JP2006230205A - Method for recovering fertility of male sterile lily - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means capable of using male sterile lily as pollen parent and inducing so-called functional male sterile in which anther wall is formed, but anther is indehiscent and inducing efficiency of rearing of male sterile lily and stepwise form formation in stamen of male sterile lily. <P>SOLUTION: The method for recovering fertility comprises culturing male sterile lily such as [Akita petit white which is a variety of lily] under high-temperature conditions. As a result, male sterile lily can be used as pollen parent and effective rearing of male sterile system can be performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for restoring fertility of a male sterile lily, a lily that has recovered fertility by this method, and a method for breeding a male sterile lily using this lily.

There are about 130 species of Lilium in the world, but East Asia is one of the centers of genetic resources. In Japan, there are nine native species and six wild species of six species distributed in continents such as China and Siberia. (Motoo Shimizu (1987) The Lilies of Japan; Species and Hybrids) In Japan, wild species themselves are highly appreciated, and they were collected from the wild and used for viewing. It was. In Europe and the United States, the history of lily breeding is relatively shallow compared to other flowering plants, and it has finally begun in earnest since the 1940s (Yoshito Asano (1982) Recent Progress in Breeding 23: 48-57). Lily horticultural species are classified by the Royal Horticultural Society into 8 hybrid groups based on cross parents (1964), and Asiatic Hybrid, one of them, is the largest hybrid group that contains many cultivated species. It is.

  Lily buds are relatively large compared to other flower buds, and many consumers dislike lily pollen because many pollen scatter when it tears apart, and stains are noticeable when attached to clothes. For this reason, Japanese florists have manually removed the buds from the blossoming lilies and placed them in the store. Shibata et al. Improved the varieties with the goal of producing lilies that do not scatter pollen, and the male sterile Asiantic hybrid lily “Akita Petit White,” which has very few spots on white flower rings and does not form wrinkles at the end of the yarn. (Non-patent Document 1).

2000 Research Results Selection Series, 5 pages (Ministry of Agriculture, Forestry and Fisheries, Agriculture, Forestry and Fisheries Technology Conference Secretariat)

  In male sterility lily breeding, male sterility lines can be efficiently bred by using male sterility lily as a breeding mother, but at present, in male sterility lily Since pollen is not formed, it is limited to use only for ovary parents and cannot be used for pollen parents, so the degree of breeding is limited.

  If male fertile lily can be restored to fertility and pollen formation is possible, then the male sterile lily can be used not only as an ovary parent but also as a pollen parent. The training efficiency is dramatically improved. The present invention has been made under such a technical background, and an object thereof is to provide means for recovering the fertility of a male sterile lily.

  As a result of intensive studies to solve the above problems, the present inventor has found that the fertility of the lily can be recovered by cultivating the male sterile lily under high temperature conditions.

  Regarding recovery of fertility in male sterile plants, it has been clarified that fertility may be recovered depending on environmental conditions such as temperature and day length in rice and corn. Especially in rice, the production of 1 hybrid seed is widely carried out in China by utilizing temperature-sensitive male sterility that recovers fertility with temperature. However, temperature-sensitive male sterility, such as rice and corn, maintains male sterility at high temperatures and recovers from fertility at low temperatures. Little is known about plants.

  The present invention has been completed based on the above findings.

  That is, the present invention provides the following (1) to (12).

(1) A method for recovering fertility of a male sterile lily, comprising cultivating the male sterile lily under high temperature conditions.

(2) The male sterility lily is a male sterility lily bred using the lily cultivar "Akita Petit White" or "Akita Petit White" as a breeding mother. How to recover a fertile lily

(3) The male sterility as described in (1) or (2), wherein cultivation under high temperature conditions is cultivation under an environment where the temperature is 29 ° C. or higher continuously or intermittently How to recover lily's fertility.

(4) The male sterile lily cocoon according to any one of (1) to (3), wherein the period of cultivation under high temperature conditions is from the stamen differentiation stage to the pistil differentiation stage Sexual recovery method.

