WO2022124200A1

WO2022124200A1 - Method for propagating vegetative-reproduction plant, and method for cultivating same

Info

Publication number: WO2022124200A1
Application number: PCT/JP2021/044337
Authority: WO
Inventors: 慎也牧
Original assignee: 国立大学法人長岡技術科学大学
Priority date: 2020-12-08
Filing date: 2021-12-02
Publication date: 2022-06-16
Also published as: JP2022090894A

Abstract

[Problem] To provide a method for propagating a vegetative-reproduction plant, and a method for cultivating said plant, with which it is possible to efficiently achieve a high yield. [Solution] This method for propagating a vegetative-reproduction plant includes: a placement step for placing a virus-free plant body of the vegetative-reproduction plant, and a medium including an inorganic component, in a light-transmitting container; and a cultivation step for cultivating the plant body placed in the light-transmitting container in a field environment and obtaining a seedling of the vegetative-reproduction plant.

Description

How to propagate and cultivate vegetatively propagating plants

The present invention relates to a method for growing and cultivating a vegetatively propagating plant. In particular, the present invention relates to a method for growing and cultivating a vegetatively propagating plant, which comprises a step of culturing a virus-free plant in a medium prepared in a light-transmitting container.

Vegetatively propagating plants such as potatoes, along with wheat, barley, and rice, have become extremely important as edible crops in recent years. Seed-breeding plants such as wheat, barley, and rice can harvest as many as 100 to 1,000 seeds from a single seed. On the other hand, vegetatively propagating plants can only harvest about 4 to 15 new individuals from one vegetative body. Therefore, research aimed at increasing the yield or improving the efficiency of cultivation has been conducted.

Non-Patent Document 1 describes a technique for mass breeding potatoes using a microtuber. However, in such a cultivation technique using a microtuber, there is a need for irradiation with artificial light and appropriate temperature control in the growth of plants.

Therefore, in the present invention, a method for growing and cultivating a vegetatively propagating plant capable of efficiently achieving a high yield is provided.

The present inventors have conducted diligent research to solve the above problems, and by culturing virus-free plants together with a medium containing an inorganic component in a light-transmitting container, efficient and high-yield nutritional propagation is carried out. We found that we could harvest sex plants. That is, the present invention is:
[1] A placement step of placing a virus-free plant of a vegetative propagating plant and a medium containing an inorganic component in a light-transmitting container, and
A method for propagating a vegetatively propagated plant, which comprises a culturing step of culturing the plant placed in the light-transmitting container in a field environment to obtain seedlings of the vegetatively propagated plant;
[2] The molar concentration of calcium ions in the medium is 1.0 to 10.5 mmol / L.
The molar concentration of phosphate ion in the medium is 0.4 to 4.4 mmol / L.
The growth method according to [1], wherein the molar concentration of magnesium ions in the medium is 0.5 to 5.3 mmol / L;
[3] The growth method according to [1] or [2], wherein the molar concentration ratio of calcium ion: phosphate ion: magnesium ion in the medium is 30:12:15;
[4] The inorganic component is
・ Calcium chloride,
-Proliferation of the nutritionally fertile plant according to any one of [1] to [3], which is a dihydrogen phosphate salt selected from potassium dihydrogen phosphate and sodium dihydrogen phosphate, and magnesium sulfate. Method;
[5] The nutrient-fertile plant according to any one of [1] to [4], wherein the inorganic component is calcium chloride dihydrate, potassium dihydrogen phosphate and magnesium sulfate heptahydrate. Proliferation method;
[6] The growth method according to [5], wherein the weight ratio of the calcium chloride dihydrate: the potassium dihydrogen phosphate: the magnesium sulfate heptahydrate is 44:17:37;
[7] The method for propagating a vegetatively propagating plant according to any one of [1] to [6], wherein the light-transmitting container is a glass container or a resin container;
[8] The resin container is any one of [1] to [7], which contains at least one selected from polyethylene-based resin, polypropylene-based resin, and polyvinyl chloride-based resin, and is a bag-shaped container. The proliferation method according to paragraph 1;
[9] The growth method according to any one of [1] to [8], wherein the plant is cultured in a field environment for 1 to 250 days;
[10] Vegetative propagation including a step of planting and cultivating seedlings of the vegetatively propagating plant obtained by the propagation method according to any one of [1] to [9] in a field environment without acclimatization. Cultivation method of sex plants;
[11] The cultivation method according to [10], wherein the vegetatively propagated plant is a plant derived from a rhizome;
[12] The cultivation method according to [10] or [11], wherein the vegetatively propagating plant is a potato or a sweet potato.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for growing and cultivating a vegetatively propagating plant that can efficiently achieve a high yield.

