Hydroponic cultivation method and cultivation device

Abstract

To provide a hydroponic cultivation device for leafy vegetables that makes it possible to cultivate leafy vegetables while controlling the content of metabolites so as to increase or decrease the content.SOLUTION: A cultivation device 1 is a device for cultivating leafy vegetables by hydroponic cultivation using a culture solution. A water tank 10 is a cultivation container that holds the culture solution and grows leafy vegetables. An irradiation unit 20 irradiates the rhizosphere of the leafy vegetables in the cultivation container with light of a specific wavelength in the ultraviolet to infrared wavelength range. An opaque member 30 prevents the light from the irradiation unit 20, which is directed at the rhizosphere of the leafy vegetables, from reaching the stem and leaf portion. The specific wavelength in the irradiation unit 20 is set to increase or decrease the content of minerals and / or vitamins as nutrients, compared with leafy vegetables whose stem and leaf portion is not irradiated with the light of the specific wavelength.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for hydroponic cultivation, particularly for leafy vegetables. [Background technology]

[0002] Vegetables produce or contain metabolites such as minerals (ions), vitamins, and polyphenols that affect their taste and nutritional value. Therefore, consuming vegetables is extremely important for maintaining human health. However, despite the recent problem of climate change, the world population is increasing, threatening the stable supply of vegetables using conventional cultivation methods. In response to this, great expectations are being placed on plant factories that use hydroponic cultivation to supply crops and vegetables year-round.

[0003] Here, since it is possible to artificially control growth factors such as temperature, humidity, light, and fertilizer in plant factories, there is a demand for the establishment of cultivation methods that can further improve the quality of vegetables. Among these, light is one of the most important and easily controllable factors, and light-emitting diodes (LEDs) are currently the most commonly used artificial light source in plant factories.

[0004] As an example of hydroponic cultivation technology used in conventional plant factories and the like, Patent Document 1 describes a plant cultivation method and cultivation device that, in hydroponic cultivation using a culture solution, irradiates the root zone of a plant in the culture solution with light in the visible wavelength range, thereby promoting the growth of the root zone and above-ground parts of the plant more than in hydroponic cultivation that does not irradiate the root zone with light (hereinafter referred to as "prior art"). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-196202 Summary of the Invention [Problem to be solved by the invention]

[0006] However, while conventional technology promoted plant growth by irradiating the root zone of vegetables with light, it was unclear how the content of metabolic products such as minerals and vitamins changed. Depending on the type of mineral or vitamin, it may be a nutritional component or may be desired to be excluded, so there has been a technical demand to cultivate vegetables (leafy vegetables) while controlling the content of metabolic products such as minerals and vitamins to a desired level.

[0007] The present invention has been made in view of the above circumstances, and aims to solve the above-mentioned problems. [Means for solving the problem]

[0008] The hydroponic cultivation method of the present invention is a method for cultivating leafy vegetables by hydroponics using a culture solution, characterized in that light of a specific wavelength within the wavelength range from ultraviolet light to infrared light is irradiated onto the rhizosphere of the leafy vegetables while preventing the light from being irradiated onto the stems and leaves of the leafy vegetables, and the leafy vegetables are cultivated so as to increase or decrease the content of minerals and / or vitamins that are nutritional components of the leafy vegetables compared to leafy vegetables whose stems and leaves are not irradiated with light of the specific wavelength. The hydroponic cultivation method of the present invention is characterized in that the dominant wavelength of the light of a specific wavelength irradiated onto the rhizosphere is 397 nm. The hydroponic cultivation method of the present invention is characterized in that the dominant wavelength of the light of a specific wavelength irradiated onto the rhizosphere is 464 nm. The hydroponic cultivation method of the present invention is characterized in that the dominant wavelength of the light of a specific wavelength irradiated onto the rhizosphere is 506 nm. The hydroponic cultivation method of the present invention is characterized in that the dominant wavelength of the light of a specific wavelength irradiated onto the rhizosphere is 633 nm. The hydroponic cultivation method of the present invention is characterized in that the dominant wavelength of the light of a specific wavelength irradiated onto the rhizosphere is 730 nm. The hydroponic cultivation method of the present invention is characterized in that the dominant wavelength of the light of a specific wavelength irradiated onto the rhizosphere is 850 nm. The hydroponic cultivation method of the present invention is characterized in that the dominant wavelength of the light of a specific wavelength irradiated onto the rhizosphere is 940 nm. The cultivation device of the present invention is a cultivation device for leafy vegetables by hydroponic cultivation using a culture solution, and comprises a cultivation container that holds the culture solution and cultivates the leafy vegetables, an irradiation unit that irradiates the rhizosphere of the leafy vegetables in the cultivation container with light of a specific wavelength in the wavelength range from ultraviolet light to infrared light, and an opaque member that prevents the light irradiated onto the rhizosphere of the leafy vegetables by the irradiation unit from being irradiated onto the stems and leaves, and is characterized in that the specific wavelength is set so as to increase or decrease the content of minerals and / or vitamins that are nutritional components of the leafy vegetables compared to leafy vegetables whose stems and leaves are not irradiated with light of the specific wavelength. [Effects of the Invention]

