JPH107483A - Culture promotion agent for plant and method for promoting culture of plant using the agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promote the germination of seed and the growth of plant by placing a specific microorganism belonging to the genus Agrobacterium radiobacter and/or its cultured product in contact with or near the seed or root of a plant. SOLUTION: The above microorqanism is Agrobacterium radiobacter H3501 or TBR27 and the plant is cereal, vegetable, flower or fruit tree. The culture of the microorganism is carried out preferably in M523 medium, King medium, etc., as well as a conventional medium such as meat extract medium. A solid medium such as agarcontaining slant medium or plate medium may be used in place of a liquid medium. A desired amount of microbial cells are produced by proliferating the microorganism in the above medium. Any substance can be used as a carbon source and a nitrogen source provided that the source is assimilable by the microorganism. The culture is carried out under aerobic condition at 2-28 deg.C, preferably 25-28 deg.C and pH5-8, preferably 6-7 for 1-5 days, preferably 2-3 days.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for promoting germination and growth of plants, and more particularly to promoting germination and growth of plants using microorganisms belonging to Agrobacterium radiobacter. About the method.

[0002] to produce the background technology crops, to increase its commercial value, it is necessary to maintain a certain level that the quality and yield of crops. For that purpose, it is important to produce a large number of healthy and uniform seedlings. However, depending on the type of crop, the germination rate and initial growth are poor, and the management of seedlings may not be easy.

[0003] For example, with respect to tobacco, operations such as thinning and temporary planting after germination are performed to obtain uniform seedlings. But it takes a lot of labor and time. Therefore, coated seeds have been developed for the purpose of easy handling of the seeds and elimination of the work (Japanese Patent Publication No. 47-197).
No. 31122, JP-A-48-13110). But,
Even in such coated seeds, it is observed that germination is not uniform and the subsequent growth is not uniform, and it can be said that there is still room for improvement.

[0004] In the case of flowers such as eustoma,
The germination rate is low and it takes a long time to germinate. In spinach and the like, the growth after germination is abnormal, and the seedlings often lodge and die. As described above, there are many crops in which it is often difficult to obtain a large amount of uniform healthy seedlings by using a normal control.

[0005] As described above, promotion of initial growth and uniformization of crops are important issues in agricultural production.

In order to solve such problems, utilization of a plant growth promoting substance has been proposed. Gibberellins and auxin plant hormones have been reported as plant growth promoting substances. However, these plant hormones
Since it has a multifaceted effect and may be harmful to plants, its use is practically limited at present.

[0007] On the other hand, a variety of microorganisms inhabit the rhizosphere or root surface of a plant, and some of them have an action of promoting the growth of the plant.

[0008] Therefore, attempts have been made to isolate useful microorganisms having a growth promoting effect from these rhizosphere microorganisms and to utilize them for improving agricultural productivity. is there.

[0009] In particular, there are many research cases using bacteria, and among them, the case where the genus Pseudomonas is examined is the most.

For example, it has been reported that the use of Pseudomonas fluorescens increased the yield of greenhouse tomatoes by 13.3%, increased the size of fruits by 11.1%, and decreased the yield of nonstandard products (Soil Biology Biochemistry).
(1993) vol 25 (2); 269-272). In addition, the use of P. putida has led to an increase in sales of winter wheat by 11% (Soil
Biology Biochemistry (1992) vol 24 (11): 1137-1146
), And the case where the nodulation rate and the above-ground dry matter on the clover are increased by the mixture treatment with VAM mycorrhizal fungi (Soil Biology Biochemistry (1986) vol 18 (2):
185-190) has been reported. In addition, the use of P. cepacia resulted in a 6% increase in winter wheat sales (So
il Biology Biochemistry (1992) vol24 (11): 4 (11): 11
37-1146). In addition, the use of P. aeruginosa has been reported to promote the growth of 13-32% in spinach and corn (Soil Biology Biochemistry).
(1992) vol24 (8): 751-759).

Examples other than Pseudomonas spp. Include Enterbacter cloacae and Agrobacterium rh
Growth promoting activity of izogenes have been reported, respectively (JP 63-102668 and JP 59-16
No. 1306). Ag robacterium tumefacien
It has been disclosed that oligosaccharides, which are membrane substances of s , have a cultivation promoting effect on plants (Japanese Patent Application Laid-Open No. 64-7910).
No. 1).

