JPH06225637A - Method for proliferating va mycorrhizal fungus - Google Patents

Abstract

(57) [Summary] [Structure] A plant infected with VA mycorrhizal fungi belonging to the genus Gigaspora, Scatellospora, etc. is cultivated using heat-treated red jade soil as a base material and grown to produce VA mycorrhizal spores. At the same time as collecting, the plants infected with VA mycorrhizal fungus are transplanted to a new, heat-treated red terrestrial soil to repeatedly sporulate. [Effects] In the method of the present invention, the use of fired red tama soil can prevent contamination of indigenous VA mycorrhizal fungi, pathogens, etc., and pure VA mycorrhizal fungi, especially gigaspora (Gigaspora) Genus or Scatellospora (Scute
It is possible to grow VA mycorrhizal fungi belonging to the genus Llospora). Moreover, according to the method of the present invention, a VA mycorrhizal preparation having a high spore density and easy to handle can be produced and propagated at low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for growing VA mycorrhizal fungi useful in fields such as agriculture and horticulture. The present invention relates to a method for efficiently obtaining a high VA mycorrhizal preparation.

[0002]

The usefulness of VA mycorrhizal fungus (Vesicular Arbuscular Mycorrhizae) has been known for a long time (Ogawa Makoto: VA mycorrhizal and its function, forest location, No. 30 ( 2) Volume 57-65, 1
988. Norihiko Kobayashi: VA Mycorrhizal fungi and utilization for soil diseases, Plant protection, 42, 259-266, 198
8 years. Such). However, V that can be used commercially
A mycorrhizal fungi, especially VA mycorrhizal fungi belonging to the genus Gigaspora or the genus Scutellospora, have not been produced so far.

This is a VA mycorrhizal fungus, especially gigaspora (G
igaspora) or Scutellospora
) Mass cultivation of VA mycorrhizal fungi belonging to the genus is very difficult,
Further, it is said that the main reason is that the culturing operation is complicated and costly. Therefore, in order to make VA mycorrhizal fungi commercially available, there is a demand for a method that is simple in culture operation and can be mass-produced at low cost.

Therefore, some proposals have been made as a method for increasing VA mycorrhizal fungi. For example, soil for growing VA mycorrhizal fungus by collecting VA mycorrhizal fungus from soil on fallow land or inoculating VA mycorrhizal fungus on soil on fallow land and culturing an appropriate host plant on the soil. The cultivation method is known. However, this soil cultivation method requires an operation to separate VA mycorrhizal spores, and when raw soil is used,
There was a risk that indigenous VA mycorrhizal fungi and pathogenic bacteria would be mixed. This can be avoided by sterilizing the soil with a chemical agent, steam or the like, but it requires additional labor. In addition, there is a new problem that growth of VA mycorrhizal fungus is inhibited by the residual drug.

In this soil cultivation method, V
As a method for separating a large amount of mycorrhizal mycorrhizal spores, a method of separating the soil with a sieve and then utilizing the difference in specific gravity (Tatsuhiko Suzuki: Problems concerning VA mycorrhiza 5, Agriculture and Horticulture, No. 62) Vol. 3, No. 28-33, 1987) and a method by centrifugation (JP-A-63-309178).
However, it requires a very complicated operation and makes it difficult to produce it on a commercial scale.

As a method for increasing VA mycorrhizal fungus, a nutrient thin film culture method has been proposed which is carried out by using a material which is porous and enables plant roots to be distributed (JP-A-55-1).
No. 18390), when used as an inoculum, there was a problem that infectivity was reduced by drying the roots.

Further, a method of culturing VA mycorrhizal fungi in vitro using hairy roots has been proposed (Japanese Patent Publication No. 62-62-62).
49047, JP-A-3-83522, etc.). Since this method is an aseptic method, it is possible to prevent the contamination of pathogenic bacteria and the like, but there is a drawback that the operation becomes very complicated.