Hereinafter, embodiments in which the breeding method and cultivation method of the present invention are carried out will be described in detail. However, the embodiment is an example for explaining the present invention, and the present invention is not intended to be limited only to the embodiment.

The propagation and cultivation of vegetatively propagated plants according to this embodiment relates to the vegetatively propagated plants exemplified below.

In the present specification, the "vegetatively propagating plant" is a plant that propagates the next generation of plants and propagates individuals by vegetative propagation derived from vegetative organs. Examples of the nutritional organ include rhizomes, tubers, corms, rhizomes, liners and the like derived from rhizomes, root masses derived from roots, and transverse roots. The vegetative and fertile plant used in the present invention is preferably a plant derived from a rhizome such as a bulb, a tuber, a bulb, or a rhizome, and more preferably a plant derived from a tuber. Examples of vegetatively propagating plants include potatoes, taros, garlic and sweet potatoes. As used herein, the vegetatively propagating plant is preferably potato or sweet potato, most preferably potato. The breeding method and cultivation method according to the present invention are preferably applied to the cultivation of crops cultivated for food or feed among the vegetatively propagating plants exemplified above.

One aspect of the present invention relates to a method for propagating a vegetatively propagating plant, which method comprises the following steps:
(I) A placement step of placing a virus-free plant of a vegetatively propagating plant and a medium containing an inorganic component in a light-transmitting container.
(Ii) A culture step of culturing the plant placed on the light-transmitting container in a field environment to obtain seedlings of the vegetatively propagating plant.

1. 1. Placement process 1.1. Plants In this step, vegetatively propagated plants are used as virus-free plants. Here, with respect to the plant body of a vegetative breeding plant, the term "virus-free" refers to a state in which the plant body is not infected with a virus, and it is known in the art that the plant body is virus-free. It can be confirmed by means, for example, by antigen-antibody reaction and PCR. The method for obtaining a virus-free plant is not particularly limited, and the virus-free plant can be obtained by artificially growing the growth point of the plant by, for example, a known growth point culture technique.

In growth point culture, a tissue called growth point, in which cell division is actively performed in a plant, is taken out and cultured in a medium for growth point culture. For example, if the vegetatively propagated plant is a potato, the stem apex is mainly used for its culture. By performing this growth point culture, it becomes possible to produce a virus-free plant.

For growth point culture, for example, MS (Murashige and Skoog) medium is used. The medium contains water, major inorganic components, trace inorganic components, vitamins, organic compounds, agar, and a buffer for adjusting the pH within a range suitable for culture. Specifically, the MS medium contains calcium chloride dihydrate (440 mg / L), potassium dihydrogen phosphate (170 mg / L), magnesium sulfate heptahydrate (370 mg / L), and ammonium nitrate as the main inorganic components. It contains at least one of (1650 mg / L) and potassium nitrate (1900 mg / L). The MS medium contains manganese sulfate pentahydrate (24.1 mg / L), zinc sulfate heptahydrate (8.6 mg / L), and copper sulfate pentahydrate (0.025 mg / L) as trace inorganic components. L), boric acid (6.2 mg / L), potassium iodide (0.83 mg / L), sodium molybdenate dihydrate (0.25 mg / L), cobalt chloride (II) hexahydrate (0) .025 mg / L), iron sulfate heptahydrate (27.8 mg / L), ethylenediamine tetraacetic acid-sodium (37.3 mg / L), and the like. The above component is an example, and other components may or may not be added depending on the intended use.

