阅读说明：本技术 植物病原性真菌的检测装置、以及使用了该检测装置的检测方法和农药浓度的选择方法 (Detection device for plant pathogenic fungi, detection method using same, and selection method for pesticide concentration ) 是由 山口佳织 河合志希保 石堂太郎 狩集庆文 于 2019-05-21 设计创作，主要内容包括：本公开提供下述植物病原真菌检测装置、以及植物病原性真菌的检测方法和有效农药浓度的选择方法,上述植物病原真菌检测装置能够选择性地判定试验试样是否含有植物病原性真菌,并且能够在真菌性病害发病前提示对该植物病原性真菌的有效农药和有效农药浓度。本公开涉及的检测装置的特征在于,具备器件和观察部,上述器件具备人工细胞壁、设置在上述人工细胞壁的上部的试验试样投入部、和设置在上述人工细胞壁的下部的培养基层,利用所述观察部从横向观察上述培养基层,上述培养基层中包含各不相同的农药原药,并且在上述培养基层中,包含基准量和从基准量进行稀释后的浓度的农药的多个层从下向上从浓度高的层起依次叠层,并且具备不包含农药的层作为最上层。(The present disclosure provides a plant pathogenic fungus detection device capable of selectively determining whether or not a test sample contains a plant pathogenic fungus, and capable of presenting an effective pesticide and an effective pesticide concentration to the plant pathogenic fungus before onset of a fungal disease, and a method for detecting a plant pathogenic fungus and a method for selecting an effective pesticide concentration. The detection device according to the present disclosure is characterized by comprising an artificial cell wall, a test sample introduction part provided on the upper part of the artificial cell wall, and a culture medium layer provided on the lower part of the artificial cell wall, wherein the culture medium layer is observed from the lateral direction by the observation part, the culture medium layer contains different raw pesticides, and a plurality of layers containing a reference amount and a pesticide having a concentration diluted from the reference amount are stacked in order from a layer having a high concentration from the bottom to the top in the culture medium layer, and a layer containing no pesticide is provided as the uppermost layer.)

1. A detecting apparatus for a plant pathogenic fungus,

which is provided with a device and an observation part,

the device comprises an artificial cell wall, a test sample introduction part provided on the upper part of the artificial cell wall, and a culture medium layer provided on the lower part of the artificial cell wall,

observing the culture medium layer from a lateral direction by the observation part,

the culture medium layer contains different pesticide raw materials, and,

the culture medium layer is formed by stacking a plurality of layers containing a reference amount of an agricultural chemical and a concentration of the agricultural chemical diluted from the reference amount in this order from the bottom to the top, and includes a layer containing no agricultural chemical as the uppermost layer.

2. The detection device according to claim 1, wherein the artificial cell wall comprises at least:

a substrate having a through hole with a diameter of 2 to 7 μm and a thickness of 5 to 150 μm, and

a cellulose film having a thickness of 0.5 to 2 μm and provided on one surface of the substrate.

3. The detecting device according to claim 1 or 2, a plurality of the means being arranged on a circumference.

4. The detecting device according to claim 1 or 2, wherein a plurality of the devices are arranged in a line.

5. The detecting unit according to claim 3 or 4, wherein the medium layer of at least one of the plurality of the devices does not contain a technical pesticide.

6. The detecting device according to any one of claims 1 to 5,

the device is moved and, in addition,

the observation portion is fixed, and each device is observed from the lateral direction by the observation portion.

7. The detection device according to any one of claims 1 to 6, wherein the target plant is a tomato.

8. The detecting device according to claim 7, wherein the object to be detected is at least one selected from Botrytiscinerea (Botrytiscinea) which is Botrytiscinea cinerea, Pseudocercospora furigena (Pseudocercospora furigena) which is tomato, and Passalorafiava (Pseudiplodia solani).

9. The detecting unit according to any one of claims 1 to 8, wherein the raw pesticide contained in the culture medium layer is 1 or more selected from Kasugamycin hydrochloride, Mepanipyrim, Penthiopyrad, Triflumizole, Difenoconazole, fenpropiconazole, Fenpyrazamine, Iprodione, Fludioxonil, TPN, Iminoctadine albendate, Captan, tiopronil, thiobendazole-methyl, Benomyl, Diethofencarb, Azoxystrobin, and polyoxin.