[0008] A porous material such as perlite, vermiculite or clay is used as a growth medium for plants and VA mycorrhizal fungi, and VA mycorrhizal fungi are grown on the porous material (Methods and Principles of Mycorrhizal Res
earch, NCSchenck, The American Phytopathologica
l Society. p 61, 1982) and as a plant,
Using wheat, pepper, corn, sorghum, leeks, alfalfa, peanuts, etc., cultivated on a carrier such as vermiculite, peat, perlite, pumis and the like, VA
Method for growing mycorrhizal fungi (VA Mycorrhiza Conway Ll,
Powell D. Joseph Bagyaraj, CRC Press, p 190, 19
1984) is known. However, no example is shown in which VA mycorrhizal fungi belonging to the genus Gigaspora or the genus Scutellospora are grown at high density by these methods.

Further, a method using charcoal as a carrier (Makoto Ogawa, "VA mycorrhiza-symbiosis of plants and molds, chemistry and organisms",
Vol. 23, No. 2, pp. 103-111, JP-A-3-10
3124) and a method of using a porous amphoteric ion exchanger as a carrier for culturing (Japanese Patent Laid-Open No. 63-87973), both of which are for forming VA mycorrhizal spores. The complicated work of killing the plant and cultivating the plant from the beginning each time to increase the VA mycorrhizal fungi was required.

Several methods have also been proposed for inducing sporulation of VA mycorrhizal fungi, for example, a method of inducing sporulation by forced flowering by controlling the day length of a plant (Japanese Patent Laid-Open No. HEI-2). No. 227068), or a method of inducing sporulation by forcing the plant to die by performing draining or the like is known, but in each case, the plant must be discarded every time sporulation is performed, It is difficult to sporulate continuously.

As a result of earnest studies to solve such conventional problems, the present inventor has surprisingly solved all of the above problems by using heat-treated Akatamachi as a base material. Based on this finding, they have completed the present invention.

[0012]

That is, the present invention provides a VA
It is intended to provide a method for multiplying VA mycorrhizal fungi, which comprises cultivating a plant infected with mycorrhizal fungi with heat-treated red jade clay (calcined red jade earth) as a base material.

[0013] VA mycorrhizal fungus is a kind of zygomycete existing in soil, and it is known that its hyphae form mycorrhiza with respect to roots of various plants and both of them coexist. There are various kinds of VA mycorrhizal fungi used in the present invention, for example, genus Gigaspora, Scatellospora (S
cutellospora), Acaulospora
Genus, Entrophospora genus, Sclerocystis genus, Glomus
s) There are microorganisms belonging to the genus. Among these VA mycorrhizal fungi, the genus Gigaspora and Scatellospora (S
VA mycorrhizal fungi belonging to the genus cutellospora) are preferred.

More specifically, for example, Gigaspora albida, Gigaspora margarita, Scutellospora gregaria, and the like, and Acaulospora laebis.
vis), Entropospora infequens (Entro
phospora infrequens), Sclerocystis dussii, Glomus Mosae
mus mosseae), Glomus etu
nicatus) and the like.

These VA mycorrhizal fungi are collected from the natural world (Tatsuhiko Suzuki, Problems on VA mycorrhiza 5, Agriculture and Horticulture, Volume 62, No. 3, p28-33, 1987).
In addition, a nutrient thin film culture method (Japanese Patent Laid-Open No. 55-118390) or a method using organ-cultured roots (Japanese Patent Publication No. 62-4).
No. 9037) and the like can be used.

The plant to be infected with VA mycorrhizal fungus, that is, the host plant of VA mycorrhizal fungus is not particularly limited as long as it is a plant to which VA mycorrhizal fungus is infected. ，
Examples include gramineous plants such as sorghum, legumes such as soybean, alfalfa, white clover and red clover, mint plants such as perilla, and asteraceae plants such as marigold.

