JP2573952B2 - Method for forming potato microtube from adventitious buds - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a microtuber of a plant of the genus Solanum having tuber-forming ability, specifically, for example, a potato cultivar. More specifically, the present invention relates to a method for inducing adventitious buds at a position where no buds were originally present in the plant, and directly forming a microtuber therefrom.

Solanum plants, especially potato cultivars, are one of the important food sources and are cultivated all over the world.

Because plants of this type are susceptible to various diseases, especially viral diseases, it is common to plant tubers produced in the field from sterile seedlings. This tuber or tuber,
Is also inducible in vitro, but is sometimes referred to as a microtuber because the resulting one is small (eg, 1 cm in diameter) compared to a normal tuber (also referred to primarily herein). A microtuber is used as a seed tuber after growing it in the ground for about one year. This seed tuber has the following advantages over tubers produced in a conventional field. (I)
First, microtubers are made in vitro,
Completely disease-free. (B) The seed potatoes produced therefrom are also less likely to be infected. (C) Since microtubers are made in vitro, mass production is possible and annual production is possible. (D) The transportation cost is low because the microtuber is small in size.

Prior Art The acquisition of microtubers has been carried out by performing a process consisting of growing seedlings and deriving microtubers from the grown seedlings.

Propagation of the seedlings is performed by culturing sterile seedlings, that is, those obtained by cutting and cultivating the apical buds, to produce a part of the constant buds, that is, nodes, having several nodes, from which the constant buds contained in each node are produced. Cut out and culture in medium (solid medium is common)
Seedlings are grown to ~ 6cm (because they are growing to 5-6cm,
There are several nodes with constant buds generated there), and if necessary, cut out the constant buds from this seedling and carry out the same operation several times as described above to obtain a seedling. Done by

On the other hand, in the production of microtubers, the seedlings obtained as described above are cut out from their roots and placed on a microtuber generation medium (generally high sugar content and high cytokinin concentration). The stron elongates from the buds, and a microtuber is formed in about 3 months.

Such methods of producing microtubers, although in practice, are unsatisfactory. That is, since only fixed shoots are used, the number of microtubers that can be produced from a certain amount of seedlings is very limited. Also, since a large tissue of 5 to 6 cm of stem pieces is used for microtuber production, it is technically difficult to perform large-scale cultivation or automation for mass production. Requires floor space.

[Summary of the Invention]

SUMMARY The present invention aims to provide a solution to the above points, and aims to achieve this object by forming microtubers directly from adventitious buds.

Therefore, the method for forming a potato microtuber from adventitious buds according to the present invention comprises the steps of: culturing an interstem tissue piece having cells capable of inducing adventitious buds of a potato having tuber-forming ability; And transferring the adventitious buds to a microtuber induction medium before the adventitious buds grow to produce adventitious buds to form microtubers from the adventitious buds. .

Effect As described above, in the present invention, adventitious shoots are induced at a position where no shoots originally existed, and microtubers are formed directly from the shoots. Therefore, the above-mentioned problems are solved.
That is, according to the present invention, plant organs that have not been used at all in the conventional method, and furthermore, are grown in the form of chopped or cultured cells and used for microtuber formation, so that microtubers produced from a certain amount of the mother body The amount is large. In addition, the material used for inducing adventitious buds is small, such as stem pieces (about 0.1 to 0.5 cm in length) or cultured cells, and the adventitious buds obtained therefrom are also those before elongation and are similarly small. In addition, it is easy to handle a large amount, and it is also possible to mass-produce microtubers, which has been difficult by the conventional method. The number of microtubers that can be produced per unit floor space also increases. One typical example of the material used for inducing adventitious buds is the part between the stem nodes, which is extremely long compared to the length of the node, and for inducing adventitious buds, reduce this to about 0.3 to 0.5 cm. Since the cutting is performed, the method of the present invention is also advantageous in that the cutting operation of the stem piece is extremely easy as compared with the conventional method of cutting out a specific portion called a node. It should be noted that, in the conventional method using fixed shoots, as described above, the seedlings for microtuber formation have already been grown to have some nodes of fixed shoots. It must have been considered essential, so it could be unexpected that the adventitious bud could be subjected to the microtuber formation process before it extended as in the present invention. Like.

