JPH0851809A - Improvement of germination of seed - Google Patents

Abstract

PURPOSE:To efficiently improve germination of seed and to facilitate shortening of a culture period and culture control after germination by adding seeds to a highly water absorbing solid polymer having absorbed water and hydrating the seeds under specific conditions. CONSTITUTION:Seeds of spinach are added to a highly water absorbing solid polymer (e.g. cross-linked polyacrylate-based polymer) having absorbed water and hydrated for a time at a temperature sufficient for advancing activity of the seeds but insufficient for germination while supplying an oxygen containing gas such as air or an oxygen gas to the seeds to improve the germination of the seeds.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for improving germination by hydrating seeds before sowing. More specifically, the present invention relates to a seed hydration treatment technique applied to seeds before sowing for the purpose of rapid and uniform germination of seeds after sowing and improvement of germination rate in a poor environment.

[0002]

2. Description of the Related Art After sowing, seeds germinate after a certain period of time when the environmental conditions such as water, temperature, oxygen, and light are suitable.

During the germination preparation period from sowing to germination, various metabolisms are carried out inside the seeds. The length of the period depends on the grain filling degree of each seed, the type of crop, and environmental factors such as temperature and moisture. By shortening this germination preparation period and providing rapid and uniform germination, the cultivation period can be shortened and the cultivation management after germination is facilitated, and there are advantages such as reduction of production cost and labor saving in large-scale commercial cultivation. can get.

As a hydration treatment to be applied to seeds before sowing for such a purpose, conventionally, in spinach cultivation, a method such as soaking seeds in well water for 1 day and then sowing (germination treatment) has been practiced. ing. In recent years, seed hydration treatment techniques such as priming, osmoconditioning or matriconditioning have been developed,
It has been confirmed that it has effects such as faster germination and improved germination rate in poor environments.

The principle of seed hydration treatment technology such as priming is that water is applied to seeds before sowing to increase seed vitality, but insufficient time and temperature to cause seed germination. It is to accelerate germination after sowing by treating the seed. At present, various researches and developments of seed hydration treatment technology have been reported, and the following four methods are the major ones.

Priming A technology developed by W. Heydecker in 1974. It is a water-soluble polymer (polyethylene glycol, sodium polypropenate, etc.)
This is a method of controlling water supply to seeds by osmotic pressure using an aqueous solution or an aqueous salt solution as a medium. (W. Heyde
cker, J. Higgins and RL Gulliver, 1973, Nature (L
ondon) 246: 42-44) (W. Heydecker, 1974, Univ. Not.
tinghamsch. Agr. Rep. 1973/1974: 50-67) (Zuo Wein
eng et al., 1987, Chinese Science Bulletin 32: 143
8) Drum Priming A technology developed by Rose (HR Rowse) in 1987.
This is a method of directly controlling the weight of the water supply to the seeds by supplying water in the form of a spray in a rotating drum without using a medium.
(UK Patent 2192781) Solid Matrix Priming
Priming) A technique developed by AG Taylor et al. In 1988, which is a method of controlling the water supply to seeds using a leonardite shale powder material (Agro-Lig) as a medium. (AG Taylor, DE
Klein and THWhitlow, 1988, Scientia Horticultur
ae 37 (1988) 1-11) (US patent 4912874 / European patent 0309551B1 / patent application publication No. 1-503437) Matriconditioning A technology developed by AA Khan et al. in 1990, which is insoluble in water. This is a method of controlling the water supply to the seeds using a porous material (Micro-Cel E, Zonolite) as a medium. (A.
A. Khan, H. Miura, J. Prusinski and S. Ilyas, Procee
dings of the Symposium on Stand Establishment of H
orticultural Crops / Minneapolis, Minnesota, April
4-6, 1990) All of the above four methods are seed hydration treatment methods applied to seeds before sowing, and are performed inside the seeds during the germination preparation period by controlling the water content supplied to the seeds. It is common that only various metabolisms are artificially completed before seeding.

