JPH09175901A - Freshness-keeping agent for cut flower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a freshness-keeping agent for cut flowers extraordinarily enhanced in freshness-keeping characteristics by increasing a blending ratio of a nucleic acid relating material against a silver compound and keeping the ratio in a specific region. SOLUTION: In this freshness-keeping agent for cut flowers, a silver compound is blended with a nucleic acid relating material in (1:1)-(1:16) molar ratio, especially in (1:1)-(1:8) molar ratio. As the silver compound, a monovalent silver compound, e.g. silver nitrate, silver phosphate, silver acetate, etc., and silver nitrate is most preferable. As the nucleic acid relating material, e.g. an alkali hydrolyzed or enzymatically degraded material of a nucleic acid (DNA or RNA) derived from animal tissues, microorganisms, etc., and further, a chemical synthetic compound such as a nucleotide, an oligonucleotide, a nucleoside, a nucleic acid base and a compound having a similar chemical structure to those, e.g. inosinic acid which is a derivative of purine, can be used. Among those, a commercially available hydrolyzed product of an yeast RNA extracted from the yeast mycelia. In this freshness-keeping agent, it is referable to adjust the silver concentration to 0.004-0.4mM.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a freshness-retaining agent for cut flowers. More specifically, by preventing freshness degradation during transportation of cut flowers after harvesting, and preventing freshness degradation due to withering of petals and leaves of cut flowers or yellowing of leaves, freshness over a long period of time. The present invention relates to a cut flower freshness preserving agent capable of maintaining its beauty.

[0002]

2. Description of the Related Art Consumption of cut flowers such as chrysanthemums, roses and carnations has been increasing year by year, and competition for production and sales between producing regions or between countries has been intensifying. Therefore, development of techniques for maintaining freshness of cut flowers such as flower retention and good landing is becoming more and more important, and there is great expectation for cut flower freshness retaining agents.

There are a pretreatment agent and a post-treatment agent in the cut flower freshness-retaining agent, each having a different component and role. The pretreatment agent is used when the cut flowers are processed for a short time before they are shipped to retailers, in order to extend the flower life of the cut flowers after harvesting.The anion of silver thiosulfate is also used. A mixture of a complex with a sulfite as a stabilizer (Japanese Patent Publication No. 2-23
No. 521) is currently widely used. Post-treatment agents are mainly composed of nutrients necessary for flowers (sugar, nitrogen, phosphoric acid, potassium, etc.), bactericides, surfactants, etc., and when retailers sell cut flowers, or when consumers sell flowers in vases. It is intended to extend the life of the flower, for example, when viewing it.

Various agents have been provided as a pretreatment agent, and the anion complex of silver thiosulfate described above is widely used at present. Silver ions are a kind of plant hormone and inhibit the action of ethylene, which is a major cause of flower aging (wilt). Spraying silver nitrate on carnations extends the life of the flowers. However, when silver nitrate is absorbed from the stem, the migration speed of silver ions in the duct is extremely slow, and it is difficult to transfer silver ions to flower and leaf tissues (Halevy, AH and Kofranek. AM (1977) Sil.
ver treatment of carnation flowers for reducing et
hylene damageand extending longevity. J. Amer. So
c. Hort. Sci., 102, 76-77). Veen of the Netherlands mixed silver nitrate and sodium thiosulfate to form an anion complex of silver thiosulfate (silver thiosulfate, Ag (S203) 23-, hereinafter referred to as "silver thiosulfate complex"), and As a result of investigating the movement, it is revealed that it is possible to move inside the carnation conduit at a very high speed, and the flower shelf life is significantly extended (Veen,
H. and van de Geijn, SC (1978) Mobility and ionic
form of silver as related to longevity of cut carn
ations. Planta, 140,93-96, Veen, H. (1977) Effect of
silver on ethylene synthesis and action in cut ca
rnations. Planta, 145, 467-470). The silver thiosulfate complex is currently used in large quantities around the world because of its high freshness preserving effect on cut flowers and its low cost.

As described above, the widely used silver thiosulfate complex is concerned that (1) silver is a heavy metal and thus has an influence on the environment; (2) silver thiosulfate complex is carnation, gypsophila, Flowers that are highly sensitive to ethylene, such as syupi and delphinium, have a freshness-retaining effect, but flowers that are less sensitive to ethylene, such as chrysanthemum, roses, and orchids, have no effect.

