A method for promoting germination of hybrid seeds of Camellia chrysantha

Abstract

The present invention discloses a method for promoting the germination of hybrid camellia chrysantha seeds, comprising the following steps: (1) collecting hybrid seeds: timely collecting when the fruit shell just cracks, removing the peel, and obtaining pure hybrid seeds; (2) cutting the hybrid seeds: cutting the outer seed coat of the hybrid seeds from the hilum without damaging the inner seed coat, so that the seed kernel can be seen; (3) treating the hybrid seeds: soaking the seeds with a germination promoting liquid; (4) sowing and post-sowing management: fishing out the seeds that have sunk to the bottom and sowing them in a container filled with a substrate, placing them in a rain-proof greenhouse, and keeping them moist during the period. The present invention is easy to operate, can quickly check the fullness of hybrid camellia chrysantha seeds, and promote the germination of hybrid camellia chrysantha seeds.

Description

Technical Field

[0001] The invention belongs to the technical field of plant sexual reproduction, and in particular relates to a method for promoting germination of hybrid seeds of Camellia chrysantha. Background Art

[0002] Camellia nitidissima is a plant of the genus Camellia in the family Theaceae. It is one of the first-class protected plants in China and has high ornamental and medicinal value. The flowers of Camellia nitidissima are golden yellow and dazzling, as if coated with a layer of wax. At the same time, it is rich in tea polyphenols, vitamins, amino acids and other essential nutrients for the human body, as well as natural organic trace elements such as germanium, selenium, and zinc. It is a precious health product in the 21st century. Although Camellia nitidissima has the excellent characteristics of golden color, fleshy petals, and waxy luster, it has the disadvantages of long internodes, loose plant shape, prominent barefoot phenomenon of adult plants, and fear of sun exposure. Interspecific hybridization is an important means of germplasm innovation and variety improvement of Camellia nitidissima.

[0003] The existing hybridization results of Camellia chrysantha have shown that the affinity of different hybrid combinations varies greatly. According to existing literature reports, the fruit set rate of most hybrids within the genus Camellia is below 35.20%, and a considerable number of hybrid combinations have empty seeds and incomplete kernels. In order to quickly check the fullness of Camellia chrysantha hybrid seeds and promote early germination of hybrid seeds, hybrid F 1 To produce seedlings, the hybrid seeds need to be processed before sowing and raising seedlings, which is of great significance for the selection and breeding of new varieties of Camellia chrysantha.

[0004] Chinese patent CN107197641B discloses an efficient method for aseptic sowing and seedling raising of hybrid camellia chrysantha, comprising the following steps: selecting hybrid seeds free of pests and diseases and without external injuries; sterilizing hybrid seeds to obtain aseptic hybrid seeds; sterilizing the sowing matrix, and then sowing the sterilized hybrid seeds in sterilized fine sand or fine sand added with 6-benzylaminoadenine under aseptic conditions; after sowing, the hybrid seeds are cultured in full darkness at a temperature of 23-25°C until the cotyledons are exposed to the sowing matrix, then cultured at a temperature of 23-25°C and a natural scattered light intensity of 2800-3200lx until the seedling height is 4-5cm, and then transplanted to a transplanting matrix placed in a closed environment with an air humidity of 80-90% and a temperature of 23-25°C. The present invention can improve the germination rate of hybrid camellia chrysantha seeds, improve the efficiency of sowing and seedling raising, and reduce the loss of hybrid germplasm.

[0005] According to existing literature reports, Camellia chrysantha hybrid fruits are harvested promptly after maturity (October to December), and hybrid seeds are sown as soon as they are harvested using sterile sowing or conventional sowing methods (Wu Lijun et al., 2018) and seeds are treated in sand and then sown and raised in batches for seedling cultivation (Hong Yonghui et al., 2020).