The difference lies in the method principle of water control. In this method, a liquid is used as a medium, and the water supply to the seeds is controlled by the osmotic pressure (Osmotic Potential) of the liquid. In the above, the water content is controlled directly by weight without using a medium. , Use a solid medium insoluble in water, and
Water is controlled by moticum) and / or capillary force (Matric Potential).

[0008]

All of these methods have the same effect in improving germination, but each of them has the following drawbacks.

The priming method (1) is not suitable for industrial mass treatment because the viscosity of the polyethylene glycol solution used is high, the solubility of oxygen is low, and it takes time to dry the seeds after the treatment. There is.

The drum priming method (1) is a simple and clear method, but precise mechanical control is required to actually control the water amount, and it is difficult to carry out because the mechanical equipment and operation are substantially complicated. is there.

The method and method utilizing the capillary force of a water-insoluble solid medium can be processed with simple equipment and solve the problem of oxygen supply. However, there is a problem that the powdery solid medium adheres to the seeds and remains, so that reliable sieving is difficult. When the fine powder of the solid medium adheres to and remains on the treated seed, dust is generated in the packaging and distribution of the seed, which is a product, and the commercial value of the seed is significantly impaired.

An object of the present invention is to provide a method for improving germination of seeds in which fine powder of a solid medium does not adhere and remain on the seeds and the seeds can be easily dried after the hydration treatment.

[0013]

Means for Solving the Problems The inventors of the present invention, as a result of studying a better technique for hydrating seeds, have solved the above-mentioned problems by using a superabsorbent polymer and have improved germination as well. The present invention has been completed by finding a seed hydration treatment technology that is easy to industrialize.

That is, according to the present invention, seeds are added to a solid superabsorbent polymer which has absorbed water, and while oxygen-containing gas is supplied, it is sufficient to enhance the vitality of the seeds, but to cause germination. This is a method for improving seed germination by hydrating seeds for an insufficient time and temperature.

In the present invention, a super absorbent polymer is used as a medium for supplying water to the seeds, and the water supply to the seeds is controlled by utilizing the sustained water release characteristic of the super absorbent polymers. Although the principle of sustained water release is unknown, the water absorption of superabsorbent polymers (affinity of superabsorbent polymers and water, osmotic pressure of water to gel) and the ability to stop water absorption (high water absorption) It is considered to be caused by the interaction of the elastic force based on the three-dimensional network structure of the polymer), which is basically different from the method using osmotic pressure and the method using capillary action as in the prior art.

More specifically, the conventional method involves directly wetting the seed coat (seed surface) with a large amount of water, osmoticum (osmoticum) and / or capillary force (Matric Potenti).
This is a technique for controlling the permeation of water from the seed coat to the inside of the seed by coexisting with a medium having al). On the other hand, the method of the present invention rarely directly wets the seed coat with liquid water temporally and spatially, and a very small amount of gas exuded from the superabsorbent polymer having a hydrophobic surface containing a large amount of water. This is a method of absorbing water in the form of water in the form of seeds through the seed coat, and the mechanism of water supply is essentially different from the conventional method.

The water retention mechanism of the superabsorbent polymer used is composed of antifreeze water fixed by the hydrophilic groups of the superabsorbent polymer, bound water that hydrogen bonds with the antifreeze water, and free water around the bound water. Has been confirmed by the nuclear magnetic resonance (NMR) method, which is clearly different from the capillary force of the conventional method or the water retention mechanism of salt or hydrophilic polymer.

Therefore, according to the method of the present invention, the treatment medium is less likely to adhere to the seeds and the separation is easy,
It is industrially useful.

The superabsorbent polymer used in the present invention is
A commercially available product may be used. Superabsorbent polymers include, for example, crosslinked polyacrylate type, crosslinked isobutylene / maleic acid type, crosslinked starch / polyacrylic acid type, crosslinked polyvinyl alcohol / polyacrylic acid type, crosslinked polyvinyl alcohol type, crosslinked A chemical product having a structure in which a water-soluble polymer such as a polyelectrolyte, a cross-linked poly (ethylene glycol) or a cross-linked carboxymethyl cellulose is insolubilized by some method, regardless of its type, and if it has the following characteristics, it is used it can. High water absorption Moderate controlled water release pH harmless to seeds (neutral range: 5-9) Moderate particle size (seed and selectable particle size) Moderate fluidity after water absorption Difficult to adhere to) Safety to the human body.

