JP2001081102A - Plant growth accelerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject accelerator capable of increasing germination rate when spread after seeding and also of improving subsequent growth conditions by including a specific cyclodextrin as an active ingredient. SOLUTION: This plant growth accelerator is obtained by including a cyclodextrin which is composed of 6 to 8 glucose units and produced by subjecting 1 to 2 hydroxyl group(s) per glucose unit to chemical modification preferably through glycosylation, maltosylation, methylation or the like. The cyclodextrin has a solubility in water of preferably >=80 g/100 ml, and is preferably used as a 1-3% aqueous solution, and it is preferable that the above aqueous solution is sprayed on sown seed surface at 100 to 1,000 ml per m2 about once a week until the resulting plant sprouts grow to around 10 cm high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a plant growth promoting agent containing a chemically modified cyclodextrin as an active ingredient and a method for promoting plant growth using the same.

[0002]

2. Description of the Related Art Cyclodextrins are cyclic oligosaccharides produced from starch by an enzymatic reaction.
The ones composed of 7, 8 are called α-, β-, and γ, respectively.
-Called cyclodextrin. These cyclodextrins have a cylindrical structure in which 6 to 8 α-D-glucoses are bonded by a 1,4-glucosidic bond, and the outside of the cylinder is hydrophilic because a hydroxyl group is overhanging.
It is known that the inside has hydrophobicity because the hydrogen at the axial position is arranged. Currently, β-cyclodextrin, which is the most widely used, has a low solubility in water of 1.8 g / 100 ml (25 ° C), so it is glycosylated, maltosylated by enzymatic modification, or methylated, acetylated or hydroxypropyl by chemical modification Derivatives with improved solubility have been developed. The solubility of α-cyclodextrin and γ-cyclodextrin in water was 14.5 g / 100 ml and 23.2 g /
100 ml and large compared to β-cyclodextrin,
Greater solubility is required for some applications. Derivatives in which solubility is improved by chemically modifying these are also known. Heretofore, these cyclodextrins have been used in many industrial fields by utilizing their inclusion ability. For example, in the pharmaceutical field, it is used as a functional preparation for the purpose of stabilizing a drug, improving solubility and transdermal absorbability, and the like. In the food field, it is used for removing cholesterol from grated wasabi, kneaded wasabi or egg yolk and butter, and in clothing, for moisturizing clothing, antibacterial and deodorant clothing, and in other cosmetics and packaging materials. Also, as an effect of natural cyclodextrin on plant growth, pre-emergence treatment with α- and β-cyclodextrin promotes branching in cereals such as barley, wheat and rye, and discloses that the yield is increased. (Chemical Abstract 97: 194520r, 99: 34442e). However, the vast majority of their uses are naturally occurring cyclodextrins, and the uses of chemically modified cyclodextrins are not yet widespread.

[0003]

SUMMARY OF THE INVENTION In the process of developing applications of cyclodextrin in which a part of its hydroxyl group is chemically modified, the present inventors have found that when a chemically modified cyclodextrin aqueous solution is sprayed after sowing, the germination rate is improved. And the subsequent growth situation improved. An object of the present invention is to provide a plant growth promoter.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a plant growth promoter comprising as an active ingredient a water-soluble cyclodextrin comprising 6 to 8 glucose units, wherein one or two hydroxyl groups per glucose unit are chemically modified. And a method for promoting plant growth using the same.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The chemically modified cyclodextrin used in the present invention is obtained by chemically modifying a part of the hydroxyl group of α-, β-, γ- or branched cyclodextrin. Examples thereof include a lower alkyl group such as a group, a hydroxy lower alkyl group such as a hydroxypropyl group, a lower alkylcarbonyl group such as an acetyl group, and a sugar residue such as a glucosyl group and a maltosyl group. The introduction of the modifying group may be carried out by a synthetic chemistry technique or by utilizing an enzymatic reaction. Therefore, the chemically-modified cyclodextrin referred to in the present invention also includes a so-called enzyme-modified cyclodextrin in which a hydroxyl group is modified by utilizing an enzyme reaction. The lower alkyl group, hydroxy lower alkyl group, lower alkyl carbonyl group and the like are preferably carried out by a synthetic chemistry technique, and the sugar residue is preferably carried out by utilizing an enzymatic reaction. It is preferable that these modifying groups are introduced into hydroxyl groups of 1 to 2 glucose units of cyclodextrin. Some of the cyclodextrins into which these modifying groups have been introduced are commercially available and can be used.

