JP2001258389A - Method for cultivating plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for cultivating a plant, designed to efficiently regulate flower bud formation thereof. SOLUTION: This method for cultivating a plant is characterized by that the plant in growth is irradiated with artificial light comprising blue light having the maximum value of output wavelength of 400-500 nm and a photon flux density of >=10 μ mol/m2/s.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for promoting flower bud formation of a plant using blue light having a peak wavelength of 400 to 500 nm, and for efficiently controlling flowering of a plant regardless of a natural environment.

[0002]

2. Description of the Related Art Techniques for supplementing light in a greenhouse or the like to regulate flower bud formation have been known so far, and have been put to practical use in chrysanthemums, strawberries and the like. This technique is a technique utilizing the physiological action of phytochrome which is a chain tetrapyrrole compound contained in plant tissue, and is a technique utilizing a flower bud formation inhibitory action caused by phytochrome acting as a photoreceptor. In other words, by irradiating red light, which is the absorption wavelength of phytochrome, phytochrome of far-red absorption type is generated, and the phytochrome becomes a bioactive substance and utilizes the mechanism of suppressing flower bud formation of plants. In such technology, inexpensive incandescent lamps, which contain a relatively large amount of red light and are inexpensive, have been widely used, and have been used in electric cultivation in many chrysanthemum production areas and strawberry production areas.

[0003] On the other hand, various studies have been made on a method of using a light emitting diode as a light source for cultivating a plant, and also, mainly, a method of irradiating red light by utilizing the physiological action of phytochrome is used. As a method of irradiating blue light, Japanese Patent Application Laid-Open No. 8-37930 discloses that a shortage of blue light is supplemented in order to prevent plant growth during indoor cultivation of plants.

[0004]

However, the technique using the above-mentioned red light is used only when all of the other conditions (temperature, moisture, nutritional conditions, etc.) necessary for flower bud formation are in place. Is a method of controlling flowering time by suppressing flower bud formation, and is not a method of actively promoting flower bud formation by lightening and regulating flowering.

In the field of flowering and horticulture in recent years, it has been demanded to cultivate higher value-added plants. For example, it is possible to promote the formation of flower buds and to increase the number of flowers originally having a small number of flowers, or to add flowers. Adjusting the flowering timing of difficult plants to increase the number of flowers is important for increasing consumer confidence, and the emergence of cultivation methods that enable this has been widely demanded in this field.

[0006] Also, in the cultivation of fruits and vegetables, orchards and cereals, adjustments such as increasing the number of flowers by promoting flower bud formation, or adjusting the timing of flowering to a time suitable for harvesting, increase the amount of harvest, For stable harvesting, it is an important point, and the establishment of such a technique was desired. Also,
In the above-mentioned Japanese Patent Application Laid-Open No. 8-37930, only the insufficient blue light is supplemented in indoor cultivation of plants as compared with outdoor cultivation, and the photon flux density is also several μmol / m ^2. / s, which was extremely weak, and no flower bud formation promoting effect was found.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made intensive studies on the wavelength of irradiation light and the formation of flower buds of a plant. They found that they specifically promote flower bud formation, and completed the present invention. That is, the gist of the present invention is that a growing plant has an output wavelength of 400 to 500 n.
m and a photon flux density of 10 μmol / m
A plant cultivation method characterized by irradiating artificial light composed of blue light of ² / s or more.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The cultivation method of the present invention irradiates a growing plant with blue light of a specific intensity. The blue light of the present invention has an output wavelength peak of 400 to 5
It is included in the blue region of 00 nm. However, in the case of a light source having a plurality of output peaks or an irregular and broad spectrum output pattern, at least 50% or more of the output energy is included in the blue wavelength region of 400 to 500 nm according to the present invention. It is included in.

The spectral width of the peak wavelength of the blue light is preferably 150 nm or less in half width, from the viewpoint of effective flower bud formation and promotion of flowering, and 100 n.
m or less is particularly preferable. As the irradiation light to the plant, in addition to the blue light, for another purpose such as root elongation or stem differentiation, if necessary, it may be irradiated with light having another peak wavelength, Since light in the red wavelength range of 600 to 800 nm has a remarkable effect of inhibiting flower bud formation, the amount of radiant energy contained in this wavelength range is 3% of the total radiant energy.
It is preferable to keep it to 0% or less, and more preferably to keep it to 15% or less.

