Method for improving hybrid breeding efficiency of small-fruit camellia oleifera

Abstract

The invention provides a method for improving hybrid breeding efficiency of small-fruit camellia oleifera, and belongs to the technical field of crop breeding. The method comprises the following steps: spraying a 1%-2.5% compound sodium nitrophenolate solution from the early stage of flower bud differentiation of a hybrid male parent to the stage that flower buds begin to expand; spraying a mixed solution of 10-20mg / L gibberellin and 0.1%-0.3% borax at the early bloom stage of the hybrid male parent; male parent pollen is collected for pollination in the full-bloom middle stage. The compound sodium nitrophenolate lays a good foundation for pollen germination and fruit development in the flower bud differentiation and flower development stages, gibberellin promotes pollen germination and pollen tube growth, borax plays an important role in the pollen tube growth and fertilization process and the later fruit development stage, and the compound sodium nitrophenolate, the gibberellin and the borax cooperate with one another to achieve the effect of promoting pollen germination and fruit development. The pollination and fruit development processes of the small-fruit camellia oleifera are jointly promoted, and the hybridization breeding efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of crop breeding, and in particular relates to a method for improving the efficiency of hybrid breeding of small-fruited camellia oleifera. Background Art

[0002] Camellia meiocarpa is an important oil-bearing tree species in my country. Its fruit has a high oil content, strong adaptability and disease resistance, and plays an important role in the oil-bearing tea industry. However, Camellia meiocarpa currently faces many problems in the hybrid breeding process, which limits the breeding efficiency of its excellent varieties and the development of the industry.

[0003] In actual production, there is a lack of effective technical means to regulate the flowering process of small-fruited tea and improve pollen vitality to achieve flowering synchronization and improve hybrid affinity. Traditional breeding methods often rely on natural conditions and the growth characteristics of the plants themselves, lacking precise intervention measures, making hybrid breeding work slow and inefficient. Liu Linxiu et al. studied the effects of several plant hormones on pollen germination and pollen tube growth of four species of Camellia. The results showed that as the flowering period prolonged, the pollen germination rate gradually increased, and the pollen germination rate was the highest at the end of the flowering period; GA3 can increase the pollen germination rate of small-fruited tea and promote pollen tube growth. However, the above literature is limited to experimental research and is not suitable for promotion in field pollination environments. In addition, although the pollen germination rate of small-fruited tea is high at the end of the flowering period, most of the flowers have withered at this time, the tree carries less flowers, and the amount of pollen is greatly reduced; a pollen germination rate of 50% cannot meet the hybrid breeding needs of small-fruited tea.

[0004] Therefore, there is an urgent need for an effective method to improve the efficiency of hybrid breeding of small-fruit tea oil trees to solve the problems existing in the existing technology and promote the development of the small-fruit tea oil tree industry. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a method for improving the efficiency of hybridization and breeding of small-fruited tea oil plants, thereby ensuring higher pollen vigor and pollination success rate, thereby increasing seed production and improving the efficiency of hybridization and breeding of small-fruited tea oil plants.

[0006] The invention provides a method for improving the hybrid breeding efficiency of small-fruited tea oil, comprising the following steps: spraying 1%-2.5% sodium nitrophenolate solution from the early stage of flower bud differentiation of hybrid male parents to the stage when flower buds begin to expand; spraying 10-20 mg / L gibberellin and 0.1%-0.3% borax mixed solution at the early stage of full flowering of hybrid male parents; collecting pollen of male parents for pollination in the middle stage of full flowering.

[0007] Preferably, the sodium nitrophenolate solution is sprayed 2 to 4 times, with an interval of 7 to 10 days between each spraying.

[0008] Preferably, the sodium nitrophenolate solution is sprayed on leaves, branches and flower buds of plants until water droplets appear but do not flow down.

[0009] Preferably, the mixed solution of gibberellin and borax is sprayed on the 1st to 2nd day after the flowers of the hybrid male parent open.

[0010] More preferably, the spraying site of the mixed solution of gibberellins and borax is the stamens of the hybrid male parent's flowers, and the solution is sprayed until the anthers adhere to the solution.

[0011] More preferably, the spraying time of the mixed solution of gibberellin and borax is 9 to 11 am or 4 to 6 pm.

