A stigma viscosity regulating solution and a method of increasing the pollination rate of bananas

Abstract

The application provides a stigma viscosity adjusting solution and a method for improving the pollination rate of bananas, and belongs to the technical field of banana breeding. The stigma viscosity adjusting solution comprises the following components in percentage by mass: 0.008-0.012% of boric acid, 5-7% of sucrose, 0.02-0.04% of calcium nitrate tetrahydrate, 0.008-0.012% of potassium nitrate, and the balance of water. The stigma viscosity adjusting solution can provide the material basis required for banana pollen germination, promote pollen germination and elongation, and increase the stigma viscosity, so that more pollen can be adhered; before pollination, spraying the stigma viscosity adjusting solution on the stigma of the female parent plant can obtain more hybrid seeds, and the method can be widely applied to banana breeding.

Description

Technical Field

[0001] This invention relates to the field of banana breeding technology, and more particularly to a stigma viscosity adjustment solution and a method for improving banana pollination rate. Background Technology

[0002] Bananas are plants belonging to the genus *Musa* in the family Musaceae, and the term also refers to their fruit. Native to Southeast Asia, they are now cultivated in many regions. Bananas are fragrant, nutritious, and the plant is a large herbaceous plant that grows from a rhizome, forming a pseudostem 3-6 meters tall from the lower part of the leaf sheaths. The leaves are oblong to elliptical, 65 cm wide, and 10-20 are clustered at the top of the stem. The drooping spike-like inflorescence emerges from the top of the pseudostem, bearing numerous pale yellow flowers. The fruit cluster is also drooping, producing 10-20 bunches of fruit, approximately 50-150 bananas. After fruiting, the plant dies, but continues to propagate through suckers growing from the rhizome; each plant can live for many years.

[0003] In banana breeding, hybridization is a common method. This involves removing the male reproductive organs and bagging the fruit before flowering. Once the stigma is ready for pollination, pollination is performed using prepared pollen from the male parent. After pollination, the bagging is repeated. After 3-5 days, the pollination is checked, and the ovary is observed to ensure proper ovary development. The bag is then removed, and the hybrid seeds are harvested after the fruit matures. However, the yield of hybrid seeds is low, and many banana varieties cannot be seeded, severely limiting the efficiency and progress of hybridization breeding. Therefore, finding an effective method to improve banana pollination and increase the yield of hybrid seeds is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a stigma viscosity-adjusting solution for improving banana pollination rate and a method for improving banana pollination rate, so as to solve the problem of low yield of banana hybrid seeds in the prior art.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a column viscosity adjusting solution comprising the following components in weight percentage: 0.008–0.012% boric acid, 5–7% sucrose, 0.02–0.04% calcium nitrate tetrahydrate, 0.008–0.012% potassium nitrate, and the balance being water.

[0007] Preferably, the pH of the column viscosity-adjusting solution is 6.5 to 7.5.

[0008] This invention also provides the application of the aforementioned stigma viscosity-adjusting solution in banana breeding.

[0009] This invention also provides a hybridization method for improving banana pollination rate, comprising the following steps:

[0010] S1. Select male parent plants with complete male stamens as sampling plants, collect pollen from the inflorescences on the day of pollination, dry and sterilize them, and then store them in cold storage.

[0011] S2. Prepare the stigma viscosity-adjusting solution;

[0012] S3. One to three days before the mother plant flowers, spray the stigma with the stigma viscosity-adjusting solution, and then apply pollen.

[0013] S4. After the fruit ripens, it is harvested to obtain banana seeds.

[0014] Preferably, pollen is collected between 5 a.m. and 7 a.m., from the outermost fresh male inflorescences.

[0015] Preferably, the hybridization pollination period is from August to October, and the pollination time is from 4 PM to 6 PM.

[0016] Preferably, the hybrid female parent is banana and the hybrid male parent is wild banana from South China.