(5) The method for recovering fertility of male sterile lily according to (4), wherein the period of cultivation under high temperature conditions is 5 days or longer.

(6) A lily that has recovered its fertility by the method according to any one of (1) to (5).

(7) A method for breeding male sterile lily, characterized in that mating is performed using the lily according to (6) as a pollen parent.

(8) A method for producing a functional male sterile lily characterized by cultivating a lily that does not form a cocoon under high temperature conditions.

(9) The functional lily according to (8), wherein the lily that does not form a cocoon is a lily that does not form a cocoon bred using the lily cultivar "Akita Petit White" or "Akita Petit White" as a breeding mother How to make a male sterile lily.

(10) The method for producing a functional male sterile lily according to (8) or (9), wherein the period of cultivation under high temperature conditions is from the stamen differentiation stage to the stamen differentiation stage .

(11) The method for producing a functional male sterile lily according to (10), wherein the period of cultivation under high temperature conditions is 5 days or longer.

(12) A functional male sterile lily produced by the method according to any one of (8) to (11).

  The present invention makes it possible to recover the fertility of a male sterile lily. As a result, the male sterile lily can be used as a pollen parent, and an efficient male sterile line can be bred.

  Hereinafter, the present invention will be described in detail.

  The male sterile lily recovery method of the present invention is characterized by cultivating male sterile lilies under high temperature conditions.

  The lily targeted by this fertility recovery method is not particularly limited as long as it exhibits male sterility. For example, the lily varieties “Akita Petit White (Category Registration Number: No. 11418)” and “Akita Petit White” Can be targeted for male-sterile lilies, etc. In addition, male sterile lily varieties other than “Akita Petit White” may be targeted, and examples of such lily varieties include “Akita Petit Cream”, “Akita Petit Lemon”, and “Akita Petit Gold”.

  “Cultivation under high temperature conditions” refers to cultivating continuously or intermittently under high temperature conditions that lily does not encounter in general cultivation methods. The specific temperature is not particularly limited as long as the recovery of inertia is observed, but is usually 29 ° C or higher, and preferably 31 ° C or higher. Cultivation under high temperature conditions may be carried out by artificial treatment (eg, heat retention, warming, etc.) that causes the temperature to rise, and the bulb planting time should be adjusted so that the lily encounters high temperatures. You may go by.

  The period of cultivation under high temperature conditions is not particularly limited as long as recovery of fertility is observed, but is preferably from the stamen differentiation stage to the pistil differentiation stage. Cultivation under high-temperature conditions may be performed over the entire period of the lily growth process, or may be performed only from the stamen differentiation stage to the pistil differentiation stage. Furthermore, it is also possible to carry out only for a specific period from the stamen differentiation stage to the stamen differentiation stage. In this case, the cultivation period under high temperature conditions is preferably 5 days or longer.

  The lily that has recovered fertility by the above method is used as a pollen parent for breeding male sterile lines because the individual itself forms pollen while retaining the trait of male sterility. be able to.

  It is also possible to produce lily with a high commercial value by applying the above-described recovery method. The male sterile lily cultivar “Akita Petit White” does not form cocoons, but cultivates under the high temperature conditions described above to form cocoons and restores fertility. When cultivated at a temperature slightly lower than the temperature at which this fertility is restored, a wrinkle is formed, but the wrinkle is not dehiscenced. A lily showing 稔 appears.

  “Akita Petit White” has no cocoon in the stamen as a characteristic of the variety, and in the common lily on the market, the cocoon is removed manually to prevent the pollen from being polluted. However, these lily vases may have a problem of lack of three-dimensionality and presence due to the absence of wrinkles, and there is a concern that the relative competitiveness of the market with other flowers other than lilies may be reduced. Has been. The above-described functional male sterile lily eliminates the appearance problem of the “Akita Petit White” vase and adds an excellent property that pollen does not scatter.

[Example 1]
The flower buds were observed with a stereomicroscope in order to clarify the onset of flower bud differentiation and the process of flower bud development.

