How to germinate upright plants from the discs of Mozuku seaweed

Abstract

To provide a germination method of upright Nemacystus decipiens from discal Nemacystus decipiens.SOLUTION: Provided is a germination method of upright Nemacystus decipiens from discal Nemacystus decipiens, characterized by irradiating discal Nemacystus decipiens with (A) light in the wavelength range of 400 nm or more and less than 500 nm and / or (B) light in the wavelength range of 500 nm or more and less than 600 nm, each of which has a light quantity of 25 μmol / m2 / s or more, as well as with (C) light in the wavelength range of 600 nm or more and less than 700 nm, which has a light quantity of 35 μmol / m2 / s or less, in the presence or absence of white light.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for germinating upright bodies from discs of Mozuku seaweed in the presence or absence of white light. [Background technology]

[0002] Mozuku has traditionally been eaten all over Japan, but in recent years it has been recognized as a health food and natural food, and demand is increasing. Currently, farmed mozuku is the main product in circulation, and in Japan, the majority of mozuku farmed in Okinawa is particularly prevalent. In order to further increase the yield of mozuku, efforts are being made to develop farming techniques.

[0003] Methods for cultivating mozuku in Okinawa, particularly the process of sprouting mozuku discs and growing them into mozuku, include, for example, a method that sequentially involves the steps of (1) attaching the mozuku discs to a net or the like to make a seed net, (2) setting the seed net in the sea, (3) causing upright bodies to sprout from the mozuku discs attached to the seed net, (4) causing the upright bodies to grow and develop into mozuku, and (5) harvesting the mozuku that has been grown.

[0004] There have been many reports on the ecology and cultivation techniques of Okinawa Mozuku, including, for example, a report on the appropriate light intensity to promote the growth of Okinawa Mozuku (Non-Patent Document 1), a report on cultivation techniques for Okinawa Mozuku (Non-Patent Document 2), a report summarizing the effects of water temperature, light intensity, salinity, and nutrients on the growth of the upright body (sprouted algal body) of Okinawa Mozuku (Non-Patent Document 3), a report on the relationship between the germination of the upright body of Okinawa Mozuku and water temperature (Non-Patent Document 4), and a report on the low water temperature limit for the growth of Okinawa Mozuku disc bodies (Non-Patent Document 5).

[0005] However, in the above-mentioned Mozuku cultivation method, "(3) the step of causing upright bodies to germinate from the Mozuku discs attached to the seed net," the conditions for causing upright bodies to germinate from the Mozuku discs have not yet been clearly elucidated. Therefore, in order to ensure a stable harvest of Mozuku, a method for efficiently causing upright bodies to germinate from the Mozuku discs is required. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Takeshi Touma, "Okinawa's Seaweeds and Seagrass (Natural Environment, Aquaculture, 250 Types of Seaweed)," Mugen Publishing Co., Ltd., pp. 237-260 (2012) [Non-Patent Document 2] Iwao Niimura, "Fundamental Research on the Cultivation of Okinawan Cladozuku," Doctoral Thesis, Hokkaido University (1976) [Non-Patent Document 3] "Growth characteristics of Okinawa mozuku under indoor cultivation" Okinawa Prefectural Fisheries and Marine Technology Center, FY2011 Research and Extension Information [Non-Patent Document 4] Satoshi Moromizato et al. "Indoor cultivation and filamentous culture of Mozuku algae," Okinawa Prefectural Fisheries Experiment Station Business Report 2000 (2000) [Non-Patent Document 5] "Low water temperature limit for growth of Okinawan mozuku discoids" Okinawa Prefectural Fisheries and Marine Technology Center, FY2012 Research and Extension Information Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a method for germinating upright bodies from discs of Mozuku in the presence or absence of white light. [Means for solving the problem]

