A method for increasing the utilization of corn hybrid pollination pollen

Abstract

The application provides a method for improving utilization rate of corn hybrid pollination pollen, relates to the technical field of hybrid breeding, and comprises (1) treatment of parents, (2) collection of pollen, (3) treatment of pollen and (4) pollination. The utilization rate of the pollen is improved while the activity of the pollen is ensured through the above steps, the method is beneficial to improving economic benefits of corn planting, reducing planting cost, and is worth promoting.

Description

[Technical Field]

[0001] This invention relates to the field of hybridization breeding technology, specifically to a method for improving the utilization rate of pollen in maize hybrid pollination. [Background Technology]

[0002] Corn is an important grain widely cultivated in tropical and temperate regions worldwide. Currently, my country's corn planting area is around 300 million mu (approximately 20 million hectares), ranking third among grain crops after rice and wheat. Corn is extremely high in vitamins, containing 5-10 times more than rice and wheat. Among all staple foods, corn has the highest nutritional value and health benefits. The riboflavin and other nutrients in corn are highly beneficial to the human body, making it a popular food.

[0003] Corn is a cross-pollinated plant. Pollen from male flowers is carried by the wind to the silks of female ears for fertilization and seed production, thus completing the generational cycle. Artificial emasculation for hybrid seed production is the main way to utilize the heterosis of corn. In hybrid seed production, a common practice is to alternate planting of several rows of female parents with one row of male parents, ensuring no other corn is planted within a 500-meter radius. The female parents are emasculated during flowering, allowing for natural pollination. However, this natural pollination method is affected by various factors, such as temperature, humidity, and pests and diseases, all of which affect the success rate. High temperatures can easily lead to pollen grain abortion, high humidity causes pollen grains to absorb water and swell, resulting in death, and drought slows down the silking of the female ears, with silking only beginning after the male ears have shed pollen, leading to low pollen utilization. Therefore, natural pollination, due to many uncertainties, suffers from problems such as high pollen consumption, low effective pollen utilization, and high seed production costs.

[0004] To address the aforementioned problems, this invention proposes a method for improving the utilization rate of pollen in maize hybrid pollination. [Summary of the Invention]

[0005] In view of this, the purpose of the present invention is to provide a method for improving the utilization rate of pollen in maize hybrid pollination, thereby improving the utilization rate of pollen while ensuring its activity.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A method for improving pollen utilization in maize hybrid pollination includes the following steps:

[0008] (1) Treatment of parents: Demasculate the female parent and put a paper bag on the female ear of the female parent; put a bag on the male ear of the male parent one day before pollen is released, and cut off the male ear 2-4 days after bagging.

[0009] (2) Pollen collection: The collected male spikes are sterilized, then dried in a sterile room under light, and then the male spikes are shaken to scatter the pollen and collected for later use.

[0010] (3) Pollen treatment: The collected pollen is frozen and stored at low temperature. Before pollination, the pollen is thawed and then mixed with corn flour, boric acid, magnesium carbonate, salicylic acid and water in a mass ratio of 4-5:1-2:0.5:0.2-0.3:0.2-0.3:10-20 to prepare a pollination solution for later use.

[0011] (4) Pollination: Put the pollination liquid into a sprayer and spray it onto the silks of the maize parent to complete the pollination.

[0012] In this invention, the time for the emasculation treatment of the maize female parent in step (1) is 13:00 noon.

[0013] In this invention, further, step (1) of bagging the male ear specifically involves putting a transparent plastic bag over it.

[0014] In this invention, the temperature of the sterile room in step (2) is 25-27°C and the light intensity is 125-145W.

[0015] In this invention, step (3) pollen cryopreservation involves placing the pollen in a cryopreservation tube and then storing it in an environment below 3°C.

[0016] In this invention, further, step (3) pollen thawing involves taking out the pollen and thawing it at 10-15℃ for 10-15 minutes, followed by thawing it at 25-26℃ for 20-30 minutes to complete pollen thawing.

[0017] In this invention, further, in step (4), the silks of the maize parent plant are wrapped in a bag after pollination.

