JP2016220603A - Method for diagnosing growth state of potato crop - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique against diseases that cause lesions or symptom expressions in potato tubers, the technique enabling to diagnose the growth state of a crop with respect to an influence from a pathogenic microorganism without digging out the tubers as well as irrespective of the presence or absence of lesion or symptom expression of tuber disease.SOLUTION: The method for diagnosing the growth state of potato (Solanum tuberosum) crop with respect to influence from a pathogenic microorganism of tuber disease comprises the steps of: providing as an index value the content of organic acid in an aboveground part of a potato crop or a level based on the content of the organic acid; and, with respect to the aforementioned index value, making a comparison between an index value from an aboveground part of potato provided as a diagnosis target and an index value from an aboveground part of a crop in a healthy field to determine the presence or absence of or the degree of substantial difference between the indexes.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for diagnosing the growth state of a potato crop body related to the effects from a tuber disease-causing microorganism and a method for evaluating the quality of potato tubers.

With the growing interest in crop safety and nutritional value in recent years, the development of techniques for assessing the physiological state of crops can be expected to create new added value for products.
Crops produce various physiologically active substances such as potato glycoalkaloids and phytoalexins when stressed by diseases or physical and chemical stimuli. Among these substances are those that reduce the taste of crops and those that cause food poisoning.
In addition, crops that are infected by diseased microorganisms during the cultivation period may appear damaged at the time of harvest, but the disease may spread and be damaged during subsequent “storage”. Therefore, in order to produce a delicious and safe crop, it is important to appropriately evaluate the characteristics of the field to be cultivated and the growth state of the crop derived therefrom.

Among crop diseases related to potato, there are diseases that can predict the degree of damage during the cultivation period, such as potato plague that manifests symptom on the leaves, but in the case of soil diseases such as scab, It is difficult to grasp the damage situation until the tubers are harvested. In addition, there are diseases such as silver scabs that cause the disease to spread during storage even if the harvest is apparently normal.
In particular, the economic loss due to potato scab disease is enormous, for example, about 1 billion yen in Hokkaido and 1.1 billion yen in Kyushu, and the development of effective disease control methods is required. .

  Therefore, regarding diseases that develop on tubers, which are potato crops, without digging up the tubers (underground), and regardless of the occurrence of lesions or symptoms of tubers, If the “growth state of the reflected crop body” can be evaluated, it can be used as an index of the quality of the harvest. Furthermore, since such an index can be used to formulate a storage plan, there is a great need for a technique for evaluating or diagnosing a crop under cultivation.

  Here, as a method for diagnosing the growth state of a plant, a method for determining a lesion or a dead state of an irradiation site by laser-excited fluorescence (Patent Document 1), or a method for diagnosing a photosynthetic function by chlorophyll fluorescence measurement (Non-Patent Document) 1) etc. have been developed. However, since these techniques are methods for directly diagnosing the state of the above-ground part, index information relating to tuber disease cannot be obtained.

In addition, as a technique for detecting potato scab disease contamination that is a soil disease, techniques based on a selective separation culture method, a PCR method, an ELISA method, and the like have been developed for pathogenic bacteria on the surface of cultivated soil or seed potato.
For example, a method (Non-patent Document 2) for quantifying the nec1 gene characteristically present in common scabs by QCQP-PCR (Quantitative Competitive Quenching Probe PCR) has been developed.
Moreover, actinomycetes belonging to the genus Streptomyces, S. scabies (= S. scabiei), S. acidiscabies (= S. acidiscabiei), S. turgidiscabies (= S. turgidiscabiei), etc. A PCR kit for detection and quantification has been developed (Patent Document 2).
A detection method by ELISA using a monoclonal antibody against S. scabies has also been developed (Patent Document 3).
However, in a series of methods for detecting pathogenic bacteria (or genes, proteins, etc.) on these “cultivated soil” or “seed potato surface”, when pathogenic bacteria grow rapidly due to environmental conditions during the cultivation period after the inspection It cannot be handled in principle.
Moreover, in the case of diseases such as silver scab, it is not possible to cope with the expansion of disease damage during storage.

Japanese Patent No. 3807940 (diagnosis method of plant growth) Patent No. 5555060 (Reagent kit for PCR quantification of scab pathogen species) JP 2001-078763 A (Anti-potato scab mold monoclonal antibody, hybridoma and immunoassay reagent using the antibody)

Yoshiaki Sakai, Kotaro Takayama, Hiroshige Nishina, Plant Environmental Engineering, 23, p101-106, 2011, Diagnosis of photosynthetic function of tomato graft cell seedlings by chlorophyll fluorescence measurement Oyama Osamu, soil and microorganisms 63, p84-88, 2009, soil diagnosis and potato scab control technology by antagonistic microorganisms

  The present invention has been made in view of the above-mentioned background art, and the subject of the present invention is a disease or disease of a tuber disease without digging up the tuber with respect to a disease in which a disease or a disease symptom appears in a potato tuber. It is an object of the present invention to provide a technique that makes it possible to diagnose the growth state of a crop body relating to the influence from the disease-causing microorganism regardless of the presence or absence of signs.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the organic acid content in the shoots and leaves (ground part) of the growing potato plant is correlated with the presence of tuber disease-causing soil microorganisms in the field. We found that some fluctuate with positive or negative correlation. In particular, the formic acid content and L-malic acid content are higher in the stems and leaves of the potato plant grown in the field where the scab is present than in the healthy field, and conversely, the citric acid content and the chlorogenic acid content. Found to decrease.
In addition, the present inventors have found that the change in the organic acid content can be detected regardless of the disease resistance strength of each potato variety / line. Moreover, it discovered that it was detectable irrespective of the presence or absence of the lesion and symptom expression in a tuber.

The present inventors have found that by using the organic acid content as an index, it is possible to diagnose the growth state of a crop body related to the effect of potato tuber from a disease-causing microorganism.
In addition, the present inventors have found that the quality evaluation of tubers harvested from the crop body is possible by using the organic acid content as an index.