[0012] More preferably, the mixed solution of gibberellin and borax is sprayed once more 2 to 3 days after spraying.

[0013] Preferably, in the middle stage of blooming, the male parent flowers are collected, pollen is collected after drying, and artificial pollination is performed by point pollination.

[0014] More preferably, the pollination is carried out during the flowering period of the female parent.

[0015] Preferably, after the pollination is completed, the environmental temperature is controlled to be 18-25° C. and the air humidity is controlled to be 50%-60%.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention sprays a sodium nitrophenolate solution from the early stage of flower bud differentiation of the hybrid male parent to the stage when the flower buds begin to swell. The sodium nitrophenolate can promote the male parent to bloom in advance. While ensuring high pollen vitality, the tree still has a large number of flowers and carries sufficient pollen, which is beneficial to subsequent pollination with sufficient pollen sources.

[0018] The invention sprays gibberellin and borax at the initial stage of full flowering of the hybrid male parent. The gibberellin promotes the decomposition of nutrients required for pollen germination and the synthesis of pollen tube cell walls, and the borax participates in the synthesis of pectin substances in the pollen tube cell walls and regulates related metabolism. The two act synergistically, making it easier for pollen to reach the ovules to complete fertilization, thereby improving the fruit setting rate and seed production. DETAILED DESCRIPTION

[0019] The present invention provides a method for improving the hybrid breeding efficiency of small-fruited tea oil, comprising the following steps: spraying 1% to 2.5% sodium nitrophenolate solution from the early stage of flower bud differentiation of the hybrid male parent to the stage when the flower buds begin to expand; spraying 10 to 20 mg / L gibberellin and 0.1% to 0.3% borax mixed solution from the early stage of full flowering of the hybrid male parent; collecting pollen from the male parent for pollination in the middle stage of full flowering. The present invention preferably sprays 1.5% to 2.2% sodium nitrophenolate solution from the early stage of flower bud differentiation of the hybrid male parent to the stage when the flower buds begin to expand, and further preferably sprays 2% sodium nitrophenolate solution. The present invention preferably sprays 12 to 18 mg / L gibberellin and 0.15% to 0.25% borax mixed solution from the early stage of full flowering of the hybrid male parent, and further preferably sprays 15 mg / L gibberellin and 0.2% borax mixed solution. The above "%" are all mass concentration percentages.

[0020] The early blooming stage of the present invention refers to the time period from the opening of the first flower of the small-fruited tea plant to the time period when the blooming rate of the flowers reaches 20% to 30%, and the middle blooming stage refers to the time period when the blooming rate of the flowers of the small-fruited tea plant reaches 50% to 70%.

[0021] The present invention sprays the sodium nitrophenolate solution during the early stage of flower bud differentiation of the hybrid male parent to the stage when the flower buds begin to swell, which can accelerate the physiological metabolic process of the small-fruited oil-tea tea and enhance the vitality of plant cells, so that the cells can better absorb and utilize nutrients, thereby promoting the hybrid male parent to bloom in advance, that is, while ensuring high pollen vitality, the hybrid male parent tree body still grows a large number of flowers and carries sufficient pollen.

[0022] The present invention sprays a mixed solution of gibberellins and borax at the early stage of full flowering of the hybrid male parent, and the two act synergistically on pollen to promote pollen germination and pollen tube growth, so that the pollen can reach the ovule more effectively and complete the fertilization process. More pollen is successfully fertilized, so that more ovaries develop into fruits, thereby improving the fruit setting rate and seed production, and enhancing the efficiency of hybrid breeding of small-fruited tea oil.

[0023] The present invention preferably sprays 1% to 2.5% sodium nitrophenolate solution from the early stage of flower bud differentiation of the hybrid mother to the stage when the flower buds begin to expand, further preferably sprays 1.5% to 2.2% sodium nitrophenolate solution, and more preferably sprays 2% sodium nitrophenolate solution. The failure of flowering is an important reason for the low pollination success rate of small-fruited camellia. The present invention sprays sodium nitrophenolate on the hybrid mother to synchronize the flowering period of the hybrid parents of the small-fruited camellia, improve the hybrid affinity of the parents, and thus improve the pollination success rate.

