JPH0246240A - Artificial seed - Google Patents

Abstract

PURPOSE:To enable practical use of artificial seed and improve the germination rate of the seed by covering indefinite embryo of a plant with a water-soluble polymeric substance together with an oxygenation agent. CONSTITUTION:An indefinite embryo induced from callus cell, pollen, ovule, etc., is used as a raw material. The material is coated with a solution of a water-soluble polymeric substance mixed with nutrient necessary for regenerating a plant body from the indefinite embryo, an antibacterial agent, an oxygenation agent, etc., and the coating film is hardened to obtain the objective artificial seed. The encapsulation can be carried out by conventional coacervation process, curing in liquid, etc., preferably curing in liquid to suppress the variations of temperature and pH.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to improved artificial seeds that can be sown into soil in the same way as natural seeds.

[Conventional technology]

(Background) Recently, tissue culture methods have been widely adopted as a method for obtaining clones of superior plants. In particular, the callus culture method, in which callus cells that have been dedifferentiated to a certain degree are proliferated and then redifferentiated to regenerate the original plant, is a useful method for obtaining clones.
It is currently being actively researched, and some of it has already been put into practical use. (Problems with conventional technology) - However, in this callus culture method, callus cells do not grow if they are directly sown on culture soil, so callus is first transferred to a regeneration medium and then transferred to a rooting medium. The process involves growing seedlings to seedlings and then transplanting them into the soil. However, in the above method, (1) replanting requires considerable effort, (2) large culture equipment is required, and (2) a vast sterile space is required. and■ Requires special equipment and troublesome labor, such as the need for special land to acclimatize seedlings grown in artificial media to natural soil; for these reasons, industrial mass production is not possible. It was difficult. Therefore, in recent years, artificial seeds (for example, JP-A-59
-102308) has been proposed, but it has not been put into practical use yet because the germination rate is very low.

[Problem to be solved by the invention]

Therefore, an object of the present invention is to provide practicality to artificial seeds by providing a means for dramatically increasing the germination rate of artificial seeds.

[Means to solve the problem]

(Summary) Therefore, as a result of intensive research to solve the above problems, the present inventor has found that, in addition to nutrients and antibacterial agents, which are the components of conventional artificial seeds, the germination rate can be improved by coexisting an oxygen supply agent. The present invention is based on this knowledge, and its gist is that somatic embryos of plants
An artificial seed is characterized in that it is coated with a water-soluble polymer substance and an oxygen supplying agent as an essential component. Below, the main matters related to the invention will be explained in sections. (Somic embryo) The somatic embryo used in the present invention is a totipotent embryo that has the potential to develop into an individual plant in the future.
ncial>means cells or tissues, specifically,
callus cell, protoplast, leopard, pollen, corpuscle, ovary,
Those derived from ovules are preferred. (Applicable Plants) Therefore, plants to which the present invention is applied include vegetables, fruit trees, herbaceous plants for grain production, trees for gardening or afforestation, and the like. Furthermore, the artificial seeds of the present invention can also be applied to new plants obtained by cell fusion, and the artificial seeds of the present invention are particularly effective for varieties and new plants that do not produce seeds. (Nutritionals, etc.) Nutrients in this specification refer to nutritional substances such as sugars, inorganic salts, and vitamins that are necessary for raising somatic embryos and regenerating plants from somatic embryos, and are used in normal tissue culture. You can freely use what is available. In addition, if necessary, for example, 2,4-dichlorophenoxyacetic acid (2,4-D>,
2,4,5-trichlorophenoxyacetic acid (2,4,5-
T), auxins such as α-phenoxyacetic acid or α-phenoxybutyric acid, cytokinins such as kinetin, gibberellin, abscisic acid and other plant hormones can be added. (Antibacterial agent) An antibacterial agent is added to keep the inside of the coating that protects the somatic embryo in a sterile state and to prevent or suppress the growth of mold and bacteria. There are no particular restrictions on the antibacterial agent as long as it does not have a negative effect on the somatic embryo, such as R-containing copper agents such as 8-oxyquinoline steel, antibiotics such as penicillin and streptomycin, and organic sulfur agents such as thiuram. These may be used singly or in combination of two or more as necessary. (Water-soluble polymeric substance) The water-soluble polymeric substance used in the present invention includes sodium alginate, mannan, gelatin, soybean protein, serum albumin, carrageenan, agar, guar gum, gellan gum, pectin, locust bean gum, pectin,
Hydrogel-forming polymer substances such as polyacrylamide, carboxymethylcellulose, and methylcellulose can be mentioned, but among these, they are easy to gel, and do not cause harm to plants due to high temperatures etc. during gelation. Glue-forming substances having the property of being gelled by divalent metal ins such as sodium alginate and mannan are preferred from the viewpoint of ensuring that the film has appropriate hardness. (Oxygen supply agent) As the oxygen supply agent used in the present invention, calcium peroxide, barium peroxide, hydrogen peroxide, potassium peroxide,
Examples include inorganic peroxides and peroxoacid salts such as zinc peroxide, ammonium peroxide, potassium percarbonate, calcium percarbonate, and sodium pertitanate, and organic peroxides such as benzoperacid. The main selection criteria are gradual decomposition to release oxygen and no adverse effects on the somatic embryo, particularly calcium peroxide or barium peroxide are preferred. (Encapsulation method) Methods for coating somatic embryos using the water-soluble polymer substances mentioned above include core solvation method, submerged curing method, etc., but in particular submerged curing method with less temperature change and pH change. Of course, the characteristic of the artificial seeds of the present invention is that an oxygen supplying agent coexists for the purpose of increasing the germination rate, so the method is not limited to the coating means itself. A common method is to grow callus cells, cover the callus cells with a water-soluble polymer solution containing a mixture of nutrients, antibacterial agents, oxygen supplying agents, etc., and simultaneously heat and cure the callus cells. For example, when sodium alginate is used as a coating material, by dropping a sodium alginate solution in which somatic embryos are dispersed into an aqueous solution containing divalent alkaline earth metal ions, a shape containing somatic embryos can be formed with high efficiency. Capsule-type artificial seeds can be produced. However, nutrients,
If there is a risk that antibacterial agents, oxygen supply agents, etc. may have a negative effect on the somatic embryo, a multi-layer structure type may be adopted as appropriate, and the inner layer is simply coated with a water-soluble polymer substance, and the outer layer, which the somatic embryo does not come into direct contact with, is The hardness of the coated artificial seeds, preferably by applying nutrients, antibacterial agents, oxygenators, etc., can be controlled by varying the concentration of water-soluble polymeric substances, e.g. When using sodium alginate, the hardness of the capsule can also be controlled by adjusting the concentration of metal ions as a crosslinking agent and/or the immersion time in an aqueous solution of the crosslinking agent.