[0009] According to the present invention, a hydroponic cultivation method for leafy vegetables can be provided that can control the increase or decrease of the content of metabolic products such as minerals and / or vitamins that are nutritional components of leafy vegetables by irradiating the rhizosphere of leafy vegetables with light of a specific wavelength in the wavelength range from ultraviolet light to infrared light while preventing irradiation of the stems and leaves, thereby cultivating leafy vegetables in a desired state. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of a cultivation device according to an embodiment of the present invention. [Figure 2] 1 is a graph showing the ratio of dry matter weight in the stems and roots at harvest time when cultivated by irradiating the rhizosphere with each wavelength according to an example of the present invention to a control group. [Figure 3] 1 is a graph showing the ratio of the content of each ion in the stem and leaf at harvest time when cultivation was carried out by irradiating the rhizosphere with each wavelength according to an example of the present invention to a control group. [Figure 4]1 is a graph showing the ratio of the fat-soluble vitamin content in the stems and leaves at harvest time when cultivated by irradiating the rhizosphere with light of each wavelength in an example of the present invention to a control group. [Figure 5] 1 is a graph showing the ratio of the content of each water-soluble vitamin in the stem and leaf at harvest when the rhizosphere of an example of the present invention is irradiated with each wavelength and cultivated to a control group. [Figure 6] 1 is a graph showing the ratio of the content of each ion in the roots at harvest time when cultivated by irradiating the rhizosphere with each wavelength according to an example of the present invention to a control group. [Figure 7] 1 is a graph showing the ratio of the fat-soluble vitamin content in roots at harvest time when cultivated by irradiating the rhizosphere with light of each wavelength according to an example of the present invention to a control group. [Figure 8] 1 is a graph showing the ratio of the content of each water-soluble vitamin in the roots at harvest time when cultivated by irradiating the rhizosphere with each wavelength according to an example of the present invention to the control group. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Embodiment> [Configuration of cultivation device 1] The configuration of a cultivation device 1 according to this embodiment will be described with reference to FIG. The cultivation apparatus 1 is an apparatus for hydroponic cultivation using a culture solution for growing leafy vegetables P. The cultivation apparatus 1 can be suitably used for hydroponic cultivation in greenhouses, plant factories, and other facilities. The cultivation device 1 is mainly composed of a water tank 10, an irradiation unit 20, and an opaque member 30.

[0012] The aquarium 10 is a cultivation container that holds a culture solution for hydroponic cultivation and cultivates leafy vegetables P. In this embodiment, at least the side surfaces of the aquarium 10 are made of a material that transmits light irradiated from the irradiation unit 20, such as acrylic or glass. In this embodiment, the water tank 10 may be filled with a culture solution and may be substantially hollow so that the rhizosphere of the leafy vegetables P can grow within the culture solution. In addition, a holding member for holding the leafy vegetables P may be provided on the upper part of the water tank 10.

[0013] The irradiating unit 20 irradiates the root zone of the leafy vegetables P in the growing container with light of a specific wavelength in the wavelength range from ultraviolet light to infrared light. The irradiating unit 20 may be a light source that has a specific wavelength as its dominant wavelength and is capable of irradiating light of a narrower range of wavelengths than incandescent lamps, for example, such as an LED, organic electroluminescence (EL), or laser light source. Alternatively, the irradiating unit 20 may be capable of irradiating light of a wide range of wavelengths, such as incandescent lamps, by limiting the wavelength using a filter or the like. In this embodiment, the light emitting portion of the irradiation unit 20 may be disposed so as to face the side surface of the aquarium 10.

[0014] Furthermore, in this embodiment, the irradiation unit 20 may be configured to irradiate light with wavelengths such as a dominant wavelength of 397 nm (ultraviolet light), a dominant wavelength of 464 nm (blue light), a dominant wavelength of 506 nm (green light), a dominant wavelength of 633 nm (red light), a dominant wavelength of 730 nm (near-infrared light), a dominant wavelength of 850 nm (near-infrared light), or a dominant wavelength of 940 nm (near-infrared light), while controlling the irradiation so that the type of leafy vegetables P being cultivated and the content of metabolites are in a desired state. For this reason, the irradiation unit 20 may be configured as a light source with a variable wavelength or may be replaceable. Specifically, in this embodiment, the specific wavelength of the irradiation unit 20 is set so as to increase or decrease the content of minerals and / or vitamins, which are nutritional or repellent components, among the metabolic products of the leafy vegetables P compared to leafy vegetables P whose stems and leaves are not irradiated with light of the specific wavelength.

