Temasculation hybridization method of amphoteric asparagus

Abstract

The invention belongs to the technical field of crossbreeding, and particularly relates to a castration hybridization method of amphoteric asparagus. The method comprises the following steps: selecting an amphoteric asparagus in a bud pre-mature period as an asparagus maternal plant; petals and stamen groups of flower buds on the maternal plants are pinched off on the pollination day, and bare stigmas are left; picking mature and pollinated male flowers as male parent flowers on the pollination day; adhering the collected male parent pollen to the castrated female parent flower stigma after 4 p.m. at the temperature of 25-35 DEG C in clear weather from April to June every year, bagging and isolating to obtain homozygous seeds. The efficient method is provided for hybridization of the amphoteric asparagus for the first time, variety mixing in the asparagus hybrid seed production process is eradicated, the purity of the seeds is guaranteed, and the consistency of seeds for later production and the correctness of experimental research are guaranteed. In addition, the method can obtain the amphoteric asparagus with stable hereditary characteristics, and has guiding significance for the hybridization technology of the amphoteric asparagus.

Description

Technical Field

[0001] The invention belongs to the technical field of hybrid breeding, and particularly relates to a method for emasculating and hybridizing hermaphroditic asparagus. Background Art

[0002] Asparagus is a dioecious plant. During the development process, the pistils of female plants develop normally, and the stamens are highly degenerate. In male plants, the stamens of male flowers are healthy, and the pistils are generally not completely degenerate. However, in some cases, the pistil style and stigma of male plants develop normally, and the ovary is not completely degenerate, resulting in the phenomenon of hermaphroditic plants. Under natural conditions, the probability of hermaphroditic asparagus is only 0-2%, and the fruiting rate and germination rate of natural hermaphroditic plants are very low, making it difficult to obtain stable hermaphroditic asparagus.

[0003] Asparagus is dioecious, outcrossed for a long time, highly heterozygous genotype, flowering period is not met, breeding cycle is long, breeding work is difficult, usually can not be self-fertilized and inbred hybrids can not be used. Therefore, bisexual plants are of great significance to asparagus breeding. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art and provide a method for emasculating and hybridizing hermaphroditic asparagus, which specifically adopts the following technical scheme: A method for emasculating and hybridizing bisexual asparagus plants comprises the following steps: Select parents: Select hermaphroditic asparagus plants in the pre-mature stage of flower buds as female asparagus plants; select male asparagus plants with mature flowers and normal pollen shedding as male asparagus plants; Pollen collection: On sunny and warm days, pick mature male flowers that shed pollen normally as male parent flowers and collect them on the same day for later use; Female plant emasculation: On the day of pollination, cut off the petals and stamens of the flower buds on the female plant, leaving the naked stigma, and mark the pedicel with a marker; Pollination and bagging: Choose April to June every year, the temperature is 25 ℃-35 ℃, and the weather is clear after 4 pm. The collected male pollen is attached to the stigma of the female plant after emasculation. After successful pollination, the stigma will be light yellow. Then the pollinated hermaphroditic asparagus plants are bagged for isolation, and the hybrid breeding information is marked with a label. Secondary marking of hybrid fruits: One week after hybridization, use a waterproof marker pen to mark the swollen ovary for the second time; Fruit harvesting and storage: After the fruits are ripe, they are picked, peeled, cleaned and placed in the sun to dry according to the labels, and then packaged and registered for storage.

[0005] If the hybridization is successful during the above-mentioned secondary marking process, the ovary will swell, otherwise the ovary will shrivel and fall off. A waterproof marker pen is used to mark the swollen ovary for a second time for subsequent identification, observation and harvesting.

[0006] Asparagus is a perennial herb that can produce shoots all year round when the temperature is right. April to June of each year is the best flowering period for asparagus hybridization. During this flowering period, the best time is to choose a sunny afternoon (after 4 pm) with a temperature of 25-35℃. Asparagus flowers are small and are more damaged after emasculation, bad weather can easily lead to excessive damage to the stigma after emasculation, making it difficult to recover and causing hybridization failure.

[0007] As a further preferred embodiment, the time for pollen collection is from 10 am to 5 pm on the day of pollination; if the collection time is too early or too late, it will affect the pollen shedding and activity of the male flowers, resulting in hybridization failure.

[0008] As a further preferred embodiment, the male flowers that have been picked and are already mature and have lost their pollen are placed in a cool and dry storage box as male parent flowers at a temperature of about 30° C. In this process, the male flowers that have been picked and are already mature and have lost their pollen must be picked on the day of pollination.

[0009] As a further preferred embodiment, when emasculating the female plant, tight elbow tweezers are used to clip off the petals and stamens of the flower buds on the female plant. Because asparagus flowers are small, and their petals, stamens and pistils are tightly clustered together, emasculation methods such as tearing can easily cause damage to the asparagus ovary, or even cause it to fall off the pedicel.