[0024] In the present invention, the sodium nitrophenolate solution is preferably sprayed 2 to 4 times, and more preferably sprayed 3 times, with an interval of 7 to 10 days between each spraying.

[0025] The preferred spraying site of the sodium nitrophenolate solution of the present invention is the leaves, branches and flower buds of the plants, and the spraying is performed until water droplets are present but not flowing down.

[0026] In the present invention, the mixed solution of gibberellin and borax is preferably sprayed on the 1st to 2nd day after the flowers of the hybrid male parent open, and more preferably sprayed on the day when the flowers open.

[0027] In the present invention, the preferred spraying site of the mixed solution of gibberellins and borax is the stamens of the hybrid male parent flower, and the solution is sprayed until the anthers adhere to the solution.

[0028] The preferred spraying time of the gibberellin and borax mixed solution of the present invention is 9 to 11 am or 4 to 6 pm. The flowering time of small-fruited camellia oil is concentrated at 9 am and 2 pm every day. At 9 to 11 am and 4 to 6 pm, the flowers of small-fruited camellia oil are in a better opening state and have more stigma secretions, which is conducive to the absorption of the agent and the germination of pollen.

[0029] In the present invention, the mixed solution of gibberellin and borax is preferably sprayed once more 2 to 3 days after spraying to enhance the spraying effect.

[0030] The present invention has no special requirements for the specific method of spraying. As an implementable method, the sodium nitrophenolate solution is sprayed with a backpack sprayer to increase the spraying efficiency; the gibberellin and borax mixed solution is sprayed with a small sprayer to improve the spraying accuracy.

[0031] The present invention preferably collects the male parent's flowers in the middle of full flowering, collects pollen after drying, and uses spot pollination for artificial pollination; it is further preferred that the pollen is collected on the same day, dried and pollinated on the same day. As an implementable method, the male parent's flowers are collected and dried naturally or with a desiccant (such as silica gel). Before pollination, the pollen and starch are evenly mixed in a ratio of 1:5 to 10 (m / m), and the mixed pollen is dipped with a brush or a pollinator and gently tapped on the stigma of the female parent's flower. Each flower is pollinated 2 to 3 times to ensure that the stigma is fully in contact with the pollen. If pollination cannot be done on the same day, collect the pollen and store it in a dry, low temperature (0 to 5°C) environment for later use.

[0032] The preferred pollination of the present invention is carried out during the flowering period of the female parent, when pollen vitality is at a high level and the stigma has the strongest receptivity. Pollination is carried out at this time, and pollen is more likely to germinate and pollen tubes grow on the stigma, thereby improving the fertilization success rate.

[0033] After pollination is completed, the environmental temperature is preferably controlled to be 18-25° C., more preferably 20° C., and the air humidity is preferably 50%-60%, more preferably 55%. Such environmental conditions are conducive to the rapid growth of pollen tubes and the smooth progress of fertilization.

[0034] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0035] Example 1

[0036] A method for improving the efficiency of hybridization and breeding of small-fruited camellia oil trees, comprising the following steps:

[0037] (1) From the early stage of flower bud differentiation of the male and female parents of the hybrid to the stage when the flower buds begin to expand, spray 2% sodium nitrophenolate solution three times, with an interval of 7 days between each spraying. The spraying parts are the leaves, branches and flower buds of the plants, and spray until there are water droplets on each part but no water flows down;

[0038] (2) At the beginning of the flowering period of the male parent of the hybrid, spray a mixed solution of 15 mg / L gibberellin and 0.2% borax between 9 and 11 a.m. or 4 and 6 p.m. on the day when the male parent flower blooms. The spraying area is the stamens of the flower. Spray the mixed solution until the anthers are attached. Spray again after 2 days.

[0039] (3) In the middle of the flowering period of the male parent of the hybrid, collect the flowers of the male parent and dry them with a desiccant; artificially pollinate the female parent during its flowering period. Before pollination, mix the pollen and starch in a ratio of 1:9 (m / m). Dip the mixed pollen with a pollinator and gently apply it to the stigma of the female parent's flower. Pollinate each flower 2 to 3 times to ensure that the stigma is fully in contact with the pollen. If pollination cannot be done on the same day, collect the pollen and store it in a dry, low-temperature (0 to 5°C) environment for later use;

[0040] (4) After pollination is completed, the ambient temperature is controlled at 20°C and the air humidity is controlled at 55%.