[0015] The opaque member 30 is a member that prevents the light irradiated onto the rhizosphere of the leafy vegetables P by the irradiation unit 20 from being irradiated onto the stems and leaves. The opaque member 30 may be, for example, a member such as a plate or cloth with low light transmittance, such as a plastic such as polyvinyl chloride (hereinafter abbreviated as "PVC") or a metal. In this embodiment, the opaque member 30 is configured to surround the top, bottom, and side surfaces of the aquarium 10, thereby preventing the light irradiated onto the rhizosphere by the irradiation unit 20 from being irradiated onto the stems and leaves. In this embodiment, the opaque member 30 may have holes formed at the locations where the holding members of the water tank 10 are provided, through which the roots of the leafy vegetables P, which are plants, can pass.

[0016] In addition, the cultivation device 1 may be provided with an aeration mechanism, a mechanism for replenishing the culture solution, a base for holding or supporting the water tank 10, and the like, within the water tank 10. Furthermore, a mechanism for harvesting and transporting the cultivated leafy vegetables P may be provided, and members for holding and supporting the stems and leaves of the water tank 10 may be provided.

[0017] [Hydroponic cultivation method] Next, a hydroponic cultivation method for vegetables according to an embodiment of the present invention will be described. Plants are usually cultivated without exposing their roots to light. Conventional techniques have promoted growth by irradiating the root zone with light, but the effects of different wavelengths of light on roots have not been clarified. Therefore, the present inventors have considered that the development of a cultivation method using light environment control from a new perspective is necessary to further develop a method for controlling the growth and nutritional components of vegetables. For this reason, the present inventors have conducted extensive research and have established a hydroponic cultivation method for leafy vegetables P using a culture solution, in which a light source installed outside the area where the rhizosphere of the leafy vegetables P is grown is irradiated with light of a specific wavelength in the ultraviolet to infrared wavelength range to increase or decrease the mineral and vitamin content of the nutritional components of the leafy vegetables P.

[0018] Hereinafter, the hydroponic cultivation method according to the embodiment of the present invention and the leafy vegetables P to be cultivated will be described in detail.

[0019] Leafy vegetables P according to this embodiment include, for example, komatsuna, spinach, lettuce, mitsuba, green onions, chives, lettuce, parsley, bok choy, chrysanthemum, peppermint, licorice, and basil.

[0020] In the hydroponic cultivation method according to this embodiment, leafy vegetables P are grown hydroponically using a standard formulated culture solution for hydroponic cultivation. The standard formulated culture solution can be a culture solution with a typical blend ratio used in hydroponic cultivation. For example, this standard formulated culture solution for hydroponic cultivation contains major essential elements and trace essential elements for the cultivation of leafy vegetables P. The major essential elements are, for example, six elements: nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. The trace essential elements are, for example, seven elements: iron, manganese, zinc, copper, molybdenum, boron, and chlorine.

[0021] In the hydroponic cultivation method according to this embodiment, the seeds of the leafy vegetables P are germinated and then hydroponically cultivated in a culture solution normally formulated for hydroponic cultivation. At this time, the temperature, hours of sunlight, electrical conductivity (EC), pH, etc. of the culture solution are appropriately adjusted according to the type of leafy vegetables P to be cultivated. The hydroponic cultivation method of this embodiment may be, for example, a spray hydroponic method or a submerged hydroponic method. In the submerged hydroponic method, the plants may be cultivated in a static state without creating a flow of the culture solution, or in a flowing culture solution. The hydroponic cultivation method of this embodiment may be applied to ordinary greenhouse hydroponic cultivation using sunlight, or to hydroponic cultivation in a plant factory using a light source such as an LED. In this case, a light source for irradiating the stems and leaves is provided in addition to the irradiation unit 20.

[0022] The hydroponic cultivation method of the present invention is characterized in that light of a specific wavelength within the wavelength range of ultraviolet light to infrared light is irradiated by an irradiation unit 20 onto the root zone of leafy vegetables P while preventing the stems and leaves of the leafy vegetables P from being irradiated, and the leafy vegetables are cultivated so as to increase or decrease the content of minerals and / or vitamins that are nutritional components of the leafy vegetables P compared to leafy vegetables whose stems and leaves are not irradiated with light of the specific wavelength.