The MS medium used for growth point culture is preferably a solid medium from the viewpoint of facilitating the intake of oxygen necessary for the growth of plants. When the MS medium is used as a solid medium, the MS medium contains, for example, 8 g / L to 15 g / L agar. The MS medium may be used as a liquid medium as long as the node section can be kept in a stationary state in which sufficient oxygen can be ingested so as not to hinder the growth of the plant. As an example of the form of the liquid medium, the node section is placed on a table so that the node section is not completely buried in the liquid medium, and a part of the node section is always in contact with the liquid medium. Be done.

Typically, growth point culture is performed by the following procedure. First, a piece of tissue containing a shoot apex, which is a growth point, is aseptically removed from a vegetatively propagated plant surface-sterilized with ethyl alcohol or a solution of sodium hypochlorite. Next, the removed tissue pieces are placed on the above-mentioned medium dispensed in a culture vessel and cultured for a predetermined period to grow a plant. Among the grown plants, the stem and leaf parts derived from one shoot apical meristem are called "shoots", and the plants composed of multiple shoots are called "multiple shoots" or "multi-buds". Call.

When the shoots or polyblasts are cultured for an appropriate period until the size of each shoot is about 5 to 10 cm, the work of placing the shoots in a light-transmitting container becomes easy, and the work efficiency and yield are improved. be able to. However, if the culture period of the growth point culture is too long, the amount of nutrients in the medium required for the growth of the polyblasts is insufficient and the polyblasts die, so the culture is completed in less than the period during which the polyblasts do not die. Must be placed in a light-transmitting container.

In growth point culture, it is desirable that the culture vessel is sealed in order to prevent contamination by germs that interfere with the culture. However, it is not always necessary to seal the culture vessel if measures are taken to prevent contamination by germs, such as adding pesticides to suppress the growth of germs.

A virus-free plant (that is, shoot) can be obtained by cutting, plucking, or cutting with scissors a shoot containing one or more buds from a shoot obtained by performing growth point culture as described above or a shoot containing one or more buds. Obtainable. Thus, the virus-free plant of the vegetatively propagated plant used in the placement step is obtained from the shoot or polyblast of the vegetatively propagated plant cultured using the MS medium.

Next, a virus-free plant body of a vegetatively propagating plant and a medium containing an inorganic component are placed in a light-transmitting container. Here, the light-transmitting container is used as a growth chamber. Specifically, the virus-free plant is placed on a medium dispensed in a light-transmitting container. The plants placed on the medium are then subjected to growth for a predetermined period of time. In this step, the shoots are placed at a density of 1 to 40, preferably 5 to 20, more preferably 10 to 15 per container. The shoots have a density of, for example, 0.02 to 0.67 / cm ² , preferably 0.08 to 0.34 / cm ² , and more preferably 0.17 to 0.25 / cm ² in the container. It is placed in. The container used in this step is, for example, a magenta box (Merck & Co., Magenta ™ vessel GA-7).

1.2. The medium placed in the light-transmitting container in the medium placing step is, for example, an improved MS medium. The improved MS medium contains the same components as the MS medium, and specifically, in addition to water, major inorganic components, trace inorganic components, vitamins, and organic compounds, the pH is adjusted to a range suitable for culture. Contains a buffer for the purpose. As with the MS medium, other components may be added to the improved MS medium depending on the intended use, and not all the components contained in the MS medium may be added.

The improved MS medium contains an inorganic component selected from the group consisting of calcium ion, phosphate ion and magnesium ion. The improved MS medium preferably contains all of calcium, phosphate and magnesium ions. By containing such ions, cultivation can be carried out without acclimatization prior to cultivation, so that the cultivation period can be shortened, efficiency can be improved, and yield can be increased.

