JP2025071206A - How to grow grasses - Google Patents

Abstract

To provide methods and devices for growing gramineous plants that can yield hybrid seeds with high quality and large seed mass and can perform stable breeding using high-speed generation promotion technology.SOLUTION: There is provided a method for growing a gramineous plant, comprising: a first step of irradiating the seed parent and the pollen parent with white light having a color temperature of 5,000 K to 6,500 K using a standard light source to grow them; a mating step of excising the upper part of the floret of the seed parent grown in the first step and mating the same with the pollen parent grown in the first step; and a second step of irradiating the seed parent obtained through the mating step with light emitted from a standard light source and a LED light source capable of emitting light in a wavelength range of 380 nm or more and 780 nm or less, wherein the peak top of light intensity is maximized in a wavelength range of 615 nm or more and 650 nm or less, and wherein the light, within the wavelength range of 380 nm or more and 780 nm or less, has the peak top of light intensity maximized in a wavelength range of 550 nm or more and 780 nm or less.SELECTED DRAWING: Figure 1B

Description

The present invention relates to a method for cultivating grasses and an apparatus for cultivating grasses.

Rapid generation acceleration technology for grasses is expected to be applied as a fundamental technology for efficient and effective variety development, including 1) the development of near-isogenic lines (NILs) in a short period of time, 2) rapid gene accumulation starting from NILs, and 3) rapid development of initial populations for breeding selection. In all cases, crossbreeding between the desired varieties or lines is required.

Generally, the plants and panicles of grasses obtained under high-speed generation acceleration conditions are small, and the number of spikelets is limited. Under these circumstances, it is essential to reliably obtain hybrid seeds, ensure that the seeds germinate, and grow well in order to stably operate a breeding system that uses high-speed generation acceleration technology.

Conventionally, it has been known that light conditions are important in breeding systems that use rapid generation acceleration technology. For example, a rice production method has been proposed in which rice is cultivated under dense planting conditions and short-day conditions while being irradiated with blue light (see Patent Document 1). In this proposed method, blue light promotes rice flowering, and dense planting conditions increase the total number of ears, making it possible to grow and harvest rice in a short period of time at low cost.

Also, a method for growing rice has been proposed in which rice is irradiated with intermittent light, specifically, a red LED, and the illuminance at the rice is equal to or lower than the light compensation point of rice (see Patent Document 2 and Non-Patent Document 1). This proposed method can promote rice growth and increase the yield. Specifically, it can increase the total weight of the harvested unhulled rice and brown rice, the total number of grains, the number of grains per ear, the weight of the ear per ^m2 , the number of grains per ^m2 , etc. However, this proposed method does not change the 1,000-grain weight, and does not affect the size or ripening of the brown rice itself.

Therefore, there is currently a strong demand for a method for cultivating grasses that can produce high-quality hybrid seeds with good germination rates and subsequent growth, and that can stably breed using high-speed generation acceleration technology, as well as a grass-cultivation device that can be used in the method for cultivating grasses.

JP 2010-233509 A JP 2005-176798 A

Kazushige Nakamura et al., Meiji University Faculty of Agriculture Research Report, No. 138 (2004), pp. 35-39

The present invention aims to solve the above-mentioned problems in the past and achieve the following objectives. That is, the present invention aims to provide a method and an apparatus for cultivating grasses that can obtain high-quality hybrid seeds with large seed mass and can stably breed using high-speed generation acceleration technology.

The means for solving the above problems are as follows.
<1> A method for growing a grass family plant, comprising: shielding external light and irradiating only artificial light to the grass family plant to grow the grass family plant,
A first step of irradiating a grass plant with white light as the artificial light to grow the grass plant;
A second step of irradiating the grass family plant grown in the first step with light having a maximum light intensity at a peak top in a wavelength range of 550 nm to 780 nm in an emission spectrum of 380 nm to 780 nm as the artificial light, thereby growing the grass family plant;
Including,
The method for cultivating a grass family plant is characterized in that the first step is changed to the second step during the mating period of the grass family plant.
<2> A method for growing a grass family plant, comprising: shielding external light and irradiating only artificial light to the grass family plant to grow the grass family plant,
A first step of irradiating a grass plant with white light as the artificial light to grow the grass plant;
A second step of irradiating the grass family plant grown in the first step with artificial light such that, in a wavelength range of 380 nm to 780 nm in an emission spectrum, a maximum light intensity R in a wavelength range of 550 nm to 780 nm and a maximum light intensity B in a wavelength range of 400 nm to 490 nm satisfy R>B, and a maximum light intensity R in a wavelength range of 550 nm to 780 nm and a maximum light intensity G in a wavelength range of more than 490 nm and less than 550 nm satisfy R>G;
Including,
The method for cultivating a grass family plant is characterized in that the first step is changed to the second step during the mating period of the grass family plant.
<3> The method for growing a Gramineae plant according to any one of <1> to <2>, wherein the artificial light in the second step is artificial light such that, in an emission spectrum in a wavelength region of 380 nm or more and 780 nm or less, a value Rf obtained by definite integration of a wavelength region of 550 nm or more and 780 nm or less and a value Bf obtained by definite integration of a wavelength region of 400 nm or more and 490 nm or less satisfy Rf>Bf, and a value Rf obtained by definite integration of a wavelength region of 550 nm or more and 780 nm or less and a value Gf obtained by definite integration of a wavelength region of more than 490 nm and less than 550 nm satisfy Rf>Gf.
<4> The method for cultivating a gramineous plant according to any one of <1> to <3>, wherein in the first step, the crossing of the gramineous plant is carried out using a gramineous plant having a cut glume.
<5> The method for cultivating a gramineous plant according to any one of <1> to <4>, which is used for accelerating the generation of a gramineous plant.
<6> A gramineous plant growing apparatus used for growing gramineous plants,
A housing means capable of housing the Gramineae plant;
a first light irradiating means for irradiating the inside of the container means with white light;
a second light irradiating means for irradiating the inside of the container with light having a maximum light intensity at a peak top in a wavelength range of 550 nm or more and 780 nm or less in an emission spectrum of the wavelength range of 380 nm or more and 780 nm or less;
A switching means for switching between the first light irradiation means and the second light irradiation means;
The present invention relates to an apparatus for cultivating grasses, comprising:
<7> A gramineous plant growing apparatus used for growing gramineous plants,
A housing means capable of housing the Gramineae plant;
a first light irradiating means for irradiating the inside of the container means with white light;
a second light irradiating means for irradiating light into the container means such that, in a wavelength region of 380 nm or more and 780 nm or less in an emission spectrum, a maximum light intensity R in a wavelength region of 550 nm or more and 780 nm or less and a maximum light intensity B in a wavelength region of 400 nm or more and 490 nm or less satisfy R>B, and a maximum light intensity R in a wavelength region of 550 nm or more and 780 nm or less and a maximum light intensity G in a wavelength region of more than 490 nm and less than 550 nm satisfy R>G;
A switching means for switching between the first light irradiation means and the second light irradiation means;
The present invention relates to an apparatus for cultivating grasses, comprising:
<8> The device for growing grass plants according to any one of <6> to <7>, wherein the light irradiated by the second light irradiation means is artificial light such that, in an emission spectrum in a wavelength region of 380 nm or more and 780 nm or less, a value Rf obtained by definite integration of a wavelength region of 550 nm or more and 780 nm or less and a value Bf obtained by definite integration of a wavelength region of 400 nm or more and 490 nm or less satisfy Rf>Bf, and a value Rf obtained by definite integration of a wavelength region of 550 nm or more and 780 nm or less and a value Gf obtained by definite integration of a wavelength region of more than 490 nm and less than 550 nm satisfy Rf>Gf.
<9> The apparatus for cultivating a grass family plant according to any one of <6> to <8>, which is used for cultivating a grass family plant artificially cross-pollinated using a cut glume of the grass family plant.
<10> The apparatus for cultivating a grass family plant according to any one of <6> to <9>, which is used for accelerating the generation of a grass family plant.

The present invention provides a method and an apparatus for cultivating grasses that can solve the above-mentioned problems and achieve the above-mentioned objectives, produce high-quality hybrid seeds with large seed mass, and stably breed using high-speed generation acceleration technology.

1A is a diagram showing an example of an emission spectrum of white light, where the horizontal axis represents wavelength (nm) and the vertical axis represents relative light intensity. 1B is a diagram showing an example of an emission spectrum of light in which the light intensity of the peak top in the wavelength region of 550 nm to 780 nm is maximum in the wavelength region of 380 nm to 780 nm in the emission spectrum, or in which the maximum light intensity R in the wavelength region of 550 nm to 780 nm in the emission spectrum and the maximum light intensity B in the wavelength region of 400 nm to 490 nm in the emission spectrum satisfy R>B, and the maximum light intensity R in the wavelength region of 550 nm to 780 nm in the emission spectrum and the maximum light intensity G in the wavelength region of more than 490 nm and less than 550 nm satisfy R>G. The horizontal axis is wavelength (nm), and the vertical axis is relative light intensity. 1C is a diagram showing another example of an emission spectrum of light in which the light intensity of the peak top in the wavelength region of 550 nm to 780 nm is maximum in the wavelength region of 380 nm to 780 nm in the emission spectrum, or in which the maximum light intensity R in the wavelength region of 550 nm to 780 nm in the emission spectrum and the maximum light intensity B in the wavelength region of 400 nm to 490 nm in the emission spectrum satisfy R>B, and the maximum light intensity R in the wavelength region of 550 nm to 780 nm in the emission spectrum and the maximum light intensity G in the wavelength region of more than 490 nm and less than 550 nm satisfy R>G. The horizontal axis is wavelength (nm), and the vertical axis is relative light intensity. 1D is a diagram showing an example of light in which, in the wavelength region of 380 nm or more and 780 nm or less in the emission spectrum, the maximum light intensity R in the wavelength region of 550 nm or more and 780 nm or less and the maximum light intensity G in the wavelength region of more than 490 nm and less than 550 nm satisfy R>G, but the maximum light intensity R in the wavelength region of 550 nm or more and 780 nm or less and the maximum light intensity B in the wavelength region of 400 nm or more and 490 nm or less satisfy R<B. The horizontal axis represents wavelength (nm) and the vertical axis represents relative light intensity. 1E is a diagram showing an example of light whose peak top light intensity is maximum in the wavelength range of 615 nm to 650 nm in an emission spectrum in the wavelength range of 380 nm to 780 nm inclusive, where the horizontal axis represents wavelength (nm) and the vertical axis represents relative light intensity. 2 is a diagram showing the results of measuring the mass of the hybrid seeds _F1 obtained in Examples 1 and 2, and Comparative Examples 1 and 2 in Test Example 2. The vertical axis represents the average mass (mg) of brown rice. FIG. 3 is a diagram showing an example of the overall configuration of the gramineous plant-growing device of the present invention, and is a front view showing the main internal configuration of the device with a portion of the front cut away. FIG. 4 is a diagram showing an example of the overall configuration of the gramineous plant-growing apparatus of the present invention, and is a right side view with a part of the side of the gramineous plant-growing apparatus cut away to mainly show the storage means as an internal configuration thereof. FIG. 5 is a cross-sectional plan view showing the internal structure of the apparatus for cultivating gramineous plants of the present invention. FIG. 6A is a schematic cross-sectional view of the accommodation means of the gramineous plant-growing device of the present invention, showing one example of the arrangement of light sources (first light irradiation means and second light irradiation means) within the accommodation means. FIG. 6B is a plan view taken along the line bb in FIG. 6A, showing the arrangement of light sources on the ceiling surface of the accommodation means of the apparatus for cultivating grass plants of the present invention. FIG. 6C is a schematic outline view showing an example of the configuration of a light source of the gramineous plant growing device of the present invention. FIG. 6D is a diagram showing an example of an irradiation pattern of light emitted by a light source of the gramineous plant growing device of the present invention. FIG. 6E is a diagram showing another example of an irradiation pattern of light emitted by the light source of the gramineous plant growing device of the present invention. FIG. 7A is a graph showing an example of temperature change in each of the accommodation means of the gramineous plant-growing apparatus of the present invention. FIG. 7B is a graph showing an example of temperature changes in each container of the apparatus for cultivating grass plants of the present invention, which change with the day-night cycle. FIG. 7C is a graph showing an example of temperature change in the accommodation means of the gramineous plant-growing apparatus of the present invention, in which the day-night cycles are set to be different from each other.