10. A method of detection comprising the steps of: use of the detection device according to any one of claims 1 to 9 for selectively detecting a plant pathogenic fungus.

11. A method of selecting a pesticide concentration comprising the steps of: use of a test device according to any one of claims 1 to 9 to select an effective pesticide concentration.

Technical Field

The present invention relates to a device for detecting a plant pathogenic fungus having a function of selecting a concentration of an agricultural chemical, and a method for detecting a pathogenic fungus and a method for selecting a concentration of an agricultural chemical using the device.

Background

The phytopathogenic fungi have properties related to plant invasion, such as forming an attachment on a plant surface and attaching the attachment, then searching for pores such as stomata and extending hyphae from the pores into a plant body, and secreting a plant cell wall-degrading enzyme (cellulase or pectinase) from the hyphae.

Taking advantage of these characteristics, for example, patent document 1 discloses a fungus metering method using a microporous membrane support. Further, non-patent document 1 discloses: pseudo hyphae of Phytophthora sojae (Phytophthora sojae) of 1 species as a phytopathogenic oomycete seemed to try to sneak downward rather than grow horizontally and penetrated a PET (polyethylene terephthalate) film having pores of 3 μm.

In addition, in view of such properties, the present inventors have already proposed a method for determining phytopathogenic oomycetes (patent document 2).

Further, there has been reported a technique of observing the growth of bacteria as needed by scanning using a plate having a plurality of wells, and performing a fixation test of bacteria or fungi and a drug sensitivity test (patent document 3).

Disclosure of Invention

Problems to be solved by the invention

Drawings

Fig. 1 is a schematic cross-sectional view showing a part of a detection device according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of an artificial cell wall provided in a device in the detection apparatus according to the present embodiment.

Fig. 3 is a plan view (upper) and a sectional view (lower) showing an example of the detection device of the present embodiment.

Fig. 4 is a sectional view (top) and a plan view (bottom) showing an example of a detection device according to another embodiment of the present invention.

Fig. 5 is a schematic diagram showing an example of the detection operation of the detection device of the present embodiment shown in fig. 3.

Fig. 6 is a schematic diagram showing an example of the detection operation of the detection device of the present embodiment shown in fig. 4.

FIG. 7 is a photomicrograph showing the results of the examples.

Detailed Description

The embodiments of the present invention will be described below in detail, but the present invention is not limited thereto.

(detection device)

As shown in fig. 1, the apparatus for detecting a plant pathogenic fungus according to the present embodiment includes a device 1, and the device 1 includes an artificial cell wall 2, a test sample introduction part 3 provided on the artificial cell wall 2, and a culture medium layer 6 provided under the artificial cell wall 2. The device 1 in this embodiment may be otherwise referred to as an incubator. Further, the apparatus of the present embodiment includes an optical observation unit 7 for detecting growth of hyphae in each device as shown in fig. 5 and 6 described later.

The medium layer 6 contains different agricultural chemical raw materials and is composed of a plurality of layers stacked on the medium container 4. That is, in the above-mentioned medium layer, a plurality of layers containing the reference amount and the pesticide at a concentration diluted from the reference amount are stacked in this order from the layer having a high concentration from the bottom to the top, and a layer containing no pesticide is provided as the uppermost layer. For example, in fig. 1, a pesticide-free solid medium 61 is provided at the uppermost part, and a medium 62 containing a pesticide in an amount of 1/50 parts, a medium 63 containing a pesticide in an amount of 1/5 parts, and a medium 62 containing a pesticide in an amount of 1/5 parts are stacked in this order.

The test sample introduction part 3 is a container for introducing the test sample 5, and the bottom surface of the test sample introduction part 3 is formed by the artificial cell wall 2.

As shown in fig. 2, the artificial cell wall 2 preferably includes at least a substrate 21 having a through-hole 22 and a cellulose film 23 provided on one surface of the substrate 21. By using such an artificial cell wall, the target phytopathogenic fungi can be more easily and selectively detected.

The through hole 22 penetrates from the surface of the front side to the surface of the back side of the substrate 21, and the diameter of the through hole is preferably 2 to 7 μm (cross-sectional area 4.5 to 38.5 μm)²). When the pore diameter is in the above range, the target pathogenic fungi can be selectively detected more reliably.