The inorganic component is selected from the group consisting of calcium chloride, phosphate (eg potassium dihydrogen phosphate and sodium dihydrogen phosphate), magnesium sulfate, ammonium nitrate and potassium nitrate. The inorganic component is preferably calcium chloride, dihydrogen phosphate (selected from potassium dihydrogen phosphate and sodium dihydrogen phosphate) and magnesium sulfate. In one embodiment, the medium contains all of calcium chloride, potassium dihydrogen phosphate and magnesium sulfate as inorganic components.

The calcium ion concentration in the improved MS medium is
-For example, 1.0 mmol / L to 10.5 mmol / L,
-Preferably more than 3.0 mmol / L and 10.5 mmol / L or less,
-More preferably 3.3 mmol / L to 9.0 mmol / L,
-Especially more preferably 4.5 mmol / L to 9.0 mmol / L
Is.

The improved MS medium preferably contains calcium chloride as an inorganic component. Calcium chloride is preferably contained in the medium as calcium chloride dihydrate. The concentration of calcium chloride dihydrate in the medium is
-For example, 146 mg / L to 1540 mg / L,
-Preferably more than 440 mg / L and 1540 mg / L or less,
-More preferably, 484 mg / L to 1320 mg / L,
-Especially more preferably 660 mg / L to 1320 mg / L
Is.

Phosphate ion concentration in the improved MS medium
-For example, 0.4 mmol / L to 4.4 mmol / L,
-Preferably more than 1.2 mmol / L and 4.4 mmol / L or less,
-More preferably 1.4 mmol / L to 3.7 mmol / L or less,
-Especially more preferably 1.9 mmol / L to 3.7 mmol / L
Is.

The improved MS medium preferably contains phosphate as an inorganic component. The phosphate is preferably contained in the medium as potassium dihydrogen phosphate or sodium dihydrogen phosphate. The concentration of potassium dihydrogen phosphate or sodium dihydrogen phosphate in the medium is
-For example, 56 mg / L to 595 mg / L,
-Preferably more than 170 mg / L and 595 mg / L or less,
-More preferably, 187 mg / L to 510 mg / L,
-Especially more preferably 255 mg / L to 510 mg / L
Is.

The magnesium ion concentration in the improved MS medium is
-For example, 0.5 mmol / L to 5.3 mmol / L,
-Preferably more than 1.5 mmol / L and 5.3 mmol / L or less,
-More preferably 1.7 mmol / L to 4.5 mmol / L,
-Especially more preferably 2.3 mmol / L to 4.5 mmol / L
Is.

The improved MS medium preferably contains magnesium sulfate as an inorganic component. Magnesium sulfate is preferably contained in the medium as magnesium sulfate heptahydrate. The concentration of magnesium sulfate in the medium is
-For example, 123 mg / L to 1295 mg / L,
-Preferably more than 370 mg / L and 1295 mg / L or less,
-More preferably, 407 mg / L to 1110 mg / L,
-Especially more preferably 555 mg / L to 1110 mg / L
Is.

In one embodiment, the components in the improved MS medium other than calcium chloride dihydrate, dihydrogen phosphate, and magnesium sulfate heptahydrate are contained in the same concentration as the MS medium.

By using an improved MS medium containing the above three components in a specified amount, it is possible to more effectively increase the yield of vegetatively propagating plants.

When at least calcium chloride, potassium phosphate, and magnesium sulfate are contained as the main inorganic components of the improved MS medium, the yield of vegetative and fertile plants can be further increased by keeping the ratio of the three components constant. It will be possible. Specifically, the molar concentration ratio of calcium ion, phosphate ion, and magnesium ion is preferably 30:12:15. Alternatively, the weight ratio of calcium chloride dihydrate, potassium dihydrogen phosphate, and magnesium sulfate heptahydrate is as follows: calcium chloride dihydrate: potassium dihydrogen phosphate: magnesium sulfate at a ratio of 44:17:37. It is preferably contained. This molar concentration ratio or weight ratio is not strict, and it is possible to increase the yield by maintaining the above ratio.