[0023] In other words, the hydroponic cultivation method of this embodiment makes it possible to control the condition of the leafy vegetables P by irradiating the root zone of the leafy vegetables P with light having a specific dominant wavelength from the light source of the irradiation unit 20, thereby increasing or decreasing the mineral and vitamin content, etc.

[0024] Specifically, when the dominant wavelength of the specific wavelength of light irradiated onto the rhizosphere in this embodiment is 397 nm (ultraviolet light), it is possible to cultivate leafy vegetables so as to reduce the potassium and iron content in the stems and leaves.

[0025] When the dominant wavelength of the specific wavelength light irradiated to the rhizosphere according to this embodiment is 464 nm (blue light), it is possible to cultivate leafy vegetables so that the iron content in the stems and leaves is reduced, and also so that the content of phylloquinone, a type of vitamin K1, is reduced.

[0026] When the dominant wavelength of the light of the specific wavelength irradiated onto the rhizosphere according to this embodiment is 506 nm (green light), it is possible to cultivate leafy vegetables so as to reduce the phylloquinone content.

[0027] When the dominant wavelength of the light of the specific wavelength irradiated onto the rhizosphere according to this embodiment is 633 nm (red light), it is possible to cultivate leafy vegetables so as to increase the phylloquinone content.

[0028] When the dominant wavelength of the light of the specific wavelength irradiated onto the rhizosphere according to this embodiment is 730 nm (near-infrared light), it is possible to cultivate leafy vegetables so as to reduce the phylloquinone content.

[0029] When the dominant wavelength of the light of the specific wavelength irradiated onto the rhizosphere in this embodiment is 850 nm (near-infrared light), it is possible to cultivate leafy vegetables so as to reduce the potassium content in the stems and leaves.

[0030] When the dominant wavelength of the specific wavelength of light irradiated onto the rhizosphere in this embodiment is 940 nm (near-infrared light), it is possible to cultivate leafy vegetables so as to reduce the potassium and iron content in the stems and leaves.

[0031] The light of a specific wavelength irradiated to the rhizosphere according to this embodiment may contain light of other wavelengths in addition to the dominant wavelength. Furthermore, depending on the type of light source of the irradiating unit 20, the light may contain wavelengths surrounding the dominant wavelength as a peak. Alternatively, mixed light in which the light of each of the above dominant wavelengths is appropriately combined may be used.

[0032] The amount of energy of light at this specific wavelength is the photosynthetic photon flux density (μmol / m -2 / s -1 ) and may be in the range of about 1 to 1000. Furthermore, this photosynthetically active photon flux density may be adjusted as appropriate depending on the selected dominant wavelength, the state of the leafy vegetables P, etc. If the photosynthetically active photon flux density is less than 1, the effect of light irradiation on the rhizosphere is insufficient, and if it is greater than 1000, the growth of the leafy vegetables P may be inhibited.

[0033] Furthermore, the leafy vegetables P according to the embodiment of the present invention are characterized by being cultivated by the above-mentioned hydroponic cultivation method. The components of the leafy vegetables P grown by the hydroponic cultivation method of this embodiment can be analyzed by measurement methods known to those skilled in the art. Examples of such analyses include, but are not limited to, a simple analysis in which raw vegetables are physically crushed by hand or with a mixer and the components in the squeezed juice are analyzed using various measuring devices, a detailed analysis in which the vegetables are dried in a dryer, crushed, added with acid, shaken, extracted and filtered, and analyzed using measuring devices such as a spectrophotometer or chromatograph, and combinations thereof.

[0034] The above configuration can provide the following effects. Vegetables produce metabolic products such as minerals (ions), vitamins, and polyphenols that affect their taste and nutritional value. The minerals and vitamins contained in vegetables generally contribute to improving human health, so cultivation methods that increase their content, especially in the edible parts, are beneficial. In conventional plant factories, etc., the growth and nutritional content of vegetables are controlled by controlling the light environment using LEDs, as plants receive light in the above-ground parts. Specifically, it has been found that controlling the light environment for above-ground parts using LEDs can improve the yield and nutritional content of leafy vegetables such as radish, buckwheat, and strawberries. On the other hand, when light was applied to the roots using conventional technology, growth was promoted, but it was unclear how the content of nutrients such as minerals and vitamins changed.

[0035] In contrast, the hydroponic cultivation method according to this embodiment irradiates the root zone of leafy vegetables with light of a specific wavelength within the wavelength range from ultraviolet to infrared light, thereby enabling the leafy vegetables P to be cultivated while controlling the content of metabolic products such as minerals and vitamins to a desired level.

