JPH06157201A - Storage of pollen of cruciferous plant - Google Patents

Abstract

PURPOSE:To provide a stable and simple technique for the storage of pollen of a plant of the family Cruciferae. CONSTITUTION:The process for the storage of pollen of a cruciferous plant comprises a step to adjust the water content of pollen collected from a cruciferous plant to <=22% and a step to store the pollen at <=0 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for storing pollen of cruciferous plants.

[0002]

2. Description of the Related Art Pollen of angiosperms is divided into two types, that is, two-celled and three-celled, depending on the state of the nucleus in the maturation stage. It is generally known that bicellular pollen has a longer lifespan, and technological development of pollen storage has been mainly conducted on seeds having bicellular pollen. However, the species having tricellular pollen include cultivated crops that are important to humankind, such as Poaceae, Brassicaceae, Asteraceae, and Phylliaceae. Of these, the pollen storage technology has not been established for the Brassicaceae plants that are the subject of the present invention. Therefore, in breeding and collecting, it was necessary to cultivate two lines of the mating mother strain and the pollen parent strain at the same flowering time. If pollen storage technology can be developed,
Eliminating the need to cultivate pollen parents at the same place at the same time is expected to improve the efficiency of breeding and seeding work.

The technology for storing pollen is as follows: (1) A technology for fruit trees such as pears and peaches in which pollen is dried and stored at a low temperature, and after storage, water is reabsorbed under high humidity conditions before use (Akihama,
T et al., Biotechnology in Agriculture and Forest
(ry, Vol. 1, pp.101-112, 1986), (2) Pistachio technology for storing and using pollen at low temperature with controlled humidity (Po
lito et al., Euphytica 39: 265-269, 1988) and many other techniques have been reported, but the ones that mentioned the preservation technique for cruciferous plants were (3) "Method for preserving wasabi pollen" (special Kaihei 1-139510) is the only one found. This technique is simply stored under low temperature conditions (5 ° C. or lower) or in combination with a desiccant.

When the technique (3) is applied to the pollen storage of cruciferous plants such as Chinese cabbage and cabbage, stable results are always obtained depending on the humidity conditions of the environment in which the cruciferous plant from which pollen is collected grows. Absent. This is probably because this technology does not include a clear process for controlling the water content of pollen, and further does not specify the water content of pollen that is suitable for cold storage of cruciferous plants. This also applies to other existing pollen storage technologies, and stable pollen storage of crucifers could not be expected due to the application of existing pollen storage technologies.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a stable and simpler method for storing pollen for cruciferous plants.

[0006]

Means for Solving the Problems As a result of earnest research, the inventors of the present invention have achieved a stable and convenient storage of pollen by first reducing the water content of the pollen of the cruciferous plant and then storing the pollen frozen. The present invention has been completed, and it was found that the germination rate, the fruit setting ability and the fruit setting ability when the pollen after storage is used are kept high.

That is, according to the present invention, the storage of pollen of a cruciferous plant comprises the steps of adjusting the water content of pollen collected from the cruciferous plant to 22% or less, and then storing the pollen at a temperature of 0 ° C. or less. Provide a way. The water content of pollen at this time is calculated by the percentage of water weight / (water weight + pollen dry weight).

The present invention will be described in detail below.

In the first step of the storage method of the present invention,
The pollen of a cruciferous plant is adjusted to a water content of 22% or less.
The water content is not particularly limited as long as the pollen does not lose its germination ability, but if the water content becomes too low, the pollen tube germination rate tends to decrease (see Example 4), so the water content is 22. It is preferable to adjust it in the range of 13% to 13%.

The water content of pollen can be adjusted to 22% or less by leaving the pollen or anther under a condition of relative humidity of 66% or less, but not limited to this. The time for leaving it depends on the relative humidity and the amount of pollen, but it is usually preferably about 2 to 24 hours. In addition,
When the pollen is dried for 5 hours at a relative humidity of 66%, the water content becomes about 21.4%.

By leaving a saturated solution of various salts in the closed container, the humidity of the air in the closed container can be reduced to 66% or less. As the salt used here, any salt can be used as long as the relative humidity can be 66% or less, and examples thereof include lithium chloride, calcium chloride, potassium nitrate, sodium hydrogensulfate, sodium nitrate and the like. it can.

In the second step of the present invention, the pollen whose water content has been reduced in the first step is stored at a temperature of 0 ° C. or lower. For storage, it is preferable to put pollen in a closed container and store it in a freezer. The shorter the storage period, the higher the germination rate when using pollen after storage, but as shown in the examples below, the germination rate of about 60% is still maintained even after 10 months of storage. And at least 1
It can be said that practical use is not lost even if it is stored for 0 months.