(Method of growing grasses)
The method for growing a gramineous plant of the present invention is a method for growing a gramineous plant by shielding external light and irradiating the gramineous plant with only artificial light, and includes a first step and a second step, and further includes other steps as necessary. The timing for changing from the first step to the second step is during the mating period of the gramineous plant.
The method for growing a grass plant can be suitably carried out by the apparatus for growing a grass plant of the present invention described below.

The Gramineae plant is not particularly limited and may be appropriately selected depending on the purpose. For example, plants belonging to the genus Oryza such as rice; plants belonging to the genus Triticum such as bread wheat, club wheat, and durum wheat; plants belonging to the genus Zea such as corn; plants belonging to the genus Hordeum such as barley; plants belonging to the genus Secale cereale such as rye; plants belonging to the genus Echinochloa such as barnyard millet and barnyard millet; plants belonging to the genus Paspalum such as paspalum and striped barnyard millet; plants belonging to the genus Eleusine such as finger millet and goosegrass; plants belonging to the genus Digitalia such as crabgrass . Examples of suitable plants include plants belonging to the genus Setaria , such as foxtail millet, Japanese foxtail, green foxtail, golden foxtail, and Japanese knotweed; plants belonging to the genus Briza , such as briza grass and briza serrata; plants belonging to the genus Miscanthus , such as silver grass; plants belonging to the genus Andropogon , such as American silvergrass; plants belonging to the genus Eragrostis , such as winter grass and Japanese sorghum; plants belonging to the genus Sorghum , such as corn millet; and plants belonging to the genus Panicum , such as sand millet. Among these, plants belonging to the genus Oryza are preferred.

When a plant belonging to the genus Oryza is used as the Gramineae plant, the rice variety is not particularly limited and can be appropriately selected depending on the purpose.
Examples of the cultivar group of plants belonging to the genus Oryza include japonica, tropical japonica, indica, and javanica.
In addition, examples of classification of plants belonging to the genus Oryza based on their shape include long-grained, short-grained, and medium-grained varieties.
In the present invention, any of these can be used.

In this specification, the definition of "external light" varies depending on the process.
In the first step, "external light" means light other than white light.
In the second step, the term "external light" refers to light other than the following (1) or (2).
(1) Light whose peak top light intensity is maximum in the wavelength region of 550 nm or more and 780 nm or less in the emission spectrum of the wavelength region of 380 nm or more and 780 nm or less.
(2) Light in which, in the wavelength region of 380 nm or more and 780 nm or less in the emission spectrum, the maximum light intensity R in the wavelength region of 550 nm or more and 780 nm or less and the maximum light intensity B in the wavelength region of 400 nm or more and 490 nm or less satisfy R>B, and the maximum light intensity R in the wavelength region of 550 nm or more and 780 nm or less and the maximum light intensity G in the wavelength region of more than 490 nm and less than 550 nm satisfy R>G.
Therefore, the external light is not limited to natural light such as sunlight, but also includes artificial light other than the artificial light used in the first step or the second step described above.

In this specification, "shading" means an environment that is not affected by external light. Therefore, as long as the environment is free from the effects of external light, it may be partially or completely shaded, but completely shaded is preferable. This allows the grass plant to be irradiated with only artificial light.
The shielding method is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include a method using an incubator, a thermostatic device or room, a biotron, etc., which are configured to block external light. These may be used alone or in combination of two or more.

As used herein, "artificial light" means light emitted from an artificial source.
The artificial light source is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include fluorescent lamps, electric lights, strobes, neon tubes, cathode ray tubes, light-emitting diodes (LEDs), etc. These may be used alone or in combination of two or more. Among these, fluorescent lamps and LEDs are preferred.

<First step>
The first step is a step of growing the grass family plant by irradiating the grass family plant with white light as the artificial light. The time when the first step is changed to the second step is during the mating period of the grass family plant. Therefore, the first step is a step of growing the grass family plant from the seed of the grass family plant to the mating period.
The first step can shorten the number of days until heading of the gramineous plant.

The seeds of the Gramineae plant are not particularly limited as long as they are in a germinating state, and can be appropriately selected depending on the purpose.
The method for obtaining the seeds of the Gramineae plant is not particularly limited and can be appropriately selected depending on the purpose, and may be seeds obtained by growing the Gramineae plant outdoors such as in a farm field, or seeds obtained by growing the Gramineae plant in an artificial environment. Among these, from the viewpoint of quickly obtaining seeds of the Gramineae plant in breeding using a high-speed generation acceleration technique, seeds obtained by growing the Gramineae plant in an artificial environment are preferred.

The term "crossbreeding" refers to exposing the pistil (sometimes called "female") of one individual of the Gramineae plant to the pollen (sometimes called "male") of another individual, and obtaining seeds in this way is called "cross breeding."
The female plant individual is called the "seed parent" and the male plant individual is called the "pollen parent", and the hybrid seeds obtained by the cross are called " _F1 ". The "cross" also includes backcrossing, in which the _F1 is crossed with the seed parent or the pollen parent.

Since the above-mentioned grasses are self-pollinating, different varieties of grasses do not usually cross-pollinate with each other. Therefore, when the above-mentioned "cross-pollination" is carried out, the seed parent is usually treated with hot water emasculation to inactivate the pollen in the stamens, so that the seed parent does not fertilize its own pollen, and then the pollen of the pollen parent is sprinkled on the pistil of the seed parent.

When carrying out the above-mentioned crossbreeding, the number of times that pollen from the pollen parent is applied to the pistil of the seed parent may be one or more times, but it is preferable that it is multiple times.
In addition, when performing the above-mentioned crossbreeding, the frequency and method of applying pollen of the pollen parent to the pistils of the seed parent is preferably such that the crossbreeding bag is shaken from side to side once within one hour of flowering for two days including the day of flowering, preferably for five days including the day of flowering, and preferably seven times every 15 minutes over two hours from flowering, in order to increase the efficiency of crossbreeding.

The fact that the above-mentioned grasses have been crossed can be confirmed by the fact that fruits are ripe after crossing and the ovaries in the spikelets are enlarged. If fruits are not ripe after crossing, the ovaries in the spikelets usually do not enlarge.
Furthermore, it can also be confirmed by a PCR method using a marker gene according to the variety of the Gramineae plant.

In this specification, the "mating period" refers to 14 days before to 10 days after the mating, preferably 7 days before to 5 days after the mating, and more preferably 5 days before to 3 days after the mating, and does not refer only to the time when mating is performed. Therefore, the time to change from the first step to the second step may actually be before mating or after mating, but is preferably before mating. Note that the gramineous plant has multiple flowers on one panicle, and the flowers do not usually all bloom at the same time, but the flowering times of the multiple flowers are staggered. Therefore, the "mating period" can be determined based on the flowering period of the gramineous plant.

The crossbreeding of the Gramineae plant may be carried out using glume-cut Gramineae plants.

Not only the rapid generation acceleration technology, but also the artificial crossing of grasses is generally performed by a method of crossing by cutting the upper part of the spikelet (glume cutting method). The present inventors found that there is a problem that fruits ripened by crossing through glume cutting do not show sufficient swelling like fruits obtained by natural crossing (crossing by pollination at the time of flowering of the grasses themselves, not by the glume cutting method), and form small and shrunken fruits.
Furthermore, the present inventors have found that seeds obtained by the cut glume method have a problem that germination is not stable, and even if they germinate normally, the sprouts are small and the subsequent growth is delayed by about 2 to 3 days. Therefore, in the past, in backcrossing by the rapid generation acceleration technology of gramineous plants, when a gramineous plant obtained by germinating and growing seeds obtained by the cut glume method is used as one parent, the other parent gramineous plant to be crossed with this needs to be sown with a delay of about 2 to 3 days from the sowing date of the one parent, which is very troublesome. In the rapid generation acceleration technology of gramineous plants, it is also necessary to carry out the technology simultaneously for many varieties, and there is also a problem that it is difficult to stagger the sowing timing for each crossing.

In contrast, when the method for cultivating grasses of the present invention is used, even fruits obtained by the glume cutting method show sufficient enlargement, so that fruits with large seed mass can be obtained. Furthermore, the obtained fruits have a good germination rate and subsequent growth, so that high-quality hybrid seeds can be obtained. Therefore, this method is extremely useful not only as a general method for cultivating grasses, but also as a technology for promoting rapid generation of grasses.