The present invention specifically relates to the following inventions.
[Claim 1]
A method for diagnosing the growth state of a potato (Solanum tuberosum) crop body in relation to the effects from tuber disease-causing microorganisms,
(1) a step of setting an organic acid content in the above-ground part of a potato crop body or a value based on the organic acid content as an index value; and
(2) For the index value, (2a) comparing the index value from the above-ground part of the crop body to be diagnosed with (2b) the index value from the above-ground part of the crop body in a healthy field, Determining whether or not there is a general difference or the degree of difference,
A method for diagnosing the growth state of a potato crop body, comprising:
[Section 2]
After the step described in (2) above,
(3) A step of determining a growth state of a crop body to be diagnosed based on the presence or absence of the determined substantial difference or the degree of the difference,
The method of diagnosing the growth state of the potato crop body of claim | item 1 containing this.
[Section 3]
When no substantial difference is detected between the index values in the step described in (2), it is determined that the growth state of the crop body that is a diagnosis target in the step described in (3) is good. Item 3. A method for diagnosing the growth state of a potato crop body according to Item 2.
[Claim 4]
In the step described in (2) above,
The above-ground part of the crop body according to (2a) and the above-ground part of the crop body according to (2b) are stems and / or leaves of a crop body of the same variety / lineage.
Item 4. A method for diagnosing the growth state of a potato crop body according to any one of Items 1 to 3.
[Section 5]
The organic acid according to (1) is formic acid and / or L-malic acid,
The difference described in (2) is a difference in which the index value described in (2a) increases with respect to the index value described in (2b).
Item 5. A method for diagnosing the growth state of a potato crop body according to any one of Items 1 to 4.
[Claim 6]
Item 6. The method for diagnosing the growth state of a potato crop body according to Item 5, wherein the organic acid according to (1) is formic acid.
[Claim 7]
The organic acid described in (1) is citric acid and / or chlorogenic acids,
The difference described in (2) is a difference in which the index value described in (2a) decreases with respect to the index value described in (2b).
Item 5. A method for diagnosing the growth state of a potato crop body according to any one of Items 1 to 4.
[Section 8]
Item 8. The method for diagnosing the growth state of a potato crop body according to Item 7, wherein the organic acid according to (1) is citric acid.
[Claim 9]
The index value is
(A) With respect to the above-ground part of the crop body grown in a healthy field, the organic acid content increased in the above-ground part of the crop body grown in the field contaminated with tuber disease-causing microorganisms, or a value based on the organic acid content;
(B) The organic acid content that decreases in the above-ground part of the crop body grown in the field contaminated with the tuber disease-causing microorganism, or a value based on the organic acid content, with respect to the above-ground part of the crop body grown in the healthy field,
Or a value based on the ratio,
Item 5. A method for diagnosing the growth state of a potato crop body according to any one of Items 1 to 4.
[Section 10]
Item 10. The potato crop body according to Item 9, wherein the organic acid according to (A) is formic acid and / or L-malic acid, and the organic acid according to (B) is citric acid and / or chlorogenic acids. Of diagnosing the state of growth
[Section 11]
Item 11. The method for diagnosing the growth state of a potato crop body according to Item 10, wherein the organic acid according to (A) is formic acid and the organic acid according to (B) is citric acid.
[Claim 12]
Item 12. The method for diagnosing the growth state of a potato crop body according to any one of Items 1 to 11, wherein the tuber disease-causing microorganism is a potato scab.
[Claim 13]
A method for assessing the quality of a potato (Solanum tuberosum) tuber with respect to the effects from a tuber disease-causing microorganism,
Said (1) and (2) using the crop body above-ground part of the tuber which is an evaluation object instead of the crop body above-ground part which is a diagnostic object of said (2a) in any one of claim | item 1 -12 A method for evaluating the quality of potato tubers, comprising performing the process described in 1.
[Section 14]
After the process according to Item 13,
(4) A step of determining the quality of the tuber that is the object of evaluation based on the determined presence or absence of the substantial difference or the degree of the difference,
Item 14. A method for evaluating the quality of potato tubers according to Item 13.
[Section 15]
When no substantial difference is detected between the index values in the process according to (2) described in Item 14, the quality of the tuber that is an evaluation target in the process according to (4) is good. Item 15. A method for evaluating the quality of potato tubers according to item 14.

The present invention relates to a plant plant relating to the disease affected by the disease-causing soil microorganisms without digging up the tuber and whether or not the disease spot or disease manifestation of the tuber disease is manifested with respect to the disease manifested by the diseased potato tuber. It is possible to provide a technique capable of diagnosing the growth state of the body.
Moreover, in this invention, it becomes possible to perform quality evaluation of a potato tuber, without performing the microbe test | inspection etc. of the tuber which is a harvested product by using the above-ground part of a potato crop body for a test | inspection.

In Example 1, it is a figure which shows the photograph image which image | photographed the external appearance of the potato tuber obtained from the crop body cultivated in the scab pathogen contamination field. Left: Yukirasha (scab-resistant variety). Right: Baron potato (scab susceptibility variety). In Example 2, it is a figure which shows the general | schematic flow of ¹ H-NMR spectrum analysis which used the stem and leaves of the potato crop body for the sample. In Example 3, it is a figure which shows the measurement result of the formic acid content (relative value) in the potato crop body foliage computed from < ¹ > H-NMR spectrum analysis. In Example 3, it is a figure which shows the measurement result of the citric acid content (relative value) in the potato crop body foliage computed from < ¹ > H-NMR spectrum analysis. In Example 4, it is a figure which shows the general | schematic flow of the simple colorimetric determination method of chlorogenic acids. (A) UV method. (B) NaNO ₂ method. In Example 4, it is a figure which shows the result of the organic acid content in the potato crop body stem and leaf quantified by the simple measuring method which uses colorimetric quantification as a principle. (A) L-malic acid content (μmol / g dry weight). (B) Chlorogenic acid content (μmol / g dry weight). In Example 5, it is a result figure which computed ratio of citric acid content / formic acid content. In Example 5, it is a result figure which computed ratio of L-malic acid content / chlorogenic acid content. In Example 6, it is a figure which shows the measurement result of the citric acid content (relative value) in the potato crop body foliage computed from < ¹ > H-NMR spectrum analysis.

Hereinafter, embodiments of the present invention will be described in detail.
The present invention relates to a method for diagnosing the growth state of a potato crop body related to the effects from a tuber disease-causing microorganism and a method for evaluating the quality of potato tubers.

Here, the “tuber” in the present specification is a starch storage tissue of a potato crop called a common name of potato, potato, or potato, and refers to an enlarged potato portion. After harvesting from the crop body, it has economic value as a crop that becomes fresh vegetables, processed food materials, starch materials, seedlings, feed materials, and the like.
Further, in the present specification, “disease resistance” refers to a property in which disease groups and disease symptoms are unlikely to appear even in the presence of disease-causing microorganisms. For example, it refers to the property that the onset is slow even if it is infected or that it is mild even if it is infected. In this invention, it uses as a term including both authentic resistance and field resistance.
Further, in this specification, the “field” is a term indicating a field and a farm where a crop is cultivated.

1. Diagnosis of Growth State of Potato Crop Body The method for diagnosing the growth state of a potato crop body according to the present invention is a method of diagnosing the growth state of a potato crop body related to the influence from a tuber disease-causing microorganism.

[Diagnosis target]
The method according to the present invention is a method that enables the diagnosis of a growing state of a crop body by evaluating the effect of the growing potato crop body from a tuber disease-causing microorganism living in the growing field as an index value. is there. In this invention, it becomes possible to determine the health state as a plant body of a crop.