[0010] As a further preferred embodiment, pollination is selected from April to June each year, and the pollination temperature is selected from 25°C to 35°C; May is the most suitable month, because asparagus is dioecious, and there is often a problem of inconsistent flowering periods. Generally, May is the peak season for male and female asparagus to bloom. Early hybridization will make it difficult to screen male and female flowers suitable for hybridization due to the uneven early spring climate and plant flower states. Delaying hybridization will affect the hybridization efficiency due to abnormal temperatures and other reasons, and hinder the harvesting of asparagus mother stems in summer and the growth of asparagus in the second half of the year. The most suitable pollination temperature is about 30°C, because too low a temperature will lead to low flowering efficiency, and too high a temperature will easily make it difficult for the flowers after emasculation to recover, resulting in hybridization failure.

[0011] As a further preferred embodiment, the pollination period of the female plant is from the first flower bud to the pre-maturity period of the last flower bud.

[0012] As a further preferred embodiment, the bagging isolation uses a 40-mesh nylon gauze.

[0013] As a further preferred embodiment, the hybrid breeding information includes the hybridization time, the names of the male and female plants, and the fruit setting mark one week after pollination.

[0014] As a further preferred embodiment, fruit picking and processing includes the following steps: After the fruits are ripe, they are picked, peeled, washed and placed in the sun for drying, packaged and registered, and stored in a seed cabinet. The drying temperature is above 35°C and the drying time is 2-3 days.

[0015] The beneficial effects of the present invention are: The present invention provides an efficient method for hybridization of hermaphroditic asparagus for the first time. The double marking can prevent the mixing of varieties in the process of hybridization seed production of asparagus, ensure the purity of seeds, ensure the consistency of seeds used in later production and the correctness of experimental research. In addition, the method of the present invention makes it possible for hermaphroditic asparagus to obtain excellent traits, and has guiding significance for the hybridization technology of pure hermaphroditic asparagus. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Shown are bisexual flowers used for hybridization of bisexual asparagus; the pre-mature buds in red circles 1-3 in Figure A are in a state of bisexual flowers suitable for hybridization, the young buds in red circles 4-5 in Figure A are in a state of flowers not suitable for hybridization, and the mature flowers in red circle 6 in Figure A are in a state of flowers not suitable for hybridization; Figure B shows flowers blooming on a branch in the blooming period, and the flowers from left to right are mature flowers, pre-mature buds, and young buds, among which the pre-mature buds in the red box are suitable for hybridization.

[0017] Figure 2 Shown are the pollen shedding states of male flowers under different environments; the left picture shows a mature male flower that opened but did not shed pollen under rainy conditions at 20°C; the right picture shows a mature male flower that shed pollen normally under sunny conditions at 30°C, which can be used as the male parent to provide pollen for hybridization of hermaphroditic asparagus plants.

[0018] Figure 3 Shown are female flowers after emasculation and cross-pollination.

[0019] Figure 4 Shown are the fruits of hermaphroditic plants resulting from a failed hybridization.

[0020] Figure 5 The fruits of hermaphroditic plants that were successfully hybridized are shown; the fruits within the red line in Figure A are fruits with marked fruit stalks 5 days after hybridization, and the fruits within the red line in Figure B are fruits that were marked twice 10 days after hybridization.

[0021] Figure 6 Shown are seeds of mature hybrid hermaphroditic asparagus. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of this application can be combined with each other without conflict.

[0023] Example 1 A method for emasculating and hybridizing hermaphroditic asparagus, which specifically comprises the following steps: (1) Parent selection Choose May of each year and select the buds that are in the pre-maturity stage (such as Figure 1 The hermaphroditic asparagus plants (shown in the red box in B) were selected as the female asparagus plants; the male asparagus plants with mature flowers and normal pollen shedding were selected as the male asparagus plants (shown in the red box in B). Figure 2 as shown in the middle right picture); (2) Pollen collection According to the seed production plan, pick mature and pollinated male flowers at 11 a.m. on the morning of pollination (the temperature is about 30°C when collecting pollen), place them in a cool and dry storage box and mark them for later use; (3) Female plant emasculation At around 6 pm (the temperature during hybridization is about 28°C), first use tight elbow tweezers to clip off the petals and stamens of the target flower buds of the female plant of the hermaphroditic asparagus selected in step (1), leaving the stigma naked, and mark the pedicel with a marker pen; (4) Hybrid pollination At 4:00 p.m. on a sunny day with a temperature of 30°C, the collected pollen from the male parent is attached to the stigma of the female parent flower that has been emasculated in step (3). After successful pollination, the stigma will be light yellow (e.g. Figure 3 shown); (5) Hybridization markers Use a tag to record the names of the parents and hang it on the branches of the selected mother plant for seed production as a mark; mark the pedicel of the hybrid flower with a marker pen, and after fruit setting (about 10 days after pollination), use ink or a marker pen to mark the fruit again (secondary mark the swollen ovary) to facilitate subsequent seed harvesting; (6) Flower isolation To prevent cross-pollination due to insects or wind, cover the hermaphroditic plants marked with tags with 40-mesh nylon gauze; (7) Fruit picking and processing The fruits marked in step (5) are picked and peeled after they are ripe, washed and placed in the sun for drying, and then packaged and registered and stored in a seed cabinet.

