and became almost coil-shaped, and became a completely anhydrous survival resistant state in a total of 10 days. In this state, long-term storage in the room was possible.

The following application example relates to agricultural applications of the nematode mass-produced by this method.

[Method of controlling soil diseases by nematodes] (Application Example 1) "Cucumber germination pot test" A 300 ml styrene pot was sterilized with sandy loam and bar
Put the 15: 1 mixed soil of miculite (50% moisture)
Was. Wheat bran medium with filamentous fungi, Rhizoctonia solani
AG-4 (Rhizoctonia solani AG-4), Fusarium
Oxysporum f. sp. Lagenary (Fusarium oxy
sporum f. sp. lagenariae), Pitium sp. (Pyth
ium sp.) Or Phytoftora nicotiana var.
Lasithica (Phytophthora nicotiana var.parasitic
a) Was cultured for 2 weeks. Medium containing cultured filamentous fungi
1g each, at the same time 10,000, 50,000 and 100,000 of the main nematode
Inoculate the mixed soil, mix the soil in the container, seal and darken.
Placed at 25 ° C. for one week. Then, the disinfected cucumber
Four seeds were sown in one pot. As each processing 10 iterations
After 5 days, the germination rate was measured. Table 1 shows the results.

[0046]

[Table 1]

In this test, since sterilized soil was used, the germination rate was reduced by inoculation of nematodes alone, and the germination rate was about 80% in the 10,000-inoculation group, 70% in the 50,000-inoculation group, and 100,000 The inoculation area was about 40%. When this nematode is inoculated with bacteria, it is 70-80% in 10,000 inoculation groups and 80-85% in 50,000 inoculation groups.
% Of the 100,000 inoculated plots declined to about 50%.
Considering that the germination rate of cucumber was 0% in any of the inoculated plots with only pathogenic bacteria, the effect of this nematode application was obvious, but in this test, the appropriate amount was 50,000 per pot. It turns out that. In vitro breeding of the used Kyushu nematodes was highest for Rhizoctonia solani and very low for Fusarium and Pythium, but there was no significant difference among the fungi in the germination rate and growth effect of cucumber. Also, the ratio of nematodes grown in the pot was 2.5 to 2.7 times the number of inoculated plants (10,000 inoculated plots), and there was no significant difference between the bacteria.

(Application Example 2) "Cucumber germination pot test" 500 ml of sterilized sandy loam was placed in a styrene-made pot. On the other hand, filamentous fungi Rhizoctonia solani AG-4 were cultured in a wheat bran medium in the same manner as in Example 5. 1 g of each wheat bran medium containing the cultured filamentous fungi and 50,000, 100,000, 200,000, 500,000 and 1 million heads of this nematode were mixed with the above-mentioned sterilized sandy loam to obtain a soil moisture of about 35%. And kept in the dark at 25 ° C. for 2 weeks. Next, three cucumber seeds were sown in one pot, and one treatment was repeated 10 times.
The germination rate after 5 days and the growth state after 16 days were examined. Table 2 shows the results.

[0049]

[Table 2]

In this experiment, since no nematode-only treatment section was provided, no damage by the nematode itself was recognized, but the effect of controlling nematode by the nematode application clearly appeared. In other words, the germination rate was 13.3% when inoculated with only the diseased bacteria, whereas the nematode 5
The germination rate was 86.7% in the 10,000 inoculated plots, and the subsequent growth was favorable. However, the germination rate gradually decreased when the number of inoculated animals was 200,000 or more, and reached 66.7% for 500,000. This seems to be a germination disorder by the nematode itself. The germination rate of the plots in which neither nematodes nor pathogens were inoculated was naturally 100% [Ishibashi, N. (1993) Integrated control of insec.
t pests by Steinernema carpocpasae . In. “Nematode
s and the Biological Control of Insect Pests "(Bed
ding, R., Akhurst, R. and Kaya H. eds.), CSIRO, Ea
st Melbourne, 105-113.]

(Application Example 3) "Pot test for controlling cucumber wilt disease (combination test with root-knot nematode and entomopathogenic nematode)" A unfired pot having a capacity of 500 ml was used as a container.・ Solani ・ AG-
4 together with 1 g of wheat bran medium in which it was cultured,
100 sweet potato nematodes, fungiphagic nematodes 20
Ten thousand, 500,000 entomopathogenic nematodes, Steinernema carpocapsae, were treated with the combinations shown in Table 3 below.

[0052]

[Table 3]

After setting the soil moisture at 50% and the number of repetitions to 10, each was kept in a dark place at 25 ° C. for 2 weeks after the treatment, 4 cucumber seeds were sown. Two weeks after transferring to a glass room, the survival rate and plant height of cucumber seedlings were measured. Table 3 shows the results. The germination rate of the cucumber germination rate was 0% in the mixed plot of the fungus and the root-knot nematode only for the take-all fungus. Even in the case of 200,000 phagocytic nematodes, the germination inhibition was not observed in the mixed inoculation group with the take-all fungus in this test. However, the plant height was slightly lower than in the control group (no inoculation). When entomopathogenic nematodes are mixed, the germination rate is 10
At 0%, the plant height was not significantly different from the control.

When the root-knot nematode was further added to the three, the germination rate was reduced to 80%, but there was no significant difference in plant height. Although entomopathogenic nematodes are used for pest control, mixed application with the nematodes for the purpose of simultaneous control of pests may be possible. From this test, it was found that the mixing of the useful nematodes did not impair the application effect of the nematodes, but the mixing caused the damage of the nematodes. Similar results were obtained in a number of subsequent studies (Is
hibashi, N., and Choi, DR. (1991) Biological cont
rol of soil pests by mixed application of entomopa
thogenic and fungivorous nematodes. J. Nematol. 2
3: 175-181).

