JP2008142005A - Plant cultivating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grass form controlling method freely promoting or suppressing flower formation according to a purpose while suppressing elongation of main stems. <P>SOLUTION: This grass form controlling method includes controlling flower formation while suppressing elongation of main stems through irradiating plants with red light (R; 600-700 nm) adjusted in optical power. Alternatively, the method includes controlling flower formation while suppressing main stem elongation of plants through irradiating the plants with red light (R; 600-700 nm) adjusted in optical power, and irradiating the plants with blue light so as to promote main stem elongation and flower formation. Alternatively, the method includes controlling flower formation while suppressing main stem elongation through irradiating plants with blue light to promote main stem elongation and flower formation, and irradiating the plants with red light (R; 600-700 nm) adjusted in optical power. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plant cultivation technique. More specifically, the present invention relates to a technique for controlling plant stem elongation, flower bud differentiation, flowering, and the like by adjusting light quality and light intensity.

  When cultivating a plant, it is generally performed to control flower bud differentiation and flowering. For example, “dark-period interruption” is well known as a technique for controlling flower bud differentiation and flowering for plants that react specifically with the photoperiod, such as long-day plants or short-day plants.

  In addition, the form of the plant (also referred to as “grass form”) is directly linked to commercial value. For example, in pot flowers, the balance between pots and plants is regarded as important, and so-called “captains” whose main stems are too long have a reduced commercial value. For this reason, techniques for suppressing the growth of plants have been developed. For example, techniques for controlling the appearance of plants by foliar spraying or soil irrigation with a “dwarfing agent” are widely used. However, this dwarfing agent has a problem from the aspect of environmental load.

In addition, a technique has been proposed in which the light quality of sunlight is changed with a coating material to control plant growth, flower bud formation, flowering, fruiting time, and the like. Specifically, in Patent Document 1, using a coating material containing a pigment in a nonwoven fabric, the light whose ratio (R / B) between red light and blue light is controlled to be a predetermined value is determined for a predetermined period. A technique for irradiating a plant is disclosed. Patent Document 2 discloses the amount of transmitted light (R) of red light having a wavelength of 600 to 700 nm based on the standard light source D65 and the light quantum of far red light having a wavelength of 700 to 800 nm based on the standard light source D65. A technique for covering a plant with a film or net having a value (R / FR) divided by a bundle transmission amount (FR) of a predetermined level or more is disclosed.
JP 2002-247919A. JP 2006-191862 A.

  A simple, versatile, and environmentally friendly technology that can promote or inhibit flower bud differentiation and flowering according to the purpose while suppressing the elongation of the main stem in plant cultivation technology Is required. Then, this invention makes it the main objective to provide the said technique.

  The inventors of the present application paid attention to light quality, light intensity, switching timing of light irradiation, and the like, and have made extensive studies from these viewpoints. As a result, the following matters were newly found for red light and blue light.

  About red light (R; 600-700 nm). (1) The red light suppresses the main stem elongation of the plant regardless of the light intensity. (2) Red light promotes (induces) flower bud differentiation and flowering, or conversely suppresses (delays) the intensity of light. Specifically, in the case of strong red light with a light intensity of a predetermined value or more, the effect of promoting flower bud differentiation and flowering is exhibited while maintaining suppression of main stem elongation. On the other hand, when the red light is weak red light less than a predetermined value, effects such as suppression of flower bud differentiation and flowering and promotion of side branch development are exhibited while maintaining suppression of main stem elongation. (3) The weak red light maintains the main stem elongation suppressing effect and the side branch development effect as it is even when blue light is mixed.

  About blue light (B; 400-500 nm). (1) Blue light promotes main stem elongation. (2) Blue light promotes flower bud differentiation and flowering.

  The inventors of the present application provide the following inventions based on the research results regarding each of the red light and the blue light as described above and the research results obtained by the combination of the irradiation times of the red light and the blue light. .

  First, in the present invention, a plant cultivation method for controlling flowering while irradiating a plant with red light (R; 600 to 700 nm) whose light intensity is adjusted while suppressing main stem elongation of the plant. provide. “Flowering” means a reaction from flower bud differentiation to flowering, and “control” means artificially promoting or suppressing.

For example, using red light adjusted to a photon flux density of 150 μmolm ⁻² s ⁻¹ or higher in light intensity, a method of promoting flowering while suppressing elongation of the main stem of the plant, or light intensity of 70 to 100 μmolm Provided is a method for suppressing flowering while suppressing main stem elongation of a plant using red light set to a photon flux density of ⁻² s ⁻¹ .