[0017] By adopting the above technical solution, the present invention has the following beneficial effects: The stigma viscosity-regulating solution of the present invention comprises the following components in mass percentage: 0.008-0.012% boric acid, 5-7% sucrose, 0.02-0.04% calcium nitrate tetrahydrate, 0.008-0.012% potassium nitrate, and the balance being water. The stigma viscosity-regulating solution of the present invention can provide the material basis required for banana pollen germination, promote pollen germination and elongation, and at the same time increase stigma viscosity, facilitating the adhesion of more pollen. Spraying the stigma of the maternal plant with the stigma viscosity-regulating solution before banana pollination can obtain more hybrid seeds and can be widely used in banana breeding. Attached Figure Description

[0018] Figure 1 For a female flower to be ready for pollination, the bracts begin to turn upwards, the stigma is exposed, and it begins to secrete a small amount of mucus. Detailed Implementation

[0019] The present invention provides a column viscosity adjusting solution comprising the following components in mass percentage: 0.008-0.012% boric acid, 5-7% sucrose, 0.02-0.04% calcium nitrate tetrahydrate, 0.008-0.012% potassium nitrate, and the balance being water.

[0020] In the stigma viscosity-adjusting solution for improving banana pollination rate of the present invention, the percentage content of boric acid is 0.008-0.012%, more preferably 0.009-0.011%, and even more preferably 0.01%.

[0021] The sucrose content is 5-7%, more preferably 5.5-6.5%, and even more preferably 6%;

[0022] The percentage content of calcium nitrate tetrahydrate is 0.02-0.04%, more preferably 0.03%;

[0023] The potassium nitrate content is 0.008–0.012%, more preferably 0.009–0.011%, and even more preferably 0.01%.

[0024] The pH of the column head viscosity adjustment solution is 6.5 to 7.5, more preferably 6.8 to 7.2, and even more preferably 7.0.

[0025] This invention also provides a hybridization method for improving banana pollination rate, comprising the following steps:

[0026] S1. Select male parent plants with complete male stamens as sampling plants, collect pollen from the inflorescences on the day of pollination, dry and sterilize them, and then store them in cold storage.

[0027] S2. Prepare the stigma viscosity-adjusting solution;

[0028] S3. One to three days before the mother plant flowers, spray the stigma with the stigma viscosity-adjusting solution, and then apply pollen.

[0029] S4. After the fruit ripens, it is harvested to obtain banana seeds.

[0030] This invention first selects male parent plants with complete male stamens as sampling plants, collects pollen from the inflorescences on the day of pollination, and then dries, sterilizes, and refrigerates them. The male parent plants are preferably those with good growth. Pollen collection is preferably carried out between 5 am and 7 am to ensure pollen viability. It is preferred to collect pollen from the outermost fresh male inflorescences. After collection, the pollen is dried, sterilized, and then refrigerated at a temperature of -80°C.

[0031] This invention involves collecting pollen from male flowers and preparing a stigma viscosity-adjusting solution. One to three days before flowering of the female plant, the stigma is sprayed with this solution. At this time, the stigma of the female plant has little or no sticky substance, and the stigma has not yet begun to secrete it. During spraying, the female flower bracts and petals are rolled up to expose the stigma, which is then sprayed directly onto the stigma. Pollen is then applied to the stigma. Due to the adhesion of the sticky substance, the amount of pollen adhering to the stigma increases significantly. The stigma viscosity-adjusting solution serves two purposes: first, it increases stigma viscosity, facilitating the adhesion of more pollen; second, it provides the necessary material basis for pollen germination, promoting pollen germination and elongation. After spraying and applying the pollen, the plant is covered with tracing paper and an elastic plastic sleeve to prevent rain and sunburn. The tracing paper can block light rain from washing away the stigma, and the elastic plastic sleeve can reduce moisture loss. Pollen application is done daily from 4 PM to 6 PM, and pollination occurs annually in April and May. Pollen collection and pollination are best carried out on sunny days.

[0032] The hybrid female parent of this invention is the banana plant, and the hybrid male parent is the wild banana plant from South China.

[0033] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0034] Example 1

[0035] A column viscosity adjusting solution comprises the following components in weight percentage: 0.01% boric acid, 6% sucrose, 0.03% calcium nitrate tetrahydrate, 0.02% magnesium sulfate heptahydrate, 0.01% potassium nitrate, and the balance being water.

[0036] Comparative Example 1

[0037] A column viscosity adjusting solution comprises the following components in weight percentage: 0.05% boric acid solution, 6% sucrose, 0.03% calcium nitrate tetrahydrate, 0.02% magnesium sulfate heptahydrate, 0.01% potassium nitrate, and the balance being water.