[0008] As a result of intensive research to solve the above problems, the present inventors have found that upright plants can be efficiently germinated from the mozuku discs by irradiating the mozuku discs with a combination of a specific light amount and wavelength range in the presence or absence of white light. Based on these findings, the present inventors have further researched and completed the present invention. That is, the present invention includes the following configurations. [1] In the presence or absence of white light, The light intensity was 25 μmol / m 2 / s or more of the following light (A) and / or light (B), and Light intensity is 35μmol / m 2 A method for germinating upright bodies from the discs of Mozuku, comprising irradiating the discs with light of the following (C) at a wavelength of 1000 dpi or less. (A) Light with a wavelength range of 400 nm or more and less than 500 nm (B) Light with a wavelength range of 500 nm or more and less than 600 nm (C) Light with a wavelength range of 600 nm or more and less than 700 nm [2] A method for germinating upright plants from the mozuku discs described in [1] above, characterized in that the mozuku discs are irradiated with only light (A) and / or light (B). [3] The total light intensity on the disc-shaped bodies of Mozuku is 50 μmol / m 2 / s or more of light (A) and light (B), Light intensity is 35μmol / m 2 The method for germinating upright bodies from the discs of Mozuku described in [1] above, characterized by irradiating the discs with light of (C) at a wavelength of 1000 nm or less. [4] A method for germinating upright plants from the mozuku discs described in any one of [1] to [3] above, characterized in that the light irradiated to the mozuku discs is light derived from an LED. [5] A method for germinating upright bodies from discs of Mozuku under irradiation with white light, the method being characterized in that irradiation with the following light (C) is reduced by a material. (C) Light with a wavelength range of 600 nm or more and less than 700 nm [6] A method for germinating upright bodies from the discs of Mozuku under irradiation with white light, comprising: enhancing the light (A) and / or the light (B) below; or A method characterized by attenuating irradiation with the following light (C). (A) Light with a wavelength range of 400 nm or more and less than 500 nm (B) Light with a wavelength range of 500 nm or more and less than 600 nm (C) Light with a wavelength range of 600 nm or more and less than 700 nm Effect of the Invention

[0009] The method of the present invention for germinating upright bodies from mozuku discs is achieved by irradiating the mozuku discs with light falling within a specific wavelength range, either alone or in combination, at a specific light intensity in the presence or absence of white light, thereby achieving the effect of efficiently germinating upright bodies from the mozuku discs. [Brief description of the drawings]

[0010] [Figure 1] The life cycle of Mozuku seaweed is shown. [Diagram 2] In Example 2, a photograph of the Mozuku seed net thread taken on the 14th day of culture is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In the present invention, "mozuku" generally refers to algae belonging to the genus Myrtochna in the family Chordariaceae of the order Chordariaceales of the Phaeophyceae or the genus Myrtochna in the family Spermatochnaceae of the order Chordariaceales of the Phaeophyceae. Specific examples include Okinawa mozuku (Cladosiphon okamuranus), Tinocladia crassa, Sphaerotrichia divaricata, and Nemacystus decipiens, which belong to the genus Myrtochna. Okinawa mozuku or Myrtochna is preferred.

[0012] In the present invention, the "mozuku discoids" (hereinafter simply referred to as "discoids") are the products of the development of a zygote which develops from the union of a female gamete and a male gamete of mozuku, or the development of neutral zoospores which develop from neutral multisporangia of mozuku (see also Figure 1).

[0013] In the present invention, "upright bodies germinate from discs" usually refers to a state in which numerous assimilation threads rise from the center of the discs and then gather and grow, i.e., an upright body is formed from the discs. If the germination conditions are not met, the assimilation threads of the discs of Mozuku do not gather and they become neutral polysporangia. Neutral zoospores then emerge from the neutral polysporangia and form discs again (see also Figure 1).

[0014] In one aspect of the present invention, the light dose of 25 μmol / m was applied to the discs of Mozuku seaweed in the presence or absence of white light. 2 / s or more, and the light intensity is 35 μmol / m 2 The method for germinating upright plants from the discs of Mozuku comprises irradiating the plants with light of the following (C) at a wavelength of 1 / s or less. (A) Light with a wavelength range of 400 nm or more and less than 500 nm (B) Light with a wavelength range of 500 nm or more and less than 600 nm (C) Light with a wavelength range of 600 nm or more and less than 700 nm Light falling within the wavelength ranges (A) and (B) above is preferable for germinating upright bodies from the discs of Mozuku and can promote the germination of upright bodies from the discs of Mozuku.