[0041] Example 2

[0042] A method for improving the efficiency of hybridization and breeding of small-fruited camellia oil trees, comprising the following steps:

[0043] (1) From the early stage of flower bud differentiation of the male and female parents of the hybrid to the stage when the flower buds begin to expand, spray 2.5% sodium nitrophenolate solution twice, with an interval of 10 days between each spraying. The spraying parts are the leaves, branches and flower buds of the plants, and spray until there are water droplets on each part but no water flows down;

[0044] (2) At the beginning of the flowering of the male parent of the hybrid, spray a mixed solution of 10 mg / L gibberellin and 0.3% borax between 9 and 11 a.m. or 4 and 6 p.m. on the second day after the male parent flower blooms. The spraying site is the stamens of the flower. Spray the mixed solution until the anthers are attached. Spray again after 2 days.

[0045] (3) In the middle of the flowering period of the male parent of the hybrid, collect the flowers of the male parent and dry them with a desiccant; artificially pollinate the female parent during its flowering period. Before pollination, mix the pollen and starch in a ratio of 1:5 (m / m). Dip the mixed pollen with a pollinator and gently apply it to the stigma of the female parent's flower. Pollinate each flower 2 to 3 times to ensure that the stigma is fully in contact with the pollen. If pollination cannot be done on the same day, collect the pollen and store it in a dry, low-temperature (0 to 5°C) environment for later use;

[0046] (4) After pollination is completed, the ambient temperature is controlled at 18°C ​​and the air humidity is controlled at 60%.

[0047] Example 3

[0048] A method for improving the efficiency of hybridization and breeding of small-fruited camellia oil trees, comprising the following steps:

[0049] (1) From the early stage of flower bud differentiation of the male and female parents of the hybrid to the stage when the flower buds begin to expand, spray 1% sodium nitrophenolate solution three times, with an interval of 7 days between each spraying. The spraying parts are the leaves, branches and flower buds of the plants, and spray until there are water droplets on each part but no water flows down;

[0050] (2) At the beginning of the flowering period of the male parent of the hybrid, spray a mixed solution of 20 mg / L gibberellin and 0.1% borax between 9 and 11 a.m. or 4 and 6 p.m. on the day when the male parent flower blooms. The spraying area is the stamens of the flower. Spray the mixed solution until the anthers are attached. Spray again after 3 days.

[0051] (3) In the middle of the flowering period of the male parent of the hybrid, collect the flowers of the male parent and dry them naturally; artificially pollinate the female parent during its flowering period. Before pollination, mix the pollen and starch in a ratio of 1:10 (m / m), dip the pollen in a pollinator, and gently tap it on the stigma of the female parent's flower. Pollinate each flower 2 to 3 times to ensure that the stigma is fully in contact with the pollen. If pollination cannot be done on the same day, collect the pollen and store it in a dry, low-temperature (0 to 5°C) environment for later use;

[0052] (4) After pollination is completed, the ambient temperature is controlled at 25°C and the air humidity is controlled at 50%.

[0053] Example 4

[0054] Effects of sodium nitrophenolate and its application concentration on flowering quantity and pollen vitality of Camellia oleifera

[0055] 1. Experimental Materials

[0056] 25 healthy small-fruit tea oil plants of similar age and growth condition were selected and planted in the same soil conditions and environment to ensure that environmental factors such as light, temperature, and water were basically consistent.

[0057] 2. Experimental treatment

[0058] Different exogenous drug treatment groups were set up, with concentration gradients of sodium nitrophenolate 1%, 1.5%, 2%, and 2.5%, and a water control (CK) group was set up at the same time. Five strains were set up in each treatment group to reduce experimental errors.

[0059] 3. Processing time and method

[0060] From the early stage of flower bud differentiation to the stage when the flower buds begin to expand, use a small sprayer to spray different concentrations of sodium nitrophenolate solution evenly on the leaves, branches and flower buds of the plants according to the above set concentrations until there are water droplets but no water flows down. The spraying amount for each plant is consistent, and the spraying operation is carried out under clear and windless weather conditions to avoid the drift of the agent affecting the experimental results.