[Effect 1] In addition to known ingredients such as nutrients and antibacterial agents, the artificial seeds of the present invention contain abundant oxygen, which is essential for plant germination.
To provide commercial artificial seeds that exhibit a higher germination rate than artificial seeds produced by known methods. By doing so, it is possible to increase the production of superior crop plants, to artificially propagate rare plants that do not bear fruit, or to artificially adjust the germination period. Furthermore, it is also possible to add herbicides, insecticides, trace elements, fertilizers, etc. to the artificial seeds to reduce cultivation management after sowing. [Examples] Hereinafter, embodiments of the invention will be illustrated by examples, but each example is merely for explanation and does not limit the connotation or extension of the idea of the invention. Etosake Y Commercially available carrots (Daucus Carota L, v
After sterilizing the surface of the enlarged roots of 2,4-D.
, (1mg/41) containing Murash ige-3
Callus was induced at 25°C by placing it on a Koog agar medium. Next, about 1 g of uninduced callus was transplanted into a Murashige-3koog liquid medium not containing 2.4-D, and cultured with shaking at 25° C. for 2 weeks by a conventional method to induce somatic embryos. Antibacterial agents (8-oxyquinoline @ 10 mm, penicillin 5 mg) and 0.5 g of 50% calcium peroxide diluted with calcium carbonate) were added and mixed to the above somatic embryo culture solution 250-. In addition, as a comparative example, control artificial seeds to which calcium peroxide was not added were also prepared. Separately, a 2% sodium alginate aqueous solution was prepared, and the somatic embryo culture solution containing an oxygen supply agent (no control) prepared previously was mixed therein. When the above mixture was sucked up with a dropper and dropped into a 5% calcium chloride aqueous solution, gel particles (artificial seeds) mainly composed of calcium alginate containing carrot somatic embryos were produced after a few minutes. After leaving for about 5 minutes, the coagulated artificial seeds were taken out and immersed in sterile tap water for about 30 minutes to elute excess Ca ions out of the membrane of the artificial seeds. The resulting artificial seeds containing somatic embryos of carrots were sown on vermiculite, and a germination test was conducted at 25° C. in a conventional manner while being irrigated. The artificial seeds to which an oxygen supply agent (calcium peroxide) has been added by the method of the present invention break the coating layer and germinate in about 7 days.
Subsequent growth was also good. In addition, the germination rate at this time was 4
It was 0%. On the other hand, in the case of the comparative example (no oxygen supply agent added),
The seeds germinated about 1°8 later, about 3 days later than the artificial seeds of the present invention, and the germination rate was extremely low at 7%. Furthermore, the growth condition after germination was also considerably inferior compared to the method of the present invention. E1λ1 Lily (Lilium Iongiforu) as a somatic embryo
Artificial seeds were produced in the same manner as in Example 1, except that 0.2 g of 100% barium peroxide was used as the oxygen supply agent instead of the calcium peroxide used in the previous example, using meristem culture cells of M. Thumb, ). The above artificial seeds were sown and cultured in culture soil in a conventional manner, and the germination rate and growth status were examined. The artificial seeds to which the oxygen supply agent (barium peroxide) was added according to the present invention germinated after about 30 days, and thereafter. Growth was also good, with a germination rate of 30%. On the other hand, in the case of the artificial seeds of the comparative example (no oxygen supply agent added), germination was slow at about 40 days, and the germination rate was also low.
It was very low at 5%. Furthermore, the growth condition after germination was also considerably inferior to that of the inventive example.

【Effect of the invention】

As explained above, the present invention can make a valuable contribution to the development and promotion of agriculture and horticulture by dramatically increasing the germination rate of artificial seeds and opening the way to practical use of artificial seeds.

Claims (1)

[Scope of Claims] 1. An artificial seed characterized in that a somatic embryo of a plant is coated with a water-soluble polymer substance along with an oxygen supplying agent as an essential component. 2. The artificial seed according to claim 1, wherein the oxygen supplying agent is calcium peroxide or barium peroxide.