[0015] Examples of white light include sunlight, fluorescent light, incandescent light, and the like. It is preferable that the light contains equal amounts of the above light (A), light (B), and light (C), but the amounts do not have to be equal, and it is sufficient that the visible light rays of the wavelengths contained in light (A), light (B), and light (C) are mixed together to appear white. The amount of white light is preferably 10 μmol / m 2 / s or more, and the preferred range of light intensity is 15 to 200 μmol / m 2 / s, more preferably 25 to 100 μmol / m 2 / s, more preferably 50 to 100 μmol / m 2 / s.

[0016] Examples of the above (A) light of 400 nm or more and less than 500 nm include, but are not limited to, light from a blue LED (peak wavelength: 453 nm±10 nm, wavelength range: 430 to 500 nm) when an LED is used as the light source.

[0017] Examples of the above (B) light of 500 nm or more and less than 600 nm include, but are not limited to, light from a green LED (peak wavelength: 525 nm±10 nm, wavelength range: 490 to 550 nm) when an LED is used as the light source.

[0018] Examples of the above (C) light of 600 nm or more and less than 700 nm include, but are not limited to, light from a red LED (peak wavelength: 641 nm + / - 10 nm, wavelength range: approximately 630 to 680 nm) when an LED is used as the light source.

[0019] The light to be irradiated may be the above-mentioned light (A) and / or light (B), and light (C), or light (A) and / or light (B). Light (A) is preferred, blue light with a peak wavelength of 453 nm is more preferred, and blue LED light is even more preferred.

[0020] In the present invention, the light intensity when irradiating only the light (A) and / or the light (B) to the mozuku disc is 25 μmol / m 2 The preferred range of the light amount varies depending on the type of light, but is preferably 25 to 200 μmol / m 2 / s, more preferably 25 to 150 μmol / m 2 / s, and more preferably 25 to 100 μmol / m 2 / s, and most preferably 25 to 80 μmol / m 2 Within the above range, it is preferable for upright bodies to germinate from the discs of Mozuku, and germination is further promoted, which is preferable.

[0021] The light source for the wavelength region of the above light (A), light (B) and light (C) is not particularly limited, and examples thereof include sunlight, fluorescent lamps, incandescent lamps, sodium lamps, light from LEDs (light emitting diodes), etc. Considering that the wavelength region of the light is easy to control, there is no heat generation, and the running costs are low, light from LEDs is preferable.

[0022] In one aspect of the present invention, the light dose of 25 μmol / m was applied to the discs of Mozuku seaweed in the presence or absence of white light. 2 The present invention relates to a method for germinating upright plants from the disc-shaped bodies of Mozuku seaweed, the method being characterized by irradiating only the following light (A) and / or light (B) at a wavelength of 1000 nm or more and a wavelength of 1000 nm or more. (A) Light with a wavelength range of 400 nm or more and less than 500 nm (B) Light with a wavelength range of 500 nm or more and less than 600 nm The above light (A) and light (B) are as described above.

[0023] In one aspect of the present invention, the total amount of light emitted to the discs of Mozuku seaweed is 50 μmol / m2 in the presence or absence of white light. 2 / s or more, and the light intensity is 35 μmol / m 2 The method for germinating upright plants from the discs of Mozuku comprises irradiating the plants with light of the following (C) at a wavelength of 1 / s or less. (A) Light with a wavelength range of 400 nm or more and less than 500 nm (B) Light with a wavelength range of 500 nm or more and less than 600 nm (C) Light with a wavelength range of 600 nm or more and less than 700 nm The above light (A), light (B), and light (C) are as described above.

[0024] In the present invention, the mozuku disc is irradiated with the above-mentioned light (A) and light (B) and the above-mentioned light (C). The total light amount of the light (A) and the light (B) is 50 μmol / m 2 / s or more, preferably 50 to 200 μmol / m 2 / s, more preferably 50 to 150 μmol / m 2 / s, and more preferably 60 to 100 μmol / m 2 / s, and most preferably 60 to 80 μmol / m 2 / s.