[0012] As described above, examples of growth promotion using various microorganisms have been reported, but the target crops of all the microorganisms are limited, and it is necessary to use different microorganisms for each crop. In addition, the effect is often unstable, and it can be said that no useful microorganism has been found at present.

Further, to the knowledge of the present inventors, there has been no report that a microorganism belonging to Agrobacterium radiobacterium promotes germination and / or growth of a plant.

[0014]

SUMMARY OF THE INVENTION The present inventors have previously found a microorganism having a soil disease control effect on solanaceous plants (Japanese Patent Application No. 7-194839). Was further found to be provided. In other words, the present inventors have recently reported that microorganisms belonging to Agrobacterium radiobacter have a high germination / growth promoting effect on plants, and improve the cultivation efficiency of agricultural crops and the like by using these microorganisms. I got the knowledge that I can do it. The present invention is based on this finding.

Accordingly, an object of the present invention is to provide a cultivation promoter for promoting germination and growth of plants and a method for promoting cultivation of plants using the same.

The plant cultivation promoter according to the present invention promotes seed germination by contacting the plant with the seeds or roots of the plant or in the vicinity thereof, and / or
Or a microorganism belonging to the genus Agrobacterium radiobacter having a property of promoting the growth of the plant;
Or a culture thereof.

Furthermore, the method for promoting cultivation of a plant according to the present invention comprises a step of causing the cultivation promoting agent to be present in or near a plant seed or root.

[0018]

DETAILED DESCRIPTION OF THE INVENTION Deposit of Microorganism The H3501 strain, which is a specific example of the microorganism according to the present invention, was isolated from the root of tobacco (Michinoku No. 1) in Izumizaki-mura, Nishishirakawa-gun, Fukushima Prefecture. A TBR27 strain, which is another specific example of the microorganism according to the present invention, was isolated from the root of tobacco (BY4) in Oyama City, Tochigi Prefecture. Based on the bacteriological properties described below, these strains are based on Bergey's Man
When identified with reference to ual of Systematic Bacteriology volume 1 (1984), it was determined to be a new strain belonging to Agrobacterium radiobacter. These Agrobacterium radiobacterium strain H3501 (hereinafter referred to as “H3
501) and the TBR27 strain (hereinafter referred to as "T
BR27 ”), each having the accession number FERM BP
-5058 and FERM BP-5059 have been deposited with the National Institute of Advanced Industrial Science and Technology.

Bacteriological properties of H3501 strain The bacteriological properties of the H3501 strain used in the present invention are as shown in Table 1 below.

[0020]

[Table 1] Bacteriological properties of TRB27 strain The bacteriological properties of the TRB27 strain used in the present invention are shown in Table 2 below.

[0021]

[Table 2] Cultivation The cultivation of the microorganisms used in the present invention may be any suitable one, including the type of medium and the culturing conditions. For example, in addition to a general medium such as a meat extract medium, an M523 medium (Phytopathology (1970) vol.
69-976), King B medium (J. Lab. Clin. Med. (195
4) vol.44, 301-307). In addition to the liquid medium, a solid medium such as a slope medium containing agar and a plate medium may be used. Then, the cells can be grown by culturing to obtain a desired amount of cells.

As the carbon source of the medium, any of the above strains that can be assimilated can be used. Specifically, in addition to sugars such as glucose, galactose, lactose, arabinose, mannose, and malt extract starch hydrolyzate, there are various synthetic or natural carbon sources that can be used by the strain.

Similarly, as the nitrogen source, various synthetic or natural products that can be used by the strain, including organic nitrogen-containing substances such as peptone, meat extract, and yeast extract, can be used.

In accordance with a conventional method for culturing microorganisms, inorganic salts such as salt and phosphate, salts of metals such as calcium, magnesium and iron, and trace nutrients such as vitamins and amino acids can be added as necessary.

The culture can be performed under aerobic conditions such as shaking culture, static culture, and aeration culture. Culture temperature is 2
0-30 ° C, preferably 25-28 ° C, pH 5-8,
Preferably 6 to 7, culture period is 1 to 5 days, preferably 2 to 5 days.
~ 3 days is appropriate.

