JP2023115230A - Germination method of upright nemacystus decipiens from discal nemacystus decipiens - Google Patents

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: None

Description

There is an application for exception to loss of novelty

The present invention relates to a method for sprouting uprights from mozuku discs in the presence or absence of white light.

Mozuku has been eaten all over Japan for a long time, but in recent years it has been recognized as a health food and a natural food, and demand is increasing. At present, cultured mozuku is mainly distributed, and in Japan in particular, a large amount of mozuku cultured in Okinawa is distributed. Efforts are being made to develop aquaculture techniques to further increase mozuku yields.

The method of cultivating Nemacystus decipiens in Okinawa, particularly the process of germinating Nemacystus decipiens discs and growing them into Nemacystus decipiens, includes, for example: (1) attaching the Nemacystus decipiens discs to a net or the like to prepare a seed net; (2) Step of setting seed nets in the sea, (3) Step of sprouting upright bodies from the disc-shaped bodies of Nemacystus decipiens attached to the seed nets, (4) Growing upright bodies into Nemacystus decipiens, (5) ) the process of harvesting grown mozuku.

Many reports have been made on the ecology and aquaculture of Okinawa mozuku, for example, a report on proper illumination for promoting the growth of mozuku (Non-Patent Document 1), a report on aquaculture technology for Okinawa Mozuku (Non-Patent Document 2), A report summarizing the effects of water temperature, light intensity, salinity, and nutrients on the growth of upright mozuku (germinating algae) (Non-Patent Document 3), a report on the relationship between the germination of upright mozuku and water temperature (Non-Patent Reference 4), and a report on the low water temperature limit for the growth of the Okinawa Mozuku discus (Non-Patent Reference 5).

However, in the above-mentioned method for cultivating Nemacystus decipiens, in the “(3) step of germinating uprights from discoids of Nemacystus decipiens attached to the seed net”, the conditions for germinating uprights from discoids of Nemacystus decipiens are still clear. It is the current situation that it is not elucidated. Therefore, for stable harvesting of mozuku, there is a demand for a method for efficiently germinating upright mozuku from discoid bodies of mozuku.

Matake Toma, "Seaweeds and seaweeds in Okinawa (Natural environment, aquaculture, 250 kinds of seaweeds)" Publishing company Mugen, pp. 237-260 (2012) Iwao Niimura, "Fundamental Research on Aquaculture of Okinawa Mozuku," Hokkaido University Examination Thesis (1976) "Growth characteristics of Okinawa mozuku under indoor culture" Okinawa Prefectural Fisheries and Marine Technology Center 2011 research and dissemination information Satoshi Moromizato et al., "Indoor cultivation of Mozuku seaweed and filamentous body culture," 2000 Okinawa Prefectural Fisheries Experimental Station Project Report (2000) ``Low water temperature limit for growth of Okinawa mozuku discus'' Okinawa Prefectural Fisheries and Ocean Technology Center FY2012 research and dissemination information

It is an object of the present invention to provide a method for sprouting uprights from mozuku discs in the presence or absence of white light.

As a result of intensive research to solve the above problems, the present inventors have discovered that mozuku discs are irradiated with a combination of a specific amount of light and light in a wavelength range in the presence or absence of white light. By doing so, it was found that upright plants germinate efficiently from the discoid bodies of mozuku. Based on these findings, the inventors have further studied and completed the present invention.
That is, the present invention includes the following configurations.
[1] in the presence or absence of white light,
The following (A) light and/or (B) light with a light intensity of 25 μmol/m ² /s or more, and the following (C) with a light intensity of 35 μmol/m ² /s or less are applied to the discoid body of Nemacystus decipiens. A method for germinating upright bodies from mozuku discs, characterized by irradiating with light of
(A) Light in a wavelength range of 400 nm or more and less than 500 nm (B) Light in a wavelength range of 500 nm or more and less than 600 nm (C) Light in a wavelength range of 600 nm or more and less than 700 nm The method for germinating upright plants from discoid bodies of Nemacystus decipiens according to the above [1], wherein only the light of A) and/or the light of (B) is irradiated.
[3] The light of (A) and the light of (B) having a total light amount of 50 μmol/m ² /s or more on a disk-shaped body of mozuku;
The method for germinating erect solids from discoid bodies of Nemacystus decipiens according to the above [1], characterized by irradiating with light (C) having a light intensity of 35 μmol/m ² /s or less.
[4] An upright body is produced from a disc-shaped body of Nemacystus decipiens according to any one of [1] to [3] above, wherein the light emitted to the disc-shaped body of Nemacystus decipiens is light derived from an LED. How to germinate.
[5] A method for germinating upright mozuku from disc-like bodies of mozuku under irradiation with white light, wherein the irradiation of the following light (C) is reduced by materials.
(C) Light with a wavelength range of 600 nm or more and less than 700 nm [6] In a method for germinating upright mozuku discoidal bodies under irradiation with white light, the following light (A) and/or light (B) or attenuating the irradiation of 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