Further, in order to selectively detect the target pathogenic fungi more reliably, it is preferable to also adjust the thickness of the cellulose film 23. Specifically, the thickness of the cellulose film 23 is preferably 0.5 to 2 μm.

In the artificial cell wall 2 of the present embodiment, the diameter of the through hole 22 of the substrate 21 and the thickness of the cellulose film 23 are adjusted in the above ranges, so that the plant nonpathogenic fungi do not penetrate the cellulose film 23 in many cases, whereas the target pathogenic fungi are selectively present on the back surface of the cellulose film 23 in the present embodiment, and thus it is considered that the plant nonpathogenic fungi can be selectively detected.

The thickness of the substrate 21 is not particularly limited, but is preferably about 5 to 150 μm, for example.

As shown in fig. 1, the test sample 5 is supplied into the test sample input portion 3. In this way, when the test sample 5 contains the phytopathogenic fungi, the phytopathogenic fungi are present on the surface of the substrate 21 on the front surface side.

In the present embodiment, the test sample 5 is a solid, a liquid, or a gas. Test sample 5 is desirably a solid or a liquid. Examples of the solid test sample 5 are soil, crushed plants, and the like. Other examples are agricultural materials such as vermiculite, rock wool, and urethane. Examples of the liquid test sample 5 include agricultural water, a solution for hydroponic cultivation, a liquid used for washing plants, a liquid extracted from plants, a liquid used for washing agricultural materials, and a liquid used for washing clothes or shoes of workers.

Alternatively, when it is desired to investigate which agricultural chemical is effective and select an effective agricultural chemical for a specific plant, a pathogenic fungus harmful to the plant may be cultured in advance and the culture solution may be used as the test sample 5.

Examples of the plant pathogenic fungi targeted by the detection device of the present embodiment include tomato pathogenic fungi, and fungi belonging to the genus Fusarium (Fusarium), Pyricularia (Pyricularia), or Colletotrichum (Colletotrichum). Examples of the tomato pathogenic fungi include Botrytis cinerea (Botrytis cinerea), Pseudocercospora solanacearum (Pseudocercospora fuligena), and Pseudocercospora fulvidraco (Passalora fulva).

Examples of the plant pathogenic fungi include Fusarium oxysporum (Fusarium oxysporum), Pyrola grisea (Pyricularia grisea), and Colletotrichum gloeosporioides (Colletotrichum gloeosporioides). These phytopathogenic fungi cause Root rot disease, blast disease, anthracnose disease, Gray mold, and the like. These phytopathogenic fungi wilt plants. Examples of non-pathogenic fungi of plants are Saccharomyces cerevisiae (Saccharomyces cerevisiae), Penicillium chrysogenum (Penicillium chrysogenum), or Aspergillus oryzae (Aspergillus oryzae).

In the present embodiment, the target plant is preferably tomato, and the phytopathogenic fungus is preferably at least one fungus selected from the group consisting of Botrytis cinerea (Botrytis cinerea), pseudocercospora solanacearum (pseudocercospora destructuriana) and Botrytis fulvidraco (Passalora fulva).

In addition, in the present specification, the term "phytopathogenic" means having pathogenicity to a plant. The term "nonpathogenic to a plant" means not pathogenic to the plant. Even if a fungus is pathogenic, the fungus is "nonpathogenic" as long as it is not pathogenic to a plant. In other words, a fungus is "nonpathogenic" as long as it does not adversely affect a plant. The term "non-pathogenic" in plants encompasses the prefix "non-modifying" plants "and the prefix" non-modifying "pathogenic".

In the detection apparatus of the present embodiment, the medium layer 6 provided below the artificial cell wall 2 is composed of a plurality of layers stacked in the medium container 4 as described above. The medium used as the substrate layer 6 is not particularly limited as long as it is a culture medium capable of culturing fungi, and a general medium or culture medium can be used. For example, potato dextrose agar medium, saxase dextrose agar medium, or the like can be used, but in order to laminate a plurality of layers, a solid is desirable. In order to accelerate the culture of fungi, a culture medium may be added not only to the substrate layer 6 but also to the test sample 5.

For easy observation, the medium container 4 is preferably made of glass or a transparent resin. The shape is not particularly limited, and may be cylindrical, square, or the like.

