JP2002354943A - Infection accelerator of mycorrhizal fungus and infection/growth accelerator of mycorrhizal fungus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infection accelerator of mycorrhizal fungus, containing as the active ingredient a chemical component capable of being industrially synthesized or a specific component capable of being efficiently isolated by extraction from the natural world, to provide an infection/growth accelerator of mycorrhizal fungus, and to provide a method for accelerating mycorrhiza formation of plants using such a medicinal agent. SOLUTION: This infection accelerator of mycorrhizal fungus toward plant root contains as the active ingredient 10-1,500 ppm of mannitol. The other objective infection/growth accelerator of mycorrhizal fungus toward plant root infected with mycorrphizal fungus contains as the active ingredient 50-500 ppm of mannitol; wherein the bioactivation of the mycorrhizal fungus is activated, the infectivity of the mycorrhizal fungus toward plant root is increased and also the growth of the hypha is accelerated and plant growth becomes better and also resisting power against disease becomes high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agent for promoting mycorrhizal fungi, which promotes infection and growth of mycorrhizal fungi symbiotic with plant roots, an agent for promoting mycorrhizal infection and growth, and a method for growing plants.

[0002]

BACKGROUND OF THE INVENTION Generally, mycorrhiza of plants (mycoriza)
It is known that symbiotic fungi are symbiotic fungi in which water and nutrients are collected and supplied from soil instead of absorbing carbohydrates from plants. Such mycorrhizas,
There are ectomycorrhizal fungi in which the hypha wraps around the surface of the fine roots and the outside of the cell, and endophytic mycorrhiza, in which the mycelium penetrates into the root cells. Vesicule
Mycorrhizal fungi that produce arbuscule and dendrites are called VA mycorrhizal fungi.

[0003] VA mycorrhizal fungi belong to zygomycetes, and play an important role in absorbing phosphorus and potassium in particular. As well as resistance to disease. Examples of such mycorrhizal fungi include Gigaspora margarita and Gigaspora margarita.
Ramisporophora (Gigaspora ramisporophora) and the like.

[0004] The applicant of the present application obtained an extract from an organic solvent such as methanol from kelp or the like of a foodstuff, and filled the extract with an adsorption resin (immobilized carrier) such as ODS at a methanol concentration of 50% by weight or less. JP-A-10-201468 and JP-A-10-273410 disclose a method for producing a seaweed extract obtained by fractionation by passing through a column, and a method for promoting mycorrhizal formation of plants using the same.

[0005]

However, the above-mentioned method for promoting mycorrhizal formation of plants is not a method of isolating or specifying an active ingredient that promotes mycorrhizal formation, but is a chemical component that can be efficiently synthesized industrially or a natural component. The specific components that can be efficiently extracted and separated from the ash were unknown.

Accordingly, an object of the invention according to each claim of the present application is to solve the above-mentioned problems and to use a chemical component which can be efficiently synthesized industrially or a component having a characteristic which can be efficiently extracted and separated from nature as an effective component. It is an object of the present invention to provide a method for promoting the mycorrhizal formation of plants using such an agent as an agent for promoting infection of mycorrhizal fungi or an agent for promoting infection or growth of mycorrhizal fungi.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, in the invention relating to the mycorrhizal fungal infection promoter of the present invention,
It was an agent for promoting the infection of mycorrhizal fungi on plant roots containing mannitol as an active ingredient.

[0008] The mycorrhizal fungal infection-promoting agent containing mannitol as an active ingredient enhances the infectivity of mycorrhizal fungi to plant roots, as will be apparent from the experimental results described below. This effect is particularly remarkable when the active ingredient has a concentration of 10 to 1500 ppm.

Further, when an agent for promoting infection and growth of mycorrhizal fungi containing 50 to 500 ppm of mannitol as an active ingredient is applied to the roots of plants infected with mycorrhizal fungi, it will be apparent from the experimental results described below. In addition, the infectivity of the mycorrhizal fungi is increased, and the growth of the mycelium is promoted.

[0010] In addition, as a method for growing a plant using the mycorrhizal fungi infection / growth promoting agent described above, mannitol is added to a plant growing medium containing mycorrhizal fungi to infect the roots of the plant with mycorrhizal fungi. And a plant growing method for promoting the growth of hyphae.