The crop body to be diagnosed in the present invention is a potato crop body.
As used herein, the term “crop body” refers to the entire plant body of a growing potato including tissues and organs in both the above-ground part and the underground part.
Also, in this specification, “diagnosis of growth state” means evaluation of a growing potato crop body to be diagnosed by quantifying the effect of tuber disease causing microorganisms living in the growing field as an index value. It refers to the act of doing.
In addition, in this specification, “tuber evaluation” refers to an act of evaluating the tuber as an evaluation target by quantifying the influence of the tuber disease-causing microorganisms living in the growing field as an index value.

In the present invention, “potato” refers to a plant species classified as Solanum tuberosum belonging to the genus Solanum. It is a common name for potatoes.
Tubers, which are rhizomes, contain a large amount of starch, are excellent in preservability, and are suitable for growth in cold and thin land. Therefore, they are produced around the world as important crops, processed food materials, feed materials, and the like. There are many varieties and strains, and there are also various varieties and strains with different levels of disease resistance.

The method according to the present invention can be applied to any cultivar / line as long as it belongs to a potato species. For example, the technology can be applied to any variety or line regardless of the variety or line having different disease resistance.
Here, as varieties and strains that can be diagnosed by the method of the present invention, for example, Baron 薯, Toyoshiro, North Sea No. 104, Koganemaru, Koror, Haruka, Inca Ame, Nishiyutaka, Shizuki, Mae Queen, Kita Akari, Astarte, Benimaru, Norin No. 1, Beetle, Sanjumaru, Atlantic, Okhotsk Chip, Inca Red, Shimabara, Star Queen, Snow March, Cherokee, Island 561, Katsuku 31, Pike, Yukirsha, No King Rasset, Konafubuki, Sayaka, Matilda, Saya Akane, Yukitsubura, Beetle squirrel, Kitamusashi, Toya, Waseshiro, Kitahime, Irida, Hanabitsu, Katsushi No.20, Star Ruby, Pirka, varieties and strains that cross these Examples such as varieties and lines derived from these can be mentioned. Between these varieties and strains, the strength of disease resistance varies greatly.

In the present invention, the “tuber disease-causing microorganism” refers to a microorganism that inhabits the soil in the field, has the effect of infecting the crop body, and causing the tuber to develop disease symptoms.
Specific examples of potato tuber disease include common scab, powdery scab, turtle shell disease, elephant skin disease, dry rot disease, anthracnose disease, silver scab, finger spot disease, black spot disease, purple herb disease, Naratake disease, red spot disease, black bruise, black wilt disease, ring rot disease, plague, mycorrhizal disease, soft rot, half body rot, potato viscous rot, potato wilt disease, potato leaf rot, etc. be able to.
The diagnosis according to the present invention can be suitably used particularly for the purpose of diagnosing the effects of microorganisms that cause soil tuber disease in which no disease symptoms appear on the ground. Specifically, common scab, powdery common scab, tortoises, elephant skin disease, dry rot, anthracnose, silver scab, finger spot disease, black spot disease, purple herb disease, rape, red It can be suitably used for diagnosing the influence of causative microorganisms that cause spot disease and the like.
In particular, it can be suitably used for diagnosing the influence of causative microorganisms causing common scab, silver scab, etc.

The present invention is preferably used for diagnosis related to common scab (decubitus disease, potato scab) from the viewpoint of a producer who prevents economic loss of agricultural products.
Here, “scab” (decubitus disease, potato scab) is a disease in which dark brown and cork-like lesions characteristic on the tuber surface appear and cause deterioration in appearance. Potato tubers with frequent scab disease have a markedly reduced commercial value and cannot be shipped as a commercial product, causing enormous economic damage to producers.
As "causeous fungus" which is a causative microorganism of scab, specifically, S. scabies (= S. scabiei), S. scabies, which is a member of actinomycetes belonging to the genus Streptomyces, acidiscabies (= S. acidiscabiei), S. turgidiscabies (= S. turgidiscabiei) and the like. The symptom of scab is caused by a compound called tactosmin produced by these scabs (Lawrence et al., Phytopathology, 80, 7, 606-608 (1990)).
It is known that scab disease fungi are infected by contact with potato tubers to form lesions, and high density scab fungus is present in the disease spots of harvested potato tubers.

The crop body to be diagnosed according to the present invention is preferably a crop body that has been grown for a certain period in the field. For example, a crop body grown in the environment from the seeding or seedling transplanting stage can naturally be used as a diagnostic object, but after growing for a certain period in a healthy field, the crop body transplanted to the field Is also included in the diagnostic object according to the present invention.
Specifically, crops that have grown for at least 3 days, preferably 10 days, more preferably 1 month or more, and even more preferably 3 months or more after transplanting to the field are also included in the present invention. Such a diagnosis target can be used.
In addition, the crop body to be diagnosed according to the present invention includes not only a crop body in the tuber formation period but also a crop body in a stage before tuber formation.

The measurement or calculation of the organic acid content in the present invention can use any tissue and / or organ as a sample as long as it is an aerial part of a crop body. In particular, it is preferable to use stems and / or leaves.
Here, the stem and leaf are expressed by the term “stem and leaf”. In the present invention, it is also possible to use only stems and leaves alone. In comparison between samples, it is preferable to use an adult leaf whose developmental stage has reached the maturation stage, from the viewpoint of reducing the difference in metabolic compounds derived from the difference in the developmental stage. When only leaves are used, it is preferable to use the entire leaves so as to include the veins.
In the diagnosis according to the present invention, it is particularly desirable to use the entire upper compound leaf of the potato crop body. In addition, it is desirable to use a wing-like compound leaf which is a branch in which a plurality of adult leaves (preferably two or more, more preferably three or more) including the tip are developed. In addition, as a foliage, a flower bud may be included.

  In the diagnostic method of the present invention, in consideration of the reliability of data, it is desirable that two or more samples, preferably three or more samples are provided for analysis for each crop body to be diagnosed.

  The measurement or calculation of the organic acid content in the present invention is preferably performed in a state in which the crop body to be diagnosed is growing in the field or just after being collected. Here, the crop body sample that has undergone the storage process (for example, freeze-drying or frozen storage) is included in the state because the change information of the metabolite is stored.

In the present invention, the extraction operation of the organic acid from the sample can be performed by a conventional method. Preferably, as pretreatment, it is desirable to perform processing such as crushing, crushing, pulverizing, crushing, and grinding on the above-ground part of the crop body.
The extraction solvent is not particularly limited, but it is preferable to use a water-soluble solvent. It is more preferable to use a solvent containing a pH buffer component.

