JP2772466B2 - Seed - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seed treated with an N-acyl lactam compound and a fluorescent bacterium, and by ensuring the establishment of the fluorescent bacterium on the root surface and in the root after sowing. It is intended to improve productivity by controlling disease and promoting growth of crops.

[0002]

2. Description of the Related Art With the development and spread of technologies such as biotechnology, varieties improvement or seed management technology of vegetables, flowers and the like have rapidly advanced in recent years, and gradually, quality improvement, yield increase, and disease control effects are becoming apparent. . For example, seeds are promoted for germination using priming technology, and for disease control, fluorescent bacteria and plant growth-promoting rhizobacteria are used.
Disease control or growth promotion by seed treatment using (PGPR) has been attempted. Attempts have also been made to combine seed treatment techniques with techniques for using antagonistic microorganisms.

[0003] When cucumber and tomato seeds are conditioned with shale powder, the antagonistic filamentous fungus Trichoderma.
By adding Hazenam (Trichoderma harzianum), it is better to add seedling blight fungus than adding fungicides.
It has also been reported that mortality after emergence by ultimum (Pythium ultimum) is reduced. However, in disease control and growth promotion, cultivation management such as fertilization, irrigation, sterilization, insecticide, and weeding still occupies a large weight, and it cannot be said that sufficient effects are necessarily expressed.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present inventors
Useful seeds that have been introduced at the stage of seed priming or conditioning using useful fluorescent bacteria that inhabit the crop rhizosphere, in order to express the plant growth promoting effect of the fluorescent bacteria and the disease-causing suppression effect, As a result of various studies, the present invention has been completed.

Hitherto, polyethylene glycol, mannitol, various salt solutions and the like have been used for seed priming, and it is known that this is an effective technique for promoting germination and the like. Therefore, the present inventors have tried to fix the fluorescent bacteria to the seeds by simultaneous treatment with seed priming for the purpose of labor saving and combined effects, but the fixation degree is low,
In many cases, the fluorescent bacteria were killed, and when the bacterial density was increased or the treatment was performed for a long time, poor seed germination and decreased activity of the fluorescent bacteria were observed. In rare cases, even when fixing is performed, the manifestation and persistence of the effect are unstable, and various problems remain for practical use. In order to solve these problems, it is necessary to treat the target fluorescent bacteria at the seed stage so that the target fluorescent bacteria can be established, and that the colonized fluorescent bacteria can inhabit the seeds or the plant organism after seeding. is necessary.

[0006]

Accordingly, the present inventors have conducted intensive studies on substances which do not exhibit bactericidal activity against fluorescent bacteria and are effective for colonization of fluorescent bacteria at the stage of seed priming and conditioning. It has been reached.
That is, the present invention relates to seeds treated with an N-acyl lactam compound and a fluorescent bacterium.

[0007]

The present invention will be described below in more detail. The fluorescent bacterium used in the present invention is a bacterium belonging to the family Pseudomonadaceae (Pseudomonadaceae) or Azotobacteraceae (Azotobacteraceae) according to Bergey's classification and having a water-soluble fluorescent dye-producing ability as a physiological property. It is.

For the N-acyl lactam compounds,
As a result of many years of research, focusing on the physiologically active function of this compound, it has been used as a plant growth regulator for plants, and gram-positive bacteria such as actinomycetes, rhizobia, bifidus bacteria, methane fermentation bacteria, etc. It has been proposed to use it as a promoter of growth or metabolism of microorganisms capable of differentiating bacteria or cells. He also proposed a bacteriostatic effect on Gram-negative bacteria and filamentous fungi. These biological activities are effects on primary metabolism for plants,
The primary effect on microorganisms was secondary metabolism.

It is well known that the natural disease defense mechanism of plants is regulated in the secondary metabolic system, and the present inventors have further studied the effects of N-acyl lactam compounds on plant secondary metabolism. Was added. As a result, N-
Acyl lactam compounds showed remarkable plant secondary metabolism controlling activity in the saturated concentration range. In particular, it has been found that solanaceous crops have an effect of promoting metabolism of antibacterial substances outside the roots. In addition, N-acyl lactam compounds do not show bactericidal activity against fluorescent bacteria and type cultures separated from the root zone in the saturation concentration range, and suppress cell division but do not affect metabolism or cell growth. A promoting effect was observed. The present invention has been completed based on these findings.

