JPH11137111A - Cool temperature lawn having hot tolerance and its creation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a plant belonging to cool temperature lawn, having hot tolerance, capable of reducing a cost for maintaining a lawn and decreasing the use of agrochemicals, and useful as a material for greening a golf course and the like by selecting a plant containing tissues in which the number of chromosomes is polyploidized. SOLUTION: This plant belonging to cool temperature lawn has hot tolerance and contains tissues in which the number of chromosomes is polyploidized. The plant belonging to the cool temperature lawn is preferably created by subjecting a plant, such as bent grass, belonging to the cool temperature lawn to a polyploid expression treatment using a polyploid-inducing agent such as colchicine, selecting plants having polyploidized chromosomes from the obtained plants, and subsequently selecting a plant having strong hot tolerance from the selected plants.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plant belonging to a new cold-season turf grass having heat resistance and a method for producing the same. Cold-season turfgrass, which has heat resistance, grows well under high temperatures in the summer as well as in the winter, so that it has high resistance to diseases and can reduce the amount of pesticides used. Also,
It shows a dark green color even under high temperature and high humidity, and can maintain the quality of turfgrass throughout the year. Therefore, it is highly useful as a greening material for golf course greens and park green spaces.

[0002]

2. Description of the Related Art Turfgrass is broadly classified into two types: warm-season turfgrass such as nosiba, kouraishiba and bermudagrass, and cold-season turfgrass such as bentgrass, Kentucky bluegrass, perennial ryegrass, tall fescue, and Italian ryegrass. . When exposed to low temperatures, the warm-grown turfgrass loses its aerial part and cannot retain green color in winter.

[0003] On the other hand, cold-season turf grass is excellent in cold resistance and can maintain a green color even in winter, so that it is particularly used in golf courses and the like that are open even in winter. However, cold-season turfgrass has low resistance to high temperature and high humidity conditions in Japan in the summer, and there is a problem that illnesses such as prawn patch, fairy ring, and pismum bride occur frequently in the summer. For this reason, frequent irrigation and extensive use of pesticides suppress the occurrence of diseases and maintain the quality of green grass.

On the other hand, Japanese Unexamined Patent Publication No. 6-181773 describes a clipping bentgrass green leaf DNA belonging to cold-season turfgrass. The photosynthetic function is further improved by genetic manipulation to improve the evergreen nature. It states that turfgrass varieties can be raised.

[0005]

The method of maintaining the quality of turfgrass by irrigation and intensive use of pesticides raises the problem of increased maintenance costs in irrigation equipment and the problem of environmental pollution due to the use of a large amount of pesticides. .

Japanese Unexamined Patent Publication (Kokai) No. 6-181773 discloses that genetic manipulation makes it possible to grow evergreen turfgrass varieties, but there is no specific operation means, and a gene directly involved in heat resistance was discovered. No successful cases have been reported so far.

As described above, all of the conventional methods have a serious problem, and it is difficult to maintain the quality of cold-season turfgrass in summer, and evergreen turfgrass has been desired. The present invention has been made under such a technical background, and an object of the present invention is to provide a method of providing and producing a cold-season turf grass which is preferable as an evergreen turfgrass.

[0008]

Means for Solving the Problems The present invention has been found to produce plants with high heat resistance at high frequency by performing polyploid expression treatment on plants belonging to cold-season turfgrass. completed.

That is, the present invention is a plant belonging to cold-season turfgrass, which contains a tissue having a doubling of the number of chromosomes in a plant body and has heat resistance. In addition, a plant belonging to cold-sea type turfgrass is subjected to a polyploid expression treatment, a plant having a doubled chromosome is selected from the treated plants, and then a heat-resistant plant is selected from the selected plants. A method for producing a plant belonging to cold-season turfgrass according to claim 1.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) The plant of the present invention has the following features. It is similar in appearance to the native cultivar before improvement, but can be distinguished from the fact that the number of chromosomes has doubled. This can be determined from the size of guard cells without calculating the number of chromosomes. In addition, conventional varieties (eg, bentgrass)
'Pencloth' (Agrostisstolonifera cv. Penncros
s)) temperature at which high temperature stress is applied (air temperature 30 ° C or higher)
Is a variety that can continue normal growth.

(2) Method for producing the plant of the present invention The plant of the present invention is obtained by subjecting a plant belonging to cold-season turfgrass to a polyploid expression treatment, and selecting a plant having a doubled chromosome number from the treated plants. Then, it can be produced by selecting plants having heat resistance. Examples of the cool-season turfgrass include bentgrass, Kentucky bluegrass, perennial ryegrass, tall fescue, Italian ryegrass, and are generally native to Europe. These native species have cold resistance, but their quality deteriorates at high temperatures.

Here, the polyploid expression treatment method includes a method using a polyploid inducing agent, a method using radiation such as gamma rays, X-rays and ultraviolet rays, and a method using both of them. It is desirable to use only a polyploid inducer in terms of efficiency and workability.

Examples of polyploid inducers include colchicine, laughing gas, colcemide, acenaphthene, vinblastine, bodophilotoxin, coumarin, atropine, veratrine, nicotine, sanguinarine, benzol derivatives, diphenyl derivatives, phenanthrene derivatives, naphthalene derivatives, naphthalene derivatives, Diphenylamine, tribromoaniline,
P-dichlorobenzol, methylnaphthoquinone, methylnaphthohydroquinone, salicylic acid and similar substances, hexachlorohexane, pyruvine and its hydrochloride, alkyl-alkali metal carbamate, phenylurethane,
Cachodylate, convalarin, convalatoxin, convalamarin, heteroauxin, germisan, chloroform, amiproposmethyl, oryzalin and the like can be exemplified. Anything is acceptable.