Further, the base material used for infecting a plant with VA mycorrhizal fungi is not particularly limited as long as it is a base material on which the plant grows, but from the viewpoint of preventing contamination of indigenous bacteria, sterilization (baking) (Including treatment) is preferable,
For example, sterilized soil, vermiculite, sterilized red jade clay, calcined red jade clay (similar to those described below) and the like can be preferably used.

Further, the method of infecting a plant with VA mycorrhizal fungi is not particularly limited, but various methods such as sowing, seedling raising, cuttings, cuttings, grafts, bulbs, and plant tissues may be used.

The method of inoculating the VA mycorrhizal fungus to the host plant may be either before or after the rooting of the host plant, but especially at the time of pretreatment of sowing and cutting bud, sowing and cutting. At the same time as the shoots or at the time of transplanting the seedlings, it is preferable. As an application method, it is preferable to mix with the soil, apply it in a layer under the seeds and shoots, or apply it in the planting holes at the time of planting.

The method for infecting the host plant with VA mycorrhizal fungi may be carried out by a known method, for example, the temperature is 5 to 60.
C., preferably 15-45.degree. C., soil pH 3-9.
It is carried out under the conditions of 5, preferably 4 to 8.

With the rooting of the host plant, infection with VA mycorrhizal fungi is established. The method of the present invention is characterized in that the plant infected with the VA mycorrhizal fungus in this manner is cultivated using heat-treated red jade soil, that is, fired red jade soil as a base material. That is, the host plant VA mycorrhizal fungus-infected plant is replanted in a medium containing fired red pearl earth as a base material to grow the VA mycorrhizal fungus and to sufficiently grow the VA mycorrhizal fungal plant.

The calcined red tama soil used here may be commercially available. The particle size of the calcined red tama soil is not particularly limited, but small particles are preferred. Usually the particle size is 0.1
~ 6 mm. The degree of heat treatment is 10
What is heat-processed at a temperature of 0 ° C. or higher, preferably 200 to 800 ° C. is preferable.

A fertilizer or the like is given to a plant infected with VA mycorrhizal fungi to induce sporulation while maintaining vegetative growth. In this way, the VA mycorrhizal fungi begin to form spores while the plant continues vegetative growth. In the method of the present invention, the fired red tama soil is mixed with V
Since it is used as a mycorrhizal fungal growth substrate, it is possible to induce symptoms of strong fertilization in plants during the formation of spores. Due to this, sporulation can be promoted. In other words, by using the burned red tama soil as a VA mycorrhizal fungal growth substrate, strong stress can be applied to the plant, and therefore, while maintaining the vegetative growth of the plant,
Can lead to sporulation.

Fertilizer is applied to grow the plant vigorously, and the fertilizer may be prepared or commercially available. Although it may be solid fertilizer, liquid fertilizer (liquid fertilizer) is preferably applied so that fertilizer application can be easily adjusted. Further, it is desirable that the concentration of phosphorus contained in the fertilizer is not too high, preferably 300 ppm or less.

When the spore density is sufficiently increased, the calcined red tama soil is collected to obtain a VA mycorrhizal preparation, which is dried as necessary for commercialization. The drying may be performed at a temperature at which spores and hyphae are not damaged, for example, 70 ° C or lower, preferably 20 to 50 ° C.

According to the method of the present invention, a sufficient amount of VA mycorrhizal spores can be recovered in this manner, and the VA mycorrhizal-infected plant is transplanted to another freshly burned red terrestrial clay. Again, VA mycorrhizal sporulation can be induced. Further, it is possible to prevent undesired contamination of indigenous VA mycorrhizal fungi and pathogenic fungi.

That is, in the same manner as described above, fertilizers and the like were applied to the VA mycorrhizal fungus-infected plants transplanted to the new burned red terrestrial soil to induce sporulation while maintaining vegetative growth, and the spore density was increased. When fully heated, the calcined red tama soil is collected, dried and commercialized, and the VA mycorrhizal fungal-infected plant is separated and transplanted to another fresh calcined red tama soil. It is possible to repeatedly obtain a sufficient amount of VA mycorrhizal spores from a VA mycorrhizal infected seedling over a plurality of times.