The N-acyl lactam compounds used in the present invention include 1- [2- (4-humanperoxyphenyl) ethanoyl] -2-hydroxyperitone and 1- [3- (4-humanperoxyphenyl) fluoropernoyl] -2. -Hearyton, 1- [3-
(4-Hydroxyphenyl) cinnamoyl] -2-hydroxyperitone, 1- [2- (3,4-dihydroxyphenyl) ethanoyl] -2-hydroxyperitone, 1- [3- (3,4-dioxyphenyl) 1- [2- (4-Hydroxyphenyl) ethanoyl] -2-hydroxyl, 1- [3- (4-Hydroxyphenyl) fluorohyl] -2-hydroxyl, 1
-[3- (3,4-Dimethoxyphenyl) fluoroanoyl] -2-hydroxylithone and the like are good examples.

[0011] Seeds to be treated with an N-acyl lactam compound and a fluorescent bacterium can be prepared by the following method. These processes can be performed simultaneously or intermittently. Examples of the treatment method include a seeding method in which seeds are immersed in a mixed solution of an N-acyl lactam compound and a fluorescent bacterium, a fine powder having a slight hardness such as an N-acyl lactam compound and a fluorescent bacterium, silica, and zeolite. A seed coat abrasion method of stirring and mixing the seeds with the seed, a soaking pressure reduction method of performing a soaking method under reduced pressure, and the like can be used. Further, after treating the seed with an N-acyl lactam compound aqueous solution or a powder containing the N-acyl lactam compound, the seed may be treated with a suspension of fluorescent bacteria or a powder containing fluorescent bacteria, The order may be reversed. The most desirable method is a soaking seed decompression method in which seeds are added to a mixed solution of an aqueous solution of an N-acyl lactam compound and a suspension of fluorescent bacteria, and the pressure is reduced. Preferred examples of the carrier used for pulverization include silica, diatomaceous earth, zeolite, perlite, vermiculite, sea sand and the like.

The concentration of the N-acyl lactam compound used in the case of a solution is desirably in a high concentration range of 50 mg / L or more. The bacterial density of the fluorescent bacterium depends on the nature of the bacterium used and its use and is not limited, but it is preferable to use at least 10 ⁶ cells / ml for a solution and at least 10 ⁵ cfu / g for a solid. . The ratio of the N-acyl lactam compound and the fluorescent bacterium to the seed is determined by the seed,
It depends on the type of acyllactam compound or fluorescent bacterium, the state of the substance to be treated, and the like, and cannot be specified unconditionally. In general, 1 mg of N-acyllactam compound per 1 ml of seed, There is 10 ⁸ c
ells are preferred.

[0013]

EXAMPLES Examples of the present invention will be further described below. Table 1 shows N-acyl lactam compounds used in the examples. In the examples, these N-acyl lactam compounds are represented by substance Nos. In addition, fluorescent bacteria used in the examples are shown in Table 2, and are indicated by strain symbols in the examples.

[0014]

[Table 1]

[0015]

[Table 2] Note) * 1: Separated from the root of tomato (variety, Momotaro) * 2: Separated from the root of sansho

(Example 1) Substance Nos. (1) to (1) shown in Table 1
The N-acyl lactam compound of (8) was prepared in an aqueous solution having a concentration of 100 mg / L, sterilized by filtration, and then adjusted to 10 ⁸ cells / ml. The fluorescent bacteria (A), (B), and (B) in Table 2 were prepared. It was mixed with the cell suspension of (C), (D) and (F) at the same volume ratio to obtain a mixed liquid for seed treatment. After sterilizing tomato seeds (cultivar: House Momotaro) with 1% sodium hypochlorite aqueous solution and 80% ethanol aqueous solution,
1 ml of the seed was immersed in 10 ml of the seed treatment mixed liquid, and subjected to a seeding vacuum treatment under a reduced pressure of 10 mmHg for 6 hours (section of the present invention). Instead of the seed treatment mixture, (A), (B), (C), (D), (F) cell suspension and sterilized water using the same method as described above using the seeding vacuum treatment. (Control and untreated).