Promotion of germination and growth of plants In this specification, "promotion of cultivation of plants" refers to promotion of germination of seeds of plants and / or promotion of growth of plants. Further, in the present specification, the term “seed” is a concept that also includes tuberous roots such as potatoes. Furthermore, the term "root" refers to a portion that is present in soil or hydroponic solution when a plant is cultivated and absorbs water and nutrients.

Agrobacterium used in the present invention
The microorganism belonging to Radiobacter has a property of promoting the germination of the seed and / or the growth of the plant by bringing the microorganism into contact with or near the seed or root of the plant.

Therefore, according to the present invention, Agrobacterium having the property of promoting the germination of a plant and / or promoting the growth of a plant by being brought into contact with or near the seeds or roots of the plant. A plant cultivation promoter comprising a microorganism belonging to the genus and / or a culture thereof is provided.

Further, according to the present invention, there is provided a method for promoting cultivation of plants using the cultivation promoter.

Preferred examples of the microorganism belonging to Agrobacterium radiobacter include microorganisms belonging to Agrobacterium radiobacter, more specifically, Agrobacterium radiobacter strain H3501;
FERM BP-5058, Agrobacterium radiobacter TBR27, and FERM BP-505
9 is mentioned. The microorganism may be a single strain or a mixture of a plurality of strains having the above properties.

[0031] The cultivation promoter according to the present invention may be used for cereals,
Vegetables, flowers, and fruit trees can be widely applied, but preferably include solanaceous plants, cruciferous plants, and red coralaceae among dicotyledonous plants, and more specifically, tobacco, cabbage, spinach, bok choy, and the like. Can be Needless to say, seedlings of these plants are also applicable.

The plant cultivation promoter according to the present invention comprises the microorganism and / or a culture thereof. here,
The culture is a concept including a culture suspension, a culture supernatant, a culture filtrate, and an extract thereof. The cultivation promoter according to the present invention preferably contains the microorganism as a living microorganism or a culture supernatant or a culture obtained by removing the microorganism from a culture of the microorganism. Therefore, when a microorganism is included as a viable bacterium, the cultivation promoter according to the present invention is:
10 ⁶ to 10 ¹⁰ cells / ml, preferably 1
0 ⁷ 10 ⁹ cells / ml, in a form suspended in water or an appropriate aqueous solvent in a ratio of may be provided. When a culture supernatant is contained, the cultivation promoting agent according to the present invention may be provided as a solution obtained by diluting the culture supernatant to a stock solution to 1,000 times, preferably to a stock solution to about 100 times. Furthermore, when the culture is contained as it is, the cultivation promoter according to the present invention may be provided as a solution obtained by diluting the culture with a stock solution to 1,000 times, preferably about 100 times the stock solution.

Further, the cultivation accelerator according to the present invention may be combined with a so-called carrier to form an agrochemical composition. Examples of preferred carriers include a water-soluble solvent to which a pH buffer solution is optionally added, a powder, a granule, and a porous material such as vermiculite, which are added with a protective agent such as skim milk and freeze-dried followed by an aid such as talc. Is mentioned.

The method, timing and amount of application of the cultivation promoter of the present invention to plants are appropriately determined in consideration of the type of plant, the amount of microorganisms and / or culture when formulated, and other conditions. May be determined.

For example, when applied to seeds, the cultivation promoter of the present invention may be directly adhered to the seed surface, or the cultivation promoter of the present invention may be mixed into talc, vermiculite, etc. and adhered to the seed surface. Is also good. Furthermore, seeds may be sowed after directly coating the seeds with the cultivation promoter. Alternatively, the cultivation promoting agent may be irrigated on the soil after sowing, or the seed may be sown on soil that has been irrigated with the cultivation promoting agent in advance.

Furthermore, when applied to the roots, the cultivation promoting agent of the present invention may be irrigated on the soil where the plant is growing, or the seedling or the plant may be transplanted on the soil which has been irrigated with the cultivation promoting agent in advance. Good.

The typical use amount of the cultivation promoter according to the present invention is about 0.5 to 1 ml per seed, and about 1 to 2 ml per seedling or plant.