The white light means colorless light that does not cause color perception, and is a mixture of light of various wavelengths of visible light.
Examples of light sources capable of emitting such white light include standard light sources such as A light source, B light source, C light source, D ₆₅ light source, D ₅₅ light source, and D ₇₅ light source specified by the International Commission on Illumination (CIE). The A light source is also specified in JIS Z 8781-2, and the D ₆₅ light source is also specified in JIS Z 8105. These may be used alone or in combination of two or more types.
In addition, examples of the color temperature (K) of the white light include the color temperatures (K) of white light specified in, for example, JIS C 7601, JIS C 7620-2, JIS C 8155, and JIS C 8157, and specifically include daylight color (about 6,500 K), natural white color (about 5,000 K), incandescent color (about 3,000 K), white color (about 4,200 K), and warm white color (about 3,500 K). The color temperature (K) of the white light is, for example, a color temperature on the blackbody locus. Among these, the color temperature (K) of the white light is preferably natural white color (about 5,000 K). A specific example of a light source capable of irradiating the white light includes a fluorescent light source (LifeLook N-HG type, manufactured by Hotalux Co., Ltd.), and a specific example of the white light includes the emission spectrum shown in FIG. 1A.

In the first step, the method of irradiating the grass family plant with the white light is not particularly limited, and can be performed by irradiating the plant with light from a light source capable of irradiating the white light in an environment where the external light is blocked.

In the first step, the irradiation time for irradiating the grass plant with the white light is not particularly limited and can be appropriately determined depending on the type of grass plant, but short-day conditions are preferable, with 8 to 12 hours per day being more preferable, and 9 to 11 hours being particularly preferable.

In the first step, the illuminance when the white light is irradiated onto the grass family plant is not particularly limited and can be appropriately set depending on the type of the grass family plant, etc., but is preferably 5,000 lux to 100,000 lux, and more preferably 15,000 lux to 50,000 lux.
The illuminance can be measured by a photometer (for example, Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Equipment Co., Ltd.).

In the first step, the photosynthetic photon flux density (PPFD) when the white light is irradiated to the grass family plant is not particularly limited and can be appropriately set depending on the type of the grass family plant, etc., but is preferably 50 μmol m ⁻² s ⁻¹ to 2,500 μmol m ⁻² s ⁻¹ , and more preferably 200 μmol m ⁻² s ⁻¹ to 1,000 μmol m ⁻² s ⁻¹ .
The PPFD is a photon flux density in the wavelength region of 400 nm to 700 nm that is effective for photosynthesis, and can be measured by a photometer (for example, Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Equipment Co., Ltd.).

In the first step, the irradiation distance when the white light is irradiated onto the grass family plant is not particularly limited and can be appropriately set depending on the type of the grass family plant, but is preferably 5 cm to 75 cm, and more preferably 20 cm to 50 cm.

The environmental temperature in the first step is not particularly limited and can be appropriately set depending on the type of the Gramineae plant, and may be the same or different during the light and dark periods. The light period is preferably 20°C to 35°C, more preferably 26°C to 30°C, and the dark period is preferably 18°C to 27°C, more preferably 19°C to 27°C, and particularly preferably 20°C to 25°C.

The relative humidity in the first step is not particularly limited and can be set appropriately depending on the type of grass plant, but is preferably 50% to 100%, and more preferably 75% to 95%.

The carbon dioxide (CO ₂ ) concentration in the first step is not particularly limited and can be appropriately selected depending on the type of the Gramineous plant, etc., but is preferably 300 ppm to 1,500 ppm, more preferably 450 ppm to 700 ppm.

<Second step>
The second step is divided into the following first and second aspects.
The second step makes it possible to obtain hybrid seeds having high quality and large seed mass.

The timing for changing from the first step to the second step is the mating period of the Gramineae plant. Specifically, if the "mating period" is 14 days before mating, the second step is a step of cultivating the Gramineae plant 14 days before and after mating, and if the "mating period" is 10 days after mating, the second step is a step of cultivating the Gramineae plant 10 days after mating.

<<First Aspect>>
The second step of the first aspect is a step of irradiating the grass family plant grown in the first step with artificial light having a maximum peak top light intensity in a wavelength range of 380 nm or more and 780 nm or less in an emission spectrum, the light being the artificial light.

In this specification, the "emission spectrum" is measured using a spectrophotometer (Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Equipment Co., Ltd.), and is a continuous spectrum in which the horizontal axis represents wavelength (nm) and the vertical axis represents relative light intensity (sometimes abbreviated as "light intensity"), with the relative light intensity varying smoothly with wavelength. The relative light intensity is expressed as a number from "0" to "1."

Light in the wavelength region of 550 nm or more and 780 nm or less may be referred to as "red light" in this specification.
The light having the maximum light intensity at the peak top in the wavelength region of 550 nm or more and 780 nm or less in the emission spectrum from 380 nm or more and 780 nm or less means that, when there are one or two or more peaks in a wavelength region other than the wavelength region of red light in the wavelength region of 380 nm or more and 780 nm or less in the emission spectrum, the light intensity at the peak top in the wavelength region of red light is maximum compared to the light intensity of the peak in the wavelength region other than the wavelength region of red light.
In addition, the light intensity indicated by a peak in a wavelength region other than the wavelength region of the red light may be the light intensity of the peak top in a wavelength region other than the wavelength region of the red light, or, if the base of a peak having a peak top in the wavelength region of the red light exists in a wavelength region other than the wavelength region of the red light, it may be the light intensity at the base of the peak.

In the wavelength region of the emission spectrum from 380 nm to 780 nm, the number of peak tops in the wavelength region of 550 nm to 780 nm is not particularly limited and may be one or two or more.

If there are two or more peak tops in the wavelength region of 550 nm or more and 780 nm or less, the light intensity of at least one of the two or more peak tops should be maximum in the wavelength region of 380 nm or more and 780 nm or less in the emission spectrum.

The light having the maximum peak top light intensity in the wavelength region of 550 nm to 780 nm in the emission spectrum from 380 nm to 780 nm can be adjusted by using one type of known light source alone or in combination of two or more types. Specific examples include light irradiated from a fluorescent light source capable of irradiating white light (e.g., LifeLook N-HG type, manufactured by Hotalux Co., Ltd.) and an LED light source (e.g., an LED tube capable of irradiating light having the maximum peak top light intensity in the wavelength region of 615 nm to 650 nm in the emission spectrum from the wavelength region of 380 nm to 780 nm).
A specific example of light having a maximum peak top light intensity in the wavelength range of 615 nm to 650 nm in the emission spectrum in the wavelength range of 380 nm to 780 nm in the emission spectrum is the emission spectrum shown in FIG. 1E.
Specific examples of light having a maximum peak top light intensity in the wavelength range of 550 nm or more and 780 nm or less in the emission spectrum from 380 nm or more to 780 nm or less include the emission spectrum shown in FIG. 1B and the emission spectrum shown in FIG. 1C.

The light environment of the first aspect may utilize a known device, or may be a modified version of a known device. For example, known incubators such as LH-411PFQPT-S, LPH-411PFQPT-S, LH-411PFQPT-SP, LPH-411PFQPT-SP, and LPH-411PFQPT-SPC (all manufactured by Nippon Medical and Chemical Equipment Co., Ltd.) may be modified and combined with a fluorescent light source (e.g., LifeLook N-HG type, manufactured by Hotalux Co., Ltd.) to provide the light environment.

<<Second Aspect>>
The second step as the second aspect is a step of irradiating the grass family plant grown in the first step with artificial light, in which the maximum light intensity R in the wavelength range of 550 nm or more and 780 nm or less and the maximum light intensity B in the wavelength range of 400 nm or more and 490 nm or less satisfy R>B in the wavelength range of 380 nm or more and 780 nm or less in the emission spectrum, and the maximum light intensity R in the wavelength range of 550 nm or more and 780 nm or less and the maximum light intensity G in the wavelength range of more than 490 nm and less than 550 nm satisfy R>G.

The maximum light intensity R in the wavelength region of 550 nm or more and 780 nm or less is the maximum light intensity of red light.
The maximum light intensity R may be the light intensity of a peak top present in a wavelength region of 550 nm or more and 780 nm or less, or, in the case where the base of a peak having a peak top in a wavelength region other than the wavelength region of 550 nm or more and 780 nm or less is present in the wavelength region of 550 nm or more and 780 nm or less, it may be the light intensity at the base of the peak.

In this specification, light in the wavelength region of 400 nm or more and 490 nm or less may be referred to as “blue light.” Therefore, the maximum light intensity B in the wavelength region of 400 nm or more and 490 nm or less is the maximum light intensity of blue light.
The maximum light intensity B may be the light intensity of a peak top present in a wavelength region of 400 nm or more and 490 nm or less, or, in the case where the base of a peak having a peak top in a wavelength region other than the wavelength region of 400 nm or more and 490 nm or less is present in the wavelength region of 400 nm or more and 490 nm or less, it may be the light intensity at the base of the peak.

In this specification, light in a wavelength region of more than 490 nm and less than 550 nm may be referred to as “green light.” Therefore, the maximum light intensity G in the wavelength region of more than 490 nm and less than 550 nm is the maximum light intensity of green light.
The maximum light intensity G may be the light intensity of a peak top present in a wavelength region longer than 490 nm and shorter than 550 nm, or, in the case where the base of a peak having a peak top in a wavelength region other than the wavelength region longer than 490 nm and shorter than 550 nm is present in a wavelength region longer than 490 nm and shorter than 550 nm, it may be the light intensity at the base of the peak.

In the wavelength region of 380 nm to 780 nm in the emission spectrum, the maximum light intensity R in the wavelength region of 550 nm to 780 nm and the maximum light intensity B in the wavelength region of 400 nm to 490 nm satisfy R>B, and the maximum light intensity R in the wavelength region of 550 nm to 780 nm and the maximum light intensity G in the wavelength region of more than 490 nm and less than 550 nm satisfy R>G. Light in which R>G is satisfied can be adjusted by using one type of known light source alone or in combination of two or more types. Specific examples include light irradiated from a fluorescent light source capable of irradiating white light (e.g., LifeLook N-HG type, manufactured by Hotalux Co., Ltd.) and an LED light source (e.g., an LED tube capable of irradiating light with a maximum peak top light intensity in the wavelength region of 615 nm to 650 nm in the wavelength region of 380 nm to 780 nm in the emission spectrum).
Specific examples of light in which, in the wavelength region of 380 nm or more and 780 nm or less in the emission spectrum, the maximum light intensity R in the wavelength region of 550 nm or more and 780 nm or less and the maximum light intensity B in the wavelength region of 400 nm or more and 490 nm or less satisfy R>B, and the maximum light intensity R in the wavelength region of 550 nm or more and 780 nm or less and the maximum light intensity G in the wavelength region of more than 490 nm and less than 550 nm satisfy R>G include the emission spectrum shown in FIG. 1B and the emission spectrum shown in FIG. 1C.