[0025] The light intensity of (C) is 35 μmol / m 2 / s or less, preferably 25 μmol / m 2 / s or less, more preferably 15 μmol / m 2 / s or less, most preferably 10 μmol / m 2 / s or less. Since the light of (C), especially red light with a wavelength of more than 600 nm, tends to inhibit the germination of upright bodies from the discs of Mozuku, it is preferable for the germination of upright bodies from the discs of Mozuku to be achieved by reducing the amount of light as described above.

[0026] The environment in which the mozuku discs are irradiated with light may be in the presence or absence of white light, and is not particularly limited as long as the conditions are suitable for the growth of the mozuku discs. Examples of conditions in seawater include the following: The seawater is not particularly limited, and may be seawater collected directly from the ocean, subsurface seawater collected from underground near the coast or from the ocean floor (e.g., continental shelf), deep ocean water collected from the deep sea, etc. Also, distilled water, tap water, etc., to which necessary mineral components (e.g., salts such as calcium, potassium, sodium, magnesium, etc.) have been added to have a composition similar to that of seawater may be used. The temperature of the seawater is, for example, preferably about 10 to 30°C, more preferably 15 to 25°C, and most preferably 20 to 22°C, but is not limited thereto.

[0027] The light irradiation time cycle can be, for example, a daily light / dark time cycle of 5 to 16 hours of light and 19 to 8 hours of dark in a 24-hour period (the total of the light and dark periods is 24 hours; the same applies below), preferably a light period of 6 to 12 hours and a dark period of 18 to 12 hours, more preferably a light period of 6 to 10 hours and a dark period of 18 to 14 hours, and even more preferably a light period of 6 to 8 hours and a dark period of 18 to 16 hours, but is not limited to these. The number of days for light irradiation can be, for example, the above-mentioned light irradiation time cycle for about 14 days or more, preferably for about 28 days or more, more preferably for about 35 days or more, and even more preferably for about 42 days or more, but is not limited to these.

[0028] The nutritional conditions of the seawater are not particularly limited, but the nitrate nitrogen concentration, which is a major nutrient component for seaweed such as mozuku, is preferably 0.1 to 50 μmol / L, more preferably 0.2 to 10 μmol / L, and more preferably 0.5 to 10 μmol / L. The phosphate phosphorus concentration is preferably 0.01 to 5 μmol / L, more preferably 0.02 to 1 μmol / L, and more preferably 0.05 to 1 μmol / L. Note that the nitrate nitrogen concentration of general seawater is usually 30 μmol / L or less, and the phosphate phosphorus concentration is often 3 μmol / L or less, so it is also possible to add, for example, a nutrient salt solution for seaweed cultivation. The salinity of seawater is not particularly limited, but is preferably 1.5 to 4.5 mass %, more preferably 2 to 3.5 mass %, and even more preferably 2.8 to 3.3 mass %, for example.

[0029] There are no particular limitations on the method of irradiating the mozuku discs with light, so long as the discs are irradiated with the above-mentioned light in the presence or absence of white light, but examples include (1) a method of irradiating mozuku discs floating in seawater with light, and (2) a method of placing a substrate to which mozuku discs are attached in seawater and irradiating the discs with light in the presence or absence of white light. When considering further growing the upright bodies sprouting from the discs and harvesting the mozuku, the above method (2) is preferred.

[0030] The substrate with the above-mentioned mozuku discs attached thereto can be obtained by a conventional method, for example, by culturing the substrate in seawater containing a zygote developed by the union of a female gamete and a male gamete of mozuku, or neutral zoospores developed from a neutral multisporium of mozuku, and allowing the zygote or neutral zoospores to attach to the substrate and grow into mozuku discs.

[0031] The substrate is not particularly limited as long as it is a material to which zygotes or neutral zoospores can easily adhere, and can be, for example, polypropylene, chemical fiber made by mixing and twisting vinylon and polypropylene, palm thread, etc. The shape of the substrate is also not particularly limited, and examples thereof include a net shape, a curtain shape, and a shape in which thread is wound around a frame.

[0032] Methods for placing the substrate with the above-mentioned Mozuku discs attached thereto in seawater include placing the substrate in the ocean with calm waves, filling a container such as a water tank installed on land with seawater and placing the substrate therein, etc. The substrate is not particularly limited, but is preferably placed at a position about 0 to 2 m below the water surface, more preferably about 0.1 to 1.5 m below the water surface, and even more preferably about 0.2 to 1 m below the water surface.