On the other hand, the present inventors have previously proposed that a cut flower freshness-preserving agent containing a mixture of a silver compound and a primary amine and / or a nucleic acid-related substance and / or a reaction product thereof is
At a silver concentration lower than that of the silver thiosulfate complex, the freshness of cut flowers is kept equal to or higher than that of the silver thiosulfate complex,
And cut flowers whose silver thiosulfate complex does not show the effect of maintaining freshness,
For example, it was found that the effect was extremely great against roses, chrysanthemums, orchids, and the patent application was previously filed (WO93 /
08685).

[0007]

Problems to be Solved by the Invention WO 93/086
The cut flower freshness preservation agent described in 85 has an excellent effect,
Further, it was found that when the operation of cutting back the stem of the flower was performed for the purpose of keeping the freshness for a long period of time, the freshness keeping period was not extended as expected. Therefore, the object of the present invention is to
It is intended to further improve the cut flower freshness-retaining agent described in 93/08685.

[0008]

Therefore, in order to solve the above problems, the present inventor has variously studied the blending amount of each component of the cut flower freshness preserving agent described in WO93 / 08685, addition of a third component, etc., Surprisingly, it was found that when the compounding ratio of the nucleic acid-related substance to the silver compound was increased to a certain range, the freshness-keeping property was dramatically improved,
The present invention has been completed.

That is, in the present invention, the molar ratio of (a) silver compound and (b) nucleic acid-related substance is (a) :( b) = 1: 1.
The present invention provides a cut flower freshness-retaining agent, which is contained in a ratio of ˜1: 16.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The silver compound (a) used in the cut flower freshness-retaining agent of the present invention includes monovalent compounds of silver, such as silver nitrate, silver phosphate, and silver acetate. Of these, silver nitrate is the most preferable. preferable.

As the nucleic acid-related substance (b), for example, alkaline hydrolysis or enzymatic decomposition products of nucleic acids (DNA, RNA) derived from animal and plant tissues, microorganisms, etc. can be used, as well as chemically synthesized polynucleotides and oligonucleotides. , Nucleotides, nucleosides, nucleobases and the like, as well as those having a chemical structure similar to these, for example, inosine acid as a purine derivative may be used. Of these, RNA hydrolysates are more preferred, and commercially available yeast RNA hydrolysates extracted from yeast cells are particularly preferred.

The RNA hydrolyzate is, for example, a natural RN.
It is prepared by a conventional method, for example, by hydrolyzing A with an alkali or a nucleolytic enzyme, and one hydrolyzed with an alkali is preferable. In addition, 0.1 to 2N RNA
More preferably dissolved in sodium hydroxide or potassium hydroxide and hydrolyzed at room temperature to 120 ° C. for 15 minutes to 24 hours, and particularly preferably hydrolyzed at room temperature (20 to 25 ° C.) for 30 minutes to 2 hours. . When using these alkaline hydrolysates of RNA, it is desirable to neutralize with an acid such as acetic acid before blending. Further, when a protein or the like is mixed in the RNA hydrolyzate, it is preferably used after being deproteinized by phenol treatment and ethanol precipitation.

In the present invention, the compounding ratio of the silver compound (a) and the nucleic acid-related substance (b) is a molar ratio of (a) :( b).
= 1: 1 to 1:16, and (a):
(B) = 1: 1 to 1: 8 is more preferable. When the compounding ratio (a) :( b) was less than 1: 1, the transferability of the silver compound to the upper part of the stem was not sufficient, and as a result, the cut back was performed as a means for keeping the freshness of cut flowers. The effect of time is not obtained sufficiently. On the other hand, (a) :( b) is 1:16
If it exceeds, it is not economical.

The cut flower freshness-retaining agent of the present invention may contain a primary amine in addition to the above two components. Examples of the primary amine include methylamine, ethylamine, monoethanolamine, tris (hydroxymethyl) aminomethane;
Hereinafter referred to as Tris), 2-amino-2-methyl-1,3
-Propanediol, 2-amino-2-ethyl-1,3
-Propanediol, α-aminooxyacetic acid (α-amin
ooxyacetic acid, AOA, H ₂ NO-CH ₂ COOH) or aminoethoxyvinylglycine (AVG, H
₂ NCH ₂ CH ₂ OCH = CHCHNH ₂ COOH) and the like. The blending amount of these primary amines is not particularly limited, but is preferably 1 to 2000 times mol, particularly 50 to 500 times mol, based on the silver compound.