[0006] The existing Camellia chrysantha hybrid seed germination method still has the problems of low germination rate, late germination time and low transplant survival rate. Summary of the invention

[0007] The technical problem to be solved by the invention is to provide a method for promoting the germination of hybrid camellia chrysantha seeds, which is easy to operate and can quickly check the fullness of hybrid camellia chrysantha seeds and promote the germination of hybrid camellia chrysantha seeds.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] A method for promoting germination of hybrid camellia chrysantha seeds, comprising the following steps:

[0010] (1) Collection of hybrid seeds: Harvest the seeds promptly when the fruit shell just cracks, remove the peel, and obtain pure hybrid seeds;

[0011] (2) Hybrid seed cutting: Cut the outer seed coat of the hybrid seed from the hilum without damaging the inner seed coat, so that the seed kernel can be seen;

[0012] (3) Hybrid seed treatment: soak the seeds in germination promoting solution;

[0013] (4) Sowing and post-sowing management: Remove the seeds that have sunk to the bottom of the soil and sow them in a container filled with substrate. Place the container in a rain-proof greenhouse and keep it moist.

[0014] In step (1), the harvesting time is from November to December, and the maturity of the hybrid fruits is regularly observed.

[0015] In step (2), the diameter of the cut exocarp is 0.8 to 1.0 cm.

[0016] Preferably, the germination promoting solution comprises the following raw materials: 800-1200 mg / L of rare earth salt, 100-200 mg / L of potassium salt, 300-500 mg / L of magnesium salt, 1000-1250 mg / mL of Bacillus subtilis powder, and 300-500 mg / L of plant growth regulator.

[0017] Preferably, the plant growth regulator comprises gibberellin (GA) in a mass ratio of 1:1. 3 ) and brassinolide.

[0018] Preferably, in step (3), the soaking time is 6 hours.

[0019] Preferably, in step (4), the substrate is fresh river sand.

[0020] Preferably, the river sand needs to be exposed to sunlight for 1 to 2 days.

[0021] Preferably, in step (4), the container is a clay pot.

[0022] Preferably, in step (1), the peel of the harvested fruit is removed after being left to stand for 1 to 2 days.

[0023] Preferably, the rare earth salt is Ce(NH 4 ) 2 (NO 3 ); the potassium salt is potassium sulfate; the magnesium salt is magnesium chloride.

[0024] The present invention has the following advantages over the prior art:

[0025] 1. The method for promoting germination of hybrid camellia chrysantha seeds of the present invention can promote germination earlier than conventional sowing methods (seeds are sown immediately after being harvested without being treated) and coarse sand storage and germination methods, and obtain a higher germination rate. In addition, the method can quickly check the fullness of hybrid camellia chrysantha seeds, and the transplant survival rate is high.

[0026] 2. The germination promoter of the present invention comprises rare earth salt, potassium salt, magnesium salt, Bacillus subtilis, and plant growth regulator, wherein the plant growth regulator gibberellin can effectively break the dormancy of plant seeds and promote germination; brassinolide can increase the activity of plant enzymes and seed vitality, and promote seed germination and seedling growth. Rare earth salts can increase the chlorophyll content of plants, enhance photosynthesis, promote seed germination, improve seed germination rate, promote root development, promote seedling growth, increase root absorption of nutrients, and enhance the disease resistance, cold resistance, and drought resistance of seedlings. Potassium salt can increase the life of seeds in seed collection and cultivation, and has a significant promoting effect on the transport of assimilates, strengthens the transport of carbohydrates, promotes the conversion of sugar into starch, maintains the difference in pressure potential at both ends of the sieve tube, and is conducive to the transport of organic matter. Bacillus subtilis fermentation broth can significantly increase the activity of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), significantly reduce the content of ROS and MDA, and at the same time increase the root proline, soluble sugar content and K + / Na + Ratio. Magnesium ions are also activators of multiple enzymes, which can synergistically activate enzymes in seeds, thereby accelerating seed germination. At the same time, Bacillus subtilis has an adsorption effect on rare earth ions. When Bacillus subtilis colonizes on the surface of seeds, it can enrich rare earth ions on the surface of seeds through adsorption, which is beneficial to the absorption of rare earth ions by seeds, thereby further promoting seed germination. DETAILED DESCRIPTION

[0027] In order to facilitate a better understanding of the present invention, the following examples are used to illustrate the present invention. These examples belong to the protection scope of the present invention, but do not limit the protection scope of the present invention.