[0018] In this invention, the sterilization process further involves spraying with medical alcohol followed by irradiation under an ultraviolet lamp for 10 minutes.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0020] 1. This application first demastizes the maize female parent to avoid co-pollination. Furthermore, before the male parent's tassels release pollen, they are covered with transparent plastic bags to prevent the male flowers from attracting insects and other harmful microorganisms during pollen collection, which could affect pollen bioactivity. Therefore, the applicant covers the tassels with transparent plastic bags beforehand. Two days after bagging, the entire tassel is removed, sterilized, and dried to prevent contamination and moisture from affecting pollen viability. Drying under sunlight allows the tassels to continue photosynthesis during their peak flowering period. The pollen is then collected and stored at low temperatures. When needed, the pollen is revived. Experiments have shown that this method ensures a high pollination success rate.

[0021] 2. In this application, the specific method of pollen resuscitation is to first thaw at 10-15℃ for 10-15 minutes, and then thaw at 25-26℃ for 20-30 minutes, using a gradient temperature increase method for resuscitation. The applicant unexpectedly discovered that pollen resuscitated using this method has a higher pollination success rate than pollen that has not been cryopreserved. This may be because the phased temperature increase method of this application can effectively activate the activity of pollen that has gone through a dormant period.

[0022] 3. Furthermore, to further improve pollen utilization, this application prepares a pollination solution by mixing pollen with corn flour, boric acid, magnesium carbonate, salicylic acid, and water before pollination. Firstly, this reduces the amount of pollen used and increases its utilization rate. Secondly, research shows that using the compounded components of this application to prepare the pollination solution does not affect the pollination success rate, and it was unexpectedly discovered that the pollination solution prepared in this application can reduce the rate of barren corn tips. In summary, the method described in this application is beneficial for improving the economic benefits of corn planting and reducing planting costs, and is worthy of promotion.

Detailed Implementation Methods

[0023] The following embodiments can help those skilled in the art to more fully understand the present invention, but should not be construed as limiting the present invention in any way.

[0024] Example 1

[0025] This embodiment provides a method for improving the utilization rate of pollen in maize hybrid pollination, specifically including the following steps:

[0026] (1) Treatment of parents: At 13:00 noon, the female parent is demasked and a paper bag is placed on the female ear of the female parent; one day before the male ear of the male parent is pollinated, a transparent plastic bag is placed on the male ear. Two days after the bag is placed, the male ear is cut off.

[0027] (2) Pollen collection: The collected male spikes were sprayed with medical alcohol and then irradiated under ultraviolet light for 10 minutes. Then, they were dried in a sterile room at a temperature of 25°C and a light intensity of 125W. The male spikes were then shaken to scatter the pollen and collected for later use.

[0028] (3) Pollen treatment: The collected pollen was placed in cryovials and stored in an environment below 3°C. Before pollination, the pollen was thawed, specifically by taking out the pollen and thawing it at 10°C for 10 minutes, followed by thawing it at 25°C for 20 minutes. After thawing, the pollen was mixed with corn flour, boric acid, magnesium carbonate, salicylic acid and water in a mass ratio of 4:1:0.5:0.2:0.2:10 to prepare a pollination solution for later use.

[0029] (4) Pollination: Put the pollination liquid into a sprayer and spray it onto the silks of the maternal corn plant. After pollination, wrap the silks of the maternal corn plant with a bag to complete the pollination.

[0030] Example 2

[0031] This embodiment provides a method for improving the utilization rate of pollen in maize hybrid pollination, specifically including the following steps:

[0032] (1) Treatment of parents: At 13:00 noon, the female parent is demasked and a paper bag is placed on the female ear of the female parent; one day before the male ear of the male parent is pollinated, a transparent plastic bag is placed on the male ear. After 3 days of bagging, the male ear is cut off.

[0033] (2) Pollen collection: The collected male spikes were sprayed with medical alcohol and then irradiated under ultraviolet light for 10 minutes. Then, they were dried in a sterile room at a temperature of 26°C and a light intensity of 135W. The male spikes were then shaken to scatter the pollen and collected for later use.