According to the method of the present invention for germinating erect solids from discoidal bodies of Nemacystus decipiens, in the presence or absence of white light, the discoidal bodies of Nemacystus decipiens are exposed to a specific amount of light in a specific wavelength range, either alone or By irradiating them in combination, it is possible to efficiently germinate upright mozuku from disc-shaped mozuku.

Shows the life cycle of Mozuku. In Example 2, a photograph of Nemacystus decipiens net thread taken on the 14th day of culture is shown.

In the present invention, "mozuku" usually refers to algae belonging to the genus Mozuku, the family Chordariaceae, the family Brown algae, or the genus Mozuku, the family Spermatochnaceae. Cladosiphon okamuranus, Tinocladia crassa, Sphaerotrichia divaricata, Nemacystus decipiens belonging to the genus Nemacystus decipiens, etc., preferably Okinawa Nemacystus decipiens or Futo Mozuku.

In the present invention, the "disc of Nemacystus decipiens" (hereinafter also simply referred to as "disc") refers to the growth of a zygote generated by mating female gametes and male gametes of Nemacystus decipiens, or , and grown from neutral zoospores of Mozuku (see also Fig. 1).

As used in the present invention, the phrase “germinating an upright body from a discoid body” usually means that a large number of anabolic threads rise from the center of the discoid body, and furthermore, a state in which the anabolic threads gather and grow, i.e., a discoid It refers to the state in which an upright body is formed from the body. In addition, when the conditions for germination are not met, the discoid body of mozuku does not gather assimilated threads and becomes a neutral polythelium as it is. Neutral zoospores then develop from the neutral double sac and form discoid bodies again (see also Fig. 1).

One of the present invention is the following light (A) and/or (B) having a light amount of 25 μmol/m ² /s or more, respectively, applied to a disk-like body of mozuku in the presence or absence of white light. A method for germinating straight bodies from discoid bodies of Nemacystus decipiens, characterized by irradiating light and the following light (C) with a light intensity of 35 μmol/m ² /s or less.
(A) Light in a wavelength region of 400 nm or more and less than 500 nm (B) Light in a wavelength region of 500 nm or more and less than 600 nm (C) Light in a wavelength region of 600 nm or more and less than 700 nm Wavelength regions of (A) and (B) above The light contained in is preferable light for sprouting upright bodies from the discoid bodies of Nemacystus decipiens, and can promote the germination of upright bodies from the discoid bodies of Nemacystus decipiens.

Examples of white light include light from sunlight, fluorescent lamps, incandescent lamps, etc., and preferably include the above light (A), light (B) and light (C) in equal amounts. It does not have to be the amount of light, but it is sufficient if the visible light of each wavelength contained in the light of (A), the light of (B) and the light of (C) is mixed and looks white. The amount of white light is preferably 10 μmol/m ² /s or more, and the preferable range of the amount of light is 15 to 200 μmol/m ² /s, more preferably 25 to 100 μmol/m ² /s, still more preferably 50-100 μmol/m ² /s.

The above (A) light of 400 nm or more and less than 500 nm includes, for example, blue LED light (peak wavelength: 453 nm +/- 10 nm, wavelength range: 430 to 500 nm) when an LED is used as a light source. , but not limited to.

The above (B) light of 500 nm or more and less than 600 nm includes, for example, green LED light (peak wavelength: 525 nm +/- 10 nm, wavelength range: 490 to 550 nm) when an LED is used as a light source. , but not limited to.

The above (C) light of 600 nm or more and less than 700 nm includes, for example, red LED light (peak wavelength: 641 nm +/- 10 nm, wavelength range: about 630 to 680 nm) when an LED is used as a light source. but not limited to these.

As the light to be irradiated, the light (A) and/or the light (B) and the light (C) or the light (A) and/or the light (B) can be used. , preferably the light of (A), more preferably blue light with a peak wavelength of 453 nm, and even more preferably blue LED light.