In the present embodiment, the agricultural chemical is introduced into the medium layer 6 together with the medium. In the case where a plurality of devices are provided, different raw agricultural chemicals are put into each device. The pesticide is not particularly limited as long as it is a pesticide that is desired to be examined whether or not it is effective for a desired plant.

For example, Kasugamycin (hydroshloride monohydrate), Mepanipyrim (Mepanipyrim), Penthiopyrad (pentatropium), Triflumizole (Triflumizole), Difenoconazole (Difenoconazole), Fenpyrazamine (Fenpyrazamine), Iprodione (Iprodione), Fludioxonil (Fludioxonil), Tetrachloroisophthalonitrile (TPN), iminoctadine benzenesulfonate (iminoctadinebesilate), Captan (Captan), thiophanate-methyl (tiotropium-methyl), Benomyl (Benomyl), Diethofencarb (Diethofencarb), Azoxystrobin (Azoxystrobin), polyoxin (Polioxin), and the like can be used.

The medium layer 6 is composed of a plurality of layers, and each layer contains a raw pesticide at a different concentration. By thus making a gradient in the pesticide concentration and disposing the pesticide-free medium on the uppermost layer, when the test sample contains a pathogenic fungus, the fungus penetrating the artificial cell wall extends hyphae further downward from the pesticide-free medium. The concentration of the agricultural chemical in the layer in which the growth of the hyphae is stopped can be determined as the concentration of the agricultural chemical effective for the fungus. In addition, when the fungus grows hyphae to a culture medium containing a reference amount of the agricultural chemical in the lowermost layer, it is judged that the agricultural chemical is not effective against the fungus.

The number of layers included in the medium layer 6 is 4 layers in fig. 1, but is not particularly limited, and may be appropriately set as needed. In addition, the concentration of the agricultural chemical contained in each layer can be appropriately set by using the lowermost layer as a reference amount, stacking a plurality of layers containing the agricultural chemical diluted from the reference amount in this order from the layer having a high concentration from the bottom to the top, and using the layer containing no agricultural chemical as the uppermost layer.

In the detection apparatus of the present embodiment, after a certain period of culture has elapsed, the presence or absence of the phytopathogenic fungus in the sample can be detected by observing the presence or absence of the phytopathogenic fungus in the culture medium layer in contact with the back surface of the cellulose membrane 23 of the artificial cell wall 2, and the presence or absence of the fungus can be confirmed to confirm the effectiveness of the agricultural chemical contained in the device, and further, the effective concentration of the agricultural chemical can be determined by observing the culture medium layer on which the hyphae of the fungus grow.

For this observation, the detection apparatus of the present embodiment includes an optical observation unit 7 as shown in fig. 5 and 6 on the side surface (front surface) of the device 1. As the optical observation unit 7, an optical microscope or the like can be used.

The period of cultivation of the fungus is not particularly limited, and varies depending on the number of stacked agricultural chemical culture media and the thickness of each layer, but is preferably 72 hours or more in general. The culture temperature is preferably about 20 to 28 ℃.

The detection apparatus of the present embodiment includes a plurality of devices 1 each composed of at least a test sample introduction part 3, an artificial cell wall 2, and a culture medium layer 6 as shown in FIG. 1. The plurality of devices 1 may be arranged and aligned on the circumference as shown in fig. 3, or may be arranged in a straight line as shown in fig. 4, for example. The arrangement of the device 1 is not particularly limited as long as the culture substrate layer can be observed from the lateral direction by the optical observation unit.

Fig. 3 is a plan view (upper) and a sectional view (lower) in a case where the device 1 of the present embodiment is circumferentially arranged. Fig. 4 is a cross-sectional view (upper) and a plan view (lower) in the case where the devices 1 according to the present embodiment are arranged in a line.

The detection apparatus of the present embodiment preferably includes a plurality of devices as described above, and preferably does not contain a pesticide in the culture medium layer of at least one of the plurality of devices. For example, in fig. 5 and 6 described later, the device indicated as "blank group" does not contain a technical pesticide. One or more of the devices of the blank group may be provided. The positions of the devices in the blank group are preferably set so as to be able to be grasped and discriminated.

In the detection apparatus of the present embodiment, when a plurality of devices are arranged on the circumference, it is preferable that the devices arranged on the circumference are rotated in the horizontal direction, the optical observation unit 7 is fixed at a specific position, and when the devices 1 reach the optical observation unit 7 by the rotation, whether or not bacteria are present on the culture substrate 6 is observed from the lateral direction of the devices, as shown in fig. 5.