[0038] Comparative Example 2

[0039] A column viscosity adjusting solution comprises the following components in weight percentage: 0.08% boric acid, 6% sucrose, 0.03% calcium nitrate tetrahydrate, 0.02% magnesium sulfate heptahydrate, 0.01% potassium nitrate, and the balance being water.

[0040] Comparative Example 3

[0041] A column viscosity adjusting solution comprises the following components in weight percentage: 0.01% boric acid, 12% sucrose, 0.03% calcium nitrate tetrahydrate, 0.02% magnesium sulfate heptahydrate, and 0.01% potassium nitrate.

[0042] Comparative Example 4

[0043] A column viscosity adjusting solution comprises the following components in weight percentage: 0.01% boric acid, 15% sucrose, 0.03% calcium nitrate tetrahydrate, 0.02% magnesium sulfate heptahydrate, and 0.01% nitric acid.

[0044] Comparative Example 5

[0045] A stigma viscosity-adjusting solution is a 6% honey solution.

[0046] Experimental Example

[0047] The experiment was divided into 7 groups, all using *Musa 'Dongguan Da'* as the female parent and *Musa balbisiana Colla* as the male parent. Ten banana plants were selected in each group. In mid-April 2024, pollen was collected and pollinated on sunny days 1-3 days before flowering. The stigmas were sprayed with the solutions from Example 1 and Comparative Examples 1-5. During spraying, the female flower bracts and petals were rolled up to expose the stigma, and the spray was aimed directly at the stigma. Pollen was then applied to the stigma. The control group received no treatment before pollination. Except for the control and honey water solutions, all stigma spray solutions were sterilized under high temperature and pressure to ensure sterility. After spraying and applying pollen, the bananas were covered with sulfuric acid paper and elastic plastic sleeves. They were ready for harvest 3 months after pollination. After harvesting, the bananas were ripened and softened until they turned yellow. Seeds were then longitudinally cut and extracted. Seeds that were mature, hard, black, and dense (sinking in water) were counted. The number of seeds that can be obtained from one finger of the middle comb of a banana bunch was counted. After removing the maximum and minimum values, the number of seeds obtained in each group is shown in Table 1.

[0048] Table 1. Statistics on the number of seeds obtained in each group

[0049]

[0050]

[0051] As shown in Table 1, spraying the stigma of the maternal parent with the stigma viscosity-adjusting solution of the present invention is beneficial to pollen germination, thereby obtaining more hybrid seeds.

[0052] As can be seen from the above embodiments, the present invention provides a stigma viscosity-adjusting solution and a method for improving banana pollination rate. The stigma viscosity-adjusting solution of the present invention can provide the material basis required for pollen germination, promote pollen germination and elongation, and at the same time increase stigma viscosity, making it easier to adhere more pollen. Spraying the stigma of the maternal plant with the stigma viscosity-adjusting solution before banana pollination can obtain more hybrid seeds.

[0053] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A column viscosity adjusting solution, characterized in that, It includes the following components by weight percentage: 0.01% boric acid, 6% sucrose, 0.03% calcium nitrate tetrahydrate, 0.02% magnesium sulfate heptahydrate, 0.01% potassium nitrate, and the balance being water.

2. The column head viscosity adjusting solution according to claim 1, characterized in that, The pH of the viscosity-adjusting solution at the column head is 6.5–7.

5.

3. The application of the stigma viscosity-adjusting solution according to claim 1 or 2 in banana breeding using plantain as the female parent and wild banana from South China as the male parent.

4. A hybridization method for improving banana pollination rate, characterized in that, Includes the following steps: S1. Select male parent plants with complete male stamens as sampling plants, collect pollen from the inflorescences on the day of pollination, dry and sterilize them, and then store them in cold storage. S2. Prepare the stigma viscosity-adjusting solution as described in claim 1; S3. One to three days before the mother plant flowers, spray the stigma with the stigma viscosity-adjusting solution, and then apply pollen. S4. After the fruit ripens, it is harvested to obtain banana seeds; The maternal parent is the banana plant, and the paternal parent is the wild banana plant from South China.

5. The hybridization method according to claim 4, characterized in that, Pollen collection was conducted between 5 a.m. and 7 a.m., collecting pollen from the outermost fresh male inflorescences.

6. The hybridization method according to claim 4, characterized in that, The hybridization pollination period is from April to May, and the pollination time is from 4 pm to 6 pm.

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