According to such a plant growing method, usually,
Addition of mannitol to soil or other plant growth media containing wild mycorrhizal fungi promotes mycorrhizal infection and hyphal growth. This allows
As plants grow better, their resistance to disease increases.

[0012]

DETAILED DESCRIPTION OF THE INVENTION Mannitol used in the present invention may be a chemically synthesized substance or an extract from a natural material. Mannitol, a sugar alcohol of mannose, is a substance widely distributed in the plant kingdom such as brown algae, vegetable celery, mushrooms, molds (genus Aspergillus), and is the sugar alcohol most abundant in nature.

For example, when shredded kelp is used as an extraction material, it can be easily obtained as colorless needles by extraction with heated ethanol. Industrially, it is obtained by electrolytic reduction or catalytic reduction of D-glucose or invert sugar under alkaline conditions, epimerization (epiation), reduction, and removal of impurities.

The concentration of mannitol used in the present invention is as follows:
50-500p to promote mycorrhizal mycelium growth
pm. Because, at a concentration of less than 50 ppm, the growth of mycelium is not remarkably promoted. Also, 5
When the concentration exceeds 00 ppm, no noticeable growth is observed, and the practicality is reduced.

In order to improve the rate of mycorrhizal fungi infecting plant roots, the concentration of mannitol should be 10 to 1500.
ppm is preferred. Because the concentration of mannitol is 1
At a low concentration of less than 0 ppm, almost no effect is observed,
If the concentration is higher than 1500 ppm, the infection rate is rather lowered, which is not practical.

The form of the growth-promoting agent for mycorrhizal fungi containing mannitol as an active ingredient at a predetermined concentration as described above is not particularly limited in its form. For example, it may be in the form of a liquid such as a water-soluble drug or a well-known agent. Mixing the excipient and powder,
It can be formulated into granules, tablets and the like.

In the present invention, examples of mycorrhizal fungi with which the infection rate is improved by the addition of mannitol or the hyphal growth is promoted include Gigaspora margarita (Gi
gaspora margarita) and Gigaspora ramisporophora.

The plant to be subjected to the plant cultivation method of the present invention may be any plant whose physiological state is improved by symbiosis with mycorrhizal fungi, and is not particularly limited. . As a general plant that mainly absorbs moisture and nutrients from the roots, and particularly to citrus fruits as described below, favorable results have been obtained.

The plant growing medium used in the plant growing method of the present invention may be any medium containing mycorrhizal fungi.
It is also possible to use soil that contains a large amount of organic matter and is well drained to some extent, or artificial soil with good microbial growth mixed with vermiculite, perlite or zeolite.

Furthermore, seedlings of plants can be grown using a medium in which microorganisms can easily propagate, such as an agar medium, and the seedlings infected with mycorrhizal fungi can be transplanted and cultivated in ordinary soil.

[0021]

EXAMPLES [Experimental Examples 1 to 5] (Confirmation test of mycelial growth rate) 10 ppm, 50 ppm, 100 ppm, 500 pp
For mannitol solutions (Experimental Examples 1 to 5 in this order of concentration) each adjusted to 1500 ppm, 10 ml of 1.5% plain agar medium (using a petri dish with a diameter of 70 mm) was prepared for each adjusted solution, and then heated at 121 ° C. It was autoclaved. Thereafter, four spores of Gigaspora ramisporophora (hereinafter abbreviated as Gr) whose surface was disinfected were placed on a petri dish at 30 ° C.
Incubated in the dark. In addition, control plot (Cont)
Was water only. After 2 weeks, elongation of hyphae from spores
It was measured by a stereo microscope equipped with a CD camera and an image processing system using a personal computer, and the results were shown in Table 1 and FIG.
It was shown to.

[0022]

[Table 1]

As is clear from the results shown in Table 1 and FIG. 1, the control (Cont) to which mannitol was not added was
Hyphae grew only about one-half of Experimental Example 1 and about one-fifth of Experimental Example 2.

On the other hand, the aqueous solution containing mannitol as an active ingredient in Examples 1 to 5 (growth promoting agent for mycorrhizal fungi) showed a growth rate 1.5 to 4.8 times that of the control. .
Experimental example 2 especially when the mannitol concentration is 50 to 500 ppm
4 to 2.4 of the control group (mannitol concentration 0).
The growth rate was as high as eight times.