After the treatment, the seeds in each section were washed with sterilized water to obtain seeds in the present invention section, control section, and untreated section. Seed the treated seeds from each plot on a white agar medium (excluding sucrose), and
It was kept at 28 ° C. for 5 days and the germination process was examined. Next, the germinated seeds of each section were cultivated for two weeks in an artificial weather device under light and aerobic conditions. The change in the germination rate during the cultivation period was measured, and the number of fluorescent bacteria in the root surface and in the root of the seedling after cultivation was measured. For the measurement of the number of fluorescent bacteria, the cultivated seedlings were extracted from the medium, and about 1 g of the seedling roots was placed in 10 ml of a 0.005% aerosol OT (manufactured by American Cyanamit Co., Ltd.) aqueous solution at 10,000 rpm.
A root grinding solution was prepared by homogenizing for 0 minutes, and the prepared solution was diluted and subjected to a pour method using a potato dextrose agar medium. The results are shown in Tables 3 and 4.

[0018]

[Table 3]

[0019]

[Table 4]

(Example 2) In the same manner as in Example 1, the N-acyl lactam compounds represented by the substance Nos. (1) to (8)
After preparing an aqueous solution having a concentration of 00 mg / L and sterilizing by filtration, 10
⁸ cells / ml in Table 2 prepared in the fluorescent bacteria (A), (B), (C),
The same volume as the cell suspension of (D) was mixed to obtain a mixed liquid for seed treatment. Komatsuna seeds (manufactured by Tohoku Co., Ltd.) are sterilized with a 1% aqueous solution of sodium hypochlorite and an 80% aqueous solution of ethanol, and then 1 ml of seeds are immersed in 10 ml of a mixture for seed treatment and immersed under reduced pressure of 10 mmHg for 2 hours. Processing was performed (section of the present invention). Similarly, a seeding vacuum treatment was performed using the cell suspensions (A), (B), (C), and (D) and sterilized water (control group and untreated group).

After the treatment, the seeds in each section were washed with sterilized water to obtain seeds in the present invention section, control section, and untreated section. Seed the treated seeds from each plot on a white agar medium (excluding sucrose), and
The temperature was kept at 20 ° C and 28 ° C for 2 days, and the change in the germination rate during the cultivation period was measured. Next, the germinated seeds of each section germinated at 28 ° C. were cultivated for 2 weeks in an artificial weather device under light and aerobic conditions. The number of fluorescent bacteria in the root surface and in the root of the seedling after cultivation was measured. The number of fluorescent bacteria was measured by extracting a grown seedling from the culture medium, placing about 1 g of the seedling root in 10 ml of a 0.005% aerosol OT (manufactured by American Cyanamit Co., Ltd.) aqueous solution, and homogenizing at 10,000 rpm for 10 minutes. Was prepared and diluted by a pour method using a potato dextrose agar medium. The results are shown in Tables 5 and 6.

[0022]

[Table 5]

[0023]

[Table 6]

(Example 3) In order to compare and examine the effect of treated seeds when soil was used, (D) and (D) in Table 2 were used as fluorescent bacteria that could be detected by re-isolation.
(E) was selected. As for the detection method from soil and plants, (D) can be re-detected by the presence or absence of a blue-white fluorescent precipitate around the colony when grown on a potato dextrose agar medium containing crystal violet 5 mg / l. . In this connection, it was confirmed by the same method that no fluorescent bacteria having the same properties were present from the plug-seedling cultivation soil and the bacterial wilt disease-causing soil used in this example. (E) 200 mg / l streptomycin sulfate, 100 mg / l nalidixic acid, 10 mg / l
When grown on King B medium containing 0 mg / l sodium ampicillin and further grown on a potato dextrose agar medium, it can be detected again depending on whether or not a colony produces a yellow pigment. In this connection, it was confirmed by the same method that no fluorescent bacteria having the same properties were present from the plug-seedling cultivation soil and the bacterial wilt disease-causing soil used in this example.

(D) and (E) in Table 2 were suspended in a 1% aqueous sodium alginate solution to prepare a cell suspension of 10 ⁹ cells / ml. This cell suspension was added to and mixed with 20% v / v of fine sea sand to prepare a cell-containing powder. Of the N-acyl lactam compounds shown in Table 1, (1)
A 0.5 w / v% solution of the compound of (2) was added to silica powder at 10 w / w.
%, And the solvent was removed while mixing to prepare N-acyl lactam compound-containing powder. Cell-containing powder and N
-Acyl lactam compound-containing powder was mixed in the same volume to obtain seed treatment powder (section of the present invention). For the control group, cell-containing powder and N-acyl lactam compound-containing powder were used. In the untreated section, the same volume mixture of fine sea sand and silica powder was used.