  On November 3, 2002, the bulbs that had been dug up from the open field field and selected to have a circumference of 14 to 16 cm were planted one by one in a 5 inch unglazed pot and directly buried in the open field field. After allowing them to overwinter in their natural state, they were dug up every 5 to 10 days from March to observe the development of flower bud differentiation.

  On March 3 when the observation started, there was still snow, but I dug up and observed the growth points. The snow cover was until April 10, but budding had already started on March 30. However, no flower bud differentiation was observed at the time of emergence. Thereafter, flower bud differentiation began between April 15th and 25th when the budding length became about 6 cm. Flower bud differentiation started, and about 1 month later, the vase was completed, and on May 20th, we saw the buds with the naked eye (Table 1). The flowering start date was June 23.

  From these observations, the flower bud differentiation type of “Akita Petit White” is in the Okawa classification (Ohkawa, K (1989) J.Japan.Soc.Hort. Sci 57 (4): 655-661) after germination in spring. It was type 2a that soon started flower bud differentiation.

[Example 2]
“Akita Petit White” was cultivated under different temperature conditions and its growth state and fertility were compared. The bulbs were planted in an open field in November 2001 and flowered in July 2002 to promote hypertrophy. A bulb dug out on November 3, 2002 was placed in a corrugated cardboard box (30cm x 22cm x 22cm) with a small hole for ventilation on the side and filled with moist vermiculite. did. It was pre-cooled from 1/13 to 12/25 at 1 ° C. in the dark for 6 weeks and then stored frozen from 12/26 to −2 ° C. The bulbs were aligned with 12-14cm bulbs.

Frozen stored bulbs were thawed for 5 days in a cardboard box in a dark refrigerator at 12 ° C from February 26, 2002. Bulbs sprouting 1-1.5cm into plug mix (Scotts-Sierra Horticultural Products Company): A mixture of 1: 1 red clay soil was planted one floor at a time, and immediately placed in a growth cabinet. Gross cabinets are high temperature zone (day temperature: 32 ° C / night temperature: 25 ° C), medium temperature zone (day temperature: 25 ° C / night temperature: 18 ° C), and low temperature zone (day temperature: 18 ° C / night temperature: 11 ° C). ), And continuously observed until it bloomed. In each group, the conditions were 14 hours long with a fluorescent lamp, the light intensity was 256 μmol / m ² / s on the upper surface of the uppermost leaf, and the relative humidity was adjusted to 70%.

  The number of days until flowering was shortest in the high temperature zone, the middle temperature zone was about 3 days longer than the high temperature zone, and the low temperature zone was about 3 weeks longer than the high temperature zone. The plant height at the time of flowering was about the same in the low temperature zone and the middle temperature zone, and the high temperature zone was lower than the other two zones. However, in the high temperature area, the plants grew smoothly until the start of brewing, but after brewing, blasting occurred in 3 out of 8 strains and did not flower. The number of flowers and the number of leaves were almost the same in the low temperature group and the middle temperature group, but in the high temperature group, the number of flowers per strain was about 6 fewer than the middle temperature group and the low temperature group, and the number of leaves was about nine more. . In the low temperature area, the number of petal spots was very small, but as the treatment temperature increased, the number of spots increased (Table 2).

  Only in the high temperature zone, wrinkles were formed on all the florets that reached flowering (Table 2). The formed cocoon was dehisced and pollen was exposed (FIG. 1). The florets that blossomed in the middle temperature zone were colored yellow with the end of the flower yarn curved, but no pollen formation was observed (FIG. 2). In the low temperature section, the tip of the flower thread was pointed and no wrinkle formation was observed (FIG. 3).

  From this, it was clarified that “Akita Petit White” forms cocoons in the high temperature zone and also forms pollen.