[0028] Example 1

[0029] On November 11, 2021, 14 hybrid fruits of Camellia chrysantha♀×Camellia dagulinii♂ with just cracked shells were collected and placed indoors. After 2 days, the peels were cracked and removed, and a total of 56 pure hybrid seeds were obtained. Then, a special cutting tool was used to cut a small hole in the hybrid seeds from the hilum, and the outer seed coat was cut open with a diameter of 0.8-1.0 cm without damaging the inner seed coat. It was observed that all 56 seeds were full, and the seeds were soaked in germination promotion liquid for 6 hours. Fresh river sand that had been exposed to the sun for 1 day was filled in the earthenware pot with a thickness of 2 cm; then the soaked seeds were sown in the river sand, and a thin layer of sand was covered after the seeds were pressed. The thickness was appropriate for the seeds not to be exposed after watering, and they were placed in a rain-sheltered greenhouse and kept moist during the period. After 27 days, the seeds began to germinate. After 90 days, statistics showed that 55 seeds germinated, with a germination rate of 98.21%. In early March of the following year, choose rainy weather, dip the roots of 8-10cm tall seedlings with 4 leaves in yellow mud and move them to flower pots or nutrient bags. The substrate is a mixture of a prepared seedling soil with a pH of 5.5 and an organic matter content of ≥50% and topsoil at a volume ratio of 2:1. After compacting the substrate, pour enough rooting water. Place the container seedlings neatly in a shaded plot with a shading rate of 85% to keep the substrate moist. After 30 days, the survival of the transplanted seedlings was counted, and all 55 plants survived, with a survival rate of 100.00%. After one month, the seedlings resumed growth, and the seedlings were topdressed with a concentration of 0.2% compound fertilizer and water fertilizer every other month, weeding was done regularly, fertilization was stopped after November, and normal water management was performed.

[0030] The germination promoting solution contains Ce(NH 4 ) 2 (NO 3 )800mg / L, potassium sulfate 100mg / L, magnesium chloride 300mg / L, Bacillus subtilis powder 1000mg / mL, gibberellin (GA 3 )150mg / L, brassinolide 150mg / L.

[0031] Example 2

[0032] On November 18, 2022, 12 hybrid fruits of Camellia chrysantha ♀×Vietnamese clasping tea ♂ with the shells just cracked were collected. After leaving them for 1 day, the peels were removed, and a total of 108 pure hybrid seeds were obtained. Then, a special cutting tool was used to cut a small hole in the hybrid seeds from the hilum, and the outer seed coat was cut open with a diameter of 0.8-1.0 cm without damaging the inner seed coat. It was observed that 107 of them were full and 1 seed was shriveled. The seeds were soaked in germination promotion liquid for 6 hours, and fresh river sand that had been exposed to the sun for 1 day was filled in the earthenware pot with a thickness of 2 cm. Then the soaked seeds were sown in the river sand, and a layer of river sand was covered after the seeds were pressed. The thickness was appropriate for the seeds not to be exposed after watering. They were placed in a rain-sheltered greenhouse and kept moist during the period. After 24 days, the seeds began to germinate. After 90 days, statistics showed that 107 seeds germinated, with a germination rate of 100.00%. In mid-March of the following year, choose rainy weather, dip the roots of 8-10cm tall seedlings with 4 leaves in yellow mud and move them to flower pots or nutrient bags. The substrate is a mixture of a prepared seedling soil with a pH of 6.0 and an organic matter content of ≥50% and topsoil at a volume ratio of 2:1. After compacting the substrate, pour enough rooting water. Place the packed container seedlings neatly in a shaded plot with a shading rate of 85% to keep the substrate moist. After 30 days, the survival of the transplanted seedlings was counted, and all 107 plants survived with a survival rate of 100.00%. After one month, the seedlings resumed growth. Every two months, the seedlings were topdressed with a concentration of 0.25% compound fertilizer and water fertilizer, and weeding was done regularly. Fertilization was stopped after November and normal water management was performed.