When calcium chloride, potassium dihydrogen phosphate, and magnesium sulfate are all contained in the medium, the concentrations of these three components are not limited as long as the above-mentioned molar concentration ratio or weight ratio is maintained, and are higher than those of the conventional MS medium. It may be low concentration or high concentration. However, if the concentration is too low, the nutrients required for culturing will be insufficient and the plant may not grow to the specified size or die, so specifically up to about 1/3 of the MS medium. Concentration is preferred. If the concentration is too high, growth failure will occur and the growth of the plant will be slowed down. Therefore, the concentration is preferably up to about 3.5 times. More preferably, the concentration of the above three components is higher than that of the MS medium.

The medium may contain at least one of boric acid, cobalt chloride, copper sulfate, iron sulfate, manganese sulfate, potassium iodide, sodium molybdate, zinc sulfate and the like as trace inorganic components. These trace inorganic components can be appropriately adjusted according to the desired culture environment and the type and variety of vegetatively propagating plants to be cultured.

1.3. Container As described above, the virus-free plant is placed in a light-transmitting container. The light-transmitting container has a transmittance of 5% or more, more preferably 60% or more, and even more preferably 70% or more with respect to natural light. By using a light-transmitting container having such a transmittance, it is possible to more effectively increase the yield of vegetatively propagating plants. The transmittance of the container is measured by a method known in the art.

The material of the light-transmitting container may be any material as long as a material sufficient for growing the chute is transmitted through the container to irradiate the chute, and examples of the material of the container include glass, resin, and rubber.

When at least a part of the light-transmitting container is a resin container made of resin, the resin container may be a polyethylene resin, a cyclic polyolefin resin, a fluororesin, a polystyrene resin, a polypropylene resin, or an acrylonitrile-butadiene-. Stylium copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), polyvinyl chloride resin, fluororesin, poly (meth) acrylic resin, polycarbonate resin, polyester resin, polysulfone resin, Polyphenylene sulfide resin, polyether sulfone resin, polyamide resin, polyimide resin, polyamideimide resin, polyarylphthalate resin, silicone resin, polyurethane resin, acetal resin, cellulose resin, and mixtures thereof. Can be used as a container containing the above as a main component. Of these, a container containing a polyethylene-based resin, a polypropylene-based resin, a polyvinyl chloride-based resin, and more preferably a polyethylene-based resin as a main component is preferably used.

The shape, size and thickness of the resin container may be any shape and size that does not hinder the growth of the chute and that is not physically damaged. The resin container has a size of, for example, 50 mm to 2,000 mm square, more preferably 700 mm to 1,000 mm square, still more preferably 100 mm to 500 mm square, and, for example, 1 μm to 2,000 μm, more preferably 5 μm to. It is a bag-shaped container having a thickness of 500 μm, more preferably 10 μm to 100 μm. As the bag-shaped container, a so-called plastic bag is typically used. By using the above-mentioned light-transmitting container for breeding, it is possible to efficiently increase the yield of vegetatively propagating plants.

As will be described later, the culturing step includes a plurality of culturing steps, that is, the proliferation can be divided into a plurality of steps. For example, when culturing is divided into two steps, in the first culturing step, a glass container or a hard resin container that can easily maintain a sealed state may be used as a light-transmitting container from the viewpoint of preventing contamination by various germs. In the second culture step, a soft resin container can be used from the viewpoint of cost.

When the culturing process is performed in one step without dividing into a plurality of steps, it is possible to further reduce the cost and obtain polyblasts by putting the virus-free shoots in a soft resin container and multiplying them.

10 mL to 5,000 mL, more preferably 50 mL to 1,000 mL, and even more preferably 100 mL to 500 mL of the improved MS medium are dispensed into the light transmission container. Virus-free plants are placed on the dispensed medium.

2. 2. Culturing step In this step, virus-free plants placed in a light-transmitting container are cultivated in a field environment. The "field environment" refers to the same environment as the natural environment in which the temperature and the amount of solar radiation are not artificially controlled. Examples of the field include a house and an open field, and therefore the field environment is, for example, a house environment and an open field environment.

