JPH03155722A - Artificial seed of graminoid hybrid plant and its production - Google Patents

Abstract

PURPOSE:To obtain a capsule in a state where Azotobactor is symbiosed by inducing a mutagenesis into a culture cell of graminoid plant at the first filial generation having character capable of giving high yield, in order to enhance the amino acid content and selecting, proliferating and differentiating the cell having both characters to grow the cell into young plant. CONSTITUTION:Seed of a graminoid plant at the first filial generation having character capable of giving high yield by heterosis, or a part of tissue thereof is taken out and subjected to tissue culture and a mutagenesis is induced to the resultant cultured cell to introduce character having a higher amino acid content (e.g. lysine) in the seed than before. A mutant cell having both characters is selected from the cultured cell group and proliferated and differentiated to afford a young plant, which is then coated with a protective coating film (e.g. calcium arginate) in a state symbiosed with an Azotobactor (e.g. Rhizobium oryzae) to provide the objective capsule.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to artificial seeds of hybrid plants of the Poaceae family. The present invention also relates to a method for producing artificial seeds of hybrid plants of the Poaceae family.

[Conventional technology]

Conventionally, first-generation hybrid plants obtained by crossing distantly related plants are known to exhibit useful properties due to hybrid vigor. Since the characteristics of this plant cannot be preserved beyond the second generation of hybrids, artificial seeds are produced as shown in JP-A No. 61-227717, and the first generation of hybrids with the same characteristics is produced.
There was an attempt to produce substitute plants in large quantities.

[Problem to be solved by the invention]

In the above-mentioned example, artificial seeds are created for the first generation of hybrid plants obtained by hybridization, and the first generation of hybrid plants share most of the characteristics of native species, such as crops. The nutritional value and resistance to temperature changes and pests and diseases were inadequate. For this reason, the above-mentioned hybrid first generation crops are not suitable as targets for artificial seeds, which are expensive to manufacture, and have been an obstacle to the practical application of artificial seeds.

The purpose of the present invention is to increase the added value of artificial seeds by applying an artificial seed generation process to a new variety of grasses with excellent properties, and to create practical rice '14 J (i.e. artificial seeds and The object of the present invention is to provide a manufacturing method thereof.

[Means for Solving the Problems] The present invention relates to a method for producing artificial seeds of grasses, in which seeds or tissues of first-generation hybrid grasses having a high-yielding trait due to hybrid vigor are used. extracting the seeds and performing tissue culture, inducing mutations in the cultured cells obtained by the tissue culture, and introducing into the cultured cells a trait in which the amino acid content in the seeds is higher than before the mutagenesis treatment. Then, mutant cells having both of the above-mentioned traits are selected from the cultured cell group by testing their usefulness, and after the mutant cells whose usefulness has been confirmed are propagated, they are redifferentiated to form seedlings. It is characterized by restoring it to its original state and making it into a capsule by covering it with a protective coating and allowing nitrogen-fixing bacteria to coexist.

Furthermore, the present invention is an artificial seed of a grass family plant, which contains an endogenous gene that expresses a high yield obtained through hybrid crossbreeding, and a trait that increases the amino acid content in the seed compared to before mutagenesis treatment. It is characterized by the fact that a young plant of a grass family plant that has a mutant gene to be expressed is covered with a protective coating in the form of a capsule in a state in which it coexists with nitrogen-fixing bacteria.

And the amino acid may be lysine. Also,
The capsule may have a double structure, and an MS medium or a modified MS medium may be contained inside the capsule.

Further, the protective coating may be formed of calcium alginate.

[For production]

In the method for producing artificial seeds of grass hybrid plants according to the present invention, mutations are induced in the cultured cells induced by tissue culture from the hybrid first generation grass plants having a high-yielding trait, and Introducing a trait in which the amino acid content is higher than before the mutagenesis treatment, selecting the mutant cells having both of the above traits, regenerating them to restore them to seedlings, and coexisting with the nitrogen-fixing bacteria. Because the artificial seeds are covered with a protective coating, the capsules as artificial seeds preserve the high-yield trait obtained through hybrid vigor, and the seeds have a high amino acid content, which makes them taste good and have high nutritional value. Grain can be harvested. Since the nitrogen-fixing bacteria coexist in this plant, it is possible to obtain a plant that grows well even in a poor field without applying nitrogen fertilizer. Moreover, a nitrogen source is always provided by the nitrogen-fixing bacteria, and the effect of the mutant gene that increases the amino acid content in the seeds can be further enhanced.

The artificial seed of the Poaceae hybrid plant according to the present invention allows the seedling having the endogenous gene and the mutant gene to coexist with the nitrogen-fixing bacterium. Large quantities of nutritious and delicious grains can be harvested.