In the present invention, the amount of light when only the light (A) and/or the light (B) is applied to the disk-shaped mozuku is 25 μmol/m ² /s or more. A preferable range of the amount of light 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, still more preferably 25 to 100 μmol/m ² . /s, most preferably 25-80 μmol/m ² /s. If it is within the above range, it is preferable for the upright growth to germinate from the discoid body of Nemacystus decipiens, and furthermore, it is preferable because the germination is promoted.

The light source for the wavelength ranges of the light (A), the light (B) and the light (C) is not particularly limited. : light-emitting diode). Considering that the wavelength range of light is easy to control, does not generate heat, and is low in running cost, light derived from an LED is preferable.

One of the present invention is the following light (A) and/or (B) having a light amount of 25 μmol/m ² /s or more, respectively, applied to a disk-like body of mozuku in the presence or absence of white light. This is a method for germinating upright plants from mozuku discs, characterized by irradiating only light.
(A) Light in a wavelength range of 400 nm or more and less than 500 nm (B) Light in a wavelength range of 500 nm or more and less than 600 nm The above light (A) and light (B) are as described above.

One of the present invention is the following light (A) and light (B) having a total amount of light of 50 μmol/m ² /s or more on a disk-like body of mozuku in the presence or absence of white light. and a method for germinating erect solids from discoid bodies of Nemacystus decipiens, characterized by irradiating the following light of (C) with a light intensity of 35 μmol/m ² /s or less.
(A) Light in a wavelength range of 400 nm or more and less than 500 nm (B) Light in a wavelength range of 500 nm or more and less than 600 nm (C) Light in a wavelength range of 600 nm or more and less than 700 nm Light of (A) above, (B) and the light of (C) are as described above.

In the present invention, the mozuku disc is irradiated with the above light (A), the light (B), and the above light (C). The combined total amount of light 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, still more preferably 60 to 100 ^μmol . /m ² /s, most preferably 60-80 μmol/m ² /s.

In addition, the light quantity of the light (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. s or less. The light of (C), especially the red light with a wavelength of over 600 nm, tends to inhibit the germination of upright bodies from the discoid bodies of mozuku. It is favorable for upright shoots to germinate from discoid bodies of mozuku.

There are no particular restrictions on the environment in which the mozuku discs are irradiated with light as long as the mozuku discs can grow in the presence or absence of white light. Such conditions can be exemplified.
The seawater is not particularly limited, but may be seawater directly sampled from the sea, underground seawater sampled from underground near the coast or from the seabed (for example, the continental shelf), or deep seawater sampled from the deep sea. good too. Distilled water, tap water, or the like may be added with necessary mineral components (for example, salts such as calcium, potassium, sodium, and magnesium) to have the same composition as seawater.
Examples of seawater temperature include, but are not limited to, preferably about 10 to 30°C, more preferably 15 to 25°C, and most preferably 20 to 22°C.

As a cycle of light irradiation time, for example, the time cycle of light and dark in a day is 5 to 16 hours in the light period and 19 to 8 hours in the dark period in 24 hours (the total of the light period and the dark period is 24 hours). The same applies hereinafter), preferably 6 to 12 hours light period, 18 to 12 hours dark period, more preferably 6 to 10 hours light period, 18 to 14 hours dark period, still more preferably light period Examples include, but are not limited to, 6-8 hour dark period and 18-16 hour dark period.
As the number of days of light irradiation, for example, the light irradiation time cycle is performed for about 14 days or more, preferably about 28 days or more, more preferably about 35 days or more, and about 42 days or more. are more preferred, but are not limited to these.

The nutritional conditions of seawater are not particularly limited, but the concentration of nitrate nitrogen, which is a major nutrient component for seaweeds such as mozuku, is preferably 0.1 to 50 μmol/L, more preferably 0.2 to 10 μmol. /L, more preferably 0.5 to 10 μmol/L. Phosphate phosphorus concentration is, for example, preferably 0.01 to 5 μmol/L, more preferably 0.02 to 1 μmol/L, more preferably 0.05 to 1 μmol/L. In general seawater, the nitrate nitrogen concentration is usually 30 μmol/L or less, and the phosphate phosphorus concentration is often 3 μmol/L or less. is also possible.
The salt concentration of seawater is not particularly limited, but is preferably 1.5 to 4.5% by mass, more preferably 2 to 3.5% by mass, and more preferably 2.8 to 3.3% by mass. is mentioned.