Modifying the hydroxyl group with these groups increases the solubility of the cyclodextrin. For example, β-cyclodextrin has a solubility of 1.8 g / 100 ml.
Solubility increases to 60 g / 100 ml when the substitution degree is increased to 1.0 with g / 100 ml and hydroxyethyl groups, and to 80 g / 100 ml when the substitution degree is increased to 1.8 with a methyl group. When γ- and α-cyclodextrins are also substituted with hydroxypropyl groups up to a degree of substitution of 0.6, the solubility increases to 80 g / 100 ml and 60 g / 100 ml, respectively. In the present invention,
The solubility in water is 45 g / 100 ml or more, preferably 60 g / 100 ml
Above, more preferably, 80 g / 100 ml or more of chemically modified cyclodextrin is used. Some of the cyclodextrins into which these modifying groups have been introduced are commercially available and can be used.

In the present invention, the above-mentioned chemically modified cyclodextrin is used in a 0.5 to 10% aqueous solution, preferably 1 to 3%.
Use as an aqueous solution. The solution to the seed sowing surface, approximately once a week seeding surface m ² per 100 ～1000Ml, sprayed to the plants shoots stretches about 10 cm, preferably preferably spray. By spraying the chemically modified cyclodextrin solution of the present invention on the seed sowing surface, the germination rate is improved,
In the subsequent growth state, a significant difference is observed as the growth progresses, not only in comparison with the case without spraying, but also in comparison with the case where unmodified cyclodextrin is sprayed. The presence of the chemically modified cyclodextrin appears to assist the plant in the process of absorbing nutrients in the soil. Hereinafter, the present invention will be described specifically with reference to examples.

[0008]

Example 1 A 0.5 m ² planter was filled with soil (40% of mountain soil, 45% of park fertilizer, 15% of mulch, etc.), and 250 slender leek seeds were sown. After seeding, 100 ml of a 1% aqueous solution of methylated β-cyclodextrin (degree of substitution 1.8) was sprayed once a week until the aerial part of the green onion became about 10 cm (about 8 weeks). Twenty days after sowing, the germination rate of the seeds was examined. Table 1 shows the results. In addition, 1 month, 2 months, 3 months, and 4 months after seeding, 20
The main takeout dry weight was measured. Table 2 shows the results.

[0009]

[Table 1] Germination rate of onion seeds ─────────────────────────────── Spraying liquid Germination number Germination ratio with controlメ チ ル Methylated β-CD 178 119% β-CD 124 78% Water (control) 160 − ───────────────────────────────

As is apparent from Table 1, the germination rate of methylated β-cyclodextrin (CD) is higher than that of the case where only water is sprayed, but that of natural β-cyclodextrin (C
D) is worse than when only water is sprayed.

[0011]

[Table 2] Growth of onion seeds (total dry weight: mg) ─────────────────────────────── Spray 30 days after 60 days after 90 days after 120 days ─────────────────────────────── methylated β-CD 63 193 280.2 357.2 β- CD 37.9 88 164.3 225.5 Water (control) 30.8 65 89 108 ───────────────────────────────

As can be seen from Table 2, the dry weight of green onion shows an effect of promoting the growth of natural β-cyclodextrin and methylated β-cyclodextrin from the early growth stage. The effect of cyclodextrin is remarkable.

[0013]

Example 2 A 0.5 m ² planter was filled with soil (40% mountain soil, 45% park fertilizer, 15% humus, etc.) and seeded with Kujo green onion seeds. After sowing, 25 ml of a 1% aqueous solution of a maltosylated cyclodextrin mixture (Iso-Elite Co., Ltd., manufactured by Yokohama International Bio-Laboratory) is applied once a week, until the aerial part of the green onion becomes approximately 5 cm (6 weeks). Sprayed. One month after seeding and five months after seeding, five samples were taken out at random and the total dry weight was measured. Was. Table 3 shows the results.

[0014]

[Table 3] Growth condition of Kujo onion (total dry weight: mg) ──────────────────────────── Spraying liquid 30 days after 120 One day later ──────────────────────────── 1% isoelite aqueous solution 16.8 546.8 Water (control) 16.2 197.3 日────────────────────

[0015]

Industrial Applicability According to the present invention, it is recognized that a chemically modified cyclodextrin improves the germination rate of plant seeds and promotes subsequent growth by being applied to a plant. Available as

Claims (3)

[Claims] 1. A plant growth promoter comprising 6 to 8 glucose units, and comprising cyclodextrin as an active ingredient, wherein one or two hydroxyl groups are chemically modified per glucose unit. 2. The plant growth promoter according to claim 1, wherein the chemical modification of the hydroxyl group is glycosylation, maltosylation, methylation, acetylation or hydroxypropylation. 3. An aqueous solution of cyclodextrin consisting of 6 to 8 glucose units, wherein 1-2 hydroxyl groups per glucose unit are glycosylated, maltosylated, methylated, acetylated or hydroxypropylated, and sprayed. Method for promoting the growth of plants.