The so-called coated seed coating agent may be coated with the cultivation promoter of the present invention. Further, the cultivation promoter according to the present invention may be directly coated on seeds. Furthermore, it is also preferable to apply the cultivation promoter according to the present invention to the roots of plant seedlings and then transplant them.

[0039]

The present invention will be further described by the following examples, but the present invention is not limited to these examples.

Example 1 : Acquisition of strains Healthy tobacco roots were dug from tobacco fields nationwide, the roots were cut off with scissors, and the attached soil was shaken off. Roots cut to a length of about 1 cm were placed in 10 ml of sterilized water and stirred with a mixer. Take one platinum loop of the obtained suspension and use an M523 medium (Shoe Rose 10.0 g, casein enzymatically decomposed product 8.0 g, yeast extract 4.0 g, dipotassium phosphate 2.0 g, magnesium sulfate heptahydrate) 0.3g, distilled water 1,000ml, agar 1
5.0 g: Phytopathology (1970) vol. 60: 969-976) or King B medium (proteose peptone No. 32)
0 g, dipotassium phosphate 1.5 g, magnesium sulfate 1.5 g, glycerin 10 ml, distilled water 1,000 m
1: J. Lab. Clin. Med. (1954) vol. 44: 301-307). After culturing at 28 ° C. for 3 days, the obtained single colony was stored in a −80 ° C. freezer. As a result, about 2,000 bacterial strains that are considered to be well established on the root surface
0 strains were obtained.

Among them, H350 was identified as a useful strain from the root of tobacco (Michinoku 1) in Izumizaki-mura, Nishishirakawa-gun, Fukushima Prefecture.
One strain was further isolated as a useful strain from the root of tobacco (BY4) in Oyama City, Tochigi Prefecture, and a TBR27 strain was isolated.

Example 2: Promotion of germination and growth of tobacco Each of the H3501 strain and the TRB27 strain was cultured with shaking (120 rpm) at 25 ° C. for 48 hours using King B liquid medium, followed by centrifugation (10, 10%). 000x
g, 15 minutes), and the cells were collected and separated into bacterial cells and culture supernatant. The cells were suspended in sterilized water at a concentration of about 10 ⁹ / ml. The supernatant was used directly below without dilution.

Vinyl pot (6 × 6 cm, depth 5c)
m) was packed with vermiculite, and 12 tobacco-coated seeds (variety: BY4) were sown. Immediately thereafter, the aqueous suspension of bacterial cells obtained by the above-described method or the supernatant of the culture solution was dripped at 1 ml per seed to irrigate. Untreated areas were irrigated with distilled water or King B liquid medium in the same manner. After treatment, use vermiculite for about 2
After covering up to about 3 mm, the soil was placed at room temperature of 22 ° C. and watered so that the soil surface was not dried. Number of germination after 14 days, 2
One day and 28 days later, the number of healthy plants and the average number of leaves per tube were examined. The results were as shown in Table 3 below.

[0044]

[Table 3] The germination rate of tobacco is inferior in the non-treated area (water) treated with bacterial cells,
The growth was somewhat asymmetric and the leaf color tended to be pale. On the other hand, in the bacterial cell treatment group, the germination rate was 100%, the growth after germination was good, the leaf color was dark, and the average number of leaves was large. The culture supernatant treatment showed almost the same tendency as the bacterial cell treatment, but did not show the growth promoting effect as much as the bacterial cell treatment.

Example 3: Promotion of growth of tobacco seedlings Each strain was cultured in the same manner as in Example 2, centrifuged, and then separated into bacterial cells and culture supernatant. The cells were suspended in sterilized water at a concentration of about 10 ⁹ / ml. The supernatant was used without dilution.

Vinyl pot (4 × 4 cm, depth 5c)
m) is filled with fertilizer for growing seedlings, and tobacco (BY4: 5)
Leaf stage seedlings) were provisionally planted. Immediately thereafter, an aqueous suspension of the bacterial cells obtained by the above method or a culture supernatant thereof was added to one seedling per one seedling.
Each ml was dripped around the base of the tobacco and irrigated. Untreated areas were irrigated with distilled water or King B liquid medium in the same manner. Then, it was placed in a greenhouse at 22 ° C. and watered so that the soil surface did not dry. Try 6 seedlings per ward,
The test was performed in duplicate. Twenty-one days after the treatment, the growth status of the tobacco in each treatment section was investigated. The number of leaves was checked for each individual. Thereafter, the plants were removed together with the soil, washed carefully with water, and the maximum root length of each individual was examined. Furthermore, after removing excess water with a paper towel, it was cut into an above-ground part and an underground part, and the weight of each individual was examined. The results were as shown in Table 4 below.