The culture step may include multiple stages. By dividing the growth into a plurality of stages, it is possible to efficiently culture and grow by using an appropriate light-transmitting container according to the growth condition such as the number and size of shoots. Specifically, a container that is too large for the size of a plant (specifically, a shoot) uses more medium than necessary, and in addition, workability is poor. On the other hand, the plant stops growing when it reaches the size of the container. Therefore, it is possible to efficiently cultivate and proliferate a plant by selecting a container having an appropriate size according to the growth condition of the plant at each stage.

Culturing is carried out for a period of 1 to 250 days, preferably 3 to 180 days, and more preferably 7 to 100 days. Here, the culture period is the total period of each step when the culture step is divided into a plurality of steps. By culturing the plant for the above period, seedlings sufficiently grown for use in the subsequent cultivation step can be obtained. Culturing is carried out in a field environment with the plant placed in a light-transmitting container. By culturing in a field environment for an appropriate period, the work of shifting to the cultivation process becomes easy, and the work efficiency and yield can be improved. If the period of the culturing process is too short, the plants that have undergone major environmental changes may die without adapting to the natural environment when the cultivation process is started. If the duration of the culturing process is too long, the plant may die due to lack of the components in the medium required for the growth of the plant.

During the culture period, it is desirable that the light-transmitting container be sealed to prevent contamination by germs that hinder the culture and growth. However, if measures are taken to prevent contamination by germs, such as adding pesticides that suppress the growth of germs, it is not always necessary to seal the light-transmitting container.

In this embodiment, especially in a field environment where the temperature and the amount of solar radiation are the same as in nature, normal house cultivation is not required without special temperature control equipment such as a heater and cooling, and sunshine duration control equipment such as LED lights. Alternatively, it can be cultivated in a field environment such as open field cultivation.

In the present embodiment, as described above, the virus-free plant (specifically, shoot) obtained by the above-mentioned vegetative point culture is placed in a light-transmitting container containing a medium having a predetermined composition, and is placed in a field. By culturing in an environment for a predetermined period, seedlings of vegetatively propagating plants are obtained. The seedlings of vegetatively propagated plants thus obtained can be directly planted in the field and used for cultivation without performing the usual acclimation step.

Another aspect of the present invention relates to a method for cultivating a vegetatively propagated plant, which comprises a cultivation step for cultivating a plant body propagated by the above-mentioned breeding method, that is, a seedling of a vegetatively propagated plant. In this cultivation method, as described above, seedlings of vegetatively propagating plants can be directly planted and used for cultivation without performing an acclimation step.

3. 3. Cultivation process In the cultivation process, seedlings of vegetatively propagated plants are cultivated in a field environment such as an open field or a house environment. In this step, specifically, the seedlings of the vegetatively propagating plant obtained by the above-mentioned culture step are planted in a field environment such as an open field cultivation or a house cultivation environment and cultivated. More specifically, in this step, one or more seedlings obtained by the culturing step are collected and planted in the field respectively. As the cultivation environment and cultivation period, it is possible to adopt a normal cultivation period in a known cultivation environment such as open field cultivation or house cultivation. When the cultivation period is reached, the harvested product is appropriately harvested by a harvesting method according to the type and variety of vegetatively propagating plants.

When growing plants in an in vitro environment using a microtuber or minituber, it is essential to acclimatize the seedlings in advance when cultivating in a normal field environment. Here, "acclimation" means that when a plant is moved to a different environment, the plant is adapted to the different environment for a certain period of time. This is done to reduce the stress on the seedlings from major environmental changes when transferring the seedlings from an in vitro environment to a field environment. For example, acclimation usually covers the plant (specifically chute) with a light-transmitting vinyl or plastic container to maintain humidity. At this time, in order to maintain the humidity, water is sprayed into the container by using a mist or the like. When the acclimation is completed, water is supplied to the plant. On the other hand, in the present invention, it is not necessary to carry out such an acclimation step by using a medium containing a predetermined component and culturing in a light-transmitting container in a field environment. Specifically, in the present invention, the plant can grow without dying by directly placing the plant in a new environment without performing "acclimation". Here, watering is not essential for plants in a new environment, but watering increases the retention rate, and watering can grow twice as much as without watering. know. Therefore, according to the breeding method or cultivation method according to the present invention, it is possible to increase the yield of vegetatively propagating plants in a short period of time, and it is possible to efficiently realize a high yield.