[0033] Another aspect of the present invention is a method for germinating upright bodies from discs of Mozuku under irradiation with white light, in which the irradiation of the following light (C) is reduced by a material. (C) Light with a wavelength range of 600 nm or more and less than 700 nm

[0034] Materials capable of reducing the irradiation of the above-mentioned (C) light include, but are not limited to, glass, wood (such as plant fibers), plastic, etc., and from the viewpoints of cost, durability, and ease of availability, preferably, for example, color sheets (sheet, net, film, etc.) used for civil engineering or agriculture. As such color sheets, for example, those having a thickness of about 0.07 to 0.11 mm can be used, but are not limited to these. The color of the color sheet is not particularly limited, but from the viewpoint of reducing the light of (C), preferably, blue, green, etc. are used, and preferably, blue. In the case of plastic, the material of the color sheet includes polyvinyl chloride, polyethylene, polypropylene, polyester, nylon, etc. In addition, color sheets may be used in layers, and usually, 1 to 6 sheets, preferably, 2 to 4 sheets are used, but are not limited to these. The above-mentioned white light and (C) light are as described above.

[0035] Further, as materials capable of reducing the irradiation of the light (C), in addition to the above, for example, materials having a shape such as a net, sheet, or film that selectively transmits the light (A) and / or the light (B) can be mentioned. For example, a net-shaped material that selectively transmits the light (A) and / or the light (B) can be preferably used, and examples thereof include, but are not limited to, Dioneo Shade Soukai (product name: manufactured by Dio Kasei Co., Ltd.) or the net-shaped material described in JP-A-2017-55686. For example, it is preferable to stack several sheets (2 to 4 sheets) of Dioneo Shade Soukai in a form in which sunlight, that is, light including the light (A), the light (B), and the light (C), is selectively transmitted light of the light (A) and / or the light (B), that is, light with a large amount of the light (A) and / or the light (B), and irradiate the mozuku disc-shaped body.

[0036] Another aspect of the present invention is a method for germinating upright plants from discs of Mozuku under irradiation with white light, which comprises increasing the irradiation of the light (A) and / or the light (B) described below, or decreasing the irradiation of the light (C) described below. (A) Light with a wavelength range of 400 nm or more and less than 500 nm (B) Light with a wavelength range of 500 nm or more and less than 600 nm (C) Light with a wavelength range of 600 nm or more and less than 700 nm In order to enhance the light (A) and / or the light (B), for example, a method of increasing the amount of light irradiated from the light source, a method of concentrating the light source light and / or white light on the mozuku disc using a reflector, a method of shortening the distance between the light source and the mozuku disc, etc. may be mentioned. In addition, in order to weaken the irradiation of the light (C), the above-mentioned materials may be used, but they may not be used. For example, in addition to the method of reducing the amount of light irradiated from the light source, when the substrate to which the mozuku disc is attached is placed in seawater, the irradiation of light may be weakened by the seawater present between the substrate and the light source. In addition, a method of increasing the distance between the light source and the mozuku disc may be performed. The above-mentioned white light, light (A), light (B), and light (C) are as described above.

[0037] The present invention will be described below with reference to examples, which are merely illustrative of the present invention and are not intended to limit the present invention. EXAMPLES

[0038] [Example 1] (1) Preparation of Mozuku discs The slide was placed in sterilized seawater in which the formation of neutral multisporangia and the swimming of neutral zoospores had been confirmed, and the water temperature was 25°C and the light intensity was 50 μmol / m 2 The slide glass with the neutral zoospores attached was then cultured for 48 hours under conditions of 12 hours light and 12 hours dark, with a water temperature of 25°C and a light intensity of 50 μmol / m2. 2 The plates were cultured for three weeks under conditions of 12 hours light and 12 hours dark / s and a daily light cycle of 12 hours light and 12 hours dark, to obtain discs of Mozuku seaweed.