[0047]

[Table 4] In the untreated area (water), the growth of tobacco was uniform, but the growth was somewhat slow and the leaf color tended to be pale.
On the other hand, in the bacterial cell treated area, the growth was good in all cases, and tended to increase in any of the survey items. When compared with the untreated area (water), the above-ground and underground fresh weights were different in H3501 respectively. An increase of 23 and 39% was observed, and an increase of TRB27 of 22 and 22% was observed. No clear section difference was observed in the culture supernatant treatment section.

Example 4: Growth promotion of cabbage A plastic pot (4 × 4 cm, depth 5 cm) was filled with fertilizer for growing seedlings, and one cabbage seed (variety: Teriyamaru) was sown. Immediately thereafter, 1 ml of an aqueous suspension of a seedling obtained by the same method as in Example 2 was irrigated per seed. Untreated areas were irrigated with distilled water in the same manner. Eight seeds were tested per plot. After that, it was placed in a greenhouse at 22 ° C. and irrigated to such an extent that the surface did not dry. All the seedlings that have germinated 14 days later are carefully excavated, washed with water and drained with a paper towel, weighed separately on the ground and underground, and then divided by the number of germinated plants to calculate the average fresh weight. did. There was no difference in the germination rate in the treatment section.
The results were as shown in Table 5 below.

[0049]

[Table 5] In the untreated group, the growth was asymmetric and some growth was delayed, but in the bacterially-treated group, the growth of the plant was good and the leaf color was dark. As compared with the untreated area (water), the above-ground and underground fresh weights increased by 2% and 143%, respectively, in H3501 and 30% in TRB27, respectively.
% And a 50% increase were observed.

Example 5: Growth promotion of bok choy A vinyl pot (4 x 4 cm, depth 5 cm) was filled with vermiculite, and seeds of bok choy were seeded one by one. Immediately thereafter, 1 ml of an aqueous suspension of bacterial cells obtained in the same manner as in Example 2 was irrigated per seed. Untreated areas were irrigated with distilled water in the same manner.
Eight seeds were tested per section. After that, it was placed in a greenhouse at 22 ° C. and irrigated to such an extent that the surface did not dry. All the seedlings that germinated 14 days later were carefully excavated and washed with water, excess moisture was removed with a paper towel, weighed separately on the ground and underground, and the value was divided by the number of germinated plants to obtain the average fresh weight. Calculated. There was no difference in the germination rate in the treatment section. The results were as shown in Table 6 below.

[0051]

[Table 6] In the non-treated group, the growth was asymmetric and the growth was partially delayed, but in the bacterial-treated group, the growth of the plant was good and the leaf color was dark. Compared with the untreated area (water), the above-ground and underground fresh weights increased by 15% and 14% in H3501 and 60% in TRB27, respectively.
% And a 50% increase were observed.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication C12R 1:01)

Claims (5)

[Claims] The present invention relates to a genus Agrobacterium radiobacter having the property of promoting seed germination and / or promoting the growth of a plant by bringing the plant into contact with or near the seed or root of the plant. A plant cultivation promoter comprising a microorganism belonging thereto and / or a culture thereof. 2. The plant cultivation promoter according to claim 1, wherein the microorganism belonging to the genus Agrobacterium is Agrobacterium radiobacterium H3501. 3. The plant cultivation promoter according to claim 1, wherein the microorganism belonging to the genus Agrobacterium is Agrobacterium radiobacter TBR27. 4. The plant cultivation promoter according to claim 1, wherein the plant is a cereal, a vegetable, a flower, or a fruit tree. 5. A method for promoting plant cultivation, comprising the step of causing the plant cultivation promoter according to any one of claims 1 to 4 to be present in or near a plant seed or root.