The method of irradiating the discoid bodies of Nemacystus decipiens with light is not particularly limited as long as the discoid bodies are irradiated with the above light in the presence or absence of white light. (1) A method of irradiating a plate-shaped body of mozuku floating in seawater under or in the absence of light, (2) A substrate with a plate-shaped body of mozuku attached to it is placed in seawater, and the plate-shaped body is exposed. A method of irradiating light can be mentioned. The above method (2) is preferable in consideration of further growing upright plants sprouted from discoid bodies and harvesting Nemacystus decipiens.

The substrate to which the discoid bodies of Nemacystus decipiens are attached can be obtained by conventional methods. Nemacystus decipiens can be obtained by culturing mozuku in seawater containing neutral zoospores generated from neutral bipodia with the above-mentioned substrate, attaching the zygotes or neutral zoospores to the substrate, and allowing the mozuku to grow into discoid bodies of Nemacystus decipiens. .

The substrate is not particularly limited as long as it is a material to which zygotes or neutral zoospores are likely to adhere. Also, the shape of the substrate is not particularly limited, and examples thereof include net-like, noren-like, and a state in which threads are wound around a frame.

As a method for installing the substrate with the mozuku disc-shaped body attached to it in seawater, there is a method of installing it in the sea with calm waves, and a method of installing it in a container such as a water tank installed on land filled with seawater and installing it in it. methods and the like. The substrate is not particularly limited, but it is preferably installed at a position of about 0 to 2 m below the water surface, more preferably at a position of about 0.1 to 1.5 m below the water surface, and is preferably installed at a position of about 0.2 to 1.5 m below the water surface. It is more preferable to install at a position of 1 m.

Another aspect of the present invention is a method for germinating upright stems from discoid bodies of mozuku under irradiation of white light, wherein the irradiation of light in the following (C) is reduced by materials.
(C) Light in a wavelength range of 600 nm or more and less than 700 nm

Materials that can reduce the light irradiation of the above (C) are not particularly limited, but include, for example, glass, wood (plant fibers, etc.), plastics, etc., cost and durability, ease of availability From these points of view, for example, color sheets (sheet-like, net-like, film-like, etc.) used for civil engineering or agriculture are preferred. As such a color sheet, for example, a sheet having a thickness of about 0.07 to 0.11 mm can be used, but it is not limited thereto. The color of the color sheet is not particularly limited, but from the viewpoint of reducing the light of (C), blue, green, etc. are preferably used, and blue is preferred. Materials for the color sheet include polyvinyl chloride, polyethylene, polypropylene, polyester, and nylon in the case of plastic. In addition, color sheets may be stacked and used, and usually 1 to 6 sheets, preferably 2 to 4 sheets are used, but the number is not limited to these. The white light and the light of (C) are as described above.

Furthermore, as the material capable of reducing the irradiation of the light (C), in addition to the above, for example, a net-like, sheet-like, or film that selectively transmits the light of (A) and/or the light of (B) A material having a shape such as a shape is exemplified. For example, a net-like material that selectively transmits the light (A) and/or the light (B) can be preferably used. Examples include, but are not limited to, net-like materials described in JP-A-2017-55686. For example, in the form of several sheets (2 to 4 sheets) of Dioneo Shade Soukai, from sunlight, that is, light containing (A) light, (B) light and (C) light, (A) The light and/or the light (B) can be selectively transmitted, that is, the light (A) and/or the light (B) can be converted to light with a large amount of light, and can be irradiated onto the mozuku disc. Therefore, it is preferable.

Further, one aspect of the present invention is a method for germinating upright stems from discoid bodies of mozuku under irradiation of white light, wherein the following (A) light and/or (B) light is enhanced, or the following ( C) is a method of attenuating the irradiation of light.
(A) Light in a wavelength range of 400 nm or more and less than 500 nm (B) Light in a wavelength range of 500 nm or more and less than 600 nm (C) Light in a wavelength range of 600 nm or more and less than 700 nm Light of (A) and/or (B) In order to enhance the light of the mozuku, for example, a method of increasing the amount of light emitted from the light source, a method of concentrating the light of the light source and/or white light on the disc-shaped body of mozuku using a reflector or the like, a method of light source and mozuku For example, a method of bringing the distance from the plate-like body closer. Moreover, in order to attenuate the light irradiation of (C), the above materials may be used, but they do not have to be used. For example, in addition to the method of reducing the amount of light emitted from the light source, when the substrate to which the mozuku discoid bodies are attached is placed in seawater, the light irradiation is attenuated by the seawater existing between the substrate and the light source. good too. Alternatively, a method of securing a distance between the light source and the disc-shaped body of mozuku may be used. The white light, the light of (A), the light of (B) and the light of (C) are as described above.