Further, the form is preferably a powder, particularly a spherical form because it has little mutual adhesion even after absorbing water and has appropriate fluidity, and its size is not particularly limited, but it is in a dry state. And the particle size of 10 μm to 3 mm is commercially available, and the particle size of 50 to 300 μm is easy to use and preferred. The water absorption capacity is also not particularly limited, but one having 10 to 1000 times its own weight can be preferably used. The water-absorbed solid superabsorbent polymer is preferably spherical.

In order to make the surface of the superabsorbent polymer hydrophobic, a superabsorbent polymer in a dry state or a superabsorbent polymer absorbed by adding an arbitrary amount of water is used as a hydrophobic agent for hydrophobic silica, calcium stearate, stearin. When a small amount of fine powder of metal soap such as magnesium acid salt or barium stearate is added, the fluidity is improved and the adhesion between superabsorbent polymers is reduced, resulting in a controlled hydration treatment (cont.
Rolled hydration) is easier and more preferable. Further, a super absorbent polymer having an increased degree of cross-linking or a degree of crosslinking to increase hydrophobicity can also be used.

The general method of practicing the present invention is as follows.

The superabsorbent polymer is made to absorb several times its own weight of water. (The amount of water absorption varies depending on the type of superabsorbent polymer and the treated seed (target seed).) At that time, if necessary, 0.1 to 5% of the superabsorbent polymer before or after water absorption. A weight of hydrophobic agent is added and mixed to coat the surface of the superabsorbent polymer particles with the hydrophobic agent.

Then, seeds in an amount of 0.2 to 5 times the volume of the superabsorbent polymer after absorbing water are added and mixed by stirring.

Thereafter, this mixture is kept at a temperature of about 10 to 30 ° C. (usually a suitable temperature for germination of the seeds to be treated) for a fixed period of 1 to 14 days (the time required for the metabolic activity carried out inside the seed to proceed). Normally, the time required from seeding to germination of seeds to be treated ± α) is maintained. During the retention period
The mixture of superabsorbent polymer and seed is supplied with oxygen-containing gas required for metabolic respiration of seed. Examples of the oxygen-containing gas include air, oxygen gas, and a mixture of oxygen and another gas. The oxygen-containing gas is supplied by aeration or encapsulation exchange of oxygen or air. During aeration, it is preferable to supply slightly humidified air to prevent the system from drying. In order to carry out a uniform treatment, it is preferable to carry out the stirring and mixing intermittently or continuously.

After the retention period has elapsed, the superabsorbent polymer and the seeds are separated with an appropriate sieve. Since the super absorbent polymer hardly adheres to the seed, it can be easily separated without damaging the seed.

The seeds after separation are dried if necessary, but the amount of water adhering to the seeds is not enough for germination, so that they can be stored for a short period even in an undried state under low temperature and low humidity. Yes, controlled hydration
The effect of can be maintained. In addition, the treated seeds are susceptible to damage due to heat drying, because the seeds, which are originally durable, start active life activities due to water absorption. Therefore, it is desirable that the drying is performed at the lowest possible temperature and speed.

The seeds used in the present invention may be vegetable seeds such as carrots and lettuce, and pansies and other flower seeds of any size.

The seeds may be treated with a bactericidal agent before or after the hydration treatment, and film coating or granulation may be performed after the hydration treatment.

[0030]

EXAMPLES Examples of the present invention will now be described, but the present invention is not limited to these.

Example 1 A cross-linked polymer (PQ polymer BL100, Osaka Organic Chemical Industry Co., Ltd.) using an acrylate-based monomer was used as the superabsorbent polymer. The properties of this super absorbent polymer are shown in Table 1.