The measurement of the organic acid content in the present invention can be obtained by subjecting the above-ground part of the potato crop body to be diagnosed as a sample to an analytical test.
Here, as an analytical test, any method can be adopted as long as it can measure or calculate the organic acid content with a sensitivity capable of detecting a difference between samples of the potato crop body to be diagnosed. is there.
For example, NMR method (a method of measuring a one-dimensional ¹ H-NMR spectrum and calculating from the peak of chemical shift corresponding to the organic acid from an external standard calibration curve obtained from the peak area value); chromatography Fractionation using paper chromatography, thin layer chromatography, high performance liquid chromatography, gas chromatography, capillary electrophoresis, etc., mass spectrometer, electrochemical detector, evaporation light scattering detection A colorimetric method (a method for quantifying the absorbance in the visible light and / or UV region after the enzyme reaction, etc., a direct quantification of the absorbance in the visible light and / or the UV region, etc.) Any method can be used.
In particular, when the colorimetric determination method is employed, there is an advantage that the operability is easy and the method is inexpensive, so that simple and quick measurement is possible, which is preferable. For example, a commercially available colorimetric kit or a method for directly measuring the absorbance in the UV region can be suitably used for measuring the organic acid content according to the present invention in terms of simple and rapid measurement and detection sensitivity.

[Changes in organic acid content]
The diagnostic method according to the present invention is a method including a step of using an organic acid content in the above-ground part of a potato crop body to be diagnosed or a value based on the organic acid content as an index value.

The “organic acid content” as an index value in the present invention refers to a value representing the organic acid content contained in the above-ground part of the crop body. It is preferable to employ the amount per dry weight, but when calculating the ratio of two or more components described later, it is possible to employ not only the dry weight but also the raw weight value.
In addition, the “value based on the organic acid content” is a value calculated from the organic acid content contained in the above-ground part of the crop body, and a value that can be used as an index value that allows comparison of the organic acid content among multiple samples. Point to.
Here, the value based on the organic acid content includes not only the absolute value of the organic acid content but also a value represented by a relative value that enables comparison of the organic acid content between samples. Also included are values calculated by multiplying coefficients and values calculated by adjusting constants.

In addition, the value based on the organic acid content includes setting a value based on the organic acid content of two or more components as the value.
The values based on the organic acid content of two or more components include the total content of two or more organic acids that show the same fluctuation behavior due to the influence of the disease-causing microorganism, and the two or more components that show opposite fluctuation behavior due to the influence of the disease-causing microorganism. The ratio of organic acid (ratio divided into an increase fluctuation component and a decrease fluctuation component), etc. can be mentioned. Further, values based on these sums and ratios are also included in the values.

As the “organic acid content” as the index value or the basic value thereof according to the present invention, when a crop body is grown in a field contaminated with a tuber disease causing microorganism (contaminated field of a tuber disease causing microorganism), It refers to the organic acid content at which a difference due to a substantial increase or decrease is detected compared to when grown.
The variation due to the increase or decrease in the organic acid content is a quantitative result that reflects the variation in the composition of metabolic compounds due to the influence from the tuber disease-causing microorganism.
In this regard, the degree of fluctuation of the organic acid content is estimated to be a reaction degree reflecting the amount of tuber disease causing microorganisms in the field, specifically the density of tuber disease causing microorganisms. In addition, the degree of change is estimated to be a quantitative result that reflects the change in the composition of the metabolic compound of the crop body due to the stress response.

  The variation in the organic acid content has been confirmed even in varieties and lines with greatly different disease resistance, and is a phenomenon that is universally detected in potato species. Moreover, the fluctuation | variation of the said organic acid content is a phenomenon detected irrespective of the presence or absence of the appearance of the lesion and symptom of a symptom in a tuber.

・ Increased variation of organic acids Here, specific examples of organic acids that are increased and varied in crops grown in fields contaminated with tuber disease-causing microorganisms compared to those grown in healthy fields due to the effects of disease-causing microorganisms include Specifically, “formic acid” and / or “L-malic acid” can be mentioned. Therefore, in the present invention, the formic acid content, the L-malic acid content, the total content of formic acid and L-malic acid, or a value based on them can be adopted as the index value.
Here, “malic acid” refers to L-malic acid biosynthesized in plants. It should be noted that D-malic acid, which is an optical isomer, has been confirmed to exist in mammals and some microorganisms, but its presence in plants has not been reported, so the index value according to the present invention Cannot be adopted.

These values are detected as a substantial increase difference in crops grown in a field contaminated with tuber disease-causing microorganisms compared to crops grown in a healthy field.
In the present invention, it is particularly preferable that the index value is a formic acid content having a large degree of increase difference that can be detected or a value based thereon.

・ Decreasing and changing organic acids In addition, specific organic acids that decrease and change in crops grown in fields contaminated with tuber disease-causing microorganisms compared to crops that grew in healthy fields due to the effects of disease-causing microorganisms. May include “citric acid” and / or “chlorogenic acids”. Therefore, in the present invention, the citric acid content, the chlorogenic acid content, the total content of citric acid and chlorogenic acids, or a value based on them can be adopted as the index value.
In addition, as chlorogenic acids here, in addition to 5-caffeoylquinic acid (5-CQA) which is chlorogenic acid in a narrow sense, isomers 4-caffeoylquinic acid (4-CQA), 3-caffeoyl It refers to a group of compounds containing quinic acid (3-CQA).

These values are detected as a substantial decrease difference in crops grown in fields contaminated with tuber disease-causing microorganisms compared to crops grown in healthy fields.
In the present invention, in particular, it is preferable that the citric acid content having a large degree of decrease difference that can be detected or a value based thereon be used as the index value.
In particular, when a crop body at a growth stage before tuber formation is to be diagnosed, it is preferable to use a citric acid content or a value based thereon.

As used herein, the term “healthy field” refers to a field where minor symptom occurrence in potato tubers does not exceed 10% when cultivars with low resistance are cultivated (Ministry of Agriculture, Forestry and Fisheries, Seed potato Quarantine regulations Article 8 item 2).
In the present invention, a field where no substantial symptom occurrence is observed is preferable in that accurate determination is performed. Preferably, a field in which the disease rate indicating disease incidence is less than 10%, more preferably the value is 5% or less, more preferably 3% or less is suitable.

In addition, in this specification, “a field contaminated with tuber disease-causing microorganisms (or a contaminated field)” refers to a field in which symptom occurrence in potato tubers is 10% or more when cultivars with low resistance are cultivated. (Ministry of Agriculture, Forestry and Fisheries Seed Potato Quarantine Regulation, Article 8, Item 2). According to Hokkaido standards, if it exceeds 30%, soot will be generated.
In the present invention, a field in which symptom occurrence clearly occurs is preferable in that accurate determination is performed. Preferably, a field in which the disease potato rate indicating the disease occurrence rate is 10% or more, preferably 30% or more, more preferably 50% or more, and further preferably 60% or more is suitable.

[Ratio of organic acid content of two or more components showing opposite fluctuations]
As the value based on the organic acid content, which is an index value according to the present invention, it is preferable that the index value is a ratio of organic acid contents of two or more components exhibiting opposite fluctuations due to the influence of disease-causing microorganisms, or a value based on the ratio. It is.