[0039] (2) Irradiation and cultivation of Mozuku discs The obtained Mozuku discs were placed in a 6-well microplate filled with sterilized seawater (nitrate nitrogen concentration: 2 μmol / L, phosphate phosphorus concentration: 0.2 μmol / L) with 5-10 pieces per well, and then placed in a thermostatic chamber (model: CN-40A, manufactured by Mitsubishi Mechanical Engineering Co., Ltd.). Light was irradiated under the following conditions for cultivation. Note that the number of Mozuku discs increased from the initial 5-10 pieces by about 100-200 times because assimilation threads rose from the Mozuku discs during cultivation, some of which became neutral complex sporangia and produced neutral zoospores, after which they formed discs again.

[0040] [Culture conditions and light conditions] Culture temperature: set at 25°C. Light cycle: Light was continuously illuminated for 12 hours each day (light period) and the lights were turned off for 12 hours in darkness (dark period). Irradiated light: A three-wavelength variable LED irradiation device (model: 3LH-64, manufactured by Nippon Medical Instruments Co., Ltd.) was used as the light source, and the following light was irradiated. (C) Light with a wavelength in the range of 600 nm or more and less than 700 nm (peak wavelength 641 nm). Hereinafter, this may be abbreviated as "R". (B) Light in the wavelength range of 500 nm or more and less than 600 nm (peak wavelength 525 nm). Hereinafter, this may be abbreviated as "G". (A) Light with a wavelength range of 400 nm or more and less than 500 nm (peak wavelength 453 nm). Hereinafter, this may be abbreviated as "B." White light (light containing equal amounts of the above light (A), light (B), and light (C)). Hereinafter, this is sometimes abbreviated as "RGB." Irradiation light intensity: The light intensity shown in Table 1 was irradiated.

[0041] (3) Observation method for upright germination from the mozuku disc After 14, 21, 28, 35, and 42 days from the start of light irradiation, photographs were taken under a stereomicroscope and the 2The number of discoids (total number of ungerminated and germinated discoids) and germinated discoids (discs in which assimilation threads gather from the center to form an upright body and the length of the upright body reaches approximately 1 mm or more) were counted, and the germination rate was calculated using the following formula.

number

[0042] (4) Evaluation criteria The germination rates obtained for each observation date were coded and evaluated according to the following criteria. The results are shown in Table 1. The germination rates 14 and 21 days after the observation date were 0% in all test plots, and therefore are not shown in Table 1. Test plots 1 to 7 in Table 1 are examples, and test plots 8 to 15 are comparative examples. [Evaluation Criteria] D rating: 0% germination rate C rating: Germination rate is greater than 0% and less than 10% B rating: Germination rate is 10% or more but less than 20% A rating: Germination rate is 20% or more, but less than 30%. S rating: Germination rate is 30% or more but less than 50% SS rating: Germination rate is 50% or more When the evaluation was B or higher, it was judged that upright bodies sprouted from the mozuku discs and that the method was effective in germination. In particular, when the evaluation was A or higher, it was judged that the method was not only very effective in sprouting upright bodies from the mozuku discs and that the method also had a germination promotion effect.

[0043] [Table 1]

[0044] As is clear from the evaluation results on the 42nd day of observation, only the light (A) (peak wavelength 453 nm: wavelength range approximately 400 to 500 nm) was irradiated, and the light dose was set at 25 to 100 μmol / m 2 In the test plots where the soil condition was adjusted to / s, the soil was rated A or SS, and upright bodies sprouted from the disc-shaped bodies of the mozuku seaweed, which was very effective in promoting germination. The light of (B) (peak wavelength 525 nm: wavelength range approximately 500-600 nm) and the light of (A) (peak wavelength 453 nm: wavelength range approximately 400-500 nm) were used in combination, with the light dose set at 25 μmol / m 2 In the test area where the soil temperature was adjusted to / s, the soil was rated S, and upright bodies sprouted from the disc-shaped bodies of the mozuku seaweed, which was very effective in promoting germination and was also confirmed. Only light (B) (peak wavelength 525 nm: wavelength range approximately 500 to 600 nm) was irradiated, with a light dose of 50 μmol / m 2 The test area where the concentration was adjusted to / s was rated an A, with upright bodies sprouting from the disc-shaped bodies of the mozuku seaweed, which was very effective in promoting germination and was also confirmed. The light of (C) (peak wavelength 641 nm: wavelength range approximately 600-700 nm), the light of (B) (peak wavelength 525 nm: wavelength range approximately 500-600 nm), and the light of (A) (peak wavelength 453 nm: wavelength range approximately 400-500 nm) were irradiated, and the light dose was 33.3 μmol / m 2 The test area where the concentration was adjusted to / s was rated B, and upright bodies sprouted from the disc-shaped bodies of the Mozuku seaweed, which was effective in germination. Only light (B) (peak wavelength 525 nm: wavelength range approximately 500 to 600 nm) was irradiated, and the light dose was 100 μmol / m 2 The test area where the concentration was adjusted to / s was rated B, and upright bodies sprouted from the disc-shaped bodies of the Mozuku seaweed, which was effective in germination.