  In the present invention, the plant is irradiated with the red light having the light intensity adjusted to control the flowering while suppressing the main stem elongation of the plant, and then the plant is irradiated with blue light. Provided is a plant cultivation method for turning stem elongation into promotion and promoting flowering.

  In the plant cultivation method, when strong red light of a predetermined light intensity or higher is used in the red light irradiation stage before blue light irradiation, flowering is promoted while suppressing the main stem elongation of the plant, and the subsequent blue light As a result, the elongation of the main stem can be changed to promotion, and the flowering can be further promoted. On the other hand, in the case of using weak red light less than a predetermined light intensity in the red light irradiation stage before the blue light irradiation, the flowering is suppressed while suppressing the main stem elongation of the plant, and the main stem elongation and Both flowering can be turned into promotion.

  Next, in the present invention, after irradiating the plant with blue light to promote main stem elongation and flowering, the plant is irradiated with red light with adjusted light intensity to suppress main stem elongation. A plant cultivation method for controlling flowering is provided.

  In the plant cultivation method, when strong red light of a predetermined light intensity or higher is used in the red light irradiation stage after the blue light irradiation, the main stem elongation of the plant is shifted to suppression and further flowering is further promoted. Can be made. On the other hand, in the red light irradiation stage after the blue light irradiation, when weak red light having a light intensity lower than a predetermined light intensity is used, both the main stem elongation and the flowering of the plant can be turned to suppression, and in addition, the side branch Can be developed.

  According to the present invention, by selecting the light quality (red light and blue light), the light intensity of red light, and the irradiation timing of red light and blue light according to the plant species and purpose, the environment The elongation of the main stem can be controlled without using any rusting agent that has a problem of load, and flowering can be freely promoted or suppressed depending on the purpose.

  Preferred embodiments according to the present invention will be described with reference to the accompanying drawings. In addition, a present Example shows one Example of this invention, and, thereby, the range of this invention is not interpreted narrowly.

<Materials and methods used in experiments>
Petunia 'Baccarat Blue' was adopted as the test plant. In each environment, 4 seeds are sown on the cell tray in the environmental control room, and when the main leaves begin to spread, one strain is left and thinned out. After the three main leaves are deployed, they are raised in a 7.5 cm diameter plastic pot. did. Using white fluorescent light as a light source, after raising seedlings to about 5 true leaves, they were cultivated under an LED (light emitting diode) panel light source installed in the same room. The temperature of the environmental control room was 20 ° C., and the light period was 14 hours and the dark period was 10 hours.

(Example 1)
It is an experimental system that verifies that flower bud differentiation, flowering and stem elongation can be controlled by adjusting the light intensity of red light.

(1) Experiment 1-1
Red LED (R ward, MIL-R18, Sanyo Electric Co., Ltd.) and blue LED (B ward, MIL-B18, Sanyo Electric Co., Ltd.) as LED panel light source and red LED and blue as control ward A mixed light source (RB section) with an LED light source number ratio of 1: 1 was provided, and both plants were cultivated under each light source, and the light intensity irradiated was a photon flux density of 100 μmol · m ⁻² · near the top of the plant body. s ^-1 (PPF).

  Experimental result. FIG. 1 (drawing substitute table) summarizes the results of this experiment. First, in the above B section, significant elongation of stems and petioles was observed from the fifth day after the treatment was started. In particular, the main stalk continued to elongate until the end of the treatment, and showed a prominent appearance. In addition, the stalk of the B zone was about 40 mm long on the 15th day after the start of the treatment, and was about twice that of the RB zone. In addition, the change in leaf angle was confirmed about 10 hours after the start of the treatment, and the appearance of grass in the B ward became more prominent. In addition, in area B, flowering occurred one month after the start of treatment, and flowering was significantly promoted compared to other LED light source areas. From this result, it was confirmed that the blue light has an effect of promoting main stem elongation, petiole elongation, and flowering.

On the other hand, in the R group and the RB group, the elongation of the main stem was hardly observed, and the petiole length was shortened to about 18 mm. In these treatments, flowering could not be observed during the 55-day test period. However, in the R and RB districts, the development of side branches was vigorous. From this result, it was confirmed that the weak red light having a photon flux density of 100 μmol · m ⁻² · s ⁻¹ has an effect of suppressing main stem elongation, an effect of suppressing flowering, and an effect of promoting side branch development.