The light environment of the second aspect may utilize a known device, or may be a modified version of a known device. For example, known incubators such as LH-411PFQPT-S, LPH-411PFQPT-S, LH-411PFQPT-SP, LPH-411PFQPT-SP, and LPH-411PFQPT-SPC (all manufactured by Nippon Medical and Chemical Equipment Co., Ltd.) may be modified and combined with a fluorescent light source (e.g., LifeLook N-HG type, manufactured by Hotalux Co., Ltd.) to provide the light environment.

In the second step, the lighting environment using artificial light in the first embodiment and the second embodiment may be satisfied separately or simultaneously, but it is preferable that they are satisfied simultaneously.

In the second step, it is preferable that at least one of the artificial light of the first embodiment and the second embodiment is artificial light in which, in an emission spectrum in a wavelength region of 380 nm to 780 nm, a value Rf obtained by definite integration of a wavelength region of 550 nm to 780 nm and a value Bf obtained by definite integration of a wavelength region of 400 nm to 490 nm satisfy Rf>Bf, and a value Rf obtained by definite integration of a wavelength region of 550 nm to 780 nm and a value Gf obtained by definite integration of a wavelength region of more than 490 nm and less than 550 nm satisfy Rf>Gf.

The value Rf obtained by integrating the wavelength region from 550 nm to 780 nm inclusive is the value obtained by integrating the emission spectrum curve from 380 nm to 780 nm inclusive in the wavelength region from 550 nm to 780 nm inclusive.

The value Bf obtained by integrating the wavelength region from 400 nm to 490 nm inclusive is the value obtained by integrating the emission spectrum curve from 380 nm to 780 nm inclusive in the wavelength region from 400 nm to 490 nm inclusive.

The value Gf obtained by integrating the wavelength region from greater than 490 nm to less than 550 nm is the value obtained by integrating the emission spectrum curve from greater than 490 nm to less than 550 nm in wavelength region from 380 nm to 780 nm in wavelength.

The Rf, Bf, and Gf can be calculated by known theoretical calculation formulas. The calculations may be performed using known devices (e.g., functions provided in a spectrophotometer, etc.).

In the second step, the method of irradiating the grass family plant with at least one of the artificial light of the first embodiment and the artificial light of the second embodiment is not particularly limited, and can be performed by irradiating the grass family plant with light from a light source capable of irradiating at least one of the artificial light of the first embodiment and the artificial light of the second embodiment in an environment where the external light is blocked.

In the second step, the irradiation time when the grass plant is irradiated with at least one of the artificial light of the first embodiment and the artificial light of the second embodiment is not particularly limited and can be appropriately set depending on the type of the grass plant, but short-day conditions are preferable, and 8 to 12 hours per day are more preferable, and 9 to 11 hours are particularly preferable.

In the second step, the illuminance of the graminaceous plant when at least one of the artificial light of the first embodiment and the artificial light of the second embodiment is irradiated is not particularly limited and can be appropriately set depending on the type of the graminaceous plant, but is preferably 5,000 lux to 100,000 lux, and more preferably 14,000 lux to 50,000 lux.

In the second step, the photosynthetic photon flux density (PPFD) when the grass family plant is irradiated with at least one of the artificial light of the first embodiment and the artificial light of the second embodiment is not particularly limited and can be appropriately set depending on the type of the grass family plant, etc., but is preferably 50 μmol m ⁻² s ⁻¹ to 2,500 μmol m ⁻² s ⁻¹ , and more preferably 200 μmol m ⁻² s ⁻¹ to 1,000 μmol m ⁻² s ⁻¹ .

In the second step, the irradiation distance when irradiating the grass plant with at least one of the artificial light of the first embodiment and the artificial light of the second embodiment is not particularly limited and can be appropriately set depending on the type of the grass plant, etc., but is preferably 5 cm to 75 cm, and more preferably 20 cm to 50 cm.

The environmental temperature, relative humidity, carbon dioxide (CO ₂ ) concentration, etc. in the second step are not particularly limited and can be appropriately selected depending on the type of the grass family plant, etc., but the environmental temperature, relative humidity, and carbon dioxide (CO ₂ ) concentration are preferably the same as those in the first step.

<Other processes>
The method for growing a Gramineae plant may include steps other than the first step and the second step, as long as the effects of the present invention are not impaired.

The method for cultivating grasses allows for simple and rapid breeding, and even fruits obtained by the glume cutting method show sufficient growth, so that fruits with large seed mass can be obtained. Furthermore, the obtained fruits can produce high-quality hybrid seeds with good germination rates and subsequent growth, so that the method can be suitably used not only as a general method for cultivating grasses, but also as a technology for promoting rapid generation of grasses.

(Grain growing device)
The apparatus for cultivating grasses of the present invention is used for cultivating grasses, and has a storage means, a first light irradiation means, a second light irradiation means, and a switching means, and may further have other means as necessary.
The apparatus for cultivating a grass family plant is suitably used for the method for cultivating a grass family plant of the present invention described above.

The grass plant grown in the grass plant growing device is the same as that described in the above section (Grass plant growing method). In particular, the grass plant growing device is suitable for growing a grass plant that has been artificially cross-bred using a cut glume of the grass plant.

<Containment means>
The accommodation means is a means capable of accommodating the Gramineae plant.
The storage means is not particularly limited as long as it can store the gramineous plant, but it is preferable that the storage means is configured to block external light and irradiate the gramineous plant only with artificial light. The storage means having such a configuration is preferably configured so that the inside is sealed.

The number of the accommodation means in the Gramineae plant cultivating apparatus is not particularly limited and may be appropriately selected depending on the purpose, and may be one or more.
When the number of the storage means is multiple, the environmental conditions (e.g., light environment, temperature, humidity, carbon dioxide concentration, etc.) in each storage means may be controlled individually, or all the storage means may be controlled simultaneously.

The shape of the storage means is not particularly limited as long as it is capable of storing the Gramineae plant, but it is preferable that it is approximately box-shaped. When there are multiple storage means, the storage means are continuous in at least one of the left-right direction, the front-back direction, and the up-down direction.

The storage means preferably has an opening for storing and removing the grass plant, and the surface having this opening is the "front surface."

<First Light Irradiation Means>
The first irradiation means is a means for irradiating the inside of the container means with white light.
The first irradiation means is not particularly limited as long as it can irradiate the inside of the storage means with white light, and examples thereof include standard light sources such as A light source, B light source, C light source, _D65 light source, _D55 light source, and _D75 light source defined by the International Commission on Illumination (CIE). These may be used alone or in combination of two or more. A specific example of a light source capable of irradiating the white light is a fluorescent light source (LifeLook N-HG type, manufactured by Hotalux Co., Ltd.).

The color temperature (K) of the light irradiated by the first irradiating means may be, for example, the color temperature (K) of white light specified in JIS C 7601, JIS C 7620-2, JIS C 8155, JIS C 8157, etc., and specifically includes daylight color (about 6,500 K), natural white (about 5,000 K), incandescent light (about 3,000 K), white (about 4,200 K), warm white (about 3,500 K), etc. The color temperature (K) of the white light is, for example, a color temperature on the blackbody locus. Among these, the color temperature (K) of the white light is preferably natural white (about 5,000 K).

<Second Light Irradiation Means>
The second light irradiation means is divided into the following first and second aspects.

<<First Aspect>>
The second light irradiation means as the first aspect is a means for irradiating the inside of the containing means with light having a maximum peak top light intensity in the wavelength region of 550 nm or more and 780 nm or less in the emission spectrum of the wavelength region of 380 nm or more and 780 nm or less.

The second light irradiation means as the first embodiment is not particularly limited as long as it can irradiate light inside the storage means with a maximum peak top light intensity in the wavelength range of 550 nm to 780 nm in the wavelength range of 380 nm to 780 nm in the emission spectrum, and one or more known light sources can be used alone or in combination, but it is preferable to arrange both a fluorescent light source capable of irradiating white light (e.g., LifeLook N-HG type, manufactured by Hotalux Co., Ltd.) and an LED light source (e.g., an LED tube capable of irradiating light with a maximum peak top light intensity in the wavelength range of 615 nm to 650 nm in the wavelength range of 380 nm to 780 nm in the emission spectrum).

<<Second Aspect>>
The second light irradiation means as the second aspect is a means for irradiating light into the inside of the containing means, such that in the wavelength region of 380 nm or more and 780 nm or less in the emission spectrum, a maximum light intensity R in the wavelength region of 550 nm or more and 780 nm or less and a maximum light intensity B in the wavelength region of 400 nm or more and 490 nm or less satisfy R>B, and a maximum light intensity R in the wavelength region of 550 nm or more and 780 nm or less and a maximum light intensity G in the wavelength region of more than 490 nm and less than 550 nm satisfy R>G.

As the second light irradiation means of the second aspect, there is no particular restriction on the second light irradiation means as long as it can irradiate light inside the storage means such that in the wavelength region of 380 nm to 780 nm in the emission spectrum, the maximum light intensity R in the wavelength region of 550 nm to 780 nm and the maximum light intensity B in the wavelength region of 400 nm to 490 nm satisfy R>B, and the maximum light intensity R in the wavelength region of 550 nm to 780 nm and the maximum light intensity G in the wavelength region of more than 490 nm and less than 550 nm satisfy R>G. One or more known light sources can be used alone or in combination, but it is preferable to arrange both a fluorescent light source capable of irradiating white light (e.g., LifeLook N-HG type, manufactured by Hotalux Co., Ltd.) and an LED light source (e.g., an LED tube capable of irradiating light in which the peak top light intensity in the wavelength region of 615 nm to 650 nm in the emission spectrum is maximized in the wavelength region of 380 nm to 780 nm in the emission spectrum).

It is preferable that the light irradiated by the second light irradiation means is artificial light in which, in an emission spectrum of a wavelength region of 380 nm or more and 780 nm or less, the value Rf obtained by definite integration of the wavelength region of 550 nm or more and 780 nm or less and the value Bf obtained by definite integration of the wavelength region of 400 nm or more and 490 nm or less satisfy Rf>Bf, and the value Rf obtained by definite integration of the wavelength region of 550 nm or more and 780 nm or less and the value Gf obtained by definite integration of the wavelength region of more than 490 nm and less than 550 nm satisfy Rf>Gf.