[0045] From the results of Example 1, it was hypothesized that upright bodies would be more likely to germinate from the disc bodies of Mozuku when the light (A) (i.e., the blue "B" light color) was irradiated in large amounts and / or the light (C) (i.e., the red "R" light color) was reduced, and further experiments were conducted.

[0046] [Example 2] (1) Preparation of Mozuku seed filaments with Mozuku discs attached Neutral polysporangia formed in Okinawan mozuku were placed in a glass container (plum wine bottle) and sterilized seawater was placed in the container. The water temperature was 25°C and the container was illuminated with white fluorescent light (light intensity: 50 μmol / m 2 / s) was exposed to light for 12 hours a day and 12 hours a dark period and cultured for 30 days with aeration, and the swimming of neutral zoospores was confirmed. A part of a net (composition: 70% nylon, 30% polyethylene) used for cultivating Mozuku was cut and placed in the sterilized seawater in which the neutral zoospores were swimming, and the net thread (about 30 cm long after the mesh was unraveled) was cultured under the same conditions as above for two weeks with aeration, to obtain Mozuku seed net thread with disc-shaped bodies attached to the surface of the net thread. The presence or absence of disc-shaped bodies attached was confirmed by visual inspection of the surface of the net thread.

[0047] (2) Irradiation and cultivation of Mozuku discs The obtained Mozuku seed net threads were cut into 1.5-2.0 cm pieces, and the cut Mozuku seed net threads were placed one by one in 300 mL aerated culture flasks (hereinafter simply referred to as "flasks") filled with sterilized seawater (nitrate nitrogen concentration: 2 μmol / L, phosphate phosphorus concentration: 0.2 μmol / L). These were then placed in a thermostatic chamber (model: CN-40A, manufactured by Mitsubishi Mechanical Engineering Co., Ltd.) and cultured under light irradiation under the following conditions (test areas 16-23). Two flasks were placed in each thermostatic chamber, one as is (tests 16-19) and the other covered with a blue net (product name: Dioneoshade Soukai, manufactured by Daio Kasei Co., Ltd.) (tests 20-23). ​​In order to ensure that the amount of light irradiated to each Mozuku species net thread was the same, the flask covered with the blue net was placed on a higher platform so that it was closer to the light source installed on the top of the thermostatic chamber than the uncovered flask.

[0048] [Culture conditions] Culture temperature: set at 24°C. Irradiation time cycle: Four thermostatic chambers were used, and the light / dark cycle of each chamber per day (out of 24 hours) was set to four stages: light period 6, 8, 10, and 12 hours (dark period 18, 16, 14, and 12 hours). Frequency of changing sterilized seawater: The sterilized seawater was replaced with new sterilized seawater once a day.

[0049] [Lighting conditions] <<"Light blue" light: no blue net (test areas 16-19)>> Irradiated light: A three-wavelength variable LED irradiation device (model: 3LH-64, manufactured by Nippon Medical Instruments Co., Ltd.) was used as the light source, and the ratios of the following "R," "G," and "B" lights were adjusted to irradiate each of the Mozuku species net threads in each flask with "light blue" light. "R": (C) Light in the wavelength range of 600 nm or more and less than 700 nm (peak wavelength 641 nm). "G": (B) Light in the wavelength range of 500 nm or more and less than 600 nm (peak wavelength 525 nm). "B": (A) Light in the wavelength range of 400 nm or more and less than 500 nm (peak wavelength 453 nm). Irradiation light amount: Total light amount 50μmol / m 2 / s ("R": 10.0 μmol / m 2 / s, "G": 10.0 μmol / m 2 / s, "B": 30.0 μmol / m 2 The test piece was exposed to a "light blue" light of 1000 Hz (1 / s).