[0032]

[Table 1] As the seeds to be treated (seeds to be treated), carrots (Dauc
us carota L.), celery (Apium graveolens L.),
Spinach (Spinacia oleracea L.), onion (Al
lium Cepa L.), Pansy (Viola x wittrockiana),
Lettuce (Lactuca sativa L.) seeds were used.

A sealable cylindrical closed container (500 ml volume) equipped with a small hole for aeration is mixed with 0.1% thiuram wettable powder (bactericidal agent for preventing the propagation of various bacteria during treatment) mixed water 150.
30 g of super absorbent polymer was metered in while pouring ml (when the water absorption capacity was × 5).

After the superabsorbent polymer has uniformly absorbed water, 1% by weight of the hydrophobic agent (calcium stearate 0.3 g) is added to the superabsorbent polymer weight, and the mixture is sufficiently stirred and mixed to absorb the superabsorbent polymer. The surface of the water-absorbent polymer particles was coated with a hydrophobic agent (calcium stearate).

The seeds 100 to be treated were placed in a cylindrical treatment container containing the super absorbent polymer coated with the hydrophobic agent.
After metering in the amount of ml and sealing, while using a mix rotor (powder mixer) to perform stirring and mixing intermittently,
The treatment was carried out for a certain period in a constant temperature room set to a predetermined temperature. Conditions for seed treatment of each crop are
It is as shown in Table 2.

The water absorption capacity to the superabsorbent polymer, the mixing ratio with seeds, the treatment temperature, the number of treatment days, and the like are slightly different depending on the type of seeds to be treated and the seed lot, and therefore a preliminary test was conducted to determine.

The method of supplying oxygen into the container during the treatment is slightly different depending on the ratio of the mixture of the superabsorbent polymer and the seed to the volume of the treatment container and the length of the treatment period. In the present example, those requiring a relatively long period of time were carried out by the continuous aeration method, and those requiring a relatively short period of time were carried out by the oxygen encapsulation exchange method. The continuous aeration method is a method in which a small amount of air is continuously supplied using an air pump, and the oxygen entrapment exchange method is in a high-concentration oxygen gas (9
It is a method of encapsulating (0% concentration) and exchanging every 24 hours.

[0038]

[Table 2] After the lapse of a predetermined treatment period, the seeds and the superabsorbent polymer were selected using an appropriate sieve, and the seeds were dried in a ventilation oven at 35 ° C. The water content of seeds after drying was adjusted to be approximately the same as the water content of seeds before treatment.

A germination test was carried out on the treated seeds after drying to confirm the germination improving effect. The germination test was carried out by sowing in a petri dish, and basically, it was carried out based on the standards of the International Seed Inspection Regulation (ISTA).

The deadline for germination was 14 days, and the average number of germination days was calculated as an index of the speed of germination. The average number of germination days is

[Equation 1] It was calculated from the formula. In this formula, k represents the number of days elapsed after sowing, and Gk represents the number of seed solids germinated k days after sowing. n is the germination deadline of 14 days.

The results of the germination test are shown in Tables 3 and 4 and FIGS.
Shown in

(Improvement of germination speed) Table 3 and FIGS.
As shown in Figs. 3 and 5, accelerated germination by controlled hydration treatment was observed in carrot, celery, spinach, and pansy species. The effect was remarkably observed in carrots, celery, and pansies, which require relatively long days for germination in untreated seeds, and the average germination time was shortened by about 2 days.

[0043]

[Table 3] (Improvement of germination speed at low temperature) In a germination test of onion at a suitable germination temperature (20 ° C), controlled hydration-treated seeds showed the same germination as untreated seeds (data not shown).
However, in a germination test under low temperature (10 ° C.), germination was remarkably accelerated as compared with untreated seeds, and a shortened average germination period was observed. See Table 3 and Figure 4.

(Improvement of germination rate at high temperature) Although lettuce seeds enter secondary dormancy at high temperature, all of the four cultivars tested under high temperature (35%) by controlled hydration treatment.
An improvement in the germination rate at (° C) was observed (see Table 4). The germination rate of untreated seeds is 0 to 12.0%, whereas the germination rate of controlled hydration treated seeds is 74.7 to 96.0%, and the effect of controlled hydration treatment is It was remarkable.