[0028]

EXAMPLES The present invention will be described in more detail with reference to examples.

Example 1 and Comparative Example 1 In a 150 ml (ml) vinyl pot, 8
After filling Akatama soil (particle size 1 to 4 mm) (Example 1) or vermiculite (particle size 2 to 4 mm) (Comparative Example 1) fired at 00 ° C as a base material, it was collected from a fallow land as an inoculum. Gigaspora albid
50 spores of a) were inoculated and seeds of white clover were sown to prepare VA mycorrhizal fungal infected seedlings. After cultivating this seedling for 3 weeks at 25 to 30 ° C., red jade soil (particle size 1 to 4 mm) fired at 800 ° C. in a 1 / 10,000 are Wagner pot (Example 1), or 1.5 liters of vermiculite (particle size 2 to 4 mm) (Comparative Example 1) was used as a base material, and infected seedlings were transplanted therein.
Then, after culturing at 25 to 30 ° C. for 7 weeks while giving the liquid fertilizer shown below, the base material was collected to obtain a VA mycorrhizal preparation. In order to measure the number of spores, a wet sieving method, that is, using a sieve having an opening of 1.5 mm to remove a portion having a large particle size, and then using a sieve having an opening of 173 μm to remove a portion having a small particle size, The spores were collected by the method of obtaining the medium particle size portion.
In addition, in both Example 1 and Comparative Example 1, no special sporulation treatment such as artificial day length adjustment was performed. as a result,
In the case of Comparative Example 1 using vermiculite as a base material, the number of spores was 5267 (pieces / pot). on the other hand,
In the case of Example 1 using fired red tama soil as the base material, the number of spores was extremely large at 16722 (pieces / pot), and Gigaspora albida (Gigaspora albida) used as an inoculum was used.
No VA mycorrhizal spores other than da) were present.

As the liquid fertilizer, the trace metal nutrient liquid shown in (1) below and the nutrient liquid fertilizer shown in (2) are used.
The trace metal nutrient solution of (1) was diluted 100 times, 10 g of the nutrient solution fertilizer of (2) was mixed with 1 liter of this diluted solution, and 0.25 g of magnesium sulfate heptahydrate was added to prepare the solution. (1) Composition Fe · EDTA 0.12 trace metal nutrients solution _{g H 2 BO 3 2.86 g MnCl} 2 · 4H 2 O 0.18 g ZnSO 4 · 7H 2 0 0.22 g CuSO 4 · 5H 2 0 0.08 g Na 2 Mo0 4 · 2H ₂₀ 0.027g CoSO ₄・ 6H ₂ 0 0.053g CaCl ₂ 1.0 g Al ₂ (SO ₄ ) ₃ 0.10 g KI 0.10 g KBr 0.10 g H ₂ 0 10 liters (2) Composition of nutrient liquid fertilizer Normal liquid fertilizer (N: P: K = 15: 6: 6)

Example 2 Instead of using the calcined red tama soil as in Example 1,
Example 1 was repeated except that vermiculite was used to prepare VA mycorrhizal infected seedlings. As a result, the number of spores was 15062 / pot, and the number of spores used was Gigaspora albida (Gigaspora albida).
There were no VA mycorrhizal spores other than a).