[0033] The germination promoting solution contains Ce(NH 4 ) 2 (NO 3 )1000mg / L, potassium sulfate 150mg / L, magnesium chloride 400mg / L, Bacillus subtilis powder 1100mg / mL, gibberellin (GA 3 )200mg / L, brassinolide 200mg / L.

[0034] Example 3

[0035] On December 20, 2022, 9 hybrid fruits of Camellia chrysantha ♀×Camellia sinensis ♂ with the shells just cracked were collected. After leaving them for 1 day, the peels were removed, and a total of 36 pure hybrid seeds were obtained. Then, a special cutting tool was used to cut a small hole in the hybrid seeds from the hilum, and the outer seed coat was cut open with a diameter of 0.8-1.0 cm, without damaging the inner seed coat. It was observed that all 36 seeds were full; the seeds were soaked in germination promotion liquid for 6 hours, and fresh river sand exposed to the sun for 2 days was filled in the earthenware pot with a thickness of 2 cm; then the soaked seeds were sown in the river sand, and a layer of river sand was covered after the seeds were pressed tightly. The thickness was appropriate that the seeds were not exposed after watering, and they were placed in a rain-proof greenhouse and kept moist during the period. After 28 days, the seeds began to germinate. After 90 days, statistics showed that 35 seeds germinated, with a germination rate of 97.22%. In late March of the following year, choose rainy weather, dip the roots of 8-10cm tall seedlings with 2 leaves in yellow mud and move them to flower pots or nutrient bags. The substrate is a mixture of a prepared seedling soil with a pH of 6.5 and an organic matter content of ≥50% and topsoil at a volume ratio of 2:1. After compacting the substrate, pour enough rooting water. Place the container seedlings neatly in a shaded plot with a shading rate of 85% to keep the substrate moist. After 30 days, the survival of the transplanted seedlings was counted, and all 35 plants survived, with a survival rate of 100.00%. After one month, the seedlings resumed growth, and the seedlings were topdressed with a concentration of 0.3% compound fertilizer and water fertilizer every other month, weeding was done regularly, fertilization was stopped after November, and normal water management was performed.

[0036] The germination promoting solution contains Ce(NH 4 ) 2 (NO 3 )1200mg / L, potassium sulfate 200mg / L, magnesium chloride 500mg / L, Bacillus subtilis powder 1250mg / mL, gibberellin (GA 3 )250mg / L, brassinolide 250mg / L.

[0037] Comparative Example 1

[0038] It is basically the same as Example 2, except that the germination promoting solution does not contain rare earth salts and Bacillus subtilis.

[0039] Comparative Example 2

[0040] It is basically the same as Example 2, except that the germination promoting solution does not contain rare earth salt.

[0041] Comparative Example 3

[0042] It is basically the same as Example 2, except that the germination promoting solution does not contain Bacillus subtilis.

[0043] Comparative Example 4

[0044] Distant hybridization breeding of several species of Camellia chrysantha group, Wu Lijun et al., 2018.

[0045] The specific method is as follows: hybrid seeds are sown as soon as they are harvested by sterile sowing and conventional sowing. Conventional sowing: sow untreated hybrid seeds directly on a mixed matrix of loess soil + peat soil + coconut bran (1:1:1) (in a flower pot), cover with 1 cm of soil, and then cover with a film to keep moisture and heat. Sterile sowing: refer to the aseptic treatment method of explants in tissue culture technology, and sow hybrid seeds on a sterile matrix. Observe the germination of seeds, and count the germination rate of seeds of each hybrid combination 3 months after sowing.

[0046] Comparative Example 5

[0047] Research on hybrid breeding of high-quality germplasm resources of Camellia chrysantha group, Hong Yonghui et al., 2020.

[0048] The specific method is as follows: After the fruits mature and crack in October, the fruits are collected in batches, the seeds are treated with sand and then sown and raised in batches, and coarse sand with a moisture content of 5% is used for storage and germination. On March 8, 2019, the collected 37 seeds are directly sown in nutrient bags made of peat soil and coconut bran, and covered with 0.5m high bamboo and plastic film for heat preservation and moisture retention. After 2 months, the seedlings are 3 to 4 cm exposed from the substrate, and the germination rate is 43.2%.