As described above, in the growth method or cultivation method according to the present invention, a virus-free plant is grown in a field environment using a light-transmitting container dispensed with a medium having a specific ionic composition or component composition. Therefore, it is possible to efficiently increase the yield as compared with the conventional cultivation that requires a culture facility such as a microtuber or a minituber. Further, in the culturing step, it is possible to increase the yield more efficiently by using a medium containing a specific inorganic component in a certain ratio.

In the present specification, the numerical range indicated by using "-" indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively. Within the numerical range described stepwise herein, the upper or lower limit of the numerical range at one stage may be optionally combined with the upper or lower limit of the numerical range at another stage.

<1> Acquisition of plants by growth point culture In order to obtain virus-free plants (specifically, shoots), growth point culture was first performed.

Potato (Solanum tuberosum) was used as a vegetatively propagating plant. A tissue piece at the tip (stem apex) of the bud germinated from the tuber of the potato was aseptically cut and collected. Then, the collected tissue pieces were placed in a test tube on an MS solid medium in which 15 mL was dispensed, and cultured for 21 days to obtain virus-free shoots. The composition of the MS solid medium used is shown in Table 1 below. Table 2 shows the concentrations of the three major ions of calcium ion, phosphate ion, and magnesium ion among the components of this MS solid medium.

<2> Placement and culture in a light-transmitting container [Comparative Examples, Examples 1 to 6]
The following materials and methods were used as Comparative Examples and Examples 1 to 6. As described below, the culture was divided into two steps, a first culture and a second culture, and the culture was carried out.

The virus-free shoot obtained by the growth point culture in <1> above was placed on a medium in which 40 mL was dispensed in a light-transmitting container and cultured for 21 days (first culture).

As the medium, MS solid medium was used for Comparative Example, and improved MS solid medium was used for Examples 1 to 6.

In the comparative example, virus-free shoots were cultured using a medium having the same composition as the MS solid medium shown in Table 1, and shoots used in the second culture were obtained.

In Examples 1 to 6, the concentrations of calcium chloride dihydrate, potassium dihydrogen phosphate, and magnesium sulfate heptahydrate are as shown in Table 3, and the concentrations of other components are as shown in Table 1. A virus-free shoot was cultured using the improved MS solid medium, and the shoot used in the second culture was obtained.

In Examples 1 to 4, a magenta box (manufactured by Merck, Magenta (trademark) vessel GA-7) of 77 mm × 77 mm × 97 mm, which is a container made of hard resin, was used as a light-transmitting container during the first culture, and a chute was used. After placing, the container was sealed.

In Examples 5 and 6, a glass container was used as the light-transmitting container during the first culture. Of these, in Example 5, after the chute was placed, the first culture was performed in an open system without sealing the container, and in Example 6, after the chute was placed, the first culture was performed with the container sealed. ..

In the first culture, in all of Comparative Examples and Examples 1 to 6, a light-transmitting container containing a chute in contact with the medium was placed in a house installed for growing potatoes in a house. At this time, no heater or cooling was used in the house, and the illuminance time was not adjusted by using LED lighting or the like.

In the second culture step of the culture step, all of Comparative Examples and Examples 1 to 6 were shots, which are a mass of plants (polyblasts) obtained in the first culture, and 150 mm × 260 mm containing 100 mL of medium. The cells were placed in a polyethylene bag (colorless and transparent) having a thickness of 30 μm on all sides. At this time, a 60 mm × 40 mm polystyrene container was used in the polyethylene bag to support the chute. The same medium as in the first culture was used in all of Comparative Examples and Examples 1 to 6.