In the present invention, the detection accuracy can be obtained by using, as an index value, the “ratio of two or more organic acid contents exhibiting opposite fluctuations due to the influence of disease-causing microorganisms” (ratio of increasing fluctuation component contents and decreasing fluctuation component contents). Can be remarkably improved, which is extremely suitable.
Specifically, as the ratio, (A) the organic acid content increased in the above-ground part of the crop body grown in the field contaminated with tuber disease-causing microorganisms or (A) the above-ground part of the crop body grown in the healthy field The value based on the organic acid content, and (B) the organic acid content that decreases in the above-ground part of the crop body grown in the field contaminated with the tuber disease causing microorganism, A ratio based on the organic acid content or a value based on the ratio can be given.
Here, the “value based on the ratio” in the (A) and (B) can include a value calculated based on the ratio. For example, a value calculated by multiplying the ratio by a coefficient or a value calculated by adding or subtracting a constant is included here.
In addition, when dealing with organic acids having three or more components, the value according to (A) and the value according to (B) are divided into the increasing component described in (A) and the decreasing component described in (B). It can be calculated as a ratio or a value based on the ratio.

As the notation method of the ratio or the value based on the ratio, as long as the notation using the value according to (A) and the value according to (B) is used, it is expressed as a divided value, a fraction notation, a percentage (%) notation, etc. The method is not particularly limited.
Further, the ratio or the value based on the ratio is not particularly limited as to which of the value according to (A) and the value according to (B) is used as the numerator or the denominator. For example, when expressed as a divisor of “value relating to (A) / value relating to (B)”, the degree of increase fluctuation is detected as an amplified value. On the other hand, when expressed as a divisor of “values related to (B) / values related to (A)”, the degree of decrease fluctuation is detected as an amplified value.

Here, as the organic acid having two or more components exhibiting the opposite fluctuations, it is preferable to employ the following combinations.
Specific examples of the organic acid described in (A) include formic acid and / or L-malic acid. Preferably, it is suitable to use a formic acid content having a large degree of increase fluctuation or a value based thereon.
In addition, examples of the organic acid described in (B) include citric acid and / or chlorogenic acids. Preferably, it is suitable to use a citric acid content having a large degree of variation of fluctuation or a value based on this.

[Detection of differences from crops grown in healthy fields]
In the diagnosis according to the present invention, for the index value measured or calculated as described above, (a) the index value of the crop body ground part to be diagnosed, and (b) the index value of the crop body ground part in a healthy field, Are compared to determine the presence or absence of a substantial difference between index values or the degree of difference.

In the diagnostic method according to the present invention, it is desirable that only the change in the organic acid composition derived from the influence from the tuber disease-causing microorganism can be accurately detected. In this regard, in the present invention, in the comparison between (a) a crop body to be diagnosed and (b) a crop field in a healthy field, changes in metabolite composition derived from factors other than the effects from the tuber disease-causing microorganisms are observed. It is desirable to keep it as uniform as possible to make the background of metabolite composition uniform or substantially uniform between samples to be compared.
Therefore, in the present invention, the crop body to be diagnosed and the growing crop body in a healthy field have the same or substantially the same genetic background, such as the same variety / line, a related variety / line derived from the line / line. It is desirable to use the same one. In particular, it is desirable to use the same variety / line.
In addition, if the origins of varieties and strains differ significantly between comparison samples, the difference in genetic background becomes large, and it tends to be difficult to make an accurate comparison.

Further, in the present invention, the above-ground part of the diagnostic target crop collected for measurement or calculation of the value based on the organic acid content, and the value based on the organic acid content of the site recognized as substantially the same growth stage, It is optimal to measure or calculate from crops grown in a healthy field.
However, here, “substantially the same growth stage” does not necessarily mean a plant that has been cultivated on the same number of days in consideration of the accuracy of detection of differences in actual measurement sites. If so, the leaf development stage is the same growth stage. For example, in the case of adult leaves that have completed the formation of feathery compound leaves, it is possible to compare them as samples at substantially the same growth stage even if they differ in a certain number of days, sizes, etc. In other words, comparisons can be made without problems between adult leaves.
Further, as an embodiment of the present invention, even if the crop body to be diagnosed and the crop body grown in a healthy field are in a different growth stage to some extent, diagnosis of the growth state is possible although there is a decrease in accuracy. In this regard, the present invention does not exclude detection of differences in comparison of values between different growth stages.

In the present invention, the organic acid content or the value based on the organic acid content in the above-ground part of the crop body in a healthy field was obtained from a crop body cultivated in a neighboring field at the same time as the diagnosis target crop body in terms of the strictness of the experiment It is best to be information.
However, in consideration of the accuracy of detection of the difference at the actual measurement site, it is sufficiently possible to use the information on the organic acid content obtained from the already grown crops.
In the diagnosis according to the present invention, a sample is collected only from the crop body to be diagnosed and used for the test of measuring the organic acid content, and compared with the corresponding organic acid content data stocked in healthy field cultivation. Thus, it is possible to detect the difference.
That is, in the present invention, by storing stock data information of organic acid content of growing crops in healthy fields, materials for comparison with the diagnosis target crops, leaflets, databases, etc. are created, so that in healthy fields An embodiment in which comparison with an index value of a diagnosis target crop is possible without simultaneous cultivation of growing crops.

[Determination of growth state]
The diagnosis according to the present invention is a method for determining the growth state based on whether or not a substantial difference is detected by the comparison.

  Here, “determination of the presence or absence of substantial difference or the degree of difference” is reproducible, taking into account the reliability of data, by subjecting two or more samples, preferably three or more samples, to repeated analysis for each sample. Only in this case, it is desirable to determine whether there is a difference between index values.

As the index value used for the diagnosis, it is preferable to use formic acid content, citric acid content, or a value based on them for detection accuracy. If these values contradict each other component and these values, it is preferable to employ formic acid, citric acid, or values based on these.
In addition, when the determination based on the content of one component and the determination based on the ratio of the content of two or more components are contradictory, it is preferable to employ the determination using the ratio of the content of two or more components.

In the diagnosis according to the present invention, it is possible to qualitatively diagnose the growth state of a crop body by determining whether or not “the presence or absence of a substantial difference” is detected.
i) As the determination of the growth state according to the present invention, a substantial difference between (a) an index value of the above-ground part of the crop body to be diagnosed and (b) an index value of the above-ground part of the crop body in a healthy field When the difference is not detected, the diagnosis target crop can be determined to be “good”.
Here, it is desirable that the determination that there is no substantial difference be made when there is no substantial difference between the index values only when there is no statistically significant difference. Preferably, statistical analysis such as calculation of mean value, standard error, standard deviation, t-test, analysis of variance, multiple comparison, discriminant analysis is performed, and (a) the index value of the above-ground part of the crop body to be diagnosed and (b ) It is preferable to determine that there is no substantial difference between the index values based on the presence or absence of a significant difference between the index values of the crop body above the ground in a healthy field.

ii) On the other hand, if a substantial difference is detected between (a) the index value of the above-ground part of the crop body to be diagnosed and (b) the index value of the above-ground part of the crop body in a healthy field, The diagnosis target crop can be determined to be “not good”.
Here, it is desirable to determine that there is a substantial difference only when there is a statistically significant difference that it is determined that there is a substantial difference between index values. Preferably, statistical analysis such as calculation of mean value, standard error, standard deviation, t-test, analysis of variance, multiple comparison, discriminant analysis is performed, and (a) the index value of the above-ground part of the crop body to be diagnosed and (b ) It is preferable to determine that there is a substantial difference between the index values based on the presence or absence of a significant difference from the index value of the crop body above the ground in a healthy field.