The present invention is illustrated by the following examples, which are merely illustrative of the invention and are not intended to limit the invention.

[Example 1]
(1) Preparation of a discoid body of Nemacystus decipiens A slide glass was placed in sterilized seawater in which Nemacystus decipiens (Okinawa Nemacystus decipiens), which confirmed the formation of neutral bipodia and the swimming of neutral zoospores, was cultured under aerobic conditions, and the water temperature was 25. C., a light intensity of 50 .mu.mol/ ^m.sup.2 /s, a light period of 12 hours and a dark period of 12 hours. Place the slide glass with neutral zoospores attached in a petri dish filled with sterilized seawater, under the conditions of a water temperature of 25° C., a light intensity of 50 μmol/m ² /s, and a daily irradiation time cycle of 12 hours light period and 12 hours dark period. was cultured for 3 weeks to obtain discoid bodies of Nemacystus decipiens.

(2) Light irradiation and culture of Nemacystus decipiens discs The obtained Nemacystus decipiens discs were filled with sterilized seawater (nitrate nitrogen concentration: 2 μmol/L, phosphate phosphorus concentration: 0.2 μmol/L). 5 to 10 cells were placed in each well of a 6-well microplate and allowed to stand in a constant temperature bath (model: CN-40A, manufactured by Mitsubishi Mechanical Engineering Co., Ltd.). The cells were irradiated with light under the following conditions and cultured. In the discoid body of mozuku, anabolic threads are raised from the discoid body of mozuku by culturing. The number of disk-like bodies increased from 5 to 10 at the beginning to about 100 to 200 times.

[Culture conditions and irradiation light conditions]
Culture temperature: set at 25°C.
Irradiation time cycle: In one day, light was continuously applied for 12 hours (light period), and light was turned off for 12 hours to create a dark place (dark period).
Irradiation light: A three-wavelength variable LED irradiation device (model: 3LH-64 manufactured by Nippon Medical Instruments Co., Ltd.) was used as a light source, and the following light was irradiated.
(C) Light in a wavelength range of 600 nm or more and less than 700 nm (peak wavelength 641 nm). It may be abbreviated as "R" hereinafter.
(B) Light in a wavelength range of 500 nm or more and less than 600 nm (peak wavelength 525 nm). It may be abbreviated as "G" hereinafter.
(A) Light in a wavelength range of 400 nm or more and less than 500 nm (peak wavelength 453 nm). It may be abbreviated as "B" hereinafter.
White light (light containing equal amounts of light (A), light (B) and light (C) above). Hereinafter, it may be abbreviated as "RGB".
Amount of light to be irradiated: The amount of light described in Table 1 was applied.

(3) Observation method of upright germination from mozuku discoids 14 days, 21 days, 28 days, 35 days, and 42 days after the start of light irradiation, photographs were taken under a stereoscopic microscope, and 1 mm ² The number of discoids inside (the total number of ungerminated and germinated discs) and the number of germinated discoids The length of about 1 mm or more) was counted, and the germination rate was calculated by the following formula.

(4) Evaluation Criteria The germination rate obtained for each observation day was symbolized and evaluated according to the following criteria. Table 1 shows the results. The germination rate after 14 days and 21 days of observation was 0% in all test plots, so it is not shown in Table 1. Also, test groups 1 to 7 in Table 1 are examples, and test groups 8 to 15 are comparative examples.
[Evaluation criteria]
D rating: 0% germination rate
C rating: germination rate is over 0% and less than 10% B rating: germination rate is 10% or more and less than 20% A rating: germination rate is 20% or more and less than 30% S rating: germination rate is 30% or more , less than 50%, SS evaluation: germination rate of 50% or more When the evaluation was B or higher, it was judged that mozuku germinates upright from the disk-like body of Nemacystus decipiens and is effective for germination. In particular, when the evaluation was A or higher, it was judged that not only was the mozuku disc-shaped body germinated upright, but also the germination promotion effect was observed.