The Rf, Bf, and Gf are as described in the section (Method for growing grasses).

<Switching Means>
The switching means is a means for switching between the first light irradiation means and the second light irradiation means.
The switching means is not particularly limited as long as it can switch between the first light irradiation means and the second light irradiation means, and can be appropriately selected depending on the purpose. For example, a known switch can be used.

The following describes the apparatus for cultivating grasses of the present invention in detail with reference to the drawings, but the apparatus for cultivating grasses of the present invention is not limited to this.

Figure 3 is a front view of the apparatus for cultivating grasses, Figure 4 is a side view of the apparatus, Figure 5 is a plan cross-sectional view of the apparatus, Figures 6A to 6C are schematic diagrams showing the details of the configuration of the light source of the apparatus for cultivating grasses, Figures 6D and 6E are schematic explanatory diagrams showing different types of irradiation patterns, and Figures 7A to 7C are graphs showing the temperature changes of each storage means in an example of operation set to specified environmental conditions. The apparatus for cultivating grasses in this embodiment has storage means arranged in five vertical tiers, and grasses are stored in these storage means, and each storage means can be set to a specified environmental condition individually.

That is, as shown in Figs. 3 to 5, the apparatus 1 for cultivating gramineous plants has a tank 3 formed in the main body 2 of the apparatus, which is shielded from the outside of the apparatus to a predetermined degree. The tank 3 is preferably of a heat-insulated sealed structure. In the tank 3, a plurality of storage means 4 for storing gramineous plants arranged in multiple stages are formed by dividing the tank 3 into predetermined sections while securing a circulation passage (for feeding) 5A and a circulation passage (for returning) 5B for circulating the air in the tank to the outside of the storage means 4. The lower part of the main body 2 of the apparatus is provided with an air conditioning unit 6, which is a first temperature control means for adjusting the air in the tank as a medium with a specified reference temperature to a predetermined temperature and feeding and circulating it. On the other hand, the upper part of the main body 2 of the apparatus is provided with a setting input unit 8 having an operation panel 7 for inputting and setting the environmental conditions of each storage means 4 and displaying the current environmental state, and a control unit (not shown) for controlling the operation of each unit according to the inputted setting conditions. These storage means 4 have heaters 9 as second temperature control means that adjust the temperature inside each storage means 4 to a respective predetermined temperature based on the temperature of the circulating air, and the temperature inside the tank 3 increases toward the upper levels, making it possible to set the temperature of each storage means 4 individually and independently. In other words, the Gramineae plant cultivation device 1 is designed to obtain a temperature gradient in which the temperature of each storage means 4 increases stepwise as it moves toward the upper levels, ensuring a predetermined temperature difference between them.

The device main body 2 is made of thin stainless steel and steel plates, and the outer shape of the tank 3 is an upright rectangular parallelepiped. The front part of the tank 3 is an outer door part 3a shown in FIG. 4, which is provided so that it can be opened and closed sideways, with the vertical edge at the right end in FIG. 3 acting as a vertical hinge axis. In addition, the vertical side wall surfaces and the upper and lower horizontal wall surfaces as the inner surface of the tank 3 may be provided with sheet-shaped polystyrene foam 11, which is a lightweight and inexpensive insulating material, so that it is in contact with each surface almost entirely. This allows the tank 3 to function as an insulated sealed tank, ensuring insulation.

Each storage means 4 is formed in a roughly box-like shape with airtightness, and has a floor space of, for example, about 40 cm wide and about 50 cm deep. That is, each storage means 4 divides the tank 3 in the left-right direction by vertical plates 12 that form the left and right side walls and the back wall of each storage means, and also divides the back side of the tank 3, securing a long space in the vertical direction in the center of the tank 3, and then divides this space evenly in the vertical direction by horizontal shelves 13. These storage means 4 are stacked in multiple stages aligned vertically, and an air circulation passage (for supply) 5A and a circulation passage (for return) 5B are formed and secured on both the left and right sides of each storage means 4, respectively, from the lowest storage means 4 to the highest storage means 4. Therefore, the air circulation passage (for supply) 5A on the right side of the figure supplies air upward from the air conditioning unit 6 and passes through each storage means 4, and a circulation path is formed in which the air that has passed through each storage means 4 is returned to the air conditioning unit 6 below by the air circulation passage (for return) 5B on the left side.

The openings in FIG. 3, which are the fronts of these storage means 4, may be closed by plate-like, opaque inner door parts 4a shown in FIG. 4, which are provided so that they can be opened and closed horizontally with the right vertical edge of the opening edge as a vertical hinge axis, and these inner door parts 4a can be opened and closed individually without interfering with the inner door parts 4a of the storage means 4 above and below. Therefore, when storing or removing a grass plant in a certain storage means 4, it is necessary to open and close only the inner door part 4a of that storage means 4, so that the set temperature of the other storage means 4 is not disturbed. In addition, a magnet 14 is installed on the right opening edge of these storage means, and the magnetic force of this magnet 14 attracts the opening and closing end side of the inner door part 4a, locking the inner door part 4a in the closed state. If the inner door part 4a is made of a non-magnetic material such as a plastic plate, a magnetically attractable member such as an iron piece may be provided at the location of the inner door part 4a corresponding to the magnet 14.

Therefore, in the case of a double door configuration consisting of the outer door part 3a of the tank 3 and the inner door part 4a of each storage means 4, the effect of blocking light entering the storage means from outside the device can be improved compared to a configuration in which each storage means 4 is closed only by a single door part for each storage means. Therefore, the light conditions and light and dark environment inside the storage means can be controlled freely without depending on the external environment. In addition, in the case of a double door configuration like this, a gap may be formed between the inner door part 4a and the outer door part 3a, and an air jacket may be formed in which circulating air flows through this gap. Therefore, with this configuration, in addition to the insulating effect of the outer door part 3a as a fixed member, a heat-shielding effect is obtained by constantly intervening the air flow of the air jacket to carry away the air that has been transferred heat, so a higher heat blocking effect can be expected.

Furthermore, horizontally arranged, vertically elongated slit-shaped suction ports 4b are formed at the bottom of the right side wall of each storage means 4, and these suction ports 4b open to the air circulation passage 5A for supply to communicate with the room. A similarly formed exhaust port (not shown) is provided on the left side wall opposite this side wall, and this exhaust port opens to the air circulation passage (for return) 5B to communicate with the room. In addition, each suction port 4b other than the suction port 4b provided on the lowest storage means 4 is provided with an internal fan 15, which is a small blower fan with the air blowing direction facing the inside of the room, and this internal fan 15 draws air from the air circulation passage (for supply) 5A into the room. Note that the internal fan 15 does not need to be provided on the suction port 4b of the lowest storage means 4. This storage means 4 is located near the air conditioning unit 6, and the circulating air that reaches the suction port 4b of this storage means 4 has a sufficiently strong blowing force, so that the circulating air can be reliably taken into the storage means 4. Therefore, the air sucked into the room from the right air circulation passage 5A through each suction port 4b passes through each of these storage means 4 and is discharged to the left air circulation passage (for return) 5B.

In each storage means 4, a storage means temperature sensor (not shown) is installed as a temperature detection means, and the output lines of the detection signals of these storage means temperature sensors are connected to the control unit, so that the control unit can individually and constantly detect the temperature inside the storage means of each storage means 4. Note that instead of providing an interior fan 15 near the intake port 4b that draws circulating air into the room, it is also possible to provide an exhaust fan at the exhaust port that exhausts air from the room, or to provide two fans, the interior fan 15 and the exhaust fan.

In addition, a heater 9 is provided near the suction port 4b of each storage means 4 as a second temperature control means. The heater 9 is provided in the circulation passage (for feeding) 5A arranged outside the storage means 4, at a location upstream of the air sent through the circulation passage (for feeding) 5A with respect to the suction port 4b of the storage means 4 opened to the circulation passage (for feeding) 5A, and a long rod-shaped electric heater extending in a direction crossing the circulation passage (for feeding) 5A is installed at this location. These heaters 9 have a heat generation capacity sufficient to heat at least the circulating air sucked into the suction port 4b to the set temperature of each storage means 4, and the heating operation by each heater 9 is controlled by the control unit. In addition, the temperature of the circulating air adjusted by the air conditioning unit 6 becomes the temperature inside the storage means as it is for the storage means 4 at the lowest level, so the heater 9 for this storage means 4 does not need to be provided.

As shown in Figs. 6A to 6C, the shelf 13, which is a member forming the ceiling surface of each storage means 4, has a lower surface (the surface opposite to the surface in contact with the floor surface or the grass family plant) that serves as the ceiling surface, i.e., the shelf 13 that separates one storage means 4 from another storage means, on the surface that functions as a shelf for one storage means 4 and functions as a ceiling surface for the other storage means 4, a plurality of light sources 17 formed in a thin straight tube shape are arranged in a predetermined manner and installed. The light sources 17 are a plurality of the first light irradiation means and a plurality of the second light irradiation means. The light sources 17 are thin straight tubes, preferably thin straight tubes with a tube diameter of 3.0 mm (selectable in the range of 1.6 mm to 3.0 mm), formed to the same length, and have a length slightly shorter than the length from one front side to the other back side on the ceiling surface. The light sources 17 are arranged in parallel at a predetermined interval from each other in the left-right width direction of the storage means 4. Therefore, the ceiling surface of the storage means 4 is made into a surface light, so that the grass plants stored in the storage means 4 can be illuminated from above. In this case, the shelf board 13 includes the member that constitutes the ceiling surface of the uppermost storage means 4, in addition to the shelf board 13 that divides each storage means interposed between the upper and lower storage means 4.

Note that, although an example in which light sources 17 are installed only on the ceiling surface of each storage means has been described here, this is not limiting, and as long as the surfaces form the inner wall surface of each storage means 4, one surface or multiple surfaces may be appropriately selected as necessary, and multiple light sources 17 may be installed on the selected surfaces. For example, multiple light sources 17 may be installed only on the floor surface of each storage means 4, multiple light sources 17 may be installed on both the ceiling surface and the floor surface, and even multiple light sources 17 may be installed on five surfaces other than the floor surface.

