JP5224322B2 - Method for improving plant disease resistance and plant disease resistance improver - Google Patents

Description

  The present invention relates to a method for improving plant disease resistance and a drug for improving plant disease resistance.

  Crop diseases reduce production efficiency and cause a shortage of food supply. Conventionally, agricultural chemicals have been mainly used to control such diseases. However, if a large amount of pesticide is used, resistant bacteria may be generated. Above all, pesticides have biotoxicity problems.

  In recent years, in order to reduce the impact on the environment, researches on highly selective drugs that reduce the toxicity to warm-blooded animals and enhance the action against pathogenic bacteria and the like are also progressing. However, it is difficult to eliminate the toxicity of synthetic drugs to warm-blooded animals, and resistance to agricultural chemicals itself is increasing due to the recent health orientation.

  Therefore, drugs that increase the disease resistance of plants themselves, rather than acting on pathogenic bacteria, have been studied. Such drugs have little risk of causing resistant bacteria and are considered to be low in biotoxicity, and thus are attracting attention as environmentally friendly disease control methods. As such plant disease resistance improvers, benzoisothiazole derivative probenazole, benzothiadiazole derivative acibenzoral S-methyl, and thiadiazole carboxamide derivative thiazinyl are known (Non-patent Document 1).

  However, the current situation is that the spread of drugs that increase disease resistance is not sufficiently advanced. One reason for this is that, although these drugs are synthetic compounds similar to agricultural chemicals, in some cases they cause phytotoxicity to crops.

  By the way, oysters have been edible in Japan since ancient times, and are cultivated not only in Hiroshima and Miyagi prefectures, which are famous as production areas, but also in the treatment of their shells. In other words, oysters are very bulky if they are still attached to the shell, so that the shell is often removed from the production area and only the shellfish is distributed in the market. On the other hand, since the use of oyster shells has not been established, large amounts of oyster shells are disposed of as waste during the oyster shipping season. Therefore, the effective use of oyster shells is in demand.

For example, Patent Documents 1 to 3 describe that baked oyster shells can be used as a bactericidal agent against Escherichia coli, Salmonella, or viruses that cause food poisoning and the like.
Hideo Ishii, “Disease control using induced resistance of crops”, [online], September 13-14, 2004, [Search July 23, 2007], Internet <URL: http: // www .niaes.affrc.go.jp / techdoc / inovlec2004 / 2-5.pdf> International Publication No. 93/11670 Pamphlet International Publication No. 00/72685 Pamphlet JP 2001-226210 A

  As described above, drugs that increase the disease resistance of plants themselves are attracting attention as a substitute for existing agricultural chemicals. However, plant disease resistance improvers that have been put into practical use are synthetic drugs, and have not yet spread due to problems such as drug damage.

  Therefore, the problem to be solved by the present invention is extremely excellent in safety, and provides a drug capable of effectively increasing the disease resistance of the plant itself and a method for improving the plant disease resistance using the drug. There is.

  The present inventors have intensively studied to solve the above problems. As a result, fired oyster shells that had not yet been used effectively and were disposed of as waste were not only safe, but also resistant to the disease of not only the directly applied leaves but also the subsequent leaves. The present invention was completed by finding that it has an excellent effect of improving.

  The plant disease resistance improving method according to the present invention is characterized in that the baked oyster shell powder is administered to a plant body.

  As the above method, one that activates a peroxidase gene is suitable. Peroxidase has the effect of suppressing the invasion of various pathogenic bacteria and viruses as part of a plant defense system. Therefore, the disease resistance of plants can be effectively increased by activating the peroxidase gene to induce peroxidase expression.

  The said method shows a remarkable effect in the improvement of the plant disease resistance of a Cucurbitaceae plant. Such an effect is demonstrated by the following examples.

  The plant disease resistance improver of the present invention is characterized by containing calcined oyster shell powder. The fired powder is preferably fired at 800 ° C. or higher. Although the main component of oyster shell is calcium carbonate, it is considered that calcium carbonate or other components change in quality around 700 ° C. and contribute to improvement of plant disease resistance. Therefore, if the oyster shell is fired at 800 ° C. or higher, the disease resistance improving component is sufficiently contained.