When the amino acid is lysine, the nutritional balance can be particularly improved in rice, which has a low lysine content.

Furthermore, when the capsule has a double structure, it is possible to contain various substances such as MS medium in different phases, and to suppress the invasion of various bacteria, thereby increasing the efficiency of restoration from artificial seeds to plants.

Since gel-like calcium alginate can be formed by simply adding a solution of sodium alginate or potassium alginate to a solution containing calcium ions, if the protective film is formed of calcium alginate,
It is sufficient to simply drop the seedling or the cultured cells at a pre-stage thereof into a solution containing calcium ions together with a sodium alginate solution or a potassium alginate solution.

〔Effect of the invention〕

Therefore, in the method for producing artificial seeds of hybrid plants of the family Poaceae according to the present invention, it is possible to obtain artificial seeds of hybrid plants of the family Gramineae that can be restored to plants that yield a large quantity of grains with high nutritional value and good taste.

In addition, with the artificial seeds of hybrid plants of the Poaceae family according to the present invention, it is possible to ensure a high yield, and also to harvest grains with high nutritional value (and good taste).

When the present invention is applied to rice, etc. whose seeds have a low lysine content, the amino acid balance of rice can be improved if the amino acid is lysine, and if the capsule has a double structure, the artificial seeds can be made stably. It can be stored for a long time and transformed into a plant.

Moreover, when the protective coating is composed of calcium alginate, the protective coating can be easily formed.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail in order by giving Examples, but the present invention is not limited to these Examples.

In advance, two distantly related rice varieties (Nipponbare (
1) and Hongqi No. 1 (2)), and pollinate the pistil of Nipponbare (1) with the pollen of Hongqi No. 1 (2) to obtain seeds (3) of the first hybrid plant (Figure 1 a). ).

After sterilizing the seeds (3) with absolute alcohol and sodium hypochlorite (available chlorine 1%), they were placed on a N solid medium (4) containing agarose and cultured for 20 to 30 days, resulting in callus (5). induce.

This callus (5) was prepared from the above N containing 2mM methionine.

After transplanting to solid medium (6) and culturing for 40 to 50 days (
Figure 1(b)), the callus was again transplanted to the above N solid medium (7) containing 20mM methionine, and cultured continuously for 60 to 90 days to determine the total amino acid content and the ratio of lysine to total amino acids in the seeds. A mutation was induced that increases the amount of the virus (Fig. 1 (C)).

After performing the above treatment, a part of the surviving callus (8) was grown in MS medium (9), and the grown callus (lO) was
In addition to removing 2.4-D from the above N and solid medium (4), IAAo, 2 mg, Q', NA AO, 1 mg/,
The plants were transplanted to a medium (11) containing i7 and induced to differentiate into seedlings (12), which were then grown into rice seedlings (13) in a greenhouse and further grown. Subsequently, seeds (14) are harvested, and the total amino acid content and lysine content in the seeds are measured to test the usefulness of the seeds (FIG. 1(d)).

The remainder of the proliferated callus (10) whose usefulness has been confirmed is broken up into a large number of small lumps or cells, and then these are placed in MS liquid medium (
15) Perform suspension culture in a medium. Next, the proliferated cultured cells were mixed with 2 μM-6-benzyladenine (6-BA).
The cells are redifferentiated using S medium (16) and led to seedlings (17). Then, this seedling (17) is encapsulated by covering it with a protective coating (20) made of calcium alginate together with an MS medium (19) in which Rhizobium oryzae (18) is suspended, and an artificial seed (21) is created. (Fig. 1(f)).

[Another example]

Each of the above operations can be replaced by the following operations.

(i) As the original plant shown in FIG. 1(a), rice varieties other than Nipponbare and Hongqi No. 1 may be used, or other gramineous plants may be used.

(ii) The tissue culture shown in FIG. 1(b) may be carried out using seeds (roots, leaves, shoots) derived from seeds instead of seeds (3).

(ii) The mutagenesis treatment in FIG.
Similar results can be obtained using selenomethionine, α-methylmethionine, methylmethionine sulfonium bromide, etc.). Also, other mutagens, heat,
Mutation may be induced using ultraviolet rays or radiation to increase the content of amino acids other than lysine.

(iv) The cell suspension culture shown in Fig. 1(e) is suitable for plants with a low redifferentiation rate into young plants, as shown in Fig. 2. If carried out in a state wrapped in (22), the incidence of the next redifferentiation step will be higher.

The first protective coating (22) is composed of components through which various nutritional components in the culture medium can pass, such as calcium alginate, pectin, dialdehyde starch, and the like.