Example 3 and Comparative Example 2 (1) Propagation of VA mycorrhizal fungus In a vinyl pot of 150 ml (ml) volume, as a base material, red pearl earth (particle size 3 to 6 m) was fired at 250 ° C.
m) (Example 3), or natural dried red tama soil (particle size 3-5)
mm) (Comparative Example 2), and was used as an inoculum and collected from fallow land as Scutellospora.
gregaria) (Note that this fungus was rejected for consignment at the Institute for Microbial Technology, Institute of Industrial Science and Technology), and 50 seeds of Sudangrass were sown. Moreover, in order to investigate the presence or absence of indigenous VA mycorrhizal fungi, a non-inoculated area of Scatellospora gregaria was also established. 3 seedlings of this Sudangrass
After cultivating at 25-30 ° C for a week to make infected seedlings, red jade soil (particle size 3-6mm) fired at 250 ° C in a 1 / 10,000 are Wagner pot in the same manner as above.
(Example 3) Or natural dried red tama soil (particle size 3 to 5 m
m) (Comparative Example 2) was used as a base material, and 1.5 liters thereof were filled.
The infected seedlings were transplanted there. Then, while culturing at 25 to 30 ° C. for 7 weeks while giving the liquid fertilizer shown above, the base material was recovered and spores were recovered by the wet sieving method in the same manner as in Example 1. In addition, in both Example 3 and Comparative Example 2, no special sporulation treatment such as artificial day length adjustment was performed.

As a result, in the case of Example 3 using fired red tama soil as the base material, the number of spores was 11,880 / pot.
In contrast to the large amount obtained, in the case of Comparative Example 2 in which natural dried red tama soil was used as the base material, since the indigenous VA mycorrhizal fungus (genus Glomus) was contaminated, the spores of Scutellaspora gregaria were pure. In addition to not being able to obtain spores, the number of spores obtained was as small as 4500 / pot. In addition, the results in the non-inoculated area of Scatellospora gregalia showed that indigenous VA mycorrhizal mycorrhizal spores were not found at all when fired red tamasoil was used as the base material, whereas natural dried red tamasoil was used as the base material. At this time, it was confirmed that 5328 cells / pot of indigenous VA mycorrhizal fungi (genus Glomus) were mixed.

(2) Reuse of VA Mycorrhizal Fungus-Infected Plant After that, the VA mycorrhizal fungus-infected plant obtained in (1) above was
Similar to the above, red tama soil (particle size 3 to 6) fired at 250 ° C.
mm) (Example 3), or naturally dried red tama soil (particle size 3 to
1/100 filled with 5 mm) (Comparative Example 2) as a base material
Replanted in 00 Earl Wagner pot. Above (1)
In the same manner as above, after cultivating for 7 weeks while giving liquid fertilizer,
The base material was collected and spores were collected by a wet sieving method. As a result, in the case of Example 3 in which the calcined red tama soil was used as the base material, 10564 spores of pure Skatellospora gregaria /
Although a pot could be obtained, in the case of Comparative Example 2 in which natural dry red tama soil was used as a base material, indigenous VA mycorrhizal fungi (genus Glomus) were mixed and the number of spores was 3568 / pot. There were few. As described above, according to the method of the present invention, it is found that a large number of VA mycorrhizal spores can be obtained even in the second time when the plant from which spores have been collected is reused.

[0035]

In the method of the present invention, the use of fired red tama soil can prevent contamination of indigenous VA mycorrhizal fungi, pathogenic fungi, etc. VA mycorrhizal fungi belonging to the genus Gigaspora and the genus Scutellospora can be propagated. Further, according to the method of the present invention, a VA mycorrhizal preparation having a high spore density can be produced at a low cost, and the plant can be reused.
It is extremely efficient. Further, according to the method of the present invention,
Since the VA mycorrhizal fungal growth substrate can be directly used as a product, it does not require the trouble of separating spores, and the operation is simple.

Claims (3)

[Claims] 1. A V plant characterized by cultivating a plant infected with VA mycorrhizal fungus, using heat-treated red tama soil as a base material.
Method for growing mycorrhizal fungi. 2. The method for growing VA mycorrhizal fungi according to claim 1, wherein a plant infected with VA mycorrhizal fungi is used with heat-treated red tama soil as a base material. 3. The method for growing VA mycorrhizal fungi according to claim 1, wherein the VA mycorrhizal fungus belongs to the genus Gigaspora or the genus Scatellospora.