[0010] As a light source for irradiating the blue light, a light source that efficiently emits a blue wavelength and emits less energy than blue light is required. Specifically, a blue fluorescent lamp, a blue light-emitting diode, a blue laser diode, a blue filter-equipped lamp, and the like, preferably a blue fluorescent lamp, a blue light-emitting diode and / or a blue laser diode. From the viewpoint of luminous efficiency, a blue light emitting diode and / or a blue laser diode are particularly preferable.

The light intensity required for carrying out the present invention varies depending on the target plant species, the growth stage, the spectral pattern of the light source used, and the like. The lower limit of the photon flux density is 10 μmol / m ² / s or more. In particular, it is 30 μmol / m ² / s or more, and the upper limit is 500 μmol / m ² / s or less, particularly 15 μmol / m ² / s.
It is preferable that the concentration be 0 μmol / m ² / s or less in order to induce efficient flower bud formation and promotion of flowering.

Many plants have photoperiodism (daylength response) that regulates flower bud formation in accordance with daytime (light period), but plants to which the method of the present invention is applied include long day light. Plants (plants that regulate flower bud formation in response to long days) or short day plants (plants that regulate flower bud formation in response to short days)
Neutral plants (plants that do not respond to the photoperiod) can be applied without particular limitation. Specifically, flowering garden plants, fruits and vegetables,
Fruit trees and cereals, for example, Phalaenopsis, Sympidium, orchids including dendrodium, cacti, roses, carnations, gerberas, gypsophila, lilies, flowers and flowers for cut flowers such as starches,
And potted flowers such as pansies, primula, bekonia, petunia, cyclamen and the like; fruits and vegetables such as tomato, cucumber, melon, strawberry, and pepper; fruit trees such as pear, apple, grape; and corn, wheat and the like It is also applicable to cereals and the like. In particular, in order to make the most of the effects of the present invention, plants having a slow flower bud formation, plants having a small number of flower bud formations in a natural state, or plants in a state in which more seedlings are required than in a normal state are required. It is possible to target.

The cultivation method of the target plant is not particularly limited, and a method of germinating and raising seedlings using a tray or pot filled with cultivated soil in a field and cultivating them is provided.
After germination on a sponge cube, it is possible to use a cultivation method according to the type of plant and the purpose of cultivation, such as a method of hydroponics as it is, a method of aseptically culturing and raising seedlings on agar containing nutrients. I can do it.

In the present invention, plants are irradiated with blue light usually after germination after sowing and transplantation into a nursery box, but flowers are required early for the purpose of breeding and crossing. In this case, the irradiation can be performed from an early point after the true leaves emerge, or from the point of time when the plant has grown to a target size in the case of fruits and vegetables, fruit trees, cereals, and ornamental plants. In addition, a method of irradiating blue light only at the seedling raising stage to form flower buds, planting in this field, and then cultivating under normal conditions may be adopted. The irradiation mode may be continuous irradiation or intermittent irradiation (pulse irradiation). The pulse interval in the case of the intermittent irradiation is not particularly limited as long as the integrated irradiation amount is ensured for each target plant in each of the continuous irradiation and the intermittent irradiation so that the target effect can be obtained.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

[0016]

EXAMPLES Example 1 A culture test using high-brightness light-emitting diodes (LEDs) was performed using "Dwarf Midget Blue" of Exacum affine. Seeds are disinfected with 70% ethanol and 3% sodium hypochlorite, then MS containing 0.8% agar
Germinated aseptically on medium (pH 5.6). The culture vessel used was a glass tube having a diameter of 40 mm, which was sealed with aluminum foil and sterilized with an autoclave. 20 under fluorescent light
After the day culture, when the true leaves were developed, the aluminum foil stopper was replaced with a vent filter stopper. After that, it was moved into a 24 ° C incubator, and the LED was turned on at a light / dark cycle of 16 hours / 8 hours.
Irradiated with light.