When the cells within the first protective coating have grown to an appropriate size, the second protective coating (24) is added to the outer layer of the first protective coating (22) while retaining the MS redifferentiation medium (23). ) to form a double-structured capsule (25), the redifferentiation agent can be diffused into the first protective coating within the capsule, and redifferentiation can be performed to obtain an artificial seed (26). Note that the second
The protective coating (24) is composed of a gel-like substance such as calcium alginate, pectin, dialdehyde starch, etc., and the MS redifferentiation medium (23) contains 2 μM-6-benzyladenine and rice as a redifferentiation agent in the MS medium. It is composed of a suspension of Rhizobium oryzae (27), which infects plants of the family.

[Brief explanation of the drawing]

The drawings show an example of the artificial seed of a grass hybrid plant according to the present invention and the method for producing the same, FIG. 1 is a process diagram showing the method for producing the artificial seed, and FIG. 2 shows another example of the artificial seed production process. FIG.

Claims (1)

[Scope of Claims] 1. A part of the seed or tissue of a hybrid first-generation gramineous plant that has the trait of high yield due to hybrid vigor is taken out and tissue cultured, and the cultured cells obtained by the tissue culture are suddenly A mutation is induced to introduce a trait in which the amino acid content in the seeds is higher than that before the mutagenesis treatment into the cultured cells, and a mutation having both of the above traits is selected from among the cultured cells by a utility assay. After selecting mutant cells and multiplying the mutant cells whose usefulness has been confirmed, they are redifferentiated and restored to seedlings, and are covered with a protective coating and made into capsules with symbiotic nitrogen-fixing bacteria. A method for producing artificial seeds of grass hybrid plants. 2. The method for producing artificial seeds of a grass hybrid plant according to claim 1, wherein the amino acid is lysine. 3. The method for producing artificial seeds of a grass hybrid plant according to claim 1, wherein the mutagenesis treatment is performed using methionine or an analog thereof. 4. The method for producing artificial seeds of a hybrid plant of the Poaceae family according to claim 1, wherein the nitrogen-fixing bacterium is Rhizobium oryzae. 5. Taking out a part of the seeds or tissues of the first generation of hybrid gramineous plants that have the trait of high yield due to hybrid vigor, performing tissue culture, and inducing mutations in the cultured cells obtained by the tissue culture, introducing into the cultured cells a trait that causes the amino acid content in the seeds to be higher than before the mutagenesis treatment, selecting mutant cells having both of the traits from the group of cultured cells by testing their usefulness; After growing the mutant cells whose usefulness has been confirmed while being wrapped in the first capsule,
A method for producing an artificial seed of a grass hybrid plant, which is redifferentiated and wrapped in a second film to form a double-structured capsule. 6. The method for producing artificial seeds of a grass hybrid plant according to claim 1, wherein the protective coating includes an MS medium or an MS modified medium. 7. The method for producing artificial seeds of a hybrid plant of the Poaceae family according to claim 1, wherein the protective coating is composed of calcium alginate. 8. A young plant of a grass family plant that has an endogenous gene that expresses a high yield obtained through hybrid crossbreeding and a mutant gene that expresses a trait that increases the amino acid content in the seed compared to before mutagenesis treatment. This is an artificial seed of a grass hybrid plant whose body is covered with a protective coating and encapsulated in symbiosis with nitrogen-fixing bacteria. 9. The artificial seed of a hybrid plant of the Poaceae family according to claim 8, wherein the amino acid is lysine. 10. Mutation of a grass family plant that has an endogenous gene that expresses high yield obtained through hybrid crossbreeding and a mutant gene that expresses a trait that increases the amino acid content in seeds compared to before mutagenesis treatment. An artificial seed of a hybrid plant of the Poaceae family, in which cells are grown while being wrapped in a first protective film for cell protection, redifferentiated, and wrapped in a second protective film as a double-structured capsule. 11. The double structure capsule according to claim 10,
An artificial seed of a grass family plant, wherein an MS medium or a modified MS medium is included between the first protective coating and the second protective coating. 12. The artificial seed of a hybrid plant of the Poaceae family according to claim 8, wherein the nitrogen-fixing bacterium is Rhizobium oryzae. 13. The artificial seed of a grass hybrid plant according to claim 8, wherein the mutagenesis treatment is performed using methionine or an analog thereof. 14. The artificial seed of a grass hybrid plant according to claim 8, wherein the second protective coating is composed of calcium alginate. 15. The artificial seed of a hybrid plant of the Poaceae family according to claim 8, wherein the capsule has a small spherical shape or a flattened shape.