Example 3
A germination test and pollen fertility survey were conducted using pollen in the cocoon in which "Akita Petit White" was processed in the high temperature zone. The pollen germination medium was Brewbaker and Kwack's medium (100 mg / l Boric acid 300 mg / l Ca (NO ₃ ) ₂ 4H ₂ O 200 mg / l MgSO ₄ 7H ₂ O 100 mg / l KNO ₃ ) with 20% sucrose and 0.8%. % Agar medium was added and cultured in a thermostat at 23 ° C. for 24 hours, followed by microscopic observation to calculate the germination rate. In the pollen fertility investigation, the formed pollen was dyed with lactophenol cotton blue liquid, and the colored pollen was counted as fertile pollen. Moreover, the nucleus was observed by fluorescence staining under a fluorescence microscope. Furthermore, the pollen immediately after flowering was carbon-deposited and the external morphology was observed with a scanning electron microscope (SEM).

  The germination rate after 24 hours on the medium was 58.6%, but germination tube elongation was also observed after germination. In pollen fertility survey by lactophenol cotton blue staining, it was about 10% lower than the staining rate of ovary parent cultivar “Apollo” (Table 3). In the fluorescence microscope observation, sperm nuclei and vegetative nuclei were observed in the pollen grains (FIG. 4). In addition, the scanning electron microscope (SEM) confirmed that these pollen had the general characteristics of lily pollen such as an oval shape, one germination groove, and a net-like surface structure. (FIG. 5). It was also confirmed that when the pollen formed with “Akita Petit White” was crossed with commercial varieties, berries were formed and fertilization ability (FIG. 6). From these facts, it was confirmed that the pollen formed in the anther recovered by the high temperature recovered the fertility.

Example 4
Three varieties of “Akita Petit Cream”, “Akita Petit Lemon” and “Akita Petit Gold” were cultivated in the same manner as in Example 2 and the progress of growth was observed (Table 4).

  "Akita Petit Cream" was observed to form pollen in the middle temperature and high temperature districts, and "Akita Petit Lemon" was observed to form pollen in the high temperature district. In this experiment, “Akita Petit Gold” did not form pollen in any temperature range.

Example 5
Based on the fact that Akita Petit White cocoons were formed in the high temperature area, the following experiment was conducted to identify the time when the plants were sensitive to high temperature.

Refrigerated and frozen stored “Akita Petit White” bulbs with a circumference of 12-14 cm from November 2003, thawed, planted in a 5-inch plastic pot, and cultivated in an artificial meteorograph. Three types of experimental zones shown in Table 5 below were set as the temperature conditions in the artificial weather device. The environmental conditions other than the temperature conditions were 14 hours long, the light source was a fluorescent lamp, and the light intensity was 256 μmol / m ² / s.

  No wrinkles were formed in the areas where high temperature treatment was performed for 1 week from the time of emergence, and wrinkles recovered in the strains treated with the same treatment for 1 week after emergence. In the group treated with high temperature for one week after one week after brewing, wrinkles formed at 33.3% (Table 6). In addition, among the strains in which cocoons have recovered, inflorescences in which all buds have not recovered buds, flowers that have recovered buds, flowers that do not form buds, and flowers that are colored and curved with yellow at the end of the yarn are mixed. Was also observed (FIG. 7). The frequency of cocoon recovery was also observed in which one to five buds recovered from one to six stamens. In these vases, a regularity was first observed in which wrinkles were formed in the outer flower coat and further wrinkles were formed in the inner flower coat (FIG. 8).

Example 6
The following experiment was conducted to investigate the effect of day length on the induction of wrinkle formation by high-temperature treatment.

Refrigerated and frozen stored “Akita Petit White” bulbs with a circumference of 12-14 cm from November 2003, thawed, planted in a 5-inch plastic pot, and cultivated in an artificial meteorograph. Three types of experimental zones were set for 1) 12 hours, 2) 10 hours, and 3) 8 hours. The environmental conditions other than day length were 32/25 ° C (day temperature / night temperature), the light source was a fluorescent lamp, and the light intensity was 256 µmol / m ² / s.