The light source 17 is preferably a light source that does not affect the temperature inside each storage means 4. In other words, it is preferable that the total amount of heat generated by the multiple light sources 17 is a very small ratio to the temperature adjustment capacity of the storage means 4 by the heater 9 and the amount of air flow that passes through the room after being temperature-adjusted by this adjustment capacity, so that the light source 17 does not affect the temperature inside the storage means 4.

Furthermore, the switch (not shown) of each light source 17 and the lamp driving circuit (not shown) that allows the adjustment of the irradiation intensity are connected to the control unit via wiring (not shown). Therefore, this control unit controls the on/off of the switch of each light source 17, that is, controls the lighting state of the light source 17, and controls the irradiation intensity in the lighting state. It is preferable that the switch is wired so that the first light irradiation means and the second light irradiation means can be individually controlled on/off. The light source 17 may have a light source body 17A, a ballast 17a for each light source, and a reflector 17b that is provided between the light source body 17A and the installation surface of the light source body 17A and forms a reflective curved surface toward the light source body 17A side. The reflector 17b can reflect the irradiation light from the light source body 17A toward the installation surface of the light source body 17A of the storage means 4 and direct it toward the grass family plant, thereby increasing the irradiation efficiency. In addition, a light diffusion plate that equalizes the irradiation light from the light source body 17A may be provided below the light source body 17A.

The Gramineae plant cultivating device 1 is preferably configured so that the illumination in each storage means obtained from the multiple light sources 17 arranged in this manner is illumination light that does not change in the horizontal direction of the storage means 4. In other words, it may be configured to obtain any of the illumination patterns shown in Figures 6D and 6E. Note that in Figures 6D and 6E, the length of the downward arrows shown respectively indicates the strength (amount) of illumination intensity (light quantity).

The illumination pattern in FIG. 6D is configured to provide a uniform illumination intensity (amount of light) in all horizontal plane directions within the storage means 4 as a gradient-free illumination. In other words, all light sources 17 are controlled to emit the same amount of light. Therefore, the illumination distribution within the storage means 4 is not biased, and the illumination is nearly uniform throughout the room.

The irradiation pattern in FIG. 6E is configured to repeat turning on and off with a predetermined on/off time set as a further intermittent irradiation in the irradiation pattern in FIG. 6D. That is, as a blinking illumination, all light sources 17 are controlled to repeatedly turn on simultaneously for a predetermined time and turn off simultaneously for a predetermined time.

Therefore, with a configuration having these irradiation patterns, it is possible to individually prepare a light environment and irradiation environment for each storage means according to various test conditions and requests.

In the irradiation patterns of Figures 6D and 6E, the irradiation light is configured to change in the left-right width direction of the storage means 4, but it may of course be configured to change from the front to the back of the storage means 4.

Furthermore, the Gramineae plant cultivation device 1 is configured so that the user can arbitrarily select and change the above-mentioned irradiation pattern and the emission spectrum from the light source 17. That is, the shelf boards 13 are configured so that they can be easily attached and detached from each storage means 4 and replaced, and the above-mentioned irradiation pattern and the emission spectrum from the light source 17 can be replaced with a shelf board 13 that has a different emission pattern. In addition, the number of light sources 17 can be increased or decreased according to the illuminance and/or emission spectrum required for each storage means. That is, the shelf boards 13 are configured so that the light sources 17 installed on the shelf boards 13 can be electrically connected to the device main body 2 side via a small number of sockets and connectors (not shown), and the shelf boards 13 themselves can be easily attached and detached.

Therefore, in addition to the effects of the configuration that forms each of the above-mentioned irradiation patterns and emission spectra from the light sources 17, the configuration that allows the shelves 13 to be replaced in this manner facilitates repair and replacement of the irradiation in each storage means, and allows the shelves 13 to be replaced with ones having a number of light sources 17 according to the illuminance and/or emission spectrum required for that storage means 4. Therefore, the required illuminance and/or emission spectrum can be secured using a minimum number of light sources 17 as consumable parts, thereby reducing operating costs and efficiently reducing power consumption.

The light sources 17 arranged in a predetermined order may be collectively unitized with the shelf 13 so as to be separable, and this irradiation unit may be configured to be replaceable with an irradiation unit of a different illuminance, or these may be combined. Therefore, according to a configuration in which a predetermined number of light sources 17 arranged in a predetermined order are easily attached to and detached from the shelf 13 to form a replaceable irradiation unit, in addition to the above effects, the irradiation unit can be removed from the storage means 4 where irradiation is not required, and the space within the storage means 4 can be expanded. Furthermore, compared to a configuration in which the light sources 17 are integrated into the shelf 13, it is only necessary to handle the irradiation unit mainly composed of the light sources 17, which improves the ease of handling as a replacement part and reduces the required storage space.

In addition, a small fan for stirring may be provided inside the storage means 4, and the small fan may be used to stir the air inside the storage means 4, quickly making the temperature uniform throughout the room without causing a biased temperature distribution inside the storage means 4.

The setting input unit 8 has an operation panel 7 that sets and inputs the temperature and irradiation state as environmental conditions of each storage means 4 and displays the temperature inside the storage means, and a control unit consisting of a control circuit that controls the operation of each part in a predetermined manner based on the environmental conditions set and input from this operation panel 7.

That is, the operation panel 7 has a main panel 21 and an irradiation setting panel 22. The main panel 21 has one main switch for turning the power of the entire device on and off, and a group of five input switches arranged horizontally for inputting and setting the set temperature of each storage means 4. The irradiation setting panel 22 also has a clock-type lamp timer for inputting and setting the irradiation time period of the light source 17, and a group of five lamp switches arranged vertically. By turning the lamp switches on and off, the light source 17 of each storage means is switched to an operable state and the current state of the lamp is displayed by light. Therefore, by inputting and setting various conditions from the operation panel 7, the user can freely select between a common setting that changes the temperature and irradiation of each storage means in the same way for all storage means 4, and an individual setting that changes the temperature and irradiation of each storage means individually by adjusting the time of each storage means 4.

The air conditioning unit 6 is mainly composed of a cooler 25 that adjusts the air in the tank 3 to a predetermined temperature, and a circulation fan 26 that sends the adjusted air to the circulation passage (for supply) 5A and circulates it through the tank 3, and the cooling operation of the cooler 25 is controlled by the control unit. That is, the air conditioning unit 6 is configured such that the cooler 25 and the circulation fan 26 are sequentially arranged in a passage 27 that connects the lower ends of both the air circulation passage (for supply) 5A and the air circulation passage (for return) 5B. This passage 27 is formed with a relatively large passage cross-sectional area, and the air flow speed in the passage 27 is reduced so that the cooling effect of the cooler 25 can be sufficiently obtained. In addition, downstream of the cooler 25 in the air circulation direction, a relatively large diameter circulation blower fan 26 is installed with its blowing direction facing the lower end of the air circulation passage 5A diagonally upward, and this circulation blower fan 26 ensures a sufficient air supply flow rate. 28 is a heat exchanger that exhausts heat from the cooler 25 to the outside of the device together with the exhaust air when outside air is introduced into the air conditioning unit 6 and exhausted, and 29 is a compressor that circulates a heat exchange medium between the cooler 25 and the heat exchanger 28 in a specified compression and expansion cycle, and cools the cooler 25 by transporting heat from the cooler 25 and discharging it to the outside.

A measuring means (not shown) capable of measuring the temperature of the circulating air is provided at appropriate locations through which the circulating air passes, and based on the actual temperature of the circulating air detected by this measuring means, the control unit controls the cooling operation of the cooler to maintain the temperature of the circulating air at a predetermined target temperature.

Therefore, when setting the temperature environment in the apparatus 1 for cultivating grass plants, the input switch of the operation panel 7 is operated to input the set temperature of each storage means. That is, the temperature of the storage means 4 in the lowest stage is the minimum set temperature, and as the temperature rises to the upper stage, a temperature difference gradient is formed in which the temperature in the storage means for each stage 4 rises stepwise. This temperature difference can be adjusted in a temperature gradient manner for each stage from a minimum of 2°C to five stages. For example, in the case of this five-stage system, the temperature difference of each stage storage means 4 can be adjusted to 2°C, 4°C, 6°C, 8°C, and 10°C. In addition, for example, as shown in FIG. 7A, the base minimum set temperature can be changed at any time, and the temperature difference between each storage means can also be changed. In this way, in the apparatus 1 for cultivating grass plants, the temperature difference between adjacent storage means 4 can be set evenly or randomly, or each storage means 4 can be set to the same temperature.

In other words, the temperature of the circulating air that has passed through the cooler 25 is set by the cooler 25 of the air conditioning unit 6 to the lowest temperature among the set temperatures set in each storage means 4. In other words, the control unit selects the lowest temperature among the desired set temperatures set in each storage means 4, and this selected temperature becomes the target temperature as the control target, and controls the cooling operation of the cooler 25 so that the temperature of the circulating air becomes this target temperature.

In the thus configured Gramineae plant growing device 1, the air that circulates through the tank 3 and returns passes through the cooler 25, where it is adjusted to a predetermined target temperature, and is sent out diagonally to the upper right in the figure by the circulation fan 26, and the air adjusted to the target temperature is sent upward through the circulation passage 5A. At this time, the air that is present in the gap formed between the outer wall surface of the member forming each storage means 4 and the inner wall surface of the tank 3 does not stagnate there, but eventually moves in a direction approaching the circulation fan 26, and most of it passes through the cooler 25, so that in addition to the passive heat shielding effect of the fixed insulating member, an active heat shielding effect is obtained by this air flow.

Then, the circulating air that is sent rises in the circulation passage (for sending) 5A while a part of it is sucked into the storage means 4 of each stage, and the circulating air that has passed through each storage means 4 is discharged into the circulation passage (for returning) 5B, and then descends this circulation passage (for returning) 5B and returns to the air conditioning unit 6. Therefore, the temperature of each storage means 4 is determined by the temperature of the circulating air that is sucked into each storage means 4. The actual temperature of each storage means 4 is individually controlled by the heating heater 9 that performs heating operation to compensate for the temperature difference between the set temperature of each storage means 4 and the target temperature of the circulating air. That is, the control unit controls the heating operation of the heating heater 9 to compensate for the temperature difference. In addition, the control unit is constantly aware of the room temperature of each storage means 4, and fine-tunes the heat generation amount of the heating heater 9 according to the fluctuation of the room temperature.