[0036] Specifically, the hydroponic cultivation method according to this embodiment makes it possible to cultivate leafy vegetables with a higher content of minerals and vitamins than those cultivated using conventional techniques or general cultivation methods used by those skilled in the art. Since minerals and vitamins, which are nutritional components contained in leafy vegetables, contribute to improving human health, a cultivation method that increases the content of these nutrients in the edible parts is particularly beneficial. In other words, the hydroponic cultivation method according to this embodiment can provide a new perspective on cultivating high-quality vegetables in a lumber factory that can supply high-quality crops and vegetables all year round.

[0037] On the other hand, people with certain diseases may benefit from cultivation methods that reduce potassium content. For example, patients with chronic kidney disease are resistant to potassium and have their intake restricted. Vegetables contain a lot of potassium, so their intake is restricted.

[0038] In contrast, the hydroponic cultivation method according to the present embodiment enables the cultivation of leafy vegetables with lower mineral and vitamin contents than those cultivated using conventional techniques or general cultivation methods used by those skilled in the art. Specifically, by using 397 nm, 850 nm, or 940 nm as the dominant wavelength of the specific wavelength of light in the hydroponic cultivation method according to the present embodiment, it becomes possible to cultivate vegetables with significantly reduced potassium content in the stems and leaves. This makes it possible to cultivate vegetables with low potassium content for patients with chronic kidney disease.

[0039] Furthermore, since the content of minerals such as iron and magnesium is related to bitterness and astringency, controlling these can make it possible to cultivate leafy vegetables with better taste.

[0040] Additionally, the effects of warfarin, an oral anticoagulant used to treat and prevent thromboembolism, are weakened by vitamin K. For this reason, patients taking warfarin are restricted from consuming vegetables that contain vitamin K1 (phylloquinone), a type of vitamin K, as a repellent.

[0041] In contrast, in the hydroponic cultivation method according to the present embodiment, by using 464 nm, 506 nm, or 730 nm as the dominant wavelength of the specific wavelength of light, it is possible to cultivate vegetables with significantly reduced phylloquinone content in the stems and leaves, making it possible to cultivate vegetables with a low vitamin K content for patients with thromboembolism.

[0042] Furthermore, in the hydroponic cultivation method according to this embodiment, irradiation of the rhizosphere with light of a specific wavelength can affect biosynthetic products not only in the rhizosphere (underground part) but also in the stem and leaf parts (above ground part). Therefore, it is thought that there is a mechanism in plant roots that transmits signals to above-ground parts through light reception, and using these mechanisms can contribute to the development of hydroponic cultivation methods that further utilize light environment control.

[0043] In the above embodiment, the example in which the irradiating unit 20 is provided outside the aquarium 10 has been described, but the present invention is not limited to this as long as it is possible to irradiate light onto the root zone of leafy vegetables. For example, it is possible to place waterproof string-like LED straps, tubes or panels in which LEDs are enclosed, inside the aquarium 10. Alternatively, the irradiation unit 20 may be placed on the bottom or zenith of the aquarium 10. Even in these cases, it is preferable to use the opaque member 30 to block light between the stems and leaves and the root zone so that the light emitted from the irradiation unit 20 does not strike the stems and leaves.

[0044] Next, the present invention will be further described by way of examples with reference to the drawings, but the present invention is not limited to the following specific examples. [Example]

[0045] Materials and Methods The test material used was komatsuna (scientific name: Barassica rapa var. perviridis, variety "Yokatana", manufactured by Kaneko Seed Co., Ltd.).

[0046] (1)Cultivation conditions After the germination treatment, eight individuals were hydroponically cultivated in an acrylic tank 10 at a water temperature of 28.5°C. A 500-fold diluted solution of Hyponica A and B solutions (manufactured by Kyowa Co., Ltd.) was used as the hydroponic solution (culture solution). The culture solution was thoroughly aerated during the cultivation period. To prevent external light from reaching the roots, the acrylic tank 10 was covered with an opaque polyvinyl chloride container (hereinafter referred to as "PVC container") corresponding to the tank 10 of the above-mentioned embodiment, covering the stem, top, bottom, and sides. Furthermore, a treatment group was prepared in which light of a specific wavelength was irradiated by the irradiation unit 20, and a control group was prepared in which no light was irradiated. Cultivation was carried out in a growth chamber (2S-153A, manufactured by Koito Industries, Ltd.). The photosynthetically active radiation (400-700 nm) in the growth chamber was 430 μmol / m -2 / s -1 The room temperature was 28°C, humidity was 70%, and the day length was 12 hours. The water temperature was set at 28°C.