In the second culture, in all of Comparative Examples and Examples 1 to 6, a polyethylene bag containing a chute in contact with the medium was placed in a house installed for growing potatoes in a house, and 30 days to 90 days. It was grown and cultured for days. At this time, no heater or cooling was used in the house, and the illuminance time was not adjusted by using LED lighting or the like.

As a result of the second culture, the seedlings could be cultivated in all the examples and comparative examples, although the growth condition of the shoots was different.

Table 3 shows the molar concentrations of each substance and each ion corresponding to the medium concentrations of Comparative Examples and Examples 1 to 6.

<3> Cultivation of seedlings Among the seedlings obtained by the above growth, the seedlings obtained in Comparative Example, Example 1 and Example 3 are covered with a 0.05 mesh mulch on the surface of a field under a house cultivation environment. Planted in. At this time, Examples 1 and 3 were carried out in the process from the culture step to the cultivation step without going through the acclimation step. Then, the tubers of the grown potatoes, which were cultivated in a natural environment for 60 days, were harvested and the yields were measured (Table 4). In the comparative example, cultivation in a natural environment was carried out for 60 days after undergoing a acclimation process for 7 days.

As shown in Table 4, compared with the conventional cultivation method shown in the comparative example, Examples 1 and 3 cultivated by the cultivation method according to the present invention were able to harvest a large amount of tubers.

In the cultivation of Examples 1 and 3, the shoots obtained by the growth point culture were finally put into a bag-shaped resin container and grown in a field environment. Therefore, in the cultivation methods of Examples 1 to 6, there is no need for breeding by a conventional microtuber or a minituber and equipment for that purpose, and further, as in the conventional method and the cultivation method of the comparative example, acclimatization and equipment for that purpose are not required. It was possible to harvest a large amount of tubers very efficiently and inexpensively.

Claims

A placement step of placing a virus-free plant of a vegetatively propagating plant and a medium containing an inorganic component in a light-transmitting container, and
A method for propagating a vegetatively propagating plant, which comprises a culturing step of culturing the plant placed in the light transmissive container in a field environment to obtain seedlings of the vegetatively propagating plant.
The molar concentration of calcium ions in the medium is 1.0 to 10.5 mmol / L.
The molar concentration of phosphate ion in the medium is 0.4 to 4.4 mmol / L.
The growth method according to claim 1, wherein the molar concentration of magnesium ions in the medium is 0.5 to 5.3 mmol / L.
The growth method according to claim 1 or 2, wherein the molar concentration ratio of calcium ion: phosphate ion: magnesium ion in the medium is 30:12:15.
The inorganic component is
・ Calcium chloride,
The method for growing a nutritionally fertile plant according to any one of claims 1 to 3, wherein the dihydrogen phosphate is selected from potassium dihydrogen phosphate and sodium dihydrogen phosphate, and magnesium sulfate.
The method for growing a nutritionally fertile plant according to any one of claims 1 to 4, wherein the inorganic component is calcium chloride dihydrate, potassium dihydrogen phosphate and magnesium sulfate heptahydrate.
The growth method according to claim 5, wherein the weight ratio of the calcium chloride dihydrate: the potassium dihydrogen phosphate: the magnesium sulfate heptahydrate is 44:17:37.
The method for growing a vegetatively propagating plant according to any one of claims 1 to 6, wherein the light-transmitting container is a glass container or a resin container.
The resin container according to any one of claims 1 to 7, wherein the resin container contains at least one selected from polyethylene-based resin, polypropylene-based resin, and polyvinyl chloride-based resin, and is a bag-shaped container. Proliferation method.
The growth method according to any one of claims 1 to 8, wherein the plant is cultured in a field environment for 1 to 250 days.
A method for cultivating a vegetatively propagated plant, which comprises a step of planting and cultivating the seedlings of the vegetatively propagated plant obtained by the breeding method according to any one of claims 1 to 9 in a field environment without acclimatization. ..
The cultivation method according to claim 10, wherein the vegetatively propagated plant is a plant derived from a rhizome.
The cultivation method according to claim 10 or 11, wherein the vegetatively propagated plant is potato or sweet potato.