[0050] <<"Blue" light: with blue net (test areas 20-23)>> Irradiated light: A blue net was placed over the flasks, and the same "light blue" light as in test areas 16-19 was irradiated from above, irradiating each Mozuku species net thread in each flask with "blue" light. Irradiated light intensity (under blue net): Total light intensity 50μmol / m 2 / s ("R": 3.0 μmol / m 2 / s, "G": 6.0 μmol / m 2 / s, "B": 41.0 μmol / m 2 / s) of "blue" light was irradiated.

[0051] (3) Observation method and evaluation criteria for upright germination from Mozuku discs 14 days and 36 days after the start of light irradiation, the Mozuku seed net thread was removed to a petri dish, and a full picture of the Mozuku seed net thread was taken with a digital camera. The number of upright bodies of about 1 mm or more sprouting from the disc-shaped bodies of the Mozuku seed net thread was counted to observe the germination status. The number of upright bodies counted was coded and evaluated according to the following evaluation criteria. The results are shown in Table 2 and Figure 2. [Evaluation symbols and evaluation criteria] × : 0 upright objects can be seen in the overall photo 〇: 1 to 5 upright objects can be seen in the overall photo ◎ : 6 to 15 uprights can be seen in the overall photo ◎◎: 16 or more upright objects can be seen in the overall photo When the evaluation symbol was "〇" or higher, it was judged that upright bodies sprouted from the mozuku discs and that the method was effective in germination. In particular, when the evaluation symbol was "◎◎" or higher, it was judged that the method was not only very effective in sprouting upright bodies from the mozuku discs and that the method also had a germination promotion effect.

[0052] [Table 2]

[0053] Furthermore, for the test plots 16-17 and 20-21, which showed good results, photographs of the seed net filaments taken on the 14th day of cultivation are shown in Figure 2. The shorter the light period, the finer the area of ​​the discoid bodies (dark arrows), and there were also areas where the discoid bodies were gathered to a level that could be considered as upright bodies (light arrows). Photographs of the seed net filaments taken on the 0th day of the test (before irradiation) are also shown in Figure 2.

[0054] The results in Table 2 and Figure 2 show that upright bodies could be germinated from the mozuku discs by irradiating the mozuku seed net threads with "light blue" and "blue" light, which contains a large amount of blue light. In particular, the "blue" light that penetrated the blue net was extremely effective in germinating upright bodies compared to "light blue" light, and also had a germination promoting effect. Although the details are unknown, it was found that upright bodies were more likely to germinate from the mozuku seed net threads that were irradiated with more blue light and less red light. Regarding the duration of light exposure, it was newly discovered that exposure of 6 hours light (18 hours dark) to 8 hours light (16 hours dark) is particularly effective for the germination of upright seeds.

Claims

1. When a white light selected from the group consisting of sunlight, fluorescent light, and incandescent light is not irradiated onto a disc-shaped body of Mozuku, The amount of light (A) and / or light (B) irradiated to the mozuku disc is 25 μmol / m ２ / s or more; The amount of light (C) irradiated to the mozuku disc is 35 μmol / m ２ / s or less, and The light sources of the light (A), the light (B), and the light (C) irradiated to the mozuku disc are LEDs; The method for sprouting upright plants from the disc-shaped bodies of Mozuku seaweed is characterized by the above. (A) Light in the wavelength range of 400 nm or more and less than 500 nm (B) Light in the wavelength range of 500 nm or more and less than 600 nm (C) Light in the wavelength range of 600 nm or more and less than 700 nm

2. 2. The method for germinating upright plants from the discs of Mozuku according to claim 1, characterized in that the light (C) is not irradiated onto the discs of Mozuku.

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