[0061] 4. Data Collection Time and Method

[0062] (1) Number of flowers: At the beginning of the expected flowering period, observe and record the number of flowers of plants in each treatment group at 10 a.m. every day, and continue recording until the end of flowering. The number of flowers at key time points on October 22, October 25, and October 28 were recorded to fully reflect the flowering conditions at different periods.

[0063] (2) Pollen germination rate: In the middle of the flowering period (October 25), flowers from each treatment group were collected and brought back to the laboratory. Using the liquid culture method, a glass slide was placed in a culture dish covered with moist filter paper and 200 μL of treatment medium was added, and an equal amount of pollen was evenly sprinkled on the liquid culture medium and cultured at a constant temperature of 25°C for 2 hours. Then, photos were taken under a Nikon microscope (4×4 times), and the germination standard was the length of the pollen tube exceeding the diameter of the pollen grain. The germination rate was calculated (germination rate = number of germinated pollen / total number of counted pollen × 100%). Five fields of view were selected for each treatment group, and at least 10 pollen grains were counted in each field of view to calculate the pollen germination rate.

[0064] 5. Test results

[0065] As shown in Table 1, compared with the CK group, the different concentrations of sodium nitrophenolate treatment groups increased the number of flowers of small-fruited tea oil to a certain extent and advanced the flowering period. This shows that sodium nitrophenolate can promote the differentiation of flower buds and the opening of flowers of small-fruited tea oil, and within a certain concentration range, the higher the concentration, the more obvious the promotion effect, but when the concentration reaches 2.5%, the promotion effect decreases slightly. The pollen germination rate of the sodium nitrophenolate treatment group was significantly higher than that of the CK group, and the promotion effect on pollen germination was most significant at a concentration of 2%. In summary, sodium nitrophenolate has a significant effect on promoting the increase in the number of flowers of small-fruited tea oil and improving the pollen germination rate.

[0066] Table 1 Effects of external application of sodium nitrophenolate and different concentrations on flowering quantity and pollen vitality of Camellia oleifera

[0067]

[0068]

[0069] Example 5

[0070] Effects of different exogenous pesticides and their concentrations on pollen germination and pollen tube growth of Camellia oleifera

[0071] 1. Experimental Materials

[0072] Small-fruited tea oil plants with healthy growth and no pests and diseases were selected as experimental materials. During the flowering period, buds with good growth and about to bloom were collected and brought back to the laboratory. The flowers were hydroponically cultivated at a constant temperature of 28°C indoors until they bloomed and released pollen. The anthers were cut and placed in a 1.5mL centrifuge tube. The empty anther shells were removed by vortex shaking and centrifugation, and the clean pollen was collected in a 1.5mL centrifuge tube for subsequent experiments.

[0073] 2. Experimental Grouping and Treatment

[0074] This experiment set up different concentrations of gibberellin (5mg / L, 10mg / L, 15mg / L, 20mg / L) and borax (0%, 0.1%, 0.2%, 0.3%, 0.4%) combined treatment, a total of 20 treatment groups, configured into different mother solutions, each treatment group was repeated 3 times. At the same time, pollen cultured in basal medium without any hormone treatment was used as the control (CK).

[0075] Accurately measure the mother solutions of different concentrations and add them to the basic culture medium (20% sucrose + 2% H3PO4 + 4% CaCl2) to prepare the corresponding treatment culture medium.

[0076] 3. Pollen culture and data determination

[0077] The pollen germination rate was determined in the same manner as in Example 4.

[0078] The pollen tube length of germinated pollen was measured using a Nikon NI-U Eclipse Ni microscope and its own software. At least 30 pollen tube lengths were measured for each treatment group, and the average value was calculated as the pollen tube growth.

[0079] 4. Test results

[0080] As shown in Table 2, the combination of different concentrations of gibberellins and borax has a significant effect on the pollen germination rate of Camellia oleifera. When the concentration of gibberellins solution is 15 mg / L, the pollen germination rate is generally high. When the concentration of borax is 0.2%, the pollen germination rate reaches the highest value of 79.21%. Compared with the single effect (the pollen germination rate of 15 mg / L gibberellins solution is 55.05%), the addition of borax increases the pollen germination rate to a certain extent, indicating that borax has a synergistic effect in promoting pollen germination. When the concentration of gibberellins is 5 mg / L and 10 mg / L, with the increase of borax concentration, pollen germination first increases and then decreases slightly; when the concentration of gibberellins solution is 20 mg / L, the pollen germination rate shows a slow upward trend with the increase of borax concentration, but it is lower than the 15 mg / L treatment group.