  As a result of the experiment, since the formation of wrinkles was observed under any day length condition, the day length seemed to have no direct influence on the wrinkle formation (Table 7).

Example 7
In order to investigate the effects of high temperatures during cultivation on the formation of cocoons, the thawed bulbs were planted in plastic pots, and all the meteorological instruments were set to 6 stages at 1 ° C from 27 ° C to 32 ° C. Growing period cultivation was conducted to investigate the flowering situation.

Environmental conditions other than temperature were set to 14 hours in day length, a fluorescent lamp with a light intensity of 256 μmol / m ² / s, and a relative humidity of 70%.

  The formation of wrinkles was observed with several stages that were morphologically distinguishable with increasing temperature (Table 8). That is, the lily flower has 6 stamens, but at 27 ° C, wings may be formed, but all 6 stamens will not have wings, only 1 to 4 stamens. Recovered. At that time, there were many examples in which pollen was formed only on one of the left and right sac (FIGS. 9 and 10). At 28 ° C, the buds recovered in all flowers, but of the six stamen buds, about 20% of the buds developed on both the left and right sac and formed pollen. At 29 ° C, the stamens of the left and right sac developed on the 6 stamens of all flowers, and pollen was formed, but these buds were not dehisced at all. At 30 ° C., about 30% of the buds, and at 31 ° C. or higher, all the buds were split and pollen was exposed.

A photo of "Akita Petit White" cultivated in a high temperature district. A photo of "Akita Petit White" cultivated in Chuon Ward. Photo of “Akita Petit White” cultivated in low temperature district. Fluorescence micrograph of pollen from Akita Petit White. Scanning electron micrograph of "Akita Petit White" pollen. A photograph showing the fruit of a lily obtained using "Akita Petit White" pollen formed by high-temperature treatment. A photo of “Akita Petit White” with cocoons formed by high-temperature treatment. The first flower (a in the figure) has cocoons, but the second flower (b in the figure) has no cocoons. A photo of “Akita Petit White” with cocoons formed by high-temperature treatment. The numbers in the figure indicate the number of stamens that formed the folds. Front (left) and back (right) photos of Akita Petit White grown at 28 ° C. Only one sac is developed. The photograph (left figure) which shows the cross section of the cocoon shown in FIG. 9, The photograph (right figure) which shows the cross section of the cocoon which did not form pollen.

Claims (12)

  A method for recovering fertility of male sterile lily, comprising cultivating male sterile lily under high temperature conditions.   The male sterile lily according to claim 1, wherein the male sterile lily is a male sterile lily bred using the lily variety "Akita Petit White" or "Akita Petit White" as a breeding mother. How to recover from fertility.   The fertility recovery of male sterile lily according to claim 1, wherein the cultivation under high temperature conditions is cultivation under an environment where the temperature is 29 ° C. or higher continuously or intermittently. Method.   The method for recovering the fertility of male sterile lily according to any one of claims 1 to 3, wherein the period of cultivation under high temperature conditions is from the stamen differentiation stage to the pistil differentiation stage. .   The method for recovering fertility of male sterile lily according to claim 4, wherein the period of cultivation under high temperature conditions is 5 days or longer.   The lily which recovered the fertility by the method of any one of Claims 1 thru | or 5.   A breeding method for male sterile lily, comprising mating with the lily according to claim 6 as a pollen parent.   A method for producing a functional male sterile lily characterized by cultivating a lily that does not form cocoons under high temperature conditions.   The functional male sterility according to claim 8, wherein the lily that does not form cocoons is a lily that does not form cocoons bred using the lily variety "Akita Petit White" or "Akita Petit White" as a breeding mother. How to make a sexual lily.   The method for producing a functional male sterile lily according to claim 8 or 9, wherein the period of cultivation under high temperature conditions is from the stamen differentiation stage to the pistil differentiation stage.   The method for producing a functional male sterile lily according to claim 10, wherein the period of cultivation under high temperature conditions is 5 days or more.   A functional male sterile lily produced by the method of any one of claims 8-11.