Therefore, according to the apparatus 1 for cultivating grass plants, each storage means 4 can ensure and maintain a constant temperature state at the desired set temperature with high precision. In other words, the temperature inside the storage means 4 can be precisely set by balancing the thermal energy balance inside the storage means 4. Moreover, the air flowing into each storage means 4, which is a storage means having a relatively small volume relative to the reference temperature of the circulating air, is heated by a dedicated heater 9 to compensate for the temperature, making it easier to control the temperature inside the storage means 4. Therefore, the temperature inside each storage means 4 can be set to the required temperature with high precision while eliminating the temperature interference between one storage means 4 and the other storage means 4 and keeping each storage means 4 independent.

As a result, each storage means 4 does not need to have a thick insulating layer as a member that surrounds the entire periphery, and the internal space of each storage means 4 can be made larger. On the other hand, the role of the insulating member that forms the insulating layer is thus reduced, and the device can be made thinner, so the internal space of the device can be used more efficiently and the external shape of the entire device can be made slimmer. This allows for reduction in the amount of material used to manufacture the device and space savings. As a result, a low-cost device 1 for cultivating grass plants can be created.

Furthermore, even if the grasses in each storage means generate or absorb even a small amount of heat, the control unit constantly monitors the room temperature and controls the heating operation of the heater 9, which determines the temperature of the air drawn into each storage means, so that the temperature can be maintained at a specified set temperature.

When setting a day-night cycle environment in addition to the temperature environment settings described above in the Gramineae plant cultivation device 1, the lamp timer on the operation panel 7 is operated to input the daytime hours when the light source 17 is turned on or the nighttime hours when it is turned off, thereby setting the time periods of day and night. Therefore, in this case, as shown in FIG. 7B, for example, day and night are switched repeatedly at predetermined times, and in response to this day and night switching, each storage means 4 switches to the set temperature for day or night while maintaining the temperature difference between them.

Furthermore, according to the Gramineae plant cultivation device 1, the day-night cycle can be set individually for each storage means 4, as shown in FIG. 7C, without setting the same day-night cycle for each storage means 4, and the temperature of each storage means 4 can be set to change individually in relation to these individually set day-night time periods. In other words, for each storage means 4, it is possible to change at any time from a certain indoor environment setting specific to that storage means 4, which freely combines the temperature and light (light and dark illuminance) of each storage means 4, to another indoor environment setting freely combining the temperature and light (light and dark illuminance).

As described above, according to this embodiment of the apparatus for cultivating grasses, since a plurality of light sources (first light irradiation means and second light irradiation means) are arranged in a predetermined manner on the ceiling surface or entire surface of each storage means, irradiation can be efficiently performed by direct irradiation with close proximity irradiation, and variation and waste of irradiation can be eliminated. On the other hand, since the light sources (first light irradiation means and second light irradiation means) can be formed with a small diameter, they can be arranged closely together, and the light distribution is uniform due to their long rod shape. Therefore, the grasses can be illuminated from the ceiling surface or the entire surface as uniform surface lighting. This improves the quality of illumination for the grasses.

In addition, it is possible to irradiate the grass plant close to the light source without having to place anything between the light source and the grass plant. In other words, it is possible to irradiate the grass plant at a close distance by shortening the distance between the light source and the object to be irradiated. Therefore, sufficient irradiation can be obtained without increasing the illuminance. Because the irradiation efficiency can be improved in this way, the amount of power consumption required for irradiation is reduced by the amount of this increase in efficiency, resulting in power savings.

The light source also allows for free selection of the emission color and fine adjustment of brightness. This makes it possible to obtain the lighting environment required by grasses as needed. In addition, by combining a wider variety of environmental conditions based on temperature and illuminance than ever before, precise environmental control within each storage means is possible.

The apparatus for cultivating grasses shown in the above figures is one example of the apparatus for cultivating grasses of the present invention, and any known apparatus (e.g., known apparatus for cultivating grasses, apparatus for cultivating other plants, apparatus used for cultivating algae or microorganisms, cultivating plants, raising insects or small animals, etc.) modified to have the storage means, the first light irradiation means, the second light irradiation means, and the switching means can be used as the apparatus for cultivating grasses.
Examples of the known apparatus include the apparatus described in JP-A-2009-156525, the apparatus described in JP-A-2002-345337, the apparatus described in JP-A-2001-275488, and the apparatus described in JP-A-2006-61126. These configurations can also be used in combination.

The apparatus for cultivating grasses is used for cultivating grasses, and in particular, the light environment allows simple and rapid breeding, and even fruits obtained by the glume cutting method can show sufficient enlargement and produce fruits with large seed mass. Therefore, it can be used not only for cultivating general grasses, but also can be suitably used in rapid generation promotion technology for grasses.

Although the above-mentioned Gramineae plant growing device is used for growing Gramineae plants, it can also be widely used for biological tests that require light, such as germination tests for other plants, research into the biological clocks of animals and plants including insects, algae cultivation, microbial cultivation, plant cultivation, and the rearing of insects and small animals.

The present invention will be specifically explained below with reference to test examples, examples, and comparative examples, but the present invention is not limited to these test examples and examples.

Example 1
<First step>
The first step (cultivation of seed parents, cultivation of pollen parents, and crossbreeding) described below was carried out using a plant growth incubator (LPH-350-SPC, manufactured by Nippon Medical and Chemical Equipment Co., Ltd.) under white fluorescent lamps (light environment with the emission spectrum shown in FIG. 1A), with an irradiation distance of 25 cm, a 10-hour day length of 10 hours light (temperature: 27°C to 30°C) and 14 hours dark (temperature: 18°C to 25°C), a _CO2 concentration of 600 ppm, and a relative humidity of 85%.
The emission spectrum shown in Figure 1A was measured using a spectrophotometer (Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Engineering Co., Ltd.). The illuminance measured near the plant body in a plant growth incubator (LPH-350-SPC) using a photometer (Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Engineering Co., Ltd.) was 17,521 lux, and the light quantity was PPFD: 224 μmol m ^-2 s ^-1 .

- Cultivation of seed parents -
Seeds of the rice variety "Akidawarakan 1" (owned by the National Agriculture and Food Research Organization) were immersed in a 200-fold diluted fungicide (Sportac (registered trademark) Starna (registered trademark) SE, manufactured by Sumitomo Chemical Co., Ltd.), a 1,000-fold diluted insecticide (Sumithion (registered trademark) emulsion, manufactured by Sumitomo Chemical Co., Ltd.), and 1% by mass hydrogen peroxide solution at room temperature for 24 hours, sown on a petri dish, and left for 3 days under conditions of a temperature of 30 ° C. and a relative humidity of 100% to germinate. The germinated seeds were transplanted into a horticultural plug tray (RL-40PT, manufactured by Tokai Kasei Co., Ltd.) containing rice seedling soil (Bonsol 2, manufactured by Sumitomo Chemical Co., Ltd.) and cultivated. When yellowing of the leaves was observed due to nitrogen deficiency, 50 mL of 5% (w / v) urea was added to 100 individuals.

- Cultivation of pollen parents -
The pollen parent was cultivated in the same manner as the seed parent, except that the rice variety was changed from “Akidawarakan 1” to “Sbe1 Akidawara” (owned by the National Agriculture and Food Research Organization).

-Mating-
For the rice variety "Akidawarakan No. 1," the ears that had emerged were exposed from the leaf sheath of the flag leaf (the leaf at the very tip), and emasculated in hot water at 43°C for 7 minutes (a process in which pollen activity is inactivated by heat treatment with hot water), after which the upper part of the spikelet was cut off with pollination scissors.
Next, the cut glumes were placed in a crossbreeding bag (made from glassine paper in a bag shape measuring 32 cm in length and 8 cm in width) together with the rice cultivar "Akidawarakan 1" as the seed parent and the rice line "sbe1 Akidawara" as the pollen parent, and the crossbreeding bag was shaken by hand every 30 minutes during flowering every day for 4 days to sprinkle pollen from the pollen parent onto the pistils of the seed parent.

<Second step>
The rice individual (seed parent) crossed in the first step was transferred immediately after crossing (47 days after sowing) to a plant growth incubator (a modified LPH-350-SPC with an additional LED tube (an LED tube capable of emitting light with a maximum peak top light intensity in the wavelength range of 615 nm to 650 nm in the wavelength range of 380 nm to 780 nm in the emission spectrum having the emission spectrum shown in FIG. 1E) as a light source; hereinafter, sometimes referred to as "modified incubator 1"). The plant was grown under the light environment with the emission spectrum shown in FIG. 1B, with an irradiation distance of 20 cm, a 10-hour day length with a light period of 10 hours (temperature: 27 ° C. to 30 ° C.) and a dark period of 14 hours (temperature: 18 ° C. to 25 ° C.), a CO ₂ concentration of 600 ppm, and a relative humidity of 85%.
The emission spectrum shown in Figure 1B was measured using a spectrophotometer (Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Instruments Co., Ltd.). The illuminance measured near the plant body in the modified incubator 1 using a light meter (Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Instruments Co., Ltd.) was 15,057 lux, and the light quantity was PPFD: 228 μmol m ^-2 s ^-1 .
As a result, hybrid seeds _F1 between the rice variety "Akidawarakan 1gou" and the rice line "sbe1akidawara" were obtained. The hybrid seeds _F1 were harvested 27 days after the crossing.

Example 2
A hybrid seed _F1 was obtained in the same manner as in Example 1, except that the second step in Example 1 was changed as follows.

<Second step>
In the second step of Example 1, the second step was performed in the same manner as in Example 1, except that the light environment was changed from the light environment having the emission spectrum shown in FIG. 1B to the light environment having the emission spectrum shown in FIG. 1C.
Specifically, in the second step of Example 1, the "modified incubator 1" was changed to a plant growth incubator (a plant growth incubator modified by adding an LED tube (an LED tube capable of irradiating light having an emission spectrum shown in FIG. 1E and capable of emitting light with a maximum peak top light intensity in the wavelength range of 380 nm to 780 nm in the emission spectrum) as a light source to the LPH-350-SPC; hereinafter, this may be referred to as "modified incubator 2").
The emission spectrum shown in Figure 1C was measured using a spectrophotometer (Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Instruments Co., Ltd.). The illuminance measured near the plant body in the modified incubator 2 using a light meter (Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Instruments Co., Ltd.) was 17,039 lux, and the light quantity was PPFD: 234 μmol m ^-2 s ^-1 .

(Comparative Example 1)
A hybrid seed _F1 was obtained in the same manner as in Example 1, except that the second step in Example 1 was changed as follows.