The LED has a peak wavelength of 450,
470, 525 (all manufactured by Nichia Corporation), 660, 68
0, 730 nm (above, manufactured by Kagoshima Matsushita Electronics)
A high-brightness diameter mm type was used. Monochromatic light of each wavelength was irradiated using an LED panel provided at a density of 5000 LEDs / m ² using an aluminum frame of 45 × 45 cm. A constant-voltage / constant-current power supply device is provided for each wavelength section.
By adjusting the drive current of the ED, the amount of light at the installation position of the culture vessel was adjusted to 40 μmol / m ² / s. Between the test sections, the cells were sealed with a black acrylic plate so as not to leak light from each other, and cultured for 3 months. Hereinafter, Table 1 shows the average number of days until the first inflorescence blooms after the start of the LED culture of 60 exazacams in each section, the rate of flowering strains, and the average value of the total number of flowers per strain during the three months of culture. . The results showed that among the monochromatic lights tested, blue light had an extremely strong flower bud formation promoting effect.

[0018]

[Table 1] Table 1 Exacam flowering rate under each LED monochromatic light, number of days until flowering of the first inflorescence and total number of flowers Wavelength (nm) Color Flowering rate (%) Number of flowering days (days) Total number of flowers (pieces) ) 450 Blue 100 38.2 ± 6.3 5.3 ± 0.8 470 Blue 100 41.5 ± 5.5 5.1 ± 0.9 525 Green 38 73.1 ± 3.3 1.1 ± 0 .6 660 Red 0 No flowering 0 680 Red 388.8 ± 6.2 0.1 ± 0.1 730 Far-red 0 No flowering 0 Example 2 'Castle pink' of Celosia pulmosa
And a culture test using a high-brightness LED was performed. After disinfecting the seeds as in Example 1, 0.3 containing 0.8% agar.
Germinated aseptically on a% sucrose medium (pH 5.8).
The culture vessel used was a glass tube having a diameter of 30 mm, which was sealed with aluminum foil and sterilized with an autoclave. After culturing in the dark for 3 days and in a fluorescent lamp for 7 days, the cells were transferred into a 24 ° C. incubator and irradiated with LED light in a light / dark cycle of 16 hours / 8 hours.

Using the same LED panel as in Example 1, the amount of light at the installation position of the culture vessel was adjusted to 30 μmol / m ² / s, and the sections between the test sections were sealed with a black acrylic plate so that light did not leak from each other. And cultured for 40 days. Below, each ward 50
Table 2 shows the number of days until the light emission of 50% of the strains after the start of the cell culture of the cells in the cellusia (average of three experiments), and the ratio of the lightening strains after 40 days of culture. Also in this result, a remarkable flower bud formation promoting effect was recognized by blue light.

[0020]

[Table 2] Table 2 50% lightning days and lightning rate of the first inflorescence of Serusia under the monochromatic light of each LED Wavelength (nm) Color Days of flowering (days) Flowering rate (%) 450 Blue 27.9 ± 3 .1 100 470 Blue 30.5 ± 3.0 100 525 Green 52.3 ± 4.1 21.1 660 Red 60.1 ± 5.3 3.5 680 Red 59.6 ± 5.2 2.7 730 Far-infrared 58.9 ± 6.3 3.1

[0021]

According to the present invention, a cultivation method that directly promotes flower bud formation and flowering is possible. That is, the peak wavelength of 400 to 50 during flower bud formation is required during plant cultivation.
By irradiating blue light having a specific intensity of 0 nm, flower bud formation can be directly and specifically promoted, and flowering can be promoted and the number of flowers can be promoted. This technology can be expected to be used not only in flower garden plants, but also in fruits and vegetables, fruit trees, and cereals by increasing flowering by promoting flowering, and can be expected to be used in a wide range of agricultural fields.

Claims (4)

[Claims] An output wavelength of 400 for a growing plant.
Having a maximum value of about 500 nm and a photon flux density of 1
A plant cultivation method characterized by irradiating artificial light consisting of blue light of 0 μmol / m ² / s or more. 2. The plant cultivation method according to claim 1, wherein the amount of light radiant energy in the red wavelength range of 600 to 800 nm is 30% or less of the total radiant energy. 3. The plant cultivation method according to claim 1, wherein the light source of the artificial light is a blue fluorescent lamp, a blue light emitting diode and / or a blue laser diode. 4. The method for cultivating a plant according to claim 1, wherein the spectral width of the peak wavelength is 100 nm or less in half width.