The pollen stored by the storage method of the present invention can be directly used for pollination after storage without any treatment such as re-absorption treatment.

The storage method of the present invention can be applied to cruciferous plants, and examples thereof include Chinese cabbage, broccoli, cabbage, and oilseed rape.

Hereinafter, the present invention will be described in more detail based on examples. However, the present invention is not limited to the following examples.

The method of measuring the water content was as follows. 35 mg (wet weight) pollen was seeded. The pollen was allowed to stand in a sealed container whose relative humidity was adjusted under the condition of a temperature of 20 ° C., and the weight was measured every hour. When it was confirmed that the weight of the pollen was stable after several measurements, the value was taken as the wet weight of the pollen under the set relative humidity conditions. Next, the pollen was left in a dryer at 80 ° C., and the weight was measured every hour. Since the measured values were stable after 3 hours, the drying was stopped after 8 hours, and the dry weight of pollen was measured. The water content of pollen was calculated by subtracting the dry weight of pollen from the wet weight of pollen under each relative humidity condition, and the water content of pollen under each relative humidity condition was obtained by dividing that value by the wet weight of pollen. .

[0017]

Example 1 A container A containing a saturated aqueous solution of sodium hydrogensulfate and having a lid with a large number of holes was placed in a sealed container B. In this sealed container B, 200 Chinese cabbage (variety: Shingen) pollen grains were contained and sealed. After 16 hours, take out the pollen, seal it in a plastic container and store it in a freezer at -20 ° C.
Stored in. The water content of pollen after drying for 16 hours is 1
It was 7.7%. After 1 month, 2 months, 4 months, 6 months, 8 months and 10 months after storage in the freezer, pollen was taken out and germinated on a pollen tube germination medium. The composition of pollen tube germination medium is calcium nitrate tetrahydrate 30
0 mg / l, magnesium sulfate heptahydrate 200 mg / l, potassium nitrate 100 mg / l, boric acid 100 mg / l, sucrose 20% by weight (pH
8). The germination rate (%) of pollen after each storage period was measured. The results are shown in Table 1. From Table 1, it can be seen that the germination rate remains high at 90% or more even after storage for 8 months, and it is practical at about 60% even after storage for 10 months.

[0018]

[Table 1]

Example 2 Chinese cabbage (variety: Shingen) seeds that had been stored for 3 months or 6 months in the same manner as in Example 1 were pollinated by Chinese cabbage (variety: Tsubame), and the number of fruits set and the number of seeds per ovary were determined. It was measured.
The results are shown in Table 2. From Table 2, even when pollen stored for 3 months or 6 months was used, it was 19 on average from one capsule.
It can be seen that individual seeds were obtained.

[0020]

[Table 2]

Example 3 The germination rate (%) of the seed obtained by the method of Example 2 (seed obtained by pollinating stored pollen) was examined. As a control, the germination rate (%) of Chinese cabbage (variety Shingen) seeds (commercially available, storage period 0) was also examined. The results are shown in Table 3. As is clear from Table 3, the seeds obtained by pollinating the pollen stored by the method of the present invention showed a germination rate of 100%, like the seeds obtained using pollen not stored.

[0022]

[Table 3]

Example 4 Chinese cabbage (variety: Shingen) pollen was mixed under different humidity conditions.
The pollen tube germination rate of pollens after being stored in a 20 ° C. incubator for 16 hours and then stored at −20 ° C. for one week was measured by observing 200 pollens. The pollen tube germination medium used had the same composition as described above. The results are shown in Table 4. 81% or 9
No germination of pollen tubes was observed in the samples stored after being stored under 5% relative humidity conditions, whereas the pollens stored after maintaining under 66% relative humidity maintained high germination ability. Was confirmed.

[0024]

[Table 4]

[0025]

INDUSTRIAL APPLICABILITY By the method of the present invention, a stable and convenient method for storing pollen of a cruciferous plant is provided. The pollen stored by the method of the present invention maintains a high germination rate and fruit setting ability even after long-term storage. Moreover, the pollen stored by the method of the present invention can be directly pollinated without any special treatment. Therefore, the present invention is expected to greatly contribute to the efficiency of breeding and seeding work for cruciferous plants.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sumio Iwai 12-12-62 Higashi-Shinagawa, Shinagawa-ku, Tokyo Japan Tobacco Inc.

Claims (2)

[Claims] 1. A method for storing pollen of a cruciferous plant, comprising the steps of adjusting the water content of pollen collected from the cruciferous plant to 22% or less, and then storing the pollen at a temperature of 0 ° C. or less. 2. The method according to claim 1, wherein the step of adjusting the water content of the pollen to 22% or less is performed by allowing the pollen or anther to stand under the condition of a relative humidity of 66% or less.