  ADVANTAGE OF THE INVENTION According to this invention, the disease resistance of crop itself can be improved, without having a bad influence on agricultural products and the surrounding environment. The effect is sustained. For example, when the drug of the present invention is administered at the early stage of the leaf spreading stage, the pathogenic resistance of the leaves generated thereafter is also increased. Therefore, this invention is very useful industrially as what can reduce the disease of crops etc. effectively, suppressing the use of the existing agricultural chemical.

  The plant disease resistance improving method according to the present invention is characterized in that the baked oyster shell powder is administered to a plant body. Ordinary pesticides directly act on bacteria and viruses that cause disease, but they can damage plants themselves, and residual pesticides are a problem. On the other hand, since the method of the present invention uses a safe fired oyster shell powder, there is no adverse effect on plants and the environment.

  The oyster is a bivalve belonging to the genus Coleoptera, and includes oysters such as oysters, oysters and sinoegi, and oysters such as oysters and oysters. The kind of oyster that is the basis of the oyster shell used in the present invention is not particularly limited, and any oyster shell of any oyster may be used. However, the use of oyster shells for edible oysters has not been established yet, and the processing of oyster shells in oyster production areas is problematic. Since the present invention also provides the use of such oyster shells, edible oyster shells are preferably used.

  Oyster shells have a structure in which calcium carbonate is a main component and blocks made of calcium carbonate are bound by proteins. In addition to calcium, nitrogen, potassium and phosphorus, trace elements such as iron, magnesium, zinc, molybdenum and copper are included. In the present invention, fired powder of oyster shell is used, and it is considered that calcium carbonate changes to calcium oxide by firing, but it is not clear how other components change by firing. In addition, it is unclear whether calcium oxide obtained by firing exhibits the main effect, whether the fired product such as other components exhibits the effect, or a synergistic effect thereof. However, at least the effect of improving the pathogenicity resistance of the fired oyster shell powder is demonstrated in the examples described later. In addition, the use of oyster shells was known as a fungicide or antiviral agent, but these are for the purpose of sterilization of foods, etc., and fired oyster shells increase the pathogenic resistance of plants This is a matter that has not been known so far.

  The oyster shell is preferably washed with water before firing. If salt derived from seawater remains attached, it may adversely affect plants. Moreover, in order to sinter efficiently, it is preferable to dry and finely grind after washing.

  The firing temperature of the oyster shell is preferably 800 ° C. or higher. As will be described later, the effect is low even when fired at 600 ° C. or lower, and the effect begins to increase at 700 ° C., but the oyster shell powder fired at 800 ° C. or higher shows a sufficient effect of improving disease resistance. On the other hand, the upper limit of the firing temperature is not particularly limited. However, if the temperature is raised excessively, the cost increases and the organic component exhibiting the action effect may be lost.

  The oyster shell firing time may be appropriately determined by a preliminary experiment or the like, but is usually about 1 to 5 hours.

  The fired oyster shell is pulverized into a powder. Since the baked oyster shell hardly dissolves in water, it should be fined so that it can sufficiently act on plants. The particle size is not critical as long as it is sufficiently effective, but is preferably about 200 μm or less with a 50% cumulative diameter determined from the particle size distribution measured by the particle size distribution test. On the other hand, the lower limit of the particle diameter is not particularly limited, but it is difficult to make the particle size less than 10 μm by mechanical pulverization.

  The pulverizing means for the fired oyster shell is not particularly limited, and an ordinary pulverizer may be used. The particle diameter of the baked oyster shell powder may be adjusted by a conventional method. For example, if the powder is mechanically pulverized and then sieved using a sieve or the like, a coarse pulverized product can be easily removed.