[0024] Figure 5 Shown are the fruits of successfully hybridized hermaphroditic plants. The fruits within the red line in Figure A are the fruits with marked fruit stalks 5 days after hybridization, and the fruits within the red line in Figure B are the fruits that were marked twice 10 days after hybridization.

[0025] Comparative Example 1 A method for emasculating and hybridizing failed hermaphroditic asparagus plants, which specifically comprises the following steps: (1) Parent selection In May of each year, hermaphroditic asparagus plants with flower buds in the pre-maturity stage are selected as female asparagus plants; hermaphroditic asparagus plants with mature male flowers and loose pollen are selected as male asparagus plants; (2) Pollen collection According to the seed production plan, pick mature and pollinated male flowers at 11 a.m. on the morning of pollination (the temperature is about 38°C when collecting pollen), place them in a cool and dry storage box and mark them for later use; (3) Female plant emasculation At about 2 p.m. (the temperature during hybridization is about 42°C), first use tight elbow tweezers to clip off the petals and stamens of the target flower buds of the female plant of the hermaphroditic asparagus selected in step (1), leaving the naked stigma; (4) Hybrid pollination After the female plant is emasculated, the pollen collected from the male plant is attached to the stigma of the emasculated female plant. After successful pollination, the stigma will turn light yellow. (5) Hybridization failure The day after hybridization, the stigma began to turn yellow and wilt. One week after hybridization, the ovary turned black and fell off (such as Figure 4 as shown).

[0026] Although the description of the present invention has been quite detailed and specifically describes several described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be regarded as providing a broad possible interpretation of these claims in view of the prior art by reference to the appended claims, thereby effectively covering the intended scope of the present invention. In addition, the above description of the present invention is based on the embodiments foreseeable by the inventor, and its purpose is to provide a useful description, and those non-substantial changes to the present invention that have not yet been foreseen may still represent equivalent changes to the present invention.

Claims

1. A method for emasculating and hybridizing hermaphroditic asparagus, characterized in that: The following steps are involved: Select parents: Select hermaphroditic asparagus plants in the pre-mature stage of flower buds as female asparagus plants; select male asparagus plants with mature flowers and normal pollen shedding as male asparagus plants; Pollen collection: On sunny and warm days, pick mature male flowers that shed pollen normally as male parent flowers and collect them on the same day for later use; Female plant emasculation: On the day of pollination, cut off the petals and stamens of the flower buds on the female plant, leaving the naked stigma, and mark the pedicel with a marker; Pollination and bagging: Choose April to June every year, the temperature is 25 ℃-35 ℃, and the weather is clear after 4 pm. The collected male pollen is attached to the stigma of the female plant after emasculation. After successful pollination, the stigma will be light yellow. Then the pollinated hermaphroditic asparagus plants are bagged for isolation, and the hybrid breeding information is marked with a label. Secondary marking of hybrid fruits: One week after hybridization, use a waterproof marker pen to mark the swollen ovary for the second time; Fruit harvesting and storage: After the fruits are ripe, they are picked, peeled, cleaned and placed in the sun to dry according to the labels, and then packaged and registered for storage.

2. The preparation method according to claim 1, characterized in that: Pollen collection time is from 10 am to 5 pm on the day of pollination.

3. The preparation method according to claim 1, characterized in that: Pick mature and pollen-scattered male flowers as male parent flowers and place them in a cool, dry storage box at a temperature of 25°C-35°C for standby use.

4. The preparation method according to claim 1, characterized in that: When emasculating the mother plant, use tight curved tweezers to pinch off the petals and stamens of the flower buds on the mother plant.

5. The preparation method according to claim 1, characterized in that: Pollination is selected from April to June every year, and the temperature is selected between 25℃-35℃.

6. The preparation method according to claim 1, characterized in that: The pollination period of the female plant is from the first flower bud to the pre-maturity period of the last flower bud.

7. The preparation method according to claim 1, characterized in that: The bagging isolation uses 40 mesh nylon gauze.

8. The preparation method according to claim 1, characterized in that: Hybrid breeding information includes hybridization time, names of male and female plants, and fruit setting mark one week after pollination.

9. The preparation method according to claim 1, characterized in that: Fruit picking and processing includes the following steps: After the fruits are ripe, they are picked, peeled, washed and placed in the sun to dry. After impurities are removed, they are packaged, registered and stored in a seed cabinet.

10. The preparation method according to claim 1, characterized in that: Spread the seeds flat in the sun in a dry environment. The drying temperature should be greater than 35°C and the drying time should be 2-3 days.

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