If necessary, the cut flower freshness-preserving agent of the present invention further comprises stabilizers such as alkali metal sulfites, antioxidants such as vitamin C, nutrients such as sugar and nitrogen, and various surfactants. Various germicides, buffers, water and the like may be added.

The cut flower freshness-retaining agent of the present invention can be prepared by mixing the above-mentioned components, but it is preferable that it is in the form of a buffered aqueous solution.

The cut flower freshness-retaining agent of the present invention is usually preferably used as a pretreatment agent, that is, by treating cut flowers that have been harvested for a short time as well as landing. More specifically, it is preferable that the lower part of the cut flower stem is dipped in an aqueous solution containing the cut flower freshness-retaining agent of the present invention. The aqueous solution at this time had a silver concentration of 0.00
It is preferably adjusted to 4 to 0.4 mM. Further, it goes without saying that the cut flower freshness preserving agent of the present invention may be used as a post-treatment agent.

[0018]

EXAMPLES The cut flower freshness-retaining agent of the present invention will be described in more detail below with reference to Examples and Test Examples, but the present invention is not limited thereto.

Example 1 2.5 g of enzyme-derived RNA (manufactured by Boehringer, containing about 5% of protein) 25 ml of 2N sodium hydroxide aqueous solution
And was stirred at room temperature for 1 hour. The mixture was neutralized with 2.19 ml of acetic acid (adjusted to pH 7 to 8), 65 ml of ethanol was added, and the mixture was left at -30 ° C overnight and then centrifuged at 5000 rpm for 15 minutes to collect a precipitate. 37. Water was added to the resulting precipitate.
5 ml was added, 1.875 ml of 1M silver nitrate was added thereto, and the mixture was stirred at room temperature for 1 hour. Further, add 50 ml of citric acid-sodium phosphate (pH 6.4) and mix, then add water and add 5
The volume was increased to 00 ml. The silver concentration of the obtained cut flower freshness-preserving agent was 3.75 mM, and the RNA concentration (converted as 1 gRNA / l = 3 mM from the average molecular weight (approximately 339) of four types of mononucleotides (AMP, GMP, CMP, UMP)) It was 15 mM. Further, a cut flower freshness-retaining agent of silver: RNA = 1: 1 to 1:16 (molar ratio) was obtained by adjusting the amount of silver nitrate to be added.

Test Example 1 The cut flower freshness-retaining agent of the present invention obtained in Example 1 and WO9
Preservative for cut flower freshness described in 3/08685 (silver nitrate, RN
A hydrolyzate and Tris combination, Ag: RNA: Tris =
1: 0.3: 200 (molar ratio)) was used to compare the migration of silver into the stem, the freshness-retaining effect, and the water absorption. That is, each of the test freshness-retaining agents was diluted 10-fold (adjusted to a silver concentration of 0.375 mM) to prepare a treatment liquid. 15 roses for each treatment liquid (variety "Roterose")
Was put in, and an immersion treatment was performed at 5 ° C. overnight. After the completion of the treatment, it was placed in a carton box and left overnight at room temperature (considering distribution time).
After leaving at room temperature, 10 trees were cut back to 20 cm, and the freshness retention effect (healthy flower rate: healthy flower number / total number × 100) and water absorption (g / 10 flowers / day) were observed. For the other five, the distribution of silver in the stem (migration of silver to the upper part of the stem) was measured by atomic absorption spectrometry. Tables 1 to 3 show the obtained results.

[0021]

[Table 1]

As is clear from Table 1, when the cut flower freshness-retaining agent of the present invention is used, silver is rapidly transferred to the upper part of the stem.

[0023]

[Table 2]

[0024]

[Table 3]

It can be seen from Tables 2 and 3 that the cut flower freshness preserving agent of the present invention has an extremely excellent freshness preserving effect.

[0026]

EFFECTS OF THE INVENTION The cut flower freshness-retaining agent of the present invention exhibits a more excellent freshness-retaining effect on various cut flowers than conventional freshness-retaining agents.

Claims (3)

[Claims] 1. A cut flower freshness-retaining agent containing (a) a silver compound and (b) a nucleic acid-related substance in a molar ratio of (a) :( b) = 1: 1 to 1:16. 2. The cut flower freshness preserving agent according to claim 1, wherein the silver compound is silver nitrate, silver acetate or silver phosphate. 3. The cut flower freshness-retaining agent according to claim 1 or 2, wherein the nucleic acid-related substance is a hydrolyzate of RNA.