[0047] (2) Treatment area In the treatment area where light of specific wavelengths was irradiated to the roots, seven types of light with dominant wavelengths of 397 nm (ultraviolet light), 464 nm (blue light), 506 nm (green light), 633 nm (red light), 730 nm (near-infrared light), 850 nm (near-infrared light), and 940 nm (near-infrared light) were constantly irradiated from the side of tank 10. The top and bottom of tank 10 and the sidewall were enclosed in an opaque PVC container to prevent the light irradiated to the root system from reaching the stems and leaves. Otherwise, the plants were cultivated in the same way as the control area.

[0048] Radiant heat was measured under dark conditions at a distance of 4 cm from the LED for each specific wavelength of light. The 397 nm (ultraviolet light) was 0.092 (W m -2 ), 464nm (blue light) is 4.386(W m -2 ), 506 nm (green light) is 1.731 (W m -2 ), 633 nm (red light) is 2.107 (W m -2 ), 730 nm (near infrared light) is 7.985 (W m -2 ), and 850 nm (near infrared light) is 8.377 (W m -2), and 940 nm (near infrared light) is 6.221 (W m -2 ) was.

[0049] (3)Measurement method The plants were harvested two weeks after planting, and the roots and stems were separated. The fresh weight of the stems and leaves was measured, and both were freeze-dried and then the dry weight was measured. The samples were then crushed and used to measure the content of ions, fat-soluble vitamins, and water-soluble vitamins.

[0050] The mineral ion (potassium, magnesium, calcium, boron, iron, manganese, zinc) content was measured by measuring the amount of crushed sample in a crucible, ashing it in an electric muffle furnace, adding 14 ml of 1 M nitric acid, and filtering the resulting solution, which was then diluted 20 times with 1 M nitric acid and measured using an ICP optical emission spectrometer (IRIS Adventure ICAP, Japan Jarrell Ash).

[0051] Water-soluble vitamin B complex (thiamine (vitamin B1), riboflavin (vitamin B2), nicotinic acid (vitamin B3), nicotinamide (vitamin B3), pantothenic acid (vitamin B5), pyridoxine (vitamin B6)) and vitamin C (ascorbic acid, dehydroascorbic acid) were extracted by adding 1 ml of extraction solution (10 mM ammonium acetate (pH 4.5):methanol = 50:50 (v / v), 0.1% BHT, internal standard (hippuric acid) 1 mg / ml) to 5 mg of crushed sample, shaking for 15 minutes, ultrasonicating for 15 minutes, and then storing overnight in a refrigerator. The liquid layer was then collected by centrifugation for 5 minutes, dried in a vacuum centrifuge, added 1 ml of 10 mM ammonium acetate (pH 4.5), and shaken. The solution was then filtered through a 0.45 μm nylon filter and analyzed by LC / MS / MS.

[0052] For the extraction of fat-soluble vitamins (retinal (vitamin A), α-tocopherol (vitamin E), and phylloquinone (vitamin K1)), 5 mg of ground sample was weighed and placed in a light-shielding centrifuge tube. 5 mL of extraction solution (methanol:dichloromethane = 50:50 (v / v), 0.1% BHT, internal standard (2,2,5,7,8-pentamthyl-6-chromanol) 50 μg / mL) was added and stirred. The tube was then ultrasonicated for 15 minutes and centrifuged for 5 minutes. 0.75 mL of the supernatant was transferred to a light-shielding tube, dried in a vacuum centrifugal evaporator, and 1 mL of LC / MS / MS developing solvent (10 mM ammonium formate aqueous solution: 10 mM ammonium formate methanol solution = 1:9) was added. The tube was shaken for 10 minutes and then left overnight in a refrigerator. After 5 minutes of centrifugation, the supernatant was filtered and analyzed by LC / MS / MS.

[0053] Vitamin content was measured using an LC / MS / MS system (HPLC: Ultimate 3000 (Thermo Fisher Scientific, Waltham, MA, USA); column: Inert Sustain C18 3 μm column (150 mm × 2.1 mm, GL Science, Tokyo, Japan); MS: TSQ QUANTUM ULTLA (Thermo Fisher Scientific, Waltham, MA, USA). The column temperature was maintained at 35°C. The mobile phase flow rate was 0.2 mL min-1. The sample injection volume was 5 μL. The autosampler compartment was kept at 5°C. Among the water-soluble vitamins and water-soluble vitamins measured, ascorbic acid and dehydroascorbic acid were detected in negative mode, and the others in positive mode.

[0054] The data obtained for each measurement item were expressed as a ratio (fold change) to the control group, and the presence or absence of a ratio to the control group (treated group / control group) was evaluated by a t-test using the statistical software JMP12.2.0 (SAS Institute Inc., Cary, NC, USA).