[0034] (3) Pollen treatment: The collected pollen was placed in cryovials and stored in an environment below 3°C. Before pollination, the pollen was thawed, specifically by taking out the pollen and thawing it at 12°C for 12 minutes, followed by thawing it at 25°C for 25 minutes. After thawing, the pollen was mixed with corn flour, boric acid, magnesium carbonate, salicylic acid and water in a mass ratio of 4:1:0.5:0.3:0.2:15 to prepare a pollination solution for later use.

[0035] (4) Pollination: Put the pollination liquid into a sprayer and spray it onto the silks of the maternal corn plant. After pollination, wrap the silks of the maternal corn plant with a bag to complete the pollination.

[0036] Example 3

[0037] This embodiment provides a method for improving the utilization rate of pollen in maize hybrid pollination, specifically including the following steps:

[0038] (1) Treatment of parents: At 13:00 noon, the female parent is demasked and a paper bag is placed on the female ear of the female parent; one day before the male ear of the male parent is pollinated, a transparent plastic bag is placed on the male ear. Four days after bagging, the male ear is cut off.

[0039] (2) Pollen collection: The collected male spikes were sprayed with medical alcohol and then irradiated under ultraviolet light for 10 minutes. Then, they were dried in a sterile room at a temperature of 27°C and a light intensity of 145W. The male spikes were then shaken to scatter the pollen and collected for later use.

[0040] (3) Pollen treatment: The collected pollen was placed in cryovials and stored in an environment below 3°C. Before pollination, the pollen was thawed, specifically by taking out the pollen and thawing it at 15°C for 15 minutes, followed by thawing it at 26°C for 30 minutes. After thawing, the pollen was mixed with corn flour, boric acid, magnesium carbonate, salicylic acid and water in a mass ratio of 5:2:0.5:0.3:0.3:20 to prepare a pollination solution for later use.

[0041] (4) Pollination: Put the pollination liquid into a sprayer and spray it onto the silks of the maternal corn plant. After pollination, wrap the silks of the maternal corn plant with a bag to complete the pollination.

[0042] Test case

[0043] To demonstrate the practical value of this application, the applicant conducted the following experiment:

[0044] Experiment 1: Comparison of pollen activity in different groups

[0045] The applicants divided the pollen activity into several groups after different treatments, as follows:

[0046] Group 1: Pollen obtained after treatment as described in Example 2 (after revival);

[0047] Group 2: Pollen collection: Pollen was collected on the third day after the male spikes shed their pollen, and other methods were the same as Group 1;

[0048] Group 3: Pollen collection was carried out on the third day after the male spikes shed their pollen. The pollen was collected without any processing and its activity was directly tested.

[0049] Group 4: Pollen was thawed at 25°C for 37 minutes after removal, with other methods the same as Group 1;

[0050] Group 5: The pollen was thawed at 8°C for 5 minutes after being removed, then at 12°C for 7 minutes, and then at 25°C for 25 minutes. Other methods were the same as Group 1.

[0051] The activity of the pollen from each group was compared and recorded in Table 1:

[0052] Table 1 Comparison of pollen activity among groups

[0053] Pollen activity (%) Group 1 81 Group 2 71 Group 3 77 Group 4 76 Group 5 74

[0054] As shown in Table 1, the pollen activity obtained using the treatment method described in this application was the highest. In contrast, the second group, where pollen was collected directly from the field after the male spikes shed their pollen and then preserved and revived, exhibited very low pollen activity. The applicant speculates that this is because the pollen collected directly from the field carried a large number of microorganisms, which further affected pollen activity during the preservation and revival process, resulting in lower activity—even lower than the third group, which did not undergo preservation and revival. The fourth group, which was thawed directly at 25 degrees Celsius, also showed unsatisfactory pollen activity, indicating that the cooling method during pollen revival had an unpredictable impact on its activity. Furthermore, the fifth group, which underwent three-stage cooling, showed poor activity. This demonstrates that selecting a suitable cooling method is crucial for pollen activity, suggesting that pollen that has undergone a dormant period can maintain higher activity under appropriate revival temperatures and methods.