The powder was added to a tomato seed (cultivar: large-sized fukuju), which had been surface-sterilized in the same manner as in Example 1, by a 10-fold volume, and subjected to rotational mixing at 80 rpm for 30 minutes. After heat treatment (150 ° C., 15 minutes) of commercially available plug raising seedling soil, treated seeds in each section were sown, and plug raising was performed at an average seedling raising temperature of 40 ° C. for 3 weeks. After raising the seedlings, the fluorescent bacteria on the root surface and in the root were separated and cultured by the same method as in Example 1, and then replicated in the above-mentioned discrimination medium, and the numbers of the separated bacteria (D) and (E) were counted. The plug seedlings of each section were planted in tomato bacterial wilt disease soil having a tomato bacterial wilt density of 10 ⁶ to 10 ⁷ cfu / g (soil), and the disease suppression effect was examined by examining the disease three weeks after planting. Table 7 also shows the number of fluorescent bacteria on the root surface and in the root after plug seedling raising, and the results of the disease investigation.

[0027]

[Table 7] Note) Disease severity: Disease severity = {(morbidity index × number of strains) / (10 × number of strains)} × 100. The morbidity index was set as death = 10, whole body withering = 5 and partial withering = 2. Control value: Control value was calculated by the following formula: control value = {(development degree of untreated section−development degree of test section) / development degree of untreated section} × 100.

Example 4 In the same manner as in Example 3, the effect on plant growth was examined using soil. (D) and (E) in Table 2, which can be separated and distinguished from the plug culture and the potting culture, were used as test fluorescent bacteria. Of the N-acyl lactam compounds shown in Table 1, the compounds (6) and (7) were prepared in a 100 mg / l aqueous solution to obtain an N-acyl lactam compound aqueous solution. The cell suspension (Example 3) and the aqueous solution of the N-acyl lactam compound were mixed in the same volume to prepare a seed treatment solution (section of the present invention). As a control, a cell suspension and an aqueous solution of an N-acyl lactam compound were used. Sterile water was used as an untreated section.

1 ml of tomato seeds (variety: large fukuju) which had been subjected to surface sterilization in the same manner as in Example 1 were immersed in 10 ml of various seed treatment solutions and treated at 20 ° C. for 6 hours. Plug-raised seedlings were obtained from the treated seeds in the same manner as in Example 3. Next, the seedlings were transplanted to the potting soil, cultivation was continued for another two weeks, and the growth was investigated. The results are shown in Table 8.

[0030]

[Table 8] * Total root length: Displayed as total root length by the line intersection method.

[0031]

EFFECTS OF THE INVENTION The seed of the present invention has a fluorescent bacterium having a plant growth promoting effect or an effect of suppressing the onset of phytopathogenic bacteria at the seed stage, and a fluorescent bacterium which has become established after seeding. Since it inhabits the inside of a plant or a living body of a plant, productivity can be improved by controlling disease and promoting growth of agricultural crops.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI A01N 43:40) (72) Inventor Minoru Okumura 1406-1 Shinnobe, Beppu-cho, Kakogawa-shi, Hyogo Examiner Reiko Imamura (56 References JP-A-63-190806 (JP, A) JP-A-2-211861 (JP, A) JP-A-6-92815 (JP, A) JP-A-63-304977 (JP, A)

Claims (2)

(57) [Claims] 1. A seed obtained by treating an N-acyl lactam compound with a fluorescent bacterium. 2. The method according to claim 1, wherein the N-acyl lactam compound is 1- [2-
(4-Hydroxyphenyl) ethanoyl] -2-pyrrolidone, 1- [3- (4-Hydroxyphenyl) fluorohenyl] -2-pyrperitone, 1- [3- (4-Hydroxyphenyl) cinnamoyl] -2-pyrperitone, 1 -[2- (3,4-dihydroxyphenyl) ethanoyl] -2-hydroxylithium, 1- [3- (3,4-dioxyxyphenyl) fluoroanoyl] -2-hyperidone, 1- [2- (4 -Hydroxyphenyl) ethanoyl] -2-hydroxylithone, 1- [3- (4-Hydroxyphenyl) fluoroanoyl] -2-hydroxyltone, 1- [3- (3,4-xyloxyphenyl) fluorohanoyl] -2-hydroxylithone The seed of claim 1, wherein