JPS63216804A - Growth control of plant - Google Patents

Abstract

PURPOSE:To control growth plants, particularly agricultural crops, enable productive regulation thereof and promote stabilization of price, by using a chitosan oligosaccharide. CONSTITUTION:A chitosan oligosaccharide (oligosaccharide or composition thereof containing glutamine or a derivative thereof as a constituent saccharide and having 2-10 polymerization degree) obtained by hydrolyzing chitin or a chitosan derivative, such as N-acetylchitosan, N-propionylchitosan or sulfated carboxymethylchitosan with an acid or chitosanase as an aqueous solution in 0.25-0.0025% concentration is added to soil, sprayed or added and mixed with a liquid fertilizer for nutriculture and applied to plants. Thereby the growth of plants is controlled to regulate production of agricultural crops, such as vegetables, with particularly remarkable fluctuation of prices and reduce oversupply in the market. The price is safely and lightly stabilized.

Description

[Detailed Description of the Invention] Industrial Application Fields] The present invention controls the growth of plants by applying chitosan oligosaccharides to plants or soil, thereby reducing the price in the field of producing agricultural products such as vegetables whose prices fluctuate significantly. It concerns methods that make it possible to achieve stability.

[Conventional techniques and their problems] Controlling the growth of agricultural crops and stabilizing prices in the production field of vegetables and other crops, where prices fluctuate significantly, is an important issue in agricultural production.

Plant hormones such as gibberellin and auxin have been reported as plant growth-promoting substances, and abscisic acid and other substances are known as plant growth-inhibiting substances, but the actions of these plant hormones are multifaceted. They have many effects on plants at the same time, so even if some effects are beneficial, others may be harmful, so their practical use is limited.

On the other hand, in recent years, it has been reported that oligo rings obtained by the decomposition of polysaccharides that constitute the cell walls of plants play an important role as regulators of the plant's own biological defense response and induction of differentiation. For example, when oligogalacturonic acid prepared from plant cell walls acts on soybeans, it produces a type of antibacterial substance (phytoalexin).
The oligo ring (xylo-oligo 1) prepared from the cell wall of maple has the effect of suppressing the growth-promoting effect of auxin on the budding of Japanese maple. It has been reported. The action of this kind of gosaccharide is different from that of plant hormones, and its action is said to be specific rather than pleiotropic.

[Means for Solving the Problems] The purpose of the present invention is to discover sugars that have the effect of inhibiting plant growth from among various oligosaccharides, apply this oligosaccharide to agricultural production, and stabilize the prices of agricultural products. It's about trying. In order to achieve the above object, the present inventors extensively searched for oligosaccharides that have the effect of inhibiting plant growth, and found oligosaccharides obtained by decomposing chitosan (hereinafter referred to as chitosan oligo rings). ) has the effect of suppressing the growth of roots and above-ground parts of plants, and have completed the present invention. That is, the present invention is a method for controlling plant growth, which is characterized by using chitosan oligo rings.

There are various plants that are suitable for the present invention, but in particular agricultural products such as daikon radish and daikon radish.

You can feed vegetables such as spinach, lettuce, cabbage, and taro.

Chitosan is a polysaccharide obtained by deacetylating chitin contained in the shells of arthropods, crustaceans, the epidermis of insects, and the cell walls of microorganisms such as filamentous fungi and yeast.Chitosan according to the present invention The oligo ring is defined as follows: chitosan or N-acetyl chitosan obtained by chemically modifying chitosan.

A decomposition product obtained by decomposing chitosan derivatives such as N-propionyl chitosan and sulfated carboxymethyl chitosan with acid or chitosanase, or its main component oligosaccharide, whose constituent sugar component is glucosamine or its derivative, and its polymerization An oligosaccharide having a degree of 2 to 10 or a composition thereof.

Such a chitosan oligo ring is prepared, for example, as follows. After dissolving 20 parts of 1ON hydrochloric acid per 1 part of chitosan and treating the mixture at 53° C. for 48 hours, insoluble materials are removed by passing through a door, and oligosaccharides are fractionated from the filtrate using a cation exchange resin. Furthermore, by desalting and neutralizing with an anion exchange resin, concentrating this, and drying if necessary, a chitosan oligo ring can be obtained.

The chitosan oligo ring thus obtained is 0.25~
When applied to plants by adding it to soil as a 0.0025% aqueous solution, spraying it on the leaves, or adding it to liquid fertilizer for hydroponic cultivation, it suppresses the growth of plants, and the present invention suppresses plant growth. can reach the purpose of

[Example code] Next, the present invention will be explained in detail with reference to examples.

Example 1 A 4001 ION hydrochloric acid solution was added to 20 g of chitosan, and the mixture was reacted at 53° C. for 48 hours. After the reaction is complete, water is added to make the solution 12, and the reaction solution is poured into a cation exchange resin (
BIO-RAD AG-5W) 200m1! The solution was passed through a column packed with , and eluted with a 0.6N to 3N hydrochloric acid solution to obtain both oligosaccharides with a degree of polymerization of 2 to 10. Yield is 4g
Met.

Using the chitosan oligo ring thus obtained, its plant growth inhibitory effect was investigated using radish. In other words, 36 Kaiware radish seeds were sown in a glass container set with a synthetic resin cool mat, and then soaked in 70 m of tap water.
After adding R, at 23°C for 4 days in the dark, and for the following 2 days at 23°C.
Cultivated under irradiation conditions of 000 lux. The chitosan oligo ring was added at a rate of 0.25 to 0.00025% based on tap water. The results are shown in Table 1.

Table 1 The values in Table 1 are expressed as an index based on the average value of the stem and leaf length (co+) and root length (cm) of Kaiwara radish grown under conditions without the addition of chitosan oligosaccharide as 100. .

As is clear from the table, the chitosan oligo ring has 0.25
A growth inhibitory effect was observed at an addition amount of ~0.0025%.

Example 2 Thirty-six seeds of Kaiware radish were sown in a container set with a synthetic resin wool mat, and 70 mR of liquid fertilizer was added thereto, and the seeds were cultivated at 23°C. The experimental areas are as shown below.

Control plot: Cultivated in liquid fertilizer for 6 days.

Chitosan oligosaccharide treated area: Cultivated for 3 days without adding chitosan oligosaccharide, and on the third day of cultivation, chitosan oligosaccharide was added at 250γ/mj! After cultivating for 2 days, the wool mat on which Kaiware radish was growing was transferred to liquid fertilizer without chitosan oligosaccharides and cultivated for another 3 days.

Figure 1 shows changes in stem and leaf length (cm) of Kaiware radish.

As is clear from the drawing, the growth of daikon radish in the chitosan-oligosaccharide treatment area stopped during the treatment period, but when it was grown again in liquid fertilizer that did not contain chitosan-oligosaccharide on the fifth day after the start of cultivation, it began to grow again. has been started.

[Effects of the Invention] According to the method of the present invention, it is possible to adjust the production of plants, especially agricultural products, so that it is possible to reduce duplication of agricultural products in the market and stabilize prices safely and easily.

[Brief explanation of the drawing]

FIG. 1 is a graph showing changes in stem and leaf length of Kaiware radish.

Claims (1)

[Claims] A method for controlling plant growth, characterized by using chitosan oligosaccharide.