[0081] As for the growth of pollen tubes, when the concentration of gibberellin solution was 15 mg / L, the growth of pollen tubes was longer, and when the concentration of borax was 0.2%, the growth of pollen tubes reached a maximum value of 235.99 μm. Compared with the single effect (the growth of pollen tubes treated with 15 mg / L gibberellin solution was 206.13 μm), the addition of borax promoted the elongation of pollen tubes. At other concentrations, the growth of pollen tubes also showed a trend of first increasing and then decreasing or slowly increasing with the change of borax concentration.

[0082] In summary, the combination of 15 mg / L gibberellin and 0.2% borax has the most significant effect on promoting pollen germination and pollen tube growth of Camellia oleifera.

[0083] Table 2 Effects of different exogenous agents and concentrations on pollen germination and pollen tube growth of Camellia oleifera

[0084]

[0085] Example 6

[0086] Effects of spraying gibberellins and borax on pollination efficiency of small-fruited camellia oleifera

[0087] 1. Experimental materials and planting environment

[0088] Select several healthy, pest-free, 8-year-old Camellia oleifera plants and plant them in an experimental base with the same soil type, uniform fertility, sufficient light, and good drainage. Ensure that the environmental conditions of the base are relatively stable during the experiment, such as temperature and humidity, with small changes, so as to reduce the interference of environmental factors on the experimental results.

[0089] 2. Experimental grouping and treatment settings

[0090] The small-fruited Camellia oleifera plants were randomly divided into five groups, namely, the control group (CK), the sodium nitrophenolate treatment group, the gibberellin treatment group, the gibberellin + borax treatment group, and the sodium nitrophenolate + gibberellin + borax treatment group. Ten plants were set up in each group as replicates to ensure the reliability and representativeness of the experimental data.

[0091] From the early stage of flower bud differentiation of the hybrid male parent to the stage when the flower buds begin to swell, the plants in the sodium nitrophenolate treatment group were sprayed with 2% sodium nitrophenolate solution. A small sprayer was used to evenly spray the solution on the leaves, branches and flower buds of the plants until water droplets appeared but did not flow down. The spraying was performed 3 times in total, with an interval of 7 days between each time.

[0092] At the early stage of flowering of the hybrid male parent, the plants in the gibberellin treatment group were sprayed with 10 mg / L gibberellin solution. A backpack sprayer was used to evenly spray the solution on the stamens of the flowers so that the anthers were fully attached to the solution. The spraying time was selected between 9 and 11 in the morning.

[0093] The plants in the gibberellin + borax treatment group were sprayed with a mixed solution of 10 mg / L gibberellin and 0.2% borax, and the spraying method was the same as that of the gibberellin treatment group.

[0094] For the plants in the group treated with sodium nitrophenolate + gibberellin + borax, comprehensive spraying was carried out according to the above-mentioned treatment method and concentration of sodium nitrophenolate, gibberellin and borax.

[0095] The plants in the control group (CK) were sprayed with an equal amount of clean water, and the operation method was the same as that of the treatment group.

[0096] 3. Data recording and statistical analysis

[0097] (1) Fruit setting rate statistics: Within 2 months after pollination, regularly observe and record the fruit setting of plants in each treatment group. Fruit setting rate = (number of fruits set / number of pollinated flowers) × 100%. Carefully check the development of each flower, and promptly remove fallen fruits caused by pests and diseases, mechanical damage or other non-experimental factors to ensure that the statistical number of fruit setting is accurate.

[0098] (2) Fruit setting rate statistics: After the fruits mature, count the number of fruit set in each treatment group. Fruit setting rate = (number of fruit set / number of fruit set) × 100%. Mark and track the fruits, record the changes in the fruit development process, and ensure that the determination of fruit set is accurate and reliable.