The plant to be subjected to the polyploid expression treatment may be any plant belonging to cold-season turfgrass, and is not limited to a particular variety. As a specific treatment method, for example, a method of immersing cultured cells such as plant tissues or organs, for example, seeds and rhizomes, or callus or the like in a culture medium containing a polyploid inducing agent can be used. The method is not limited to these as long as the method can double. The most preferred treatment method is a method in which seeds are immersed in a medium containing a polyploid inducer for a certain period of time.

In this case, when colchicine is used as a polyploid inducer, the concentration of colchicine is 0.01-
Preferably it is 2.0%, more preferably 0.1-0.5%. Further, the immersion time is preferably set to 1 to 10 days, more preferably 4 to 6 days. Particularly preferred is 5 days.

After the polyploid expression treatment, plants having doubled chromosomes are selected from the plants. Examples of the selection method include a method of collecting cells from a plant and measuring the amount of DNA, and a method of calculating the number of chromosomes at the root tip. In general, it is known that a doubled plant has a larger cell volume than a plant before multiplication treatment, so that leaves and petals become thicker and the size of guard cells increases. The doubling plant may be selected based on the measurement.

After selecting the plant whose chromosome number has been doubled as described above, a heat-resistant line is further selected from the selected plants. The presence or absence of heat resistance can be determined from the state of growth at high temperatures. It is possible to determine that a line that shows normal growth even if the maximum temperature of the day is 30 ° C. or more has heat resistance. Select. The normal growth state can be evaluated by the color of the leaves and the tension of the branches. With the above-described method, it is possible to produce cold-season turfgrass having heat resistance.

(3) Method of Using the Plant of the Present Invention The plant of the present invention is a cold-season type turfgrass having heat resistance, and can easily maintain its quality as turfgrass. Can be used as turfgrass.

[0019]

The present invention will be described in more detail with reference to the following examples. Creeping Bent Glass 'Pen Cloth' (Agr
ostis stolonifera cv. Penncross), 0%
Water was absorbed for 5 days on a filter paper impregnated with a 0.1% or 0.5% aqueous solution of colchicine, washed, and then seeded on vermiculite culture soil. About 300 seeds were used for each condition. Two months later, individuals that had significantly increased guard cell size were selected from those that had germinated.

[0020] Although 0% colchicine treatment did not give rise to individuals whose guard cell size was significantly increased, they did not.
In 1% colchicine treatment, 6 out of 37 individuals germinated,
With 0.5% colchicine treatment, one of 29 individuals had significantly increased guard cell size.
In the strain treated with 0.1% colchicine, 263 individuals were found, and in the strain treated with 0.5% colchicine, 2
71 individuals did not germinate.

Individuals not treated with colchicine (line-a, b, c) and individuals with significantly increased guard cell size (line-A, B, C, D, E, F ( 0.1 or more
% Colchicine-treated line) and G (0.5% colchicine-treated line)) were grown by dividing, dividing cells at the root tip of each line were collected, and their chromosome numbers were calculated. Table 1 shows the results. In Table 1, “the number of observed individuals” is the number of individuals used for calculating the number of chromosomes in each strain, and “the number of observed cells” is 2n = It is the number of cells calculated as 28 or 2n = 56. In addition, the observation of the chromosome
This was performed by the orcein acetate-enzyme dissociation method.

[0022]

[Table 1]

As shown in Table 1, the number of chromosomes in the line not treated with colchicine was 2n = 28 in the diploid type. On the other hand, among individuals in which guard cell size was significantly increased, the number of chromosomes of line-A and line-B was tetraploid 2n = 56, and the other lines were diploid 2n = 56.
28.

From these results, it was found that two lines of homotetraploids (lines A and B) and three lines of diploids not treated with colchicine (lines A, b and c) showed natural light. Heat resistance was evaluated by cultivation in a greenhouse. For cultivation, a pot of unglazed was used, using culture soil obtained by mixing an equal amount of Akadama clay, peat moss, vermiculite, and perlite. The maximum temperature during the cultivation period was 28-40 ° C, and the average of the maximum temperatures was 33 ° C. Two months later,
FIG. 1 shows the result of cutting the above-ground part and comparing the dry weight. All tetraploid lines tended to grow faster than diploid lines.

Cultivation at high temperature caused diploid lines to become lighter in green and branches to hang, while tetraploid lines were darker in green, had tight branches, and were not stressed by high temperatures. . (Fig. 2)

Further, a winter experiment (cultivation at a low temperature) was carried out using the same measurement sample as described above. As a result, both the diploid line and the tetraploid line showed favorable growth states.

[0027]

The cold-season turfgrass of the present invention has heat resistance, so that the maintenance cost of turfgrass in summer and the use of pesticides can be reduced. In addition, the method for producing a cold-season turfgrass having heat resistance according to the present invention can easily and efficiently produce a cold-season turfgrass having heat resistance.

[Brief description of the drawings]

FIG. 1 shows two tetraploid lines (lines A and B)
Three lines without colchicine treatment (lines -a, b,
FIG. 3C is a diagram showing the dry weight of lawn after growing 2) for 2 months.

FIG. 2 shows two lines that are allotetraploids (line-A, B)
3 lines without colchicine treatment (line-a, b)
1 is a photograph showing the growth state of a creature (morphological photograph of an organism).

[Procedure amendment]

[Submission date] November 14, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

Claims (2)

[Claims] 1. A plant belonging to a cold-season turfgrass which contains a tissue having a doubling of the number of chromosomes in a plant body and has heat resistance. 2. A plant belonging to cold-sea type turfgrass is subjected to a polyploid expression treatment, a plant having a doubled chromosome is selected from the treated plants, and a plant having high heat resistance is selected from the selected plants. The method for producing a plant belonging to cold-season turfgrass according to claim 1.