[Specific description of the invention]

Target plants Specific examples of plant species of the genus Solanum capable of forming tubers include, for example, potato cultivars (Solanum tub).
erosum, S. phureja), S. demissum. S. acaule and the like, and the plant species targeted in the present invention are potato cultivars among these.

Adventitious bud formation Adventitious buds can be induced from any of the cells capable of inducing it to form.

 Such cells include the following two groups.

(A) Organized cells that have not undergone dedifferentiation. For example, stem internode, petiole, leaf, vegetative point, root tip, germ cell, etc.

(B) A dedifferentiated cell group. For example, cultured cells derived from the above group of cell tissues by a tissue culture method, and the like.

Since the production of potatoes by microtubers has a major reason for the prevention of viral diseases, the above cell group (a) is preferably derived from sterile seedlings, and in either case (a) or (b) However, it is desirable that it be collected aseptically.

For the formation of adventitious buds, for example, the interstem part is cut at about 0.1 to 0.5 mm, and this is cut into a plant tissue culture medium such as Murashige-Skoog medium, Rinsmeier-Skoog medium, White medium, Gamborg B-5 medium, Place on a Heller medium, a Korenbach-Schmidt medium, or other materials to which a supporting material such as a plant hormone and / or agar is added as necessary, and place it at an appropriate temperature and time, for example, 10 to 10 hours.
It can be carried out by incubating at 30 ° C. for 10 to 100 days. Plant hormones include naphthalene acetic acid (NAA) and indole acetic acid (IAA)
And cytokinins such as benzyladenine (BA), kinetin (KN) and zeatin (Zeatin). In the present invention, cytokinins are preferred.

The adventitious buds become stems when they are grown, and some nodes containing adventitious buds are formed there, but in the present invention, before adventitious buds grow and form adventitious buds, Then, it shifts to the microtuber production process.

Production of Microtuber As described above, the adventitious shoots that have been generated are transplanted to a microtuber-forming medium before they grow to produce adventitious shoots, thereby forming microtubers.

Microtuber-forming media for adventitious buds are known in the art, and the invention contemplates that there may be changes that may be necessary due to the adventitious buds of the subject. A known medium can be used.
The medium for microtuber formation generally has a higher sugar content and higher cytocanin concentration than the medium used for adventitious bud formation. Culture temperature and time are 10-30 ° C / 20-120
It is usually a day.

Experimental Example (1) Production of microtuber from No. 1 stem piece of virus A virus-free seedling grown in vitro was collected,
The internode of the stem is shredded to about 4 mm. This small fragment (80 pieces)
Was cultured in the following medium (A). Under the optimal conditions, adventitious buds were obtained from cuts of about 80% of the fine fragments.

By transplanting the adventitious buds thus obtained into the following medium (B), an average of 1 stem piece can be obtained from one stem piece in 2-3 months.
Microtubers were obtained.

Medium (A) Murashige-Skoog medium ^* (NH ₄ NO ₃ : 300 mg / liter) + 3% sucrose + 0.01 ppm NAA + 1.0 ppm BA + 0.8% agar (p
H: 5.8) Medium (B) Murashige-Skoog medium ^* + 10 ppm BA + 8% sucrose + 0.8% agar (pH: 5.8) * The composition of Murashige-Skoog medium is Physiol. Plan
t., 15 , 473 (1962).

(2) Production of microtubers from callus derived from mesophyll protoplasts F ₂ individuals (Solanum tub) grown and raised by the present inventors
erosum) was grown under sterile conditions and protoplasts were isolated from the mesophyll cells. The protoplasts formed adventitious shoots through the callus and tuberized on the microtuber induction medium (medium (B)) of (1).

Claims (1)

(57) [Claims] The present invention relates to a method for culturing an interstem interstitial tissue piece having cells capable of inducing adventitious buds of a potato capable of forming tubers to induce adventitious buds without passing through a callus. A method of forming a potato microtuber from an adventitious bud, wherein the adventitious bud is transplanted into a microtuber induction medium before the adventitious bud is generated to form the microtuber from the adventitious bud.