In the case where a plurality of devices are arranged in a line, the optical observation unit 7 can be moved left and right without moving the devices as shown in fig. 6 to observe the devices.

In any case, only one optical observation unit 7 may be provided, and thereafter, the presence or absence of fungi in the culture medium layer 6 may be detected by rotating the device or moving the optical observation unit 7.

The detection (optical observation) preferably starts from a blank set (blank, containing no technical pesticide) of devices. When the blank group is observed first and the growth of hyphae is not confirmed, it can be judged that the test sample contains no pathogenic fungi and the subsequent detection can be stopped. Only when the growth of hyphae was confirmed in the blank group, whether each of the agricultural chemical raw materials was effective or not can be sequentially detected thereafter, and therefore, the cost can be efficiently suppressed.

The order of disposing the individual pesticide ingredients is not particularly limited, but it is preferable to prepare the pesticide ingredients from pesticide ingredients that are considered to have low resistance risk. Specifically, for example, when detecting a pathogenic fungus in tomato, it is preferable to arrange TPN, captan, iminoctadine benzenesulfonate, fenpyrazamine, and fludioxonil in this order. Then, it is desired to dispose pesticide raw materials having moderate to high resistance risks (i.e., susceptible bacteria are likely to appear). Specifically, for example, kasugamycin, mepanipyrim, penthiopyrad, azoxystrobin, polyoxin, triflumizole, difenoconazole, iprodione, thiophanate-methyl, benomyl, and diethofencarb are preferably sequentially formulated.

The number of agricultural chemical raw materials varies depending on the pathogenic fungi to be detected, and for example, when only Pseudocercospora solanacearum (Pseudocercospora furigena) is to be detected, the number of agricultural chemical raw materials can be reduced to 5.

As described above, according to the detection apparatus of the present embodiment, it is possible to present an effective pesticide and an effective concentration of the pesticide from the growth and propagation status of fungi in the device. Furthermore, it is considered that the kind of pathogenic fungi can be identified from the effect pattern of the agricultural chemical. Further, it is considered that the accumulation of the data of the results of the detection for collation may also suggest the occurrence of an resistant strain in fungi.

(method of detecting pathogenic fungi)

Further, the present invention includes a method for detecting a plant pathogenic fungus, comprising the steps of: the phytopathogenic fungi are selectively detected using the detection apparatus as described above.

The method for detecting a plant pathogenic fungus according to the present embodiment is not particularly limited as long as the detection device is used, and includes, for example, the following steps: a step of inputting a test sample into a test sample input portion 3 of the detection device; a step of allowing the test sample to stand in the detection device (a step of culturing); a step of observing the lower part of the artificial cell wall 2 (cellulose membrane 23) of the detection device after standing; and a step of determining that the test sample contains a plant pathogenic fungus when a hypha of the fungus is observed on the lower portion of the cellulose membrane 23 and/or the culture medium layer 6.

(method of selecting agricultural chemical and effective concentration of agricultural chemical)

The present invention also includes a method for selecting a concentration of an agricultural chemical, which selects an effective original agricultural chemical and a concentration of the agricultural chemical using the above-described detection device.

The method for selecting the concentration of the agricultural chemical according to the present embodiment is not particularly limited as long as the detection device is used, and preferably includes at least the following steps, for example,

a step of adding pesticide raw materials different from each other in reference amount and concentration diluted from the reference amount to the layer other than the uppermost layer of the culture medium layer 6 of the plurality of devices other than the blank group;

a step of inputting a test sample 5 into the test sample input portion 3 of the blank group of devices; a step of allowing the test sample 5 to stand in the detection device (a step of culturing); a step of observing the culture medium layer 6 of the detection device after standing;

a step of observing, when a fungus is observed in the culture medium layer 6, which layer the fungus grows to in the culture medium layer 6 of the device containing the next agricultural chemical raw material, by assuming that the test sample 5 contains a plant pathogenic fungus and moving the device;

a step of determining that the pesticide concentration in the layer in which the growth of the hyphae in the medium layer 6 is stopped is a pesticide concentration effective for the fungus.

The present specification discloses various techniques as described above, but the main techniques are summarized below.