[0045]

[Table 4] Example 2 The separation characteristics of the seed and the medium after the controlled hydration treatment, the difficulty of drying the seed after the treatment in the drying step, and the residual amount of the solid medium adhered to the seed after the treatment were compared with the conventional treatment technique (comparative). Example)

That is, each of onion and carrot seeds 5
Weighing 0g and priming (to distinguish from SMP
Osmotic Priming (hereinafter abbreviated as OP): Comparative example), Solid Matrix Priming (Solid Ma)
trix Priming: SMP, abbreviated as follows: Comparative example, Matriconditioning: MC,
And abbreviated: Comparative Example), and hydration treatment with the superabsorbent polymer of the present invention (hereinafter, abbreviated as HSAP: Example) was performed respectively controlled hydration treatment.

The controlled hydration treatment was carried out under the conditions shown in Table 5. The treatment temperature and treatment period are 15 for onions.
The test was carried out at 5 ° C. for 5 days and carrot at 20 ° C. for 7 days.

[0048]

[Table 5] After the controlled hydration treatment was completed, in OP, the seeds were washed and dehydrated in a nylon mesh bag to separate the seeds and the medium (sodium polypropeneate solution).

In SMP, MC and HSAP, the seed and the solid medium were separated using a sieve. At that time, depending on the particle size of the seed,
A 12-mesh sieve was used for onions and a 14-mesh sieve was used for carrots, respectively, and the difficulty of separating the seed and the medium by sieving was compared.

After separating the seed and the medium, the seed was dried in a ventilated oven at 40 ° C. The seeds were dried by uniformly spreading the seeds in an oven, and the moisture content of the seeds was measured and recorded over time to compare the difficulty of drying the respective hydrated seeds under controlled conditions. Seed moisture content is Cho ELECTRONIC BALANCE MC-30MB at the beginning and end of drying.
The water content of seeds during drying was calculated from the decrease in weight.

After drying, the seeds were rubbed to such an extent that they were not damaged, the medium remaining on the seed surface was forcibly peeled off, and again subjected to sieving and selection to separate and collect. The ratio of the amount of the peeling / separating and collecting medium to the total amount of the medium used in each controlled hydration treatment was calculated as the adhesion residual rate. A comparison of the surface observations of the seeds that had been finally treated was also made.

The results of the difficulty of separating the seed and the medium, the difficulty of drying the seed, and the residual adhesion of the medium to the seed are as follows.

(Difficulty of Separation of Seed and Medium) In OP, the seed and the medium (sodium polypropeneate solution) were easily and reliably separated by washing the seed with water.

In SMP and MC, the water-retaining medium (Agro-Lig, Micro-Cel E) adheres firmly to the seed surface and the medium is larger than the seed particle size. , The seeds and the medium could not be reliably separated by sieving. Particularly, carrot seeds having irregularities on the seed surface were markedly attached with the medium, and even onion seeds were markedly attached with the medium to the indented portion of the seed coat. At the same time, the adhesion of the medium to the equipment used, such as the processing container and the sieve, was also observed.

With HSAP, the medium did not adhere to the seed and the equipment used such as the processing container and sieve, and the seed and medium could be separated easily and reliably by sieving. Its operability was further improved by the addition of hydrophobic silica.

(Difficulty in Drying Seeds) As shown in FIGS. 6 and 7, the HSAP-treated seeds were effective in reducing the water content of the seeds in the shortest time compared with other treatments for both onions and carrots. I was able to dry it. The speed of drying the hydrated seeds until the water content of untreated seeds before water absorption (about 10%) was in the order of HSAP>OP> MC ≧ SMP.
The drying curves of MC and SMP showed a more gradual slope than OP, and it took a long time to dry the seeds. It is presumed that a large amount of the solid medium retained in the treated water adhered and remained. It

(Residual adhesion of medium to seeds) The results are shown in Table 6.