  Next, in the vicinity of the growth point including the petunia stem, the expression level of the GA20 oxidase gene-1 increases with the passage of time in the B zone, and after 21 hours, it is 4.1 times the initial value. It was about 2.7 times that of other treatment zones (see Fig. 2).

  Thus, in petunia, the expression level of some of the GA20-position oxidases involved in the synthesis of active GA increased under blue light. In both plants cultivated under blue light, reactions such as breakage of rosettes and elongation of the main stem and petiole are caused by the increase in the amount of endogenous gibberellin accompanying the increased expression of gibberellin biosynthesis-related genes under blue light. It was suggested that it might be attributed to the results.

(2) Experiment 1-2
For the plant grown under the red LED irradiation zone (R zone) or the blue LED irradiation zone (B zone) under the same conditions as Experiment 1-1, with the white LED irradiation zone (W zone) as the control zone, after treatment 2 Every two days from the end of the week to the completion of wrinkles, the development stage of flower bud differentiation was observed using ESEM (environmentally controlled electron microscope) and classified into undifferentiated, gourd differentiation and pistil differentiation stage.

  Experimental result. Regarding the stage of flower bud development, the number of days until the start of flower bud differentiation is 16 days after the start of treatment in the W ward, but 14 days in the B ward, and the transition from gaku differentiation to pistil differentiation is fast. The differentiation period was shortened, and as a result, the formation of wrinkles was promoted for about 2 days, and wrinkles were already formed on the 18th day after the start of the treatment (see FIG. 3). On the other hand, in the R ward, flower bud differentiation did not occur and vegetative growth continued during the treatment period (see FIG. 3). FIG. 3 is a scanning electron micrograph showing the state of the petunia main stem growth point on the 18th day after the start of the light treatment.

(3) Experiment 1-3
In the R zone and B zone, a zone (RH zone, BH zone) with an increased light intensity and a photon flux density of 150 μmol · m ⁻² · s ⁻¹ is provided, and a weak light intensity zone (RL, BL zone: photon flux density). The growth response was compared with 70 μmol m ⁻² s ⁻¹ ).

Experimental result. Weak red light (photon flux density of 70 μmol · m ⁻² · s ⁻¹ ) was suppressed in flowering as in Experiment 1-1, but RH section with increased light intensity (photon flux density of 150 μmol · m ⁻²⁾ -In s ^-1 ), flowering was confirmed 28.6 days after the start of the treatment, and the number of flowering days was about the same as in the B section (see Fig. 4). Furthermore, the strong red light condition in the RH section increased the number of arrivals to the B section or more. On the other hand, the effect of light intensity on each light quality was limited for stem elongation (see FIG. 5).

  That is, in comparison with the W group, which is the control group, in the R group (RH group, RL group), regardless of the light intensity, the elongation of the main stem was significantly suppressed, and the figure of the grass was downsized. On the other hand, for the B section, on the contrary, the elongation of the main stem was greatly promoted. However, for the R group, the main stem length is the same regardless of the light intensity. In the case of the B group, the elongation is slightly promoted in the BH group, but the difference is small (see FIG. 5). ).

Summarizing the above results, red light has the effect of suppressing the growth of the main stem regardless of the light intensity and miniaturizing the grass figure, and blue light has the effect of extending the main stem regardless of the light intensity. It turns out that there is an effect to promote. Further, in the RL Ward weak red light (70μmol m ^-2 s ^-1), flowering as in the Experiment 1-1 (photon flux density 100μmol · m ^-2 · s ^-1) is suppressed, whereas, In the RH section (light quantum flux density 150 μmol · m ⁻² · s ⁻¹ ) where the light intensity was increased, flowering was promoted and the number of arrivals was increased.

(4) Experiment 1-4
About W ward (control ward) and R ward and B ward that set the light intensity H ward and L ward, after raising seedlings for 25 days, move to the natural light condition or the experimental ward under fluorescent lamp (N ward) The growth reaction was observed.

  Experimental result. When petunia seedlings are grown in W, RH and RL for 25 days and then moved to the experimental zone (N zone) under natural light or fluorescent light, they are continuously cultivated in RH or RL zone In comparison, when moving from each light source under natural light, the main stem length tended to increase (see FIG. 6). However, as a whole, there was a tendency for the main stem to be suppressed as compared with the W section.