As is clear from the evaluation results on the 42nd day of observation, only the light of (A) (peak wavelength 453 nm: wavelength range of about 400 to 500 nm) was irradiated, and the light amount was adjusted to 25 to 100 μmol/m ² /s. In , it was evaluated as A or SS, and it was confirmed that upright shoots sprouted from the discoid body of mozuku, and that it was very effective for sprouting and promoted sprouting.
Light (B) (peak wavelength 525 nm: wavelength range approximately 500 to 600 nm) and light (A) (peak wavelength 453 nm: wavelength range approximately 400 to 500 nm) were irradiated together, and the amount of light was 25 μmol/m ² /. In the test plot adjusted to s, the evaluation was S, and it was confirmed that mozuku seeds sprouted upright from discoid bodies, and were very effective in sprouting, and also promoted sprouting.
In the test section in which only the light of (B) (peak wavelength 525 nm: wavelength range of about 500 to 600 nm) was irradiated and the light amount was adjusted to 50 μmol/m ² /s, the evaluation was A. It was found to be very effective for germination and promote germination.
(C) light (peak wavelength 641 nm: wavelength range about 600 to 700 nm), (B) light (peak wavelength 525 nm: wavelength range about 500 to 600 nm) and (A) light (peak wavelength 453 nm: wavelength range about 400 500 nm), and the light intensity was adjusted to 33.3 μmol/m ² /s.
In the test section where only the light of (B) (peak wavelength 525 nm: wavelength range of about 500 to 600 nm) was irradiated and the light amount was adjusted to 100 μmol/m ² /s, the evaluation was B, and the mozuku disc-shaped to vertical and was effective for germination.

From the results of Example 1, when (A) light (i.e., blue “B” light color) is irradiated more, and/or (C) light (i.e., red “R” light color) We hypothesized that upright bodies would germinate more easily from mozuku discs when the irradiation of mozuku was reduced, and further experiments were carried out.

[Example 2]
(1) Fabrication of Nemacystus decipiens seed net thread with adhering Nemacystus decipiens disc-like bodies Attached to a glass container (plum wine bottle) were placed Okinawa Nemacystus decipiens with neutral double sacs and sterilized seawater, water temperature 25°C, white fluorescent light (light intensity: 50 μmol). /m ² /s) under the conditions of a 12-hour light period and a 12-hour dark period, and cultured under aeration for 30 days, and neutral zoospores were confirmed to be swimming.
In the sterilized seawater in which the neutral zoospores are swimming, a net thread (about 30 cm after unwinding the mesh) obtained by cutting a part of the culture net (composition: 70% nylon, 30% polyethylene) used for cultivating mozuku seaweed Aerated culture was performed for 2 weeks under the same conditions as described above to obtain Nemacystus decipiens net thread having discoid bodies attached to the net thread surface. The surface of the mesh yarn was visually checked for the presence or absence of adhesion of the board-like body.

(2) Light irradiation and culture of Nemacystus decipiens disc-like body The obtained Nemacystus decipiens net thread was cut into 1.5 to 2.0 cm, and the cut Nemacystus decipiens net thread was added to sterilized seawater (nitrate nitrogen concentration: 2 μmol). /L, phosphoric acid phosphorus concentration: 0.2 μmol / L), placed in each 300 mL culture aerated flask (hereinafter simply referred to as “flask”), and placed in a constant temperature bath (model: CN- 40A (manufactured by Mitsubishi Mechanical Engineering Co., Ltd.), and cultured under the following conditions by irradiation with light (test groups 16 to 23).
Two of the above flasks were placed in the same constant temperature bath, one of which was left as it was (test sections 16 to 19), and the other was a blue net (trade name: Dioneo Shade Sokai Dio Kasei Co., Ltd.) (test group 20-23). In addition, the flask covered with the blue net was placed closer to the light source installed at the top of the constant temperature bath than the uncovered flask so that the amount of light irradiated to each Mozuku species net thread was the same. Installed on a high platform.

[Culture conditions]
Culture temperature: set at 24°C.
Irradiation time cycle: Four thermostatic chambers were used, and the light-dark time cycle of each thermostatic chamber was 6, 8, 10, 12 hours (dark period 18, 16, 14, 12 time).
Water replacement frequency of sterilized seawater: Replaced with fresh sterilized seawater once a day.