[0049] Comparative experiment

[0050] 1. The seeds were treated according to the methods of Examples 1 to 3 of the present invention, Comparative Examples 1 to 3, and the Camellia chrysantha hybrid seed seedling raising methods disclosed by Wu Lijun (2018) and Hong Yonghui (2020), and the effects were compared.

[0051] Germination rate (%) = number of germinated seeds / number of tested seeds × 100%;

[0052] Survival rate (%) = number of surviving transplanted seedlings / number of transplanted seedlings × 100%.

[0053] 2. Specific data are shown in the table below:

[0054]

[0055] It can be seen from Table 1 that the seed germination rates of the methods of Examples 1 to 3 of the present invention were all above 97.22%, and the transplanting survival rates of Examples 1 to 3 of the present invention and Comparative Examples 1 to 3 all reached 100%, reaching a relatively high level overall.

[0056] Comparative Examples 1 to 3 respectively reduce rare earth salts, Bacillus subtilis or both on the basis of Example 2, and investigate the effect comparison of rare earth salts and Bacillus subtilis used alone and mixed. It can be seen from the data that in Comparative Example 1, rare earth salts and Bacillus subtilis are reduced at the same time, and the germination time is delayed by 11 days and the germination rate is reduced by 22% compared with Example 2; Comparative Example 2 adds Bacillus subtilis on the basis of Comparative Example 1, and the germination time is accelerated by 4 days, and the germination rate is increased by 7.71%; Comparative Example 3 adds rare earth salts on the basis of Comparative Example 1, and the germination time is accelerated by 6 days, and the germination rate is increased by 10.33%. It can be seen that the effect of mixing rare earth salts and Bacillus subtilis is better than the sum of the effects of using them alone.

[0057] Compared with the existing camellia chrysantha hybrid seed seedling raising methods in comparative examples 4 and 5, the present invention has a higher sowing germination rate, an earlier germination time, can quickly check the fullness of camellia chrysantha hybrid seeds, and has a high transplant survival rate.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for promoting the germination of hybrid seeds of Camellia chrysantha, It is characterized in that The following steps are involved: (1) Collection of hybrid seeds: Harvest the seeds as soon as the fruit shell cracks, remove the peel, and obtain pure hybrid seeds; (2) Hybrid seed cutting: Cut the outer seed coat of the hybrid seed from the hilum without damaging the inner seed coat, so that the seed kernel can be seen; (3) Hybrid seed treatment: soaking the seeds in a germination promoting solution; the germination promoting solution includes the following raw materials: Rare earth salt 800-1200 mg / L, potassium salt 100-200 mg / L, magnesium salt 300-500 mg / L, Bacillus subtilis powder 1000-1250 mg / mL, plant growth regulator 300-500 mg / L; the plant growth regulator comprises gibberellin and brassinolide in a mass ratio of 1:1; the rare earth salt is Ce(NH 4 ) 2 (NO 3 ); (4) Sowing and post-sowing management: Pick out the seeds that have sunk to the bottom of the soil and sow them in a container filled with substrate. Place the container in a rain-proof greenhouse and keep it moist.

2. The method for promoting germination of hybrid camellia chrysantha seeds according to claim 1, Features: In step (1), the harvesting time is from November to December.

3. The method for promoting germination of hybrid seeds of Camellia chrysantha according to claim 1, Features: In step (2), the diameter of the cut outer seed coat is 0.8-1.0 cm.

4. The method for promoting germination of hybrid seeds of Camellia chrysantha according to claim 1, Features: In step (3), the soaking time is 6 hours.

5. The method for promoting germination of hybrid seeds of Camellia chrysantha according to claim 1, Features: In step (4), the substrate is fresh river sand.

6. The method for promoting germination of hybrid seeds of Camellia chrysantha according to claim 5, Features: The river sand needs to be exposed to the sun for 1 to 2 days.

7. The method for promoting germination of hybrid seeds of Camellia chrysantha according to claim 1, Features: In step (4), the container is a clay pot.

8. The method for promoting germination of hybrid seeds of Camellia chrysantha according to claim 1, Features: In step (1), the harvested fruits are left to stand for 1 to 2 days before peeling.

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