In addition, in the case of moving from the RH section of intense red light (photon flux density 150 μmol · m ⁻² · s ⁻¹ ) to the N section, it flowered immediately after natural light movement. This result shows that the flowering promotion effect of strong red light is sustained even under natural light. Moreover, when it moved from W ward which is white LED irradiation ward to N ward, it blossomed 15 days after natural light movement. In the case of moving from the RL section of weak red light (photon flux density 70 mol · m ⁻² · s ⁻¹ ) to the N section, the flower bloomed 35 days after natural light movement. Thus, it was shown that flowering was controlled by the interaction between light quality and light intensity (see FIG. 7).

(Example 2)
It is an experimental system that verifies that flowering and stem elongation of plants can be controlled by light irradiation combined with red light and blue light.

(1) Experiment 2-1
After confirming arrival of plants grown in R ward or B ward in B ward, switch from B ward to R ward (B ward → R ward) or from R ward to B ward (R ward → B ward) Went. In addition, 100 ppm of GA (in the vicinity of the growth point of petunia cultivated under red light, twice at the time of arrival and three weeks after the arrival of the plant in the R district, with reference to the arrival in the W district. 4 ml of gibberellin) was sprayed, and the subsequent growth and flowering were observed.

  Experimental result. When cultivated by switching the irradiation of red light and blue light, it was found that a large change occurred in petunia flowering (see FIG. 8).

  In addition, in the RL section of weak red light, while the main stem was hardly elongated (see FIG. 9), on the 15th day after the start of the experiment in which the anchoring was confirmed in the B section, the blue light was seen from below the red light. In the R zone to B zone that moved under the light (when switching from the red light zone to the blue light zone), after switching the light quality, the main stem grows abruptly and finally becomes about 70% of the B zone. The number of arrivals was about the same as that of B-ku, indicating that flowering was greatly promoted (see FIG. 9).

On the other hand, in the B zone → R zone (when switching from the blue light zone to the red light zone), the main stem elongation is suppressed after switching the light quality, and the number of arrivals is 4.5 on average. It was greatly suppressed compared with (blue light continuous irradiation section). In addition, when GA ₃ was sprayed in the R zone (GA zone), the main stem was greatly elongated compared to the RL zone (weak red light zone) (see FIG. 9).

(2) Experiment 2-2
Plants cultivated in R district for 2 weeks were moved to B district, cultivated for 1, 2, 3, 5, and 7 days, then returned to R district and observed for subsequent growth and flowering. FIG. 10 is a diagram illustrating the cultivation method of the experiment 2-2.

  Experimental result. About petunia cultivated under red light (R ward), after cultivating under blue light (B ward) for a certain period of time and then moving again under red light (R ward), it moved to B ward for more than 5 days. It was confirmed that it leads to hemorrhoids (see FIG. 11). Moreover, the number of arrival increased in proportion to the period grown under blue light (see FIG. 11).

  The results of Experiment 1 (Experiments 1-1 to 1-4) and Experiment 2 (Experiments 2-1 and 2-2) are summarized as follows.

From the results of Experiments 1-1 to 1-3, when the light intensity is 70 to 100 μmol · m ⁻² · s ⁻¹ , petunia flower is completely suppressed at the stage of flower bud differentiation under red light, The extension of the main stem is strongly suppressed under red light, while the side branch is vigorously developed.

From the results of Experiments 1-2 to 1-3, even with red light, when the light intensity is set to 150 μmol · m ⁻² · s ⁻¹ or more, flowering can be strongly promoted (induced), and the number of flowering Greatly increases. On the other hand, even if the light intensity is increased, the main stem elongation suppression effect by red light is not affected. Even when petunia grown under red light is moved under natural light, the effects of light intensity on flowering and main stem elongation remain.

  From the results of Experiments 2-1 to 2-2, flowering and main stem elongation are affected from the time when they move under red light or blue light, and adapt to the light environment to change the appearance of the grass. In addition, when flowering that has been suppressed under red light is induced by blue light, petunia flower bud differentiation can be induced by irradiating blue light for at least 5 days. Further, even when the light is moved from the red light to the blue light, if the blue light irradiation is performed for about 5 days, it is considered that the main stem elongation suppressing effect by the red light is not so much affected.