[Conditions of irradiated light]
<<“light blue” light: no blue net (test areas 16 to 19)>>
Irradiated light: Using a three-wavelength variable LED irradiation device (model: 3LH-64 manufactured by Nippon Medical Instruments Co., Ltd.) as a light source, the ratio of the following "R", "G", and "B" light is adjusted, and in each flask Each Mozuku species net thread was irradiated with "pale blue" light.
"R": (C) Light in a wavelength range of 600 nm or more and less than 700 nm (peak wavelength 641 nm).
"G": (B) Light in a wavelength range of 500 nm or more and less than 600 nm (peak wavelength 525 nm).
"B": (A) Light in a wavelength range of 400 nm or more and less than 500 nm (peak wavelength 453 nm).
Irradiation light amount: total light amount 50 μmol/m ² /s
(“R”: 10.0 μmol/m ² /s,
“G”: 10.0 μmol/m ² /s,
“B”: 30.0 μmol/m ² /s) of “pale blue” light was applied.

<<“Blue” light: with blue net (test zone 20-23)>>
Irradiated light: The flask was covered with a blue net, and the same “pale blue” light as used in Test Groups 16 to 19 above was applied from above to give “blue” to each Mozuku species net thread in each flask. was irradiated as the light of
Irradiated light amount (under blue net coating): total light amount 50 μmol/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.

(3) Observation method and evaluation criteria for upright germination from Nemacystus decipiens discoid bodies 14 days and 36 days after the start of light irradiation, the Nemacystus decipiens seed thread was taken out in a petri dish, and the whole Nemacystus decipiens net thread was photographed with a digital camera. was photographed, and the germination state was observed by counting the number of upright bodies of about 1 mm or more sprouting from the disk-like bodies of Mozuku seed net threads. The number of upright plants counted was evaluated by symbolizing the degree of germination according to the following evaluation criteria. The results are shown in Table 2 and FIG.
[Evaluation symbols and evaluation criteria]
×: The number of upright bodies that can be seen in the overall photo is 0 〇: The number of upright bodies that can be seen in the overall photo is 1-5 ◎: The number of upright bodies that can be seen in the overall photo is 6-15 ◎◎: The number of upright bodies that can be seen in the overall photo is confirmed 16 or more upright plants were formed When the evaluation symbol was "O" or more, upright plants sprouted from the disc-shaped body of Nemacystus decipiens, and it was judged to be effective for germination. In particular, it was determined that when the evaluation symbol was "◎◎" or higher, the upright stems sprouted from the discoid bodies of Nemacystus decipiens.

Furthermore, FIG. 2 shows photographs of the seed net threads taken on the 14th day of culture for test plots 16 to 17 and test plots 20 to 21 with good results above. The shorter the light period, the more closely the discoids are clustered (dark arrows). Fig. 2 also shows a photograph of the seed net yarn taken on the 0th day of the test (before irradiation).

From the results in Table 2 and Fig. 2, it was found that by irradiating the Nemacystus decipiens seed net threads to which the Nemacystus decipiens discoids adhered with light of "pale blue" and "blue" light, which contains a large amount of blue light irradiation, the discoids of Nemacystus decipiens It was possible to germinate upright plants from In particular, the "blue" light transmitted through the blue net was much more effective for upright germination than the "pale blue" light, and had the effect of promoting germination. Although the details are unknown, it was found that many upright germination was observed in mozuku net threads exposed to more blue light and less exposure to red light.
As for the light irradiation time, it was newly found that irradiation with a light period of 6 hours (dark period of 18 hours) to a light period of 8 hours (dark period of 16 hours) is particularly effective for upright germination.

Claims (3)

A disk-shaped body of mozuku is irradiated with the following light (A) with a light intensity of 25 μmol/m ² /s or more and the following light (C) with a light intensity of 10 μmol/m ² /s or less. A method of sprouting upright solids from the disc-shaped body of Mozuku.
(A) Light with a wavelength range of 400 nm or more and less than 500 nm (C) Light with a wavelength range of 600 nm or more and less than 700 nm A disk-shaped body of Nemacystus decipiens is irradiated with the following light (A), light (B), and light (C) with a total light intensity of 50 μmol/m ² /s or more. 2. A method for germinating upright plants from discoid bodies of Nemacystus decipiens described in 1 above.
(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 3. According to claim 1 or 2, characterized in that the daily light-dark time cycle, which is the light irradiation time, is a light period of 6 hours to 10 hours and a dark period of 18 hours to 14 hours when light is irradiated. A method of sprouting uprights from discoid bodies of Mozuku described.