An apparatus for detecting a phytopathogenic fungus according to one aspect of the present invention is characterized by comprising a device and an observation unit, wherein the device comprises an artificial cell wall, a test sample introduction unit provided above the artificial cell wall, and a culture medium layer provided below the artificial cell wall, wherein the culture medium layer is observed from a lateral direction by the observation unit, the culture medium layer contains different agrochemical, and wherein a plurality of layers containing a reference amount of agrochemical and a concentration of agrochemical diluted from the reference amount are stacked in the culture medium layer in this order from a layer having a high concentration from the bottom to the top, and a layer containing no agrochemical is provided as the uppermost layer.

With such a configuration, it is possible to provide an apparatus and a method capable of selectively detecting a phytopathogenic fungus easily and safely. In addition, effective pesticides and pesticide concentrations can be selected prior to the onset of fungal disease. This makes it possible to prevent unnecessary application of a high concentration of agricultural chemicals, reduce the possibility of the amount of agricultural chemicals, and is effective for preventing residual agricultural chemicals and the like, in addition to preventing the effort of applying unnecessary agricultural chemicals, excessive administration, and the like.

In the detection device, the artificial cell wall preferably includes at least a substrate having a through hole with a pore diameter of 2 to 7 μm and a thickness of 5 to 150 μm, and a cellulose film having a thickness of 0.5 to 2 μm provided on one surface of the substrate. This can be considered to more reliably achieve the above-described effects.

In the above-described detection device, it is preferable that the plurality of devices be arranged circumferentially or linearly. Thus, the culture substrate layer of each device is more easily viewed from the lateral direction.

In the above-described detection apparatus, it is preferable that at least one of the plurality of devices does not contain a technical pesticide in the culture medium layer. With this configuration, the following advantages are obtained: when the test sample does not contain a pathogenic fungus, the early determination can be performed, and the subsequent useless examination can be omitted.

Further, in the detection apparatus, it is preferable that the device is moved, the observation unit is fixed, and each device is observed from a lateral direction by the observation unit. This can be considered to more efficiently obtain the above-described effects.

Further, in the above-mentioned detection apparatus, it is preferable that the target plant is a tomato, and the target to be detected is at least one selected from the group consisting of Botrytis cinerea (Botrytis cinerea), Pseudocercospora solanacearum (Pseudocercospora fuligena), and Botrytis fulvidraco (Passalora fulva). This can further exhibit the above-described effects.

Further, the raw pesticide contained in the above-mentioned culture medium layer is preferably 1 or more selected from kasugamycin (kasugamycin hydroxychloromonohydrate), Mepanipyrim (Mepanipyrim), Penthiopyrad (pentapyrd), Triflumizole (Triflumizole), Difenoconazole (Difenoconazole), Fenpyrazamine (Fenpyrazamine), Iprodione (Iprodione), Fludioxonil (Fludioxonil), Tetrachloroisophthalonitrile (TPN), iminoctadine albendanate (iminoctadine albendate), Captan (Captan), thiophanate-methyl (tiotropium-methyl), Benomyl (Benomyl), Diethofencarb (Diethofencarb), Azoxystrobin (Azoxystrobin), and polyoxin (polfexin). This can further exhibit the above-described effects.

In addition, another aspect of the present invention relates to a method for detecting a plant pathogenic fungus, comprising the steps of: the phytopathogenic fungi are selectively detected using the above-described detection apparatus.

Another aspect of the present invention relates to a method for selecting a pesticide, comprising the steps of: using the above detection device, an effective pesticide concentration is selected.

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto.

(examples)

(culture of Botrytis cinerea)

Botrytis cinerea (Botrytiscinerea), a pathogenic fungus of tomato gray mold, as one of plant pathogenic fungi, was inoculated on a Potato glucose Agar medium (Difco (registered trademark) Potato Dextrose Agar). Next, the medium was allowed to stand at 25 ℃ for 1 week. Botrytis cinerea (Botrytis cinerea) is provided by professor Qingshui university, department of applied biology, the university of Fumons Functions. Subsequently, a potato dextrose agar medium cultured with botrytis cinerea (Botrytiscinerea) having a sufficiently grown hypha was left under black light irradiation for 4 days or more and then left at room temperature for 2 weeks or more, thereby promoting sporulation. Several ml of sterilized pure water was dropped into a glucose agar medium for culturing potato with Botrytis cinerea (Botrytis cinerea) treated as described above, and the surface of the hyphae was rubbed with a platinum ring, a pen, or the like to obtain a broken hypha/spore mixed suspension. Hereinafter, the aqueous solution is referred to as "plant pathogenic fungi aqueous solution".