[0058]

[Table 6] In OP, since the medium was a liquid and the seed was washed with water to separate it from the medium, no residue of the medium adhered to the seed was observed.

In the SMP, a large amount of medium adherence residue was observed when sieving was performed immediately after the controlled hydration treatment. After the seeds are dried, the medium that remains attached (agro /
When the rig) was forcibly peeled off, a large amount of medium was separated and collected. The residual adhesion rate was 24.3% (onion measurement value) and 38.1% (carrot measurement value), which were high values.

In MC, when sieving and screening were carried out immediately after the controlled hydration treatment, a large amount of medium adhesion residue was observed as in SMP. By forced peeling after seed drying,
Micro cell E is 22.6% (onion measurement value) and 4
Separated and collected at a residual rate of 0.4% (measured value of carrot).

In HSAP, the separation of the seed and the medium by sieving just after the controlled hydration treatment was reliable, so that the residual ratio of the medium adhered to the seed was 0%.

Further, in SMP and MC, even after the seed-attached medium was forcibly peeled off, the medium was not completely removed, and a small amount of the medium remained on the seed surface. From the appearance of the seed surface, the residual amount was observed to be about the same as when the normal seeds were coated with the drug.

Example 3 Tomato seeds were subjected to a controlled hydration treatment using three superabsorbent polymers having different pH and neutral chemical compositions (5 to 9). A germination test was performed on the treated seeds, and the treatment effects were compared by the difference in the type of polymer used.

That is, three kinds of super absorbent polymers of a cross-linked sodium acrylate polymer, a crosslinked starch / polyacrylic acid copolymer, and a crosslinked vinyl alcohol / polyacrylic acid copolymer were used, and the same procedure as in Example 1 was performed. The tomato seeds were subjected to controlled hydration treatment.

A germination test of petri dish was carried out on the treated seeds after drying, and the treatment effect was compared by the difference in the type of superabsorbent polymer used for controlled hydration treatment. No significant difference in treatment effect due to the difference in polymer type was observed.

From the above, the superabsorbent polymer used for the controlled hydration treatment has a pH which is harmless to seeds and has appropriate properties (water absorption and moisture retention regardless of its chemical composition). It is considered that the same treatment effect can be achieved as long as it has release property, particle size and fluidity.

[0067]

EFFECTS OF THE INVENTION According to the present invention, the fine powder of the solid medium does not adhere to or remain on the seeds, and the seeds can be dried easily after the hydration treatment. Therefore, the seeds can be germinated quickly and uniformly without damaging the seeds. Improved seeds can be manufactured industrially at low cost.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the number of days after seeding and the germination rate in a carrot germination test.

FIG. 2 is a diagram showing a relationship between the number of days after sowing and a germination rate in a celery germination test.

FIG. 3 is a graph showing the relationship between the number of days after sowing and the germination rate in a spinach germination test.

FIG. 4 is a diagram showing the relationship between the number of days after sowing and the germination rate in an onion germination test.

FIG. 5 is a diagram showing the relationship between the number of days after seeding and the germination rate in a pansy germination test.

FIG. 6 is a diagram showing a relationship between a drying time and a seed water content in an onion seed drying test.

FIG. 7 is a diagram showing the relationship between the drying time and the water content of seeds in a carrot seed drying test.

Claims (5)

[Claims] 1. Addition of seeds to a solid superabsorbent polymer that has absorbed water, and while supplying oxygen-containing gas, is sufficient to enhance the vitality of the seeds, but not sufficient to cause germination. A method for improving seed germination, comprising hydrating seeds for a period of time and temperature. 2. The method according to claim 1, wherein the water-absorbed solid superabsorbent polymer is spherical. 3. The method according to claim 1, wherein the superabsorbent polymer is treated with a hydrophobic agent. 4. The method according to claim 1, wherein the oxygen-containing gas is air, oxygen gas or a mixture of oxygen and another gas. 5. A seed treated by the method according to any one of claims 1 to 4.