  If the plant object used as the object of the method of the present invention is a crop or the like whose disease resistance is to be improved, its type is not particularly limited. For example, cucumbers, watermelons, pumpkins, cucumbers, bitterns, melons, etc .; cucurbits such as tomatoes, eggplants, potatoes, peppers, peppers; cruciferous plants, such as radish, cabbage, wasabi; And leguminous plants such as tea; The method of the present invention is preferably used to improve plant disease resistance of Cucurbitaceae plants.

  According to the method of the present invention, it has been demonstrated that at least the peroxidase gene is activated and the peroxidase is expressed, thereby improving the disease resistance of plants. Since peroxidase is involved in the suppression of microbial infection as part of the plant defense system, it is thought that it can protect plants from diseases caused by bacterial and viral infections. Therefore, the disease targeted by the method of the present invention is not particularly limited. For example, anthrax, leaf mold, gray mold, mildew, brown spot, brown rot, soft rot, white silk, sclerotia And so on. At least, it has been demonstrated that the method of the present invention can protect plants from infection by Colletotrichum orbiculare, which causes cucumber anthrax.

  In the method of the present invention, the disease resistance of a plant is improved by administering the baked oyster shell powder to the plant body.

  The administration method is not particularly limited, but it is preferably administered directly to a plant after suspending in water. The concentration of the suspension may be adjusted as appropriate. For example, the suspension may be added to 100 mL of water at a ratio of about 10 to 30 g and stirred well. Preferably a suspension of calcined oyster shell powder is applied to the leaves.

  The administration interval may be adjusted as appropriate, but the plant disease resistance improver of the present invention does not need to be administered every day because the effect is sustained to some extent. For example, it is sufficient to apply to the first leaf or the second leaf by the second leaf stage which is the initial stage of the leaf spreading stage. Thereafter, additional administration may be performed as appropriate while observing the state of the plant.

  The plant disease resistance improver of the present invention is used in the above-described method, and includes baked oyster shell powder. Therefore, it is extremely safe, and there is very little adverse effect on the human body and the environment as well as the target plant. In addition, the plant disease resistance improving action is extremely excellent. Therefore, it can be said that the plant disease resistance improver of the present invention can suppress the amount of agricultural chemicals used and is environmentally friendly.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, but may be implemented with appropriate modifications within a range that can meet the gist of the preceding and following descriptions. These are all included in the technical scope of the present invention.

Example 1 Production of plant disease resistance improver Oyster shells stored in seawater for about 2 to 3 years were washed with tap water and then dried at 110 ° C. for 24 hours. The obtained dried oyster shell (10 g) was finely pulverized with a hammer and then placed in a muffle furnace (manufactured by ADVANTEC, product name “FUL242FA”) and baked at 1050 ° C. for 3 hours. Subsequently, after leaving in a furnace to normal temperature, it grind | pulverized to the powder form with the grinder (The Osaka Chemical company make, product name "Wanda crush mill D3V-101"). The obtained powder was sieved with a sieve (manufactured by Tokyo Screen, product name “Testing Sieve”, opening: 106 μm) to exclude coarse powder.

  For comparison, oyster shell powder was produced in the same manner except that firing at 1050 ° C. was not performed.

Example 2 Plant Disease Resistance Improvement Experiment The calcined oyster shell powder (2 g) obtained in Example 1 was added to distilled water (10 mL) and stirred well to obtain a suspension. Cucumber (Takii Tanae Co., Ltd., product name “Sagami Hansakusei”) was grown to 1.5 leaf stage of seedlings, and the suspension was immersed in a cotton swab and applied to the first leaf of the main leaf. For comparison, only water and a suspension of the unfired oyster shell powder obtained in Example 1 were applied in the same manner.