(Applied Example 4) "Small field test of spinach blight disease" Fumigation agent Telon II (trade name) 6 months before in Saga University campus field
(1,3-dichloropropene, active ingredient 98%) (1
5 L / 10 a) treated and untreated test plots were used. In mid September, Rhizoctonia solani grown on a wheat bran medium together with 4 kg of a medium (approximately 200 million heads) was cultivated with 4 kg of a medium (approximately 200 million) using beet pulp as a culture medium and 6 m ² of beet pulp as a medium. AG-4 (blight fungus) 40
Each g medium was mixed or not mixed with the above nematode medium (only the wilt fungus), spread over the entire test plot and mixed with the soil. After one treatment and three repetitions, the seeds were allowed to stand for one week, and then sprouts of spinach were sown (two ridges). Growth was investigated 20 days after sowing. Table 4 shows the results.

[0056]

[Table 4]

The germination rate of spinach was higher (28%) in the non-fumigant-treated group and significantly decreased (5% germination rate) in the treated group by inoculation of the disease-free bacteria alone. When the nematode was applied, it increased in the fumigant-treated group (84%) and decreased in the untreated group (78%; both were significantly different at the 5% level). Untreated soil has more biota than treated soil,
This is probably due to the large interference between organisms.
The growth of the spinach in the inoculated group with the disease was extremely poor, and 100% died within one week after the survey, especially in the fumigant-treated group. Soil treatment with chemicals has led to a dramatic poverty of the biota and, consequently, a rapid recovery of pests. On the other hand, if the nematode is applied to such soil, it is expected that the preventive effect of soil disease will be further enhanced [Ishibashi, N. (1993) Integrated control of
insect pests by Steinernema carpocpasae . In. “Ne
matodes and the Biological Control of Insect Pest
s "(Bedding, R., Akhurst, R. and Kaya H. eds.), CS
IRO, East Melbourne, 105-113.]

(Application Example 5) "Inhibition of growth of plant parasitic nematode by main nematode" When plant infestation was carried out simultaneously on agar at a density 100 times higher than that of plant parasitic nematodes such as root-knot nematode or neksare nematode, The root penetration rate of nematodes was 1-2% of the root-knot nematode inoculation alone. Further, when a pot test using sterile soil was performed, the main nematode was inoculated one day before the inoculation of the plant parasitic nematode, and the invasion rate of the plant parasitic nematode was 20.
%. However, no significant difference was observed in non-sterilized soil compared to inoculation of plant parasitic nematode alone. On the other hand, the invasion rate of the plant parasitic nematode alone inoculation was also reduced to 30% or less in the non-sterilized soil as compared with the case where only the plant parasitic nematode was inoculated in the sterilized soil. (In nature, where there is a great variety of organisms, pathogens are the only mechanism that can not dominate).
Therefore, it was confirmed that the present nematode exerts an effect of suppressing the rapid recovery of harmful nematodes when applied as a preventive for deterioration of soil biota due to chemical application.

(Application Example 6) "Comprehensive control of soil pests by simultaneous application with entomopathogenic nematodes" The nematodes do not cause damage to plants even in sterile soil if inoculated with pathogenic bacteria. However, even when applied simultaneously with the entomopathogenic nematode Steiner nematica, no damage was observed on the plants, and the germination of cucumber was faster and the germination rate was higher than that of the nematode alone-inoculated group. Conversely, the experiment was repeated several times to confirm the control effect of the entomopathogenic nematode against the pests in the mixed application. Table 5 shows an example of the experimental results.

[0060]

[Table 5]

As is evident from Table 5, in the case of pests originally having a slight resistance to Steiner nematodes, such as the larvae of the mosquito moth, when the nematode is extremely increased compared to Steiner neem, the insecticidal ability of Steiner nematode is further reduced. I concluded that there would be almost no problem. In the future, compatibility between this nematode and useful nematodes such as Steiner nema can be expected [Ishibashi, N. (1993) I
ntegrated control of insect pests by Steinernema c
arpocpasae. In. “Nematodes and the BiologicalCont
rol of Insect Pests "(Bedding, R., Akhurst, R. and
Kaya H. eds.), CSIRO, East Melbourne, 105-11
3.].

[0062]

Advantages of the Invention Mass production of the fungus-eating nematode Aferenx avene became possible, and a long-term storage method for mass-produced main nematodes was established. Pest control of crops can be effectively used for on-the-ground agriculture.

2. Furthermore, since the method for controlling soil disease of agricultural crops and the growth of plant parasitic nematodes using the nematodes has been established, it greatly contributes to improvement of yield and quality of agricultural crops. To conclude, this nematode does not cure the diseased plants, but is expected to have a great effect when applied prophylactically.
In addition, there is an appropriate amount of nematode application, and when a larger amount is applied, the effect is rather reduced. 3. The method for controlling soil diseases of agricultural crops using the present nematode does not involve pollution and environmental problems caused by chemicals, and can contribute to environmental purification if industrial waste is effectively used for mass culture.

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Claims (1)

(57) [Claims] 1. A consisting vegetable industrial waste solid medium or artificial media fungal diet nematodes were cultured in a liquid medium consisting Aferenkusu-Abene (Aphelenchus avenae) collected to bulk and without, the relative humidity from 98 to 95 % Of the nematodes by maintaining and drying at a temperature of 20 to 30 ° C. under aerobic conditions for 8 to 12 days while gradually tilting from high humidity in the range of 35% to low humidity in the range of 35 to 25%. A long-term preservation method for a fungus-eating nematode, Apherenx avene, which is stored in an anhydrous state.