In the diagnosis according to the present invention, it is also possible to calculate a “value indicating the degree of difference” in which the difference in index value between samples is digitized. In the present invention, it is possible to quantitatively diagnose the growth state of the crop body by calculating the value.
Specifically, as a value representing the degree of the difference, a ratio between (a) the index value of the crop body part to be diagnosed and (b) the index value of the crop body part in a healthy field is calculated. Can be used. For example, the closer the value of the ratio is to “1”, the more the diagnosis target crop body can be determined to be “good”. In the present invention, it is also possible to use a value based on the ratio.

As described above, the diagnosis result of the potato crop body according to the present invention can be effectively used by producers, distributors, and the like as information that gives added value related to the growth state and quality of the crop body itself or the harvested product. Be expected.
In particular, it is expected to become a suitable technique for common scab disease with a significant reduction in commercial value and great economic loss.
Moreover, it is expected that the diagnostic method according to the present invention can be used as a screening means for controlling potato tuber disease. Specifically, if some kind of treatment is applied to the crop body grown in the contaminated field and the value is close to the index value of the above-ground part of the crop body in the healthy field, it is determined that the treatment is effective as a tuber disease control technique. Is possible.

2. Quality Evaluation of Potato Tubers In the present invention, it is possible to evaluate the quality related to the effects from the tuber disease-causing microorganisms on the potato tubers that are the harvest obtained from the crop body that is the object of diagnosis.

Since the tuber quality evaluation method according to the present invention uses the main steps of the above-mentioned crop body diagnosis method, it is a method that can be performed only by using only the above-ground part of the growing crop body as a test sample. . Therefore, it is a method that enables tuber quality evaluation without performing heavy labor such as digging up tubers and complicated tests such as microbial inspection after harvesting.
In addition, when a colorimetric method is employed for measuring the organic acid content, it is possible to make a simpler and quicker evaluation.

The tuber quality evaluation method according to the present invention is a method of performing a step of using as an index value the organic acid content in the above-ground part of the crop body of the tuber to be evaluated or a value based on the organic acid content.
Thereafter, in the present invention, the index value is compared with (a) the index value from the above-ground part of the crop body to be diagnosed and (b) the index value from the above-ground part of the crop body in a healthy field. It is the method of performing the process of determining the presence or absence of the difference between, or the degree of a difference.
These steps in the tuber quality assessment method are described in paragraph 1 above. It is possible to carry out in the same manner as described above except that instead of “the above-ground part of the crop body to be diagnosed” in FIG.

Here, “the above-ground part of the tuber crop body to be evaluated” includes not only the above-ground part of the crop body in the tuber formation period but also the crop body in the growth stage before the tuber formation.
Therefore, in the present invention, the quality evaluation of a tuber that is scheduled to be harvested in the future can be performed in advance by subjecting the above-ground part of the crop body to which the tuber is not yet attached to the inspection. In particular, when the above-ground part of the crop body at the growth stage before tuber formation is used as a sample, it is preferable to use the citric acid content or a value based on it as the index value.

In the tuber quality evaluation method according to the present invention, the method includes the step of determining the quality of the tuber that is the object of evaluation based on the presence or absence of a substantial difference between the determined index values or the degree of difference. is there. The said process in the quality evaluation method of the said tuber is the said paragraph 1. It can be performed in the same manner as the “determination of the growth state”.
In addition, regarding tuber quality evaluation, determinations such as “good” or “not good” are given in paragraph 1 above. Can be carried out in the same manner as described in “Determination of growth state”. For example, when no substantial difference is detected between the index values, the quality of the tuber that is the evaluation target can be determined to be “good”. It is also possible to perform a quantitative evaluation by calculating a value representing the degree of difference between the index values.

The variation of the index value according to the present invention or the organic acid content serving as the basis value thereof is the degree of reaction reflecting the amount of tuber disease-causing microorganisms in the field, specifically the “density of tuber disease-causing microorganisms” present in the rhizosphere. It is estimated that. Moreover, the fluctuation | variation of the said organic acid content is a phenomenon detected irrespective of the presence or absence of the lesion and symptom expression in a tuber.
Therefore, in the tuber quality evaluation method according to the present invention, it is possible to evaluate the effect of disease-causing microorganisms on the quality of tubers of resistant varieties that do not show lesions or symptoms.

  In addition, the variation of the organic acid content has been confirmed in varieties and lines with greatly different disease resistance, and is a phenomenon that is universally detected in potato species. And the fluctuation | variation of the said organic acid content is a phenomenon detected irrespective of the presence or absence of the occurrence of the lesion in a tuber, and the symptom expression as mentioned above.

As described above, the evaluation result of the potato tuber according to the present invention is expected to be effectively used by producers, distributors, and the like as information that gives added value and the like regarding the quality of the harvest. In particular, it is expected to become a suitable technique for common scab disease with a significant reduction in commercial value and great economic loss.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, the scope of the present invention is not limited by these.

[Example 1] "Cultivation test in a healthy field and a field infected with scab fungus"
Cultivation tests were conducted on potato varieties and strains with known resistance to scab disease in each of a healthy field and a field contaminated with scab.
In addition, the healthy field of the cultivation test which concerns on a present Example is a field where the disease potato ratio of the common potato tuber did not exceed 10%, when a variety with weak resistance last time was cultivated. Also, the common scab pathogen-contaminated field is a field in which symptom occurrence in potato tubers is 30% or more when a variety with low resistance was cultivated last time.

Eight potato varieties and lines with known resistance to scab disease were cultivated in the healthy field and the scab fungus-contaminated field in Memuro-cho, Hokkaido from the beginning of May 2014.
It is located in the upper part of the main stem from three varieties and strains in the middle of June (June 17), the stage before tuber formation, and in early July (July 9), the early stage of tuber formation. Compound leaves (see FIG. 2) were collected. The tubers were harvested in early October of the same year. For tubers harvested in the contaminated field, the disease rate and morbidity were calculated.
Here, the “disease rate” was calculated by calculating the ratio of tubers that developed disease symptoms to the number of harvested tubers. Further, the “morbidity” is shown by calculating the ratio of the coverage of the site where the symptom is expressed to the total surface area of the harvested tubers. The results are shown in Table 1.
Moreover, the photograph image which image | photographed the external shape of the tuber harvested after cultivation in a contaminated field about baron moth which is a kind with a weak resistance to common scab, and Yukirusha which is a kind with strong resistance is shown in FIG. .
In addition, about the tuber harvested in the healthy field, since the onset of common scab was slight, calculation of a disease potato rate and a disease severity was abbreviate | omitted.