[0055] [Test results] Figure 2 shows the ratio of dry matter weight at harvest time when cultivated with each wavelength irradiated to the rhizosphere to the control (treated area / control area). Figure 2 (a) shows the dry matter weight ratio in the shoots and leaves, and (b) in the roots. Each value represents the mean ± standard error. "*" indicates a significant difference at the 5% level compared with the control group by t-test.

[0056] As a result, no significant difference was observed in the shoots and leaves compared to the control. In the roots, the dry matter weight increased significantly in the 940 nm treatment compared to the control.

[0057] Figure 3 shows the ratio (treated / control) of each ion content in the stems and leaves at harvest time when cultivated with each wavelength irradiated to the rhizosphere. Each value shows the mean ± standard error. Figure 3 (a) shows the content of potassium, (b) shows magnesium, (c) shows calcium, (d) shows boron, (e) shows iron, (f) shows manganese, and (g) shows zinc. "*", "**", and "***" indicate significant differences at the 5%, 1%, and 0.1% levels, respectively, when compared with the control group using a t-test.

[0058] As a result, compared to the control, the potassium content significantly increased in the 464nm, 506nm, and 730nm treatments, and significantly decreased in the 397nm, 850nm, and 940nm treatments. The magnesium content increased significantly in the 464nm, 506nm, 633nm, and 730nm treatments. The calcium content increased significantly in the 633 nm treatment area, and decreased significantly in the 464 nm, 730 nm, 850 nm, and 940 nm treatment areas. The boron content in the 464nm, 506nm, and 730nm treatments increased significantly compared to the control. Iron content was significantly reduced in the 397nm, 464nm, and 940nm treatments. Manganese content significantly increased in the 506nm and 850nm treatments, and significantly decreased in the 464nm and 633nm treatments. The zinc content significantly increased in the 730nm and 850nm treatments, and significantly decreased in the 464nm, 506nm, 633nm, and 940nm treatments.

[0059] Figure 4 shows the ratio (treated group / control group) of fat-soluble vitamin content in the stems and leaves at harvest time when cultivated with each wavelength irradiated to the rhizosphere. Figure 4(a) shows the content of retinol, (b) shows the content of α-tocopherol, and (c) shows the content of phylloquinone. Each value represents the mean ± standard error. *, **, and *** indicate significant differences at the 5%, 1%, and 0.1% levels, respectively, when compared with the control group by t-test.

[0060] As a result, compared with the control, the retinal content tended to decrease in all treatments, and was significantly decreased in all treatments except for 633 nm. The α-tocopherol content tended to decrease in all treatments, and was significantly decreased in the 506nm, 730nm, and 940nm treatments. The phylloquinone content increased significantly in the 633 nm treatment area, and decreased significantly in the 464 nm, 506 nm, and 730 nm treatment areas.

[0061] Figure 5 shows the ratio (treated / control) of the water-soluble vitamin content in the stems and leaves at harvest time when the rhizosphere was irradiated with each wavelength to the control. Figure 5 (a) shows the content of dehydroascorbic acid, (b) ascorbic acid, (c) nicotinamide, (d) nicotinic acid, (e) pyridoxine, (f) pantothenic acid, (g) thiamine, and (h) riboflavin. Each value represents the mean ± standard error. *, **, and *** indicate significant differences at the 5%, 1%, and 0.1% levels compared with the control group by t-test, respectively.

[0062] As a result, the dehydroascorbic acid content was significantly reduced in the 397nm and 850nm treated areas compared to the control area. The ascorbic acid content tended to increase in all treatments except the 397nm treatment, and increased significantly in the 464nm and 506nm treatments. The nicotinamide content tended to decrease in all treatments, and was significantly reduced in the 397nm, 464nm, 730nm, 850nm, and 940nm treatments. The nicotinic acid content increased significantly in the 506 nm treatment area, and decreased significantly in the 397 nm, 730 nm, and 850 nm treatment areas. The pyridoxine content increased significantly in the 633nm and 940nm treatments. Thiamine content was significantly reduced in the 464nm, 633nm, and 850nm treatments. The riboflavin content significantly increased in the 397nm and 730nm treatments, but significantly decreased in the 633nm and 940nm treatments. In addition, no significant change in pantothenic acid content was observed due to wavelength irradiation to the rhizosphere.

[0063] Figure 6 shows the ratio (treated / control) of the ion content in the roots at harvest time when cultivated with the rhizosphere irradiated with each wavelength to the control. Figure 6(a) shows the content of potassium, (b) shows magnesium, (c) shows calcium, (d) shows boron, (e) shows iron, (f) shows manganese, and (g) shows zinc. Each value represents the mean ± standard error. *, **, and *** indicate significant differences at the 5%, 1%, and 0.1% levels compared with the control group by t-test, respectively.