  In addition, based on the Arabidopsis model, petunia presents a light quality control model in which the flower bud suppression mechanism via red light is weakened or disappears under blue light, while the signal from cryptochrome significantly induces flower bud differentiation. To do. FIG. 12 is a diagram schematically showing the concept of this light quality control model.

  Under blue light alone irradiation, in addition to flower induction, suppression of gibberellin biosynthetic systems using phytochrome as a light receptor by red light stimulation is also weakened. As a result, rosette breakage and stem elongation are promoted. In this regard, as shown in FIG. 2, it was proved that the expression of some genes related to gibberellin biosynthesis increased under blue light.

  On the contrary, in the case of single irradiation of red light, in addition to no flower bud induction stimulation from blue light, a suppression signal from red light works, and flower bud differentiation / flowering is strongly suppressed. On the other hand, it was confirmed that flower buds are induced when the light intensity is increased even under red light, and therefore flower induction can be performed through signal pathways that depend on light intensity such as photosynthesis even under red light. There is sex.

  The present invention can be used as a plant grass shape control technique. Specifically, it can be used as a technique capable of freely promoting or suppressing flower bud differentiation and flowering according to the purpose while suppressing the elongation of the main stem.

It is a table | surface which shows the result of Experiment 1-1, Comprising: It is a figure (drawing substitute table | surface) which shows the influence which the light quality of red light and blue light has on the growth of petunia. It is a graph which shows the result of Experiment 1-1, Comprising: It is a figure (drawing substitute graph) which shows the influence which red light, blue light, and the light which combined them have on the expression of petunia gibberellin 20-position oxidase gene-1. In Experiment 1-2, it is an observation photograph with a scanning electron microscope which shows the mode of the petunia main stem growth point on the 18th day after light processing start. It is a table | surface which shows the result of Experiment 1-3, Comprising: It is a figure (drawing substitute table | surface) which shows the influence which the light quality and light intensity | strength of red light and blue light have on petunia flowering. It is a graph which shows the result of Experiment 1-3, Comprising: It is a figure (drawing substitute graph) which shows the influence which each light intensity | strength of red light and blue light has on the main stem elongation of a petunia. It is a graph which shows the result of Experiment 1-4, Comprising: It is a figure (drawing substitute graph) which shows the change of the main stem elongation after moving the petunia raised under red light of different light intensity conditions under natural light. The left graph is for the strong red light condition, and the right graph is for the weak red light condition. It is a graph which shows the result of Experiment 1-4, Comprising: It is a figure (drawing substitute graph) which shows the change of the number of flowering after moving the petunia planted under red light of different light intensity conditions under natural light. It is a table | surface which shows the result of Experiment 2-1, Comprising: It is a figure (drawing substitute table | surface) which shows the influence which the irradiation period of red light and blue light has on the flowering of petunia. It is a graph which shows the result of Experiment 2-1, Comprising: It is a figure (drawing substitute graph) which shows the influence which the irradiation period of red light and blue light has on the main stem length of petunia. It is a figure which shows the cultivation method of Experiment 2-2. It is a table | surface which shows the result of experiment 2-2, Comprising: It is a figure (drawing substitute table | surface) which shows the influence on the number of arrivals by the difference in the number of days which moved under blue light during red light processing. It is a figure which shows typically the concept of the light quality control model concerning this invention.

Claims (5)

  A plant cultivation method for controlling flowering by irradiating a plant with red light (R; 600 to 700 nm) with adjusted light intensity while suppressing elongation of a main stem of the plant. The red light adjusted to a photon flux density of 150 μmol · m ⁻² · s ⁻¹ or higher in light intensity is used to promote flowering while suppressing elongation of the main stem of the plant. The plant cultivation method according to 1. Using the red light having a light intensity set to a photon flux density of 70 to 100 μmol · m ⁻² · s ⁻¹ , the flowering is suppressed while suppressing the main stem elongation of the plant. The plant cultivation method according to claim 1.   By irradiating the plant with red light (R; 600-700 nm) with adjusted light intensity, the plant growth is controlled while suppressing the elongation of the main stem of the plant, and then the plant is irradiated with blue light. A plant cultivation method characterized by promoting stem elongation and flowering.   After irradiating the plant with blue light to promote main stem elongation and flowering, the plant is irradiated with red light (R; 600-700 nm) with adjusted light intensity to suppress main stem elongation. A plant cultivation method characterized by controlling flowering.