  After 24 hours, the treated leaves were collected, immediately frozen at −70 ° C., and total RNA was extracted using Plant RNA Isolation Mini Kit (manufactured by Agilent). CDNA was synthesized from total RNA (500 ng) using Perfect Real Time RT-PCR kit (Takara Bio Inc.). The cDNA was diluted 40 times, and 1 μL thereof was subjected to PCR. A peroxidase gene was targeted as a pathogen resistance-related gene, and real-time PCR was performed with SYBR Premix Ex Taq (manufactured by Takara Bio Inc.) using a primer set specific to the gene. In the PCR, after activating polymerase at 95 ° C. for 10 seconds, DNA denaturation was performed at 95 ° C. for 5 seconds, and annealing and extension were carried out 40 times at 64 ° C. for 30 seconds. The expression level of the peroxidase gene was normalized by the expression level of the actin gene, which is an internal standard gene, and calculated as a relative value where the expression level when treated with water alone was 1. The results are shown in FIG.

  As shown in FIG. 1, when a suspension of fired oyster shells is applied to leaves, a peroxidase gene related to pathogenic resistance is activated. Its activation ability was clearly higher than that of the unfired oyster shell powder suspension. From these results, it was demonstrated that the disease resistance of plants can be improved by the present invention.

Example 3 Plant Disease Resistance Improvement Experiment The calcined oyster shell powder (2 g) obtained in Example 1 was added to distilled water (10 mL) and stirred well to obtain a suspension. Three cucumbers (Takii Tanae Co., Ltd., product name “Sagami Hansakusei”) are planted in one pot at a time and grown to 0.5 leaf stage of seedlings. The above suspension is immersed in a cotton swab and 2 pots of cucumber This was applied to the cotyledons of individuals (6 individuals in total). For comparison, only water and a suspension of the unfired oyster shell powder obtained in Example 1 were applied in the same manner. 2 days after application, spore suspension of Colletotrichum orbiculare adjusted to a spore concentration of 1 × 10 ⁶ / mL is sprayed on cotyledons and the first leaf of the main leaf approximately 2 mL per individual. Vaccinated. Next, the cucumber plant pot was allowed to stand under dark moist conditions for 24 hours, followed by a day length environmental control room with a cycle of temperature: 25 ° C., illuminance: 3000 lux in a bright environment for 16 hours, and a dark environment for 8 hours. The disease severity was investigated 3 to 4 days later. The severity of lesions is evaluated in 5 stages, less than 5%, less than 5%, less than 25%, more than 25%, less than 50%, more than 50%, less than 75%, more than 75%, and replaced with the median of each class. And it calculated as a suppression rate with respect to the case where it processed only with water. The results are shown in Table 1. Moreover, the photograph of the cucumber processed only with water and the cucumber processed with the baking oyster shell powder is shown in FIG.

  As shown in FIG. 2 (1), in the cucumber that was treated with only water and then inoculated with anthrax, clear lesions were observed in both cotyledons and true leaves. On the other hand, as shown in FIG. 2 (2), the lesion site is markedly reduced in the cucumber treated with the fired oyster shell powder and inoculated with the anthrax fungus. Even more surprisingly, despite the fact that only cotyledons were treated with the suspension of calcined oyster shell powder, the effect of reducing the lesion site is also observed in the true leaves. Considering this result together with the result of Example 2 above, it is considered that the baked oyster shell powder according to the present invention induces peroxidase related to disease resistance and enhances disease resistance throughout the whole plant. In addition, as shown in Table 1, the effect of improving plant disease resistance when treated with fired oyster shell powder is clearly higher than when treated with unfired oyster shell powder. From these results, it was proved that the disease resistance of plants can be remarkably improved by the present invention.

It is a graph which shows the effect of the plant disease resistance improving agent which concerns on this invention. It is a photograph which shows the effect of the plant disease resistance improving agent which concerns on this invention. (1) is a cucumber that has been treated only with water and inoculated with pathogenic bacteria, and (2) is a cucumber that has been treated with calcined oyster shell powder and inoculated with pathogenic bacteria.

Claims (4)

The method for improving disease resistance of Cucurbitaceae plants, which comprises administering a firing oyster shell powder plants cucurbits.   The method according to claim 1, which activates a peroxidase gene. A disease resistance improver for cucurbitaceae plants characterized by containing calcined oyster shell powder. The disease resistance improver for cucurbitaceae plants according to claim 3 , which has been baked at 800 ° C or higher.