[0055] Experiment 2: Comparing the pollination effects of each group

[0056] The applicant further grouped and compared the pollen utilization rate (the number of female ears that can be pollinated by pollen from one tassel), pollination success rate, and the rate of barren ears in maize after pollination, with the groups as follows:

[0057] The present invention group: pollinates using the method described in Example 2;

[0058] Control group 1: After pollen revival, pollen and water were mixed at a mass ratio of 4:17 to prepare pollination solution, and other methods were the same as in group 1;

[0059] Control group 2: After pollen revival, pollen was mixed with talcum powder and water in a mass ratio of 4:1:16 to prepare pollination solution.

[0060] Control group 3: Pollen collection was carried out on the third day after the male spikes shed their pollen, and other methods were the same as in group 1.

[0061] Control group 4: Pollen collection was carried out on the third day after the male spikes shed their pollen. The pollen was collected without any treatment (no preservation or revival). The pollination solution was prepared directly according to the method of group 1, and other methods were the same as group 1.

[0062] Control group 5: Pollen was thawed at 25°C for 37 minutes after removal, and other methods were the same as in group 1;

[0063] Control group 6: The pollen was thawed at 8°C for 5 minutes after being removed, then at 12°C for 7 minutes, and then at 25°C for 25 minutes. Other methods were the same as those in group 1.

[0064] The pollination effects of the methods described above were compared, and the results are shown in Table 2:

[0065] Table 2 Comparison of pollination effects among groups

[0066]

[0067] As shown in Table 2, the pollination method proposed in this application improves pollen utilization and ensures a high success rate. In contrast, control group 1, which directly used pollen, had a high success rate but low pollen utilization; one male spike could only pollinate 5-7 female spikes. Furthermore, the applicant discovered that the pollination solution, prepared by combining other ingredients, effectively reduced tip barrenness, improving pollen utilization and ensuring pollination success, resulting in unexpected benefits. Control group 2, while also ensuring a high pollination success rate, exhibited a higher tip barrenness rate when combined with talc. Control groups 3 and 4 were directly harvested in the field. Pollination success rates were unsatisfactory for both control groups (Groups 5 and 6), which used different revival methods than this approach. This resulted in lower pollination success rates and higher rates of barren tips. Silks developed first at the lower part of the ear and last at the top. Similarly, pollination also started from the lower part of the ear. Therefore, in the later stages of pollination, the silks could not obtain effective pollen, easily leading to barren tips. These results demonstrate that the method described in this application not only improves pollen utilization and ensures pollination success rates but also effectively reduces the rate of barren tips. Clearly, this method is beneficial for improving the economic benefits of corn cultivation and reducing planting costs, and is worthy of promotion.

[0068] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method of increasing the utilization of corn hybrid pollination pollen, characterized by, Includes the following steps: (1) Treatment of parents: Demasculate the female parent and put a paper bag on the female ear of the female parent; put a bag on the male ear of the male parent one day before pollen is released, and cut off the male ear 2-4 days after bagging. (2) Pollen collection: The collected male spikes are sterilized, then dried in a sterile room under light, and then the male spikes are shaken to scatter the pollen and collected for later use. (3) Pollen treatment: The collected pollen is frozen and stored at low temperature. Before pollination, the pollen is revived and then mixed with corn flour, boric acid, magnesium carbonate, salicylic acid and water in a mass ratio of 4-5:1-2:0.5:0.2-0.3:0.2-0.3:10-20 to prepare a pollination solution for later use. (4) Pollination: Put the pollination solution into a sprayer and spray it onto the silks of the maize parent to complete the pollination. The pollen thawing step (3) involves taking out the pollen and thawing it at 10-15℃ for 10-15 minutes, followed by thawing it at 25-26℃ for 20-30 minutes to complete the pollen thawing.

2. The method of claim 1, wherein, The time for the emasculation treatment of the maize female parent in step (1) is 13:00 noon.

3. The method of claim 1, wherein, The step (1) of putting a bag over the male ear specifically involves putting a transparent plastic bag over it.

4. The method according to claim 1, characterized in that, In step (2), the temperature of the sterile room is 25-27℃ and the light intensity is 125-145W.

5. The method of claim 1, wherein, Step (3) pollen cryopreservation involves placing the pollen in a cryovial and then storing it in an environment below 3°C.

6. The method of claim 1, wherein, In step (4), after pollination, the silks of the maize parent plant are wrapped in a bag.

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