[Example 2] "Identification of variable metabolic compounds"
Search for differences in detectable metabolite content between potato crops cultivated in healthy and scab-contaminated fields, and identify metabolite compounds that serve as marker markers related to the growth status of the crop plants. It was.

(1) ¹ H-NMR spectrum analysis For the lyophilized product of Baron's double leaf (3 strains) collected in Example 1 in early July 2014, 10.0 mg after pulverization was collected and 700 μL of buffer solution was obtained. And extracted with shaking at 90 ° C. for 5 minutes. Here, as buffer solutions, heavy water 90.0 mL, 1M K ₂ HPO ₄ aqueous solution 6.15 mL, 1M KH ₂ PO ₄ aqueous solution 3.85 mL, sodium 3- (trimethylsilyl) -1-propanesulfonate 21.8 mg A buffer solution consisting of
The supernatant obtained by centrifugation is placed in an NMR sample tube, and the ¹ H-NMR spectrum is analyzed and measured at a temperature of 298 K using a Bruker AVANCE 500 (cryoprobe, Dual, 13C {1H}, z-gradient). did. A schematic diagram showing the analysis flow is shown in FIG.

(2) Identification of fluctuating metabolites PLS discriminant analysis between potato crops cultivated in healthy and scab-contaminated fields with respect to the area of the ¹ H-NMR spectral region of the obtained baron candy (3 strains) And the VIP score and loading plot were analyzed.

As a result, it was shown that the difference on the ¹ H-NMR spectrum can be discriminated between the potato crops cultivated in the healthy field and the scab-contaminated field.
Specifically, as a result of detailed analysis of a spectral region having a large discriminating contribution, signals corresponding to L-malic acid (4.30 ppm) and formic acid (8.46 ppm) among NMR signals indicating metabolic compounds are healthy fields. It was shown that there was a tendency to increase in scab pathogen-contaminated fields compared to
On the other hand, it was shown that the signals corresponding to citric acid (2.54 ppm) and chlorogenic acids (7.22 ppm) tend to decrease in the common scab pathogen-contaminated field compared to the healthy field.
From these results, it was shown that the effects of soil pathogens on the crop can be detected by using the organic acid metabolizing compound in the compound leaf as an index.

[Example 3] “Applicability in varieties / lines with different resistance levels”
We examined whether the method using the organic acid content as an index can be applied between varieties and lines with different resistances.

The ¹ H-NMR spectrum was measured in the same manner as in Example 2 for the lyophilized products of the two varieties (3 strains) collected from Example 8 in early July 2014. did.
About the obtained spectrum, the area value of the NMR signal corresponding to formic acid (8.46 ppm) and citric acid (2.54 ppm) was determined, and sodium 3- (trimethylsilyl) -1-propanesulfonate (added as an internal standard compound) The relative value with respect to the signal area at a final concentration of 1 mM was calculated. The analysis was repeated 3 strains. The obtained value indicating the organic acid content is shown in FIGS. 3 and 4 as a value indicating the content of each organic acid in the compound leaf.

As a result, it was shown that for all 8 varieties / lines used in the test, the formic acid content in the compound leaves tended to increase in the field with scab pathogen contamination compared to the healthy field (FIG. 3).
On the other hand, it was shown that the citric acid content tended to decrease in the common scab pathogen-contaminated field compared to the healthy field in all 8 varieties / lines subjected to the test (FIG. 4).

These fluctuations in organic acid content were a phenomenon that was exhibited in all varieties / lines that were used in the test regardless of the specific resistance of scab disease (Table 1). . From these results, it was suggested that the method of detecting the effects of soil pathogens on crops using the organic acid content of compound leaves as an index is a method that can be universally applied to all potato (Solanum tuberosum) species.
In addition, since the variation of the organic acid content is exhibited regardless of the disease potato rate and morbidity value (Table 1), it can be used as an index even when no symptom appears on the tuber outline. It was shown that there is.

[Example 4] "Detection by simple measurement method"
It was examined whether the technique using the variation of the organic acid content as an index can be applied even when it is detected by a simple measurement method based on the principle of colorimetric determination.

  Baron 薯 compound leaves (3 strains) collected in early July 2014 in Example 1 were freeze-dried and finely pulverized, 10.0 mg was collected, and 1 mL of water was added and shaken at 90 ° C. for 5 minutes. The supernatant obtained by extraction and centrifugation was used as a sample solution.

  For the determination of malic acid, a malic acid quantification kit manufactured by Roche Diagnostics (F-kit L-malic acid) was used, and the recommended protocol attached to the kit (Japanese Unexamined Patent Publication No. 2014-003909) According to the procedure described in Example 3, the amount of the absorbance of the reaction product (NADH) using a predetermined enzyme group was quantified. In addition, the measuring object here is L-malic acid. The results are shown in FIG.

For quantification of chlorogenic acids, the present inventors established a new simple quantification method using UV and performed quantification. Here, the reason why the present inventors established an experimental system for the simple UV determination method (FIG. 5A) is that the sodium nitrite method (FIG. )) Was known because sodium nitrite, which is an essential reagent in the method, is designated as a deleterious substance by the Poisonous and Deleterious Substances Control Law and is therefore not easy to handle.
The measurement target is a group of chlorogenic acid isomers (total amount of 5-CQA, 4-CQA, and 3-CQA). The results are shown in FIG.

As a result, even when the organic acid content was quantified by the simple measurement method, it was shown that the L-malic acid content in the compound leaves tended to increase in the field contaminated with scab fungus compared to the healthy field. (FIG. 6 (A)). On the other hand, it was shown that the chlorogenic acid content tends to decrease in the scab pathogen-contaminated field compared to the healthy field (FIG. 6B).
From these results, it is possible to detect differences between potato crops cultivated in healthy fields and scabs contaminated fields by simple colorimetric quantification methods without performing advanced analysis such as NMR analysis. It was shown that.
The time required for the colorimetric determination of L-malic acid and chlorogenic acids is as short as about 10 minutes for L-malic acid and about 2 minutes for chlorogenic acids per sample, enabling rapid measurement. It was.

[Example 5] "Analysis using binary component ratio"
In order to detect the difference with higher accuracy, the difference was detected using the content ratio of the two components of the organic acid showing the increase fluctuation and the organic acid showing the decrease fluctuation as an index.

(1) Citric acid content / formic acid content ratio For the values indicating the citric acid content and the formic acid content obtained in Example 3, the ratio of citric acid content / formic acid content was calculated. The results are shown in FIG.
As a result, between the potato crops cultivated in the healthy field and the scab pathogen contaminated field, the formic acid content (the organic acid content that shows a decrease in the contaminated field) and the organic acid that shows an increase in the contaminated field It was shown that the difference detection accuracy is greatly improved by calculating the ratio to the content) as compared with the case where each single component is used as an index.