[Experimental Examples 6 to 9] (Citrus seedling cultivation test) In order to confirm the effect of mannitol on the mycorrhizal infection rate, a citrus seedling cultivation test was performed. That is, the annual seedlings of Karachi grown on sterile vermiculite are
Vermiculite, perlite, and zeolite were mixed at a ratio of 2: 1, 1: 1, respectively, and transplanted into a plastic No. 8 pot, and 15 g of magnesia lime was applied per pot. Two weeks later, all spores were inoculated with about 60 spores of Gr. Thereafter, 5 ppm, 10 p / w
The mannitol solutions of pm, 100 ppm and 1500 ppm (Experimental Examples 6 to 9 in this order) were watered at 100 ml / pot, and the same amount of water was applied to the control (Cont) (4 times in total). The amount of fertilization during the period was N: P: K = 1: 0.
2: 1 g / pot, trace elements were applied by liquid fertilizer. After the transplant,
At week 9, the pot was dismantled and the roots were removed from Phillips et al. (Trans. Br. Myc
ol. Soc. 55: 158-161. 1970) and Ishii et al. (Journal of the Horticultural Society, 63, 529-535, 1994) to determine the infection rate. The infection rate was expressed as a ratio of the infected root length to the observed root length and is shown in Table 2 and FIG.

[0026]

[Table 2]

As is clear from the results in Table 2 and FIG. 2, the control (Cont) to which no mannitol was added was
The infection rate was only about one half that of Experimental Example 8.

On the other hand, when an aqueous solution containing mannitol as an active ingredient (growth promoting agent for mycorrhizal fungi) is applied as in Experimental Examples 6 to 9, the infection rate becomes 1.2 to 1.2 in the control plot.
1.7 times.

[0029]

As is clear from the above description, the invention of the mycorrhizal fungal infection-promoting agent according to the present invention comprises, as an active ingredient, a chemical component that can be efficiently synthesized industrially or mannitol that can be efficiently extracted and separated from nature. It is an agent for promoting infection of mycorrhizal fungi. As described above, the mycobacterium infection-promoting agent containing mannitol as an active ingredient activates the mycorrhizal fungal activity, increases the infectivity of the mycorrhizal fungi to the plant roots, and enhances the mycorrhizal plant. The rate of absorption of phosphorus and the like is improved, the growth of the plant is improved, and the resistance to disease is also increased. These advantages are that the active ingredient mannitol is 10 to 1500
This is particularly noticeable in the case of ppm.

In addition, the invention relating to an agent for promoting infection and growth of mycorrhizal fungi containing 50 to 500 ppm of mannitol as an active ingredient particularly enhances the infectivity of mycorrhizal fungi and promotes mycelial growth. Become.

In the above-described method for growing a plant using the mycorrhizal fungi infection / growth promoting agent, mannitol is added to a plant growing medium containing mycorrhizal fungi. Infection and hyphal growth are promoted, the plant's absorption rate of phosphorus and the like is improved, the plant grows well, and the disease resistance is increased.

[Brief description of the drawings]

FIG. 1 is a chart showing the relationship between mannitol concentration and hyphal growth in a hyphal growth test.

FIG. 2 is a chart showing the relationship between mannitol concentration and infection rate in an infection rate test.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Itaru Matsushita 1698-6 Yoneminato, Iyo City Yamaki Corporation (72) Inventor Yu Utamura 1698-6 Yoneminato, Iyo City Yamaki Corporation (72) Inventor Takaaki Ishii Matsuyama Matsuyama 4-1-2, Oguri, Yokohama

Claims (4)

[Claims] An agent for promoting infection of mycorrhizal fungi with respect to plant roots, comprising mannitol as an active ingredient. 2. The method according to claim 1, wherein the active ingredient has a concentration of 10 to 1500 ppm. 3. 50 to 5 parts of mannitol as an active ingredient.
An infection / growth promoter for mycorrhizal fungi containing 00 ppm. 4. A plant growing method comprising adding mannitol to a medium for growing plants containing mycorrhizal fungi to promote the infection of mycorrhizal fungi on the roots of plants and the growth of mycelia thereof.