(preparation of pesticide concentration three-level laminated Medium)

To a potato dextrose agar medium, Captan (manufactured by tokyo chemical industries, ltd. (TCI)) as a main component reagent was added in an amount (concentration) changed to prepare a medium having 3 layers as a base. Each of 0, 2 and 10ml of a DMSO (manufactured by SIGMA-ALDRICH Co., Ltd.) solution was prepared in a 100-fold concentration based on the standard concentration of captan, and the resulting mixture was mixed with 1L of potato dextrose agar medium to prepare a medium having a captan concentration of 0 (no mixing), 1/5 of the standard amount of captan, and three levels of the standard amount of captan. In this example, a potato dextrose agar medium containing the aforementioned three levels of captan was stacked in the order of captan-based medium, medium 1/5 of the reference amount, and captan-free medium from the bottom, and a glass cylindrical or square molding member was used to cut through the stacked layers to prepare a device of the example.

(preparation of a layered culture Medium without agricultural chemical addition)

For comparison, a device (blank) having a medium layer containing only a medium to which no agricultural chemical was added was molded in the same manner as described above, except that potato dextrose agar medium to which no captan was added was laminated.

(addition of an aqueous solution of a plant pathogenic fungus to a device and cultivation)

In the uppermost part of the device (example 1) containing the pesticide concentration three-level layered culture medium and the device (blank group) containing the pesticide-free layered culture medium prepared in the above, 200 microliters of an aqueous solution of a plant pathogenic bacterium containing 200 pieces of hyphae and spores of botrytis cinerea (botrytis cinerea) were added to the pesticide concentration three-level layered culture medium and the potato dextrose agar medium to which captan additive was not added, respectively.

The devices to which the phytopathogen aqueous solution was added were left standing at 25 ℃ for 7 days for culture.

(results/investigation)

After incubation, the devices of the examples and the devices of the blank were observed microscopically from the side of each transparent member in a stacked agar medium. The micrograph thereof is shown in FIG. 7. The left side is the results for the blank set of devices and the right side is the results for the device of the example.

As shown in fig. 7, hyphae invaded from the uppermost Botrytis cinerea (Botrytis cinerea) hyphae mass 5 into the inside of the agar medium in the stack of each device by visual observation through an optical microscope and grew.

In the photographs of the blank group of devices, the third layer was observed in the laminated potato dextrose agar medium, while the invasion of the hyphae of Botrytis cinerea (Botrytis cinerea) and the growth of the hyphae in the medium were observed in the device of the example in the case of the top layer captan non-blending layer 61, whereas the second layer captan used amount of 1/5 blending layer 63 was confirmed in the medium in the case of the 1/5 blending layer 63, and the transparent state was observed in the medium. No hyphae were observed in the captan-based amount-matching layer 64 below the layer. This shows that the pesticidal ingredient captan exhibits an effect on Botrytis cinerea (Botrytis cinerea) in an amount of 1 in 5 out of the reference usage amount.

As shown by the above tests, according to the present invention, it is possible to selectively determine whether or not a test sample contains a phytopathogenic fungus, and to indicate an effective pesticide concentration against the phytopathogenic fungus. From this result, it was possible to show the possibility of reducing the amount of agricultural chemicals.

Industrial applicability

The detection device for a phytopathogenic fungus having a function of selecting an agricultural chemical of the present disclosure can selectively determine whether or not a test sample contains a phytopathogenic fungus, and can present an effective concentration of an agricultural chemical to the phytopathogenic fungus before the onset of a fungal disease. Therefore, the detection device of the present disclosure can be suitably used in various technical fields of agriculture and the like.

Description of the symbols

1 device

2 Artificial cell wall

3 test sample input part

4 culture medium container

5 test specimen

6 culture medium layer

7 optical observation unit

21 substrate

22 through hole

23 cellulose membranes

61 pesticide-free culture medium layer

62 base level 1/50 pesticidal medium layer

63 reference amount of 1/5 agricultural chemical

64 a medium layer containing a standard amount of the agricultural chemical.