[0099] (3) Seed production statistics: The fruits of each treatment group were harvested and the number of seeds per fruit was calculated, i.e., seed production (seeds / fruit). The fruits were carefully peeled, the seeds were collected and counted, and at least 30 fruits were randomly selected from each treatment group for statistical analysis to obtain representative data.

[0100] 4. Test results

[0101] As shown in Table 3, compared with the control group, the fruit setting rate of the sodium nitrophenolate treatment group increased, which indicates that sodium nitrophenolate has a certain effect on promoting flower bud differentiation and flower development, providing more opportunities for fruit setting; the promotion of pollen germination and pollen tube growth by gibberellins helps to increase the fruit setting rate, and the fruit setting rate of the gibberellins + borax treatment group is further improved, reflecting the significant promotion effect of borax and gibberellins on fruit setting. Sodium nitrophenolate has a certain effect on fruit development, and borax and gibberellins synergistically promote fruit development. The comprehensive treatment of the three agents has a significant effect on improving the fruit setting rate. Sodium nitrophenolate also has a certain effect on seed development, and gibberellins and borax synergistically help increase the number of seeds in the fruit.

[0102] In summary, the combined use of sodium nitrophenolate, gibberellin and borax has the most significant effect on improving the pollination efficiency of small-fruited camellia oil trees, with the fruit setting rate, fruit set rate and seed production reaching a high level. This is because sodium nitrophenolate lays a good foundation for pollen germination and fruit development during the flower bud differentiation and flower development stages, gibberellin promotes pollen germination and pollen tube growth, and borax plays an important role in pollen tube growth and fertilization as well as the late stage of fruit development. The three work together to promote the pollination and fruit development process of small-fruited camellia oil trees.

[0103] Table 3 Effects of different exogenous pesticides on pollination efficiency of Camellia oleifera

[0104] deal with Fruit setting rate (%) Fruit setting rate (%) Seed production (grains / fruits) CK 28.5±3.2 38.2±3.4 4.2±0.9 Sodium nitrophenolate 33.8±3.8 43.5±3.6 5.0±1.0 Gibberellins 39.2±3.8 49.1±4.1 5.6±1.1 Gibberellic acid + boron 48.5±4.0 58.5±4.3 6.1±1.3 Sodium nitrophenolate + gibberellin + boron 56.2±4.2 66.8±4.8 6.4±1.3

[0105] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving the efficiency of hybrid breeding of small-fruited camellia oil trees, characterized in that: The following steps are involved: In the early stage of flower bud differentiation of the hybrid male parent to the stage when the flower buds begin to swell, spray 1% to 2.5% sodium nitrophenolate solution; in the early stage of full flowering of the hybrid male parent, spray a mixed solution of 10 to 20 mg / L gibberellin and 0.1% to 0.3% borax; collect male parent pollen in the middle of full flowering for pollination.

2. The method according to claim 1, characterized in that The sodium nitrophenolate solution is sprayed 2 to 4 times, with an interval of 7 to 10 days between each spraying.

3. The method according to claim 1 or 2, characterized in that: The sodium nitrophenolate solution is sprayed on the leaves, branches and flower buds of the plants until water drops are present but not flowing down.

4. The method according to claim 1, characterized in that: The mixed solution of gibberellin and borax is sprayed on the 1st to 2nd day after the flowers of the hybrid male parent open.

5. The method according to claim 1 or 4, characterized in that: The spraying site of the mixed solution of gibberellin and borax is the stamens of the hybrid male parent's flowers, and the spraying is performed until the anthers adhere to the solution.

6. The method according to claim 1 or 4, characterized in that: The spraying time of the mixed solution of gibberellin and borax is 9 to 11 am or 4 to 6 pm.

7. The method according to claim 1 or 4, characterized in that: 2 to 3 days after spraying the mixed solution of gibberellin and borax, spray once more.

8. The method according to claim 1, characterized in that In the middle stage of blooming, the male parent flowers are collected, pollen is collected after drying, and artificial pollination is performed by point pollination.

9. The method according to claim 1 or 8, characterized in that: The pollination is carried out during the flowering period of the female parent.

10. The method according to claim 1, characterized in that It also includes controlling the environmental temperature to 18-25°C and the air humidity to 50%-60% after pollination is completed.

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