  From this result, by calculating the ratio of “Organic acid content showing increased fluctuation in the contaminated field” to “Organic acid content showing increased fluctuation in the contaminated field”, the value obtained by amplifying the decreased fluctuation in the contaminated field. It was shown that it can be detected with high accuracy.

(2) Malic acid content / chlorogenic acid content ratio With respect to the values indicating the malic acid content and the chlorogenic acid content obtained in Example 4, the ratio of malic acid content / chlorogenic acid content was calculated. The results are shown in FIG.
As a result, between potato crops cultivated in healthy and scab-contaminated fields, the chlorogenic acid content (organic acid content that shows increased fluctuation in the contaminated field) and chlorogenic acid content (organic that shows decreased fluctuation in the contaminated field) By calculating the ratio to the acid content, it was shown that the accuracy of difference detection was greatly improved compared to the case where each single component was used as an index.

From this result, by calculating the ratio of “Organic acid content showing a change in decrease in the contaminated field” to “Organic acid content showing an increase in the contaminated field”, an increase in the increase in the contaminated field was amplified. It was shown that it can be detected with high accuracy.

[Example 6] “Crop body diagnosis and tuber quality evaluation before tuber formation”
Examination of whether or not it is possible to evaluate the growth status of the crop body and the quality of the potato tubers planned to be harvested when the crop body double leaf before the tuber formation is used as a sample by the method using the organic acid content as an index did.

The ¹ H-NMR spectrum was measured in the same manner as described in Example 2 for the lyophilized product of each of the 8 cultivars / lines collected in Example 1 in the middle of June 2014.
For the obtained spectrum, the area value of the NMR signal corresponding to citric acid (2.54 ppm) was determined, and the signal area of sodium 3- (trimethylsilyl) -1-propanesulfonate (final concentration 1 mM) added as an internal standard compound The relative value was calculated. The value indicating the citric acid content obtained is shown in FIG. 9 as the value indicating the citric acid content in the compound leaf.

As a result, even when the compound leaves collected before tuber formation were used for the test, the citric acid content in the compound leaves in all 8 varieties / lines tended to decrease in the field contaminated with scab pathogens compared to the healthy field. It was shown that there is.
From this result, even when the crop body before tuber formation is used as a sample, it is possible to detect the effects on the crop body by tuber disease-causing microorganisms by detecting changes in organic acid metabolizing compounds in compound leaves It has been suggested. In addition, it was confirmed that it was possible to detect differences due to changes in organic acids, regardless of the resistance to disease caused by differences in cultivars and strains.
The said result is a result which shows that the tuber quality evaluation of a future harvest plan is attained by measuring the organic acid content of the above-ground part of the crop body in which the tuber is not yet formed.

Evaluation results of potato crops and / or tuber crops according to the present invention are effectively used by producers, distributors, etc. as information that gives added value regarding the growth status and quality of the crops themselves and the crops. It is expected that In particular, it is expected to become a suitable technique for common scab disease with a significant reduction in commercial value and a large economic loss.

1: Tuber 2: Scab disease affected part 3: Feathered compound leaf 4: Leaflet

Claims (15)

A method for diagnosing the growth state of a potato (Solanum tuberosum) crop body in relation to the effects from tuber disease-causing microorganisms,
(1) a step of setting an organic acid content in the above-ground part of a potato crop body or a value based on the organic acid content as an index value; and
(2) For the index value, (2a) comparing the index value from the above-ground part of the crop body to be diagnosed with (2b) the index value from the above-ground part of the crop body in a healthy field, Determining whether or not there is a general difference or the degree of difference,
A method for diagnosing the growth state of a potato crop body, comprising: After the step described in (2) above,
(3) A step of determining a growth state of a crop body to be diagnosed based on the presence or absence of the determined substantial difference or the degree of the difference,
The method of diagnosing the growth state of the potato crop body of Claim 1 containing this.   When no substantial difference is detected between the index values in the step described in (2), it is determined that the growth state of the crop body that is a diagnosis target in the step described in (3) is good. The method of diagnosing the growth state of the potato crop body according to claim 2. In the step described in (2) above,
The above-ground part of the crop body according to (2a) and the above-ground part of the crop body according to (2b) are stems and / or leaves of a crop body of the same variety / lineage.
The method to diagnose the growth state of the potato crop body in any one of Claims 1-3. The organic acid according to (1) is formic acid and / or L-malic acid,
The difference described in (2) is a difference in which the index value described in (2a) increases with respect to the index value described in (2b).
The method to diagnose the growth state of the potato crop body in any one of Claims 1-4.   The method for diagnosing the growth state of a potato crop body according to claim 5, wherein the organic acid according to (1) is formic acid. The organic acid described in (1) is citric acid and / or chlorogenic acids,
The difference described in (2) is a difference in which the index value described in (2a) decreases with respect to the index value described in (2b).
The method to diagnose the growth state of the potato crop body in any one of Claims 1-4.   The method for diagnosing the growth state of a potato crop body according to claim 7, wherein the organic acid according to (1) is citric acid. The index value is
(A) With respect to the above-ground part of the crop body grown in a healthy field, the organic acid content increased in the above-ground part of the crop body grown in the field contaminated with tuber disease-causing microorganisms, or a value based on the organic acid content;
(B) The organic acid content that decreases in the above-ground part of the crop body grown in the field contaminated with the tuber disease-causing microorganism, or a value based on the organic acid content, with respect to the above-ground part of the crop body grown in the healthy field,
Or a value based on the ratio,
The method to diagnose the growth state of the potato crop body in any one of Claims 1-4.   The potato crop according to claim 9, wherein the organic acid according to (A) is formic acid and / or L-malic acid, and the organic acid according to (B) is citric acid and / or chlorogenic acids. A method of diagnosing the growth state of the body.   The method for diagnosing the growth state of a potato crop body according to claim 10, wherein the organic acid according to (A) is formic acid and the organic acid according to (B) is citric acid.   The method for diagnosing the growth state of a potato crop body according to any one of claims 1 to 11, wherein the tuber disease causing microorganism is a potato scab. A method for assessing the quality of a potato (Solanum tuberosum) tuber with respect to the effects from a tuber disease-causing microorganism,
Instead of the above-ground part of the crop body that is the diagnosis target according to (2a) according to any one of claims 1 to 12, the above-described (1) and (2) The method of evaluating the quality of a potato tuber characterized by performing the process of description to). After the process of claim 13,
(4) A step of determining the quality of the tuber that is the object of evaluation based on the determined presence or absence of the substantial difference or the degree of the difference,
A method for assessing the quality of potato tubers according to claim 13.   If no substantial difference is detected between the index values in the step (2) according to claim 14, the quality of the tubers to be evaluated in the step (4) is good. The method for evaluating the quality of potato tubers according to claim 14, wherein