<Second step>
In the second step of Example 1, the light environment was not changed from that in the first step, and the second step was carried out in the same manner as in Example 1, except that the second step was carried out under white fluorescent light (under the light environment shown in Figure 1A) using a plant growth incubator (LPH-350-SPC, manufactured by Nippon Medical and Chemical Equipment Co., Ltd.).

(Comparative Example 2)
A hybrid seed _F1 was obtained in the same manner as in Example 1, except that the second step in Example 1 was changed as follows.

<Second step>
In the second step of Example 1, the second step was performed in the same manner as in Example 1, except that the light environment was changed from the light environment having the emission spectrum shown in FIG. 1B to the light environment having the emission spectrum shown in FIG. 1D.
Specifically, in the second step of Example 1, the "modified incubator 1" was changed to a plant growth incubator (a plant growth incubator modified by adding a blue LED tube as a light source to LPH-350-SPC; hereinafter, this may be referred to as "modified incubator 3").
The emission spectrum shown in Fig. 1D was measured using a spectrophotometer (Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Instruments Co., Ltd.). The illuminance measured near the plant body in the modified incubator 3 using a light meter (Light Analyzer LA-105, manufactured by Nippon Medical and Chemical Instruments Co., Ltd.) was 17,204 lux, and the light quantity was PPFD: 276 μmol m ^-2 s ^-1 .

(Test Example 1: Confirmation of hybridization in hybrid seeds _F1 )
By the following method, it was confirmed that the hybrid seeds _F1 harvested in the second step in Examples 1 and 2 and Comparative Examples 1 and 2 were obtained by crossing the rice variety "Akidawarakan 1gou" and the rice line "sbe1akidawara".

The seeds were germinated in a plant growth incubator (LPH-350-SPC, manufactured by Nippon Medical and Chemical Equipment Co., Ltd.) under conditions of a temperature of 30° C. and a relative humidity of 100%, and grown for 10 days.
DNA was extracted from the germinated seedlings (n = 10) using a DNA Sui-Sui kit (Rizo Inc, Tsukuba, Ibaraki, Japan), and the DNA marker for the sbe1 gene was used to confirm that the hybrid seeds _F1 were obtained by crossing the rice cultivar "Akidawarakan 1gou" and the rice line "sbe1akidawara."
To detect the sbe1 gene, the primer pair Sbe1_5end_12I/D_U (SEQ ID NO: 1) and Sbe1_5end_12I/D_L (SEQ ID NO: 2) (see JP 2013-172710 A) were used.
The temperature conditions for PCR were based on the touchdown PCR method (Don et al. 1991). The PCR program was as follows: 94°C for 5 min to completely denature DNA, followed by 34 cycles of 94°C for 30 s, annealing temperature (described below) for 60 s, and 72°C for 30 s, followed by 72°C for 10 min to synthesize complete double-stranded DNA. The annealing temperature was 62°C in the first cycle, decreased by 0.5°C per cycle from cycle 2 to cycle 14, and maintained at 55°C for the final 20 cycles.

In Examples 1 and 2 and Comparative Examples 1 and 2, the sbe1 gene was detected in all of the hybrid seeds _F1 harvested in the second step, and it was confirmed that they were obtained by crossing the rice variety "Akidawarakan 1gou" and the rice line "sbe1 Akidawara."

(Test Example 2: Measurement of mass of hybrid seeds _F1 )
In Examples 1 and 2 and Comparative Examples 1 and 2, the hybrid seeds _F1 harvested in the second step were dried at room temperature (25±5° C.) for 7 days, and the weight of one grain of brown rice was measured using an electronic microbalance (AB204-S, manufactured by Mettler Toledo, capable of measuring to 0.1 mg), and the average weight of 80 grains of brown rice was calculated. The results are shown in FIG.

The results in Figure 2 show that the brown rice obtained by cultivating the rice individuals (mother plants) that were crossed by cutting the glumes under the light environment with the emission spectrum shown in Figures 1B and 1C immediately after crossing and allowing the ripened fruits to ripen is significantly larger in mass than the brown rice obtained by cultivating the ripened fruits under the light environment with the conventional emission spectrum shown in Figure 1A from sowing to harvesting.

(Test Example 3: Confirmation of days to flowering depending on light environment)
The number of days to heading when rice was grown under each light environment in the second step of Examples 1 and 2, and Comparative Examples 1 and 2, was confirmed by the following method.

The rice line "sbe1 Akidawara" (owned by the National Agriculture and Food Research Organization) was used and grown from sowing to heading under a constant light environment of the light environment with the emission spectrum shown in FIG. 1A (LPH-350-SPC), the light environment with the emission spectrum shown in FIG. 1B (modified incubator 1), the light environment with the emission spectrum shown in FIG. 1C (modified incubator 2), or the light environment with the emission spectrum shown in FIG. 1D (modified incubator 3).
In all light environments, the conditions were a 10-hour day length with a 10-hour light period (temperature: 27°C to 30°C) and a 14-hour dark period (temperature: 18°C to 25°C), a _CO2 concentration of 600 ppm, and a relative humidity of 85%.
Specifically, seeds of the rice line "sbe1 Akidawara" were sown on a petri dish under each light environment and left for 3 days under conditions of a temperature of 30°C and a relative humidity of 100% to germinate. The germinated seeds were transplanted into a horticultural plug tray (RL-40PT, manufactured by Tokai Kasei Co., Ltd.) containing rice seedling soil (Bonsol No. 2, manufactured by Sumitomo Chemical Co., Ltd.) and cultivated. When yellowing of the leaves was observed due to nitrogen deficiency, 50 mL of 5% (w/v) urea was added as a top dressing for 100 individuals. The results are shown in Table 1 below.

The results in Table 1 show that the period until heading was the shortest when grown under the light environment with the emission spectrum shown in Figure 1A (under white fluorescent lamps), which is effective in promoting rapid generation.

The method for cultivating a grass plant of the present invention allows for simple and rapid breeding, and since even fruits obtained by the glume cutting method show sufficient enlargement, fruits with large seed mass can be obtained. Furthermore, the obtained fruits can produce high-quality hybrid seeds with good germination rates and subsequent growth. Therefore, the method can be suitably used not only as a general method for cultivating grass plants, but also as a technology for promoting rapid generation of grass plants.
Furthermore, the apparatus for cultivating grasses of the present invention is used for cultivating grasses, and in particular, the light environment is such that breeding can be carried out easily and quickly, and even fruits obtained by the glume cutting method can show sufficient swelling and produce fruits with large seed mass. Therefore, the apparatus can be used not only for cultivating general grasses, but also suitably for rapid generation promotion technology for grasses.

Although the above-mentioned Gramineae plant growing device is used for growing Gramineae plants, it can also be widely used for biological tests that require light, such as germination tests for other plants, research into the biological clocks of animals and plants including insects, algae cultivation, microbial cultivation, plant cultivation, and the rearing of insects and small animals.

Reference Signs List 1 Gramineae plant growing device 2 Device body 3 Tank 3a Outer door 4 Storage means 4a Inner door 4b Suction port 5A Circulation passage (for feeding)
5B Circulation passage (for return)
Reference Signs List 6 Air conditioning unit 7 Operation panel 8 Setting input unit 9 Heater 11 Styrofoam 12 Vertical plate 13 Shelf 14 Magnet 15 Internal fan 17 Light source 17A Light source body 17a Ballast 17b Reflector 21 Main panel 22 Irradiation setting panel 25 Cooler 26 Circulating air fan 28 Heat exchanger 29 Compressor

Claims (4)

A method for growing a grass family plant, comprising: shielding external light and irradiating only artificial light to the grass family plant to grow the grass family plant, the method comprising the steps of:
a first step of growing a seed parent gramineous plant and a pollen parent gramineous plant by irradiating them with white light having a color temperature of 5,000 K to 6,500 K using a standard light source defined by the International Commission on Illumination (CIE) as the artificial light;
a crossbreeding step of cutting an upper part of a spikelet of the seed parent gramineous plant grown in the first step and crossbreeding the spikelet with the pollen parent gramineous plant grown in the first step;
a second step of irradiating the seed parent Gramineae plant obtained in the crossbreeding step with the artificial light, the artificial light being a combination of the standard light source and an LED light source capable of irradiating light having a maximum peak top light intensity in a wavelength range of 615 nm to 650 nm in an emission spectrum of 380 nm to 780 nm, the light having a maximum peak top light intensity in a wavelength range of 550 nm to 780 nm in an emission spectrum of 380 nm to 780 nm;
A method for cultivating a grass family plant, comprising: A method for growing a grass family plant, comprising: shielding external light and irradiating only artificial light to the grass family plant to grow the grass family plant, the method comprising the steps of:
a first step of growing a seed parent gramineous plant and a pollen parent gramineous plant by irradiating them with white light having a color temperature of 5,000 K to 6,500 K using a standard light source defined by the International Commission on Illumination (CIE) as the artificial light;
a crossbreeding step of cutting an upper part of a spikelet of the seed parent gramineous plant grown in the first step and crossbreeding the spikelet with the pollen parent gramineous plant grown in the first step;
A second step of irradiating the artificial light to the Gramineae plant as the seed parent obtained in the crossbreeding step, the light being irradiated from both the standard light source and an LED light source capable of irradiating light having a maximum light intensity at a peak top in a wavelength range of 615 nm to 650 nm in a wavelength range of 380 nm to 780 nm in an emission spectrum, the light satisfying R>B for the maximum light intensity R in a wavelength range of 550 nm to 780 nm and the maximum light intensity B in a wavelength range of 400 nm to 490 nm in a wavelength range of 380 nm to 780 nm in an emission spectrum, and R>G for the maximum light intensity R in a wavelength range of 550 nm to 780 nm and the maximum light intensity G in a wavelength range of more than 490 nm and less than 550 nm;
A method for cultivating a grass family plant, comprising: The method for growing a grass family plant according to any one of claims 1 to 2, wherein the artificial light in the second step is artificial light such that, in an emission spectrum in a wavelength region of 380 nm to 780 nm, a value Rf obtained by definite integration of a wavelength region of 550 nm to 780 nm and a value Bf obtained by definite integration of a wavelength region of 400 nm to 490 nm satisfy Rf>Bf, and a value Rf obtained by definite integration of a wavelength region of 550 nm to 780 nm and a value Gf obtained by definite integration of a wavelength region of more than 490 nm and less than 550 nm satisfy Rf>Gf. The method for cultivating a grass family plant according to any one of claims 1 to 3, which is used to accelerate the generation of a grass family plant.