[0064] As a result, compared with the control, the potassium content significantly increased in the 464nm and 506nm treatments, and significantly decreased in the 633nm treatment. The magnesium content significantly increased in the 730 nm treatment area, and significantly decreased in the 506 nm and 850 nm treatment areas. The calcium content significantly increased in the 633 nm treatment area, but significantly decreased in the 506 nm and 730 nm treatment areas. The boron content was significantly reduced in the 506 nm treatment. The iron content significantly increased in the 730nm and 940nm treatments, and significantly decreased in the 464nm, 506nm, and 850nm treatments. Manganese content increased significantly in the 506nm, 730nm, and 850nm treatments. The zinc content significantly increased in the 850nm treatment area, and significantly decreased in the 464nm, 506nm, 633nm, and 940nm treatment areas.

[0065] Figure 7 shows the ratio (treated group / control group) of the fat-soluble vitamin content in roots at harvest time when cultivated with the rhizosphere irradiated with each wavelength to the control group. Each value represents the mean ± standard error. "**" indicates a significant difference at the 1% level when compared with the control group by t-test.

[0066] As a result, compared with the control, tinal was significantly reduced only in the 506 nm treatment, while α-tocopherol and phylloquinone were not detected.

[0067] Figure 8 shows the ratio (treated group / control group) of the content of each water-soluble vitamin in the roots at harvest time when cultivated with the rhizosphere irradiated with each wavelength to the control group. Each value represents the mean ± standard error. An asterisk (*) indicates a significant difference at the 5% level when compared with the control group by t-test.

[0068] As a result, compared with the control, tinal was significantly reduced only in the 506 nm treatment, while α-tocopherol and phylloquinone were not detected.

[0069] It goes without saying that the configurations and operations of the above-described embodiments are merely examples, and can be modified as appropriate within the scope of the present invention. [Industrial Applicability]

[0070] The present invention can provide a functional hydroponic cultivation method and cultivation device for leafy vegetables in which the content of minerals and vitamins, which are nutritional components, is controlled, and the cultivated leafy vegetables, and can be used industrially. [Explanation of symbols]

[0071] 1 Cultivation equipment 10. Aquarium 20 Irradiation unit 30 Opaque material P Leafy vegetables

Claims

1. A hydroponic cultivation method for leafy vegetables using a culture solution, Irradiating the root zone of the leafy vegetables with light of a specific wavelength in the wavelength range from ultraviolet light to infrared light while preventing irradiation of the stems and leaves of the leafy vegetables, The leafy vegetables are cultivated so as to increase or decrease the content of minerals and / or vitamins that are nutritional components of the leafy vegetables compared to leafy vegetables in which the stems and leaves are not irradiated with light of the specific wavelength. A hydroponic cultivation method characterized by:

2. The dominant wavelength of the specific wavelength of light irradiated onto the rhizosphere is 397 nm. The hydroponic cultivation method according to claim 1 .

3. The dominant wavelength of the specific wavelength of light irradiated onto the rhizosphere is 464 nm. The hydroponic cultivation method according to claim 1 .

4. The dominant wavelength of the specific wavelength of light irradiated onto the rhizosphere is 506 nm. The hydroponic cultivation method according to claim 1 .

5. The dominant wavelength of the specific wavelength of light irradiated onto the rhizosphere is 633 nm. The hydroponic cultivation method according to claim 1 .

6. The dominant wavelength of the specific wavelength light irradiated onto the rhizosphere is 730 nm. The hydroponic cultivation method according to claim 1 .

7. The dominant wavelength of the specific wavelength of light irradiated onto the rhizosphere is 850 nm. The hydroponic cultivation method according to claim 1 .

8. The dominant wavelength of the specific wavelength light irradiated to the rhizosphere is 940 nm. The hydroponic cultivation method according to claim 1 .

9. A cultivation device for leafy vegetables by hydroponic cultivation using a culture solution, A cultivation container for holding the culture solution and cultivating the leafy vegetables; an irradiation unit that irradiates light of a specific wavelength in a wavelength range from ultraviolet light to infrared light onto the root zone of the leafy vegetables in the cultivation container; an opaque member that prevents the light irradiated onto the root zone of the leafy vegetables by the irradiation unit from being irradiated onto the stems and leaves, The specific wavelength is set so as to increase or decrease the content of minerals and / or vitamins that are nutritional components of the leafy vegetables compared to leafy vegetables that are not irradiated with light of the specific wavelength. A cultivation device characterized by:

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