Method for improving germination rate of hemerocallis fulva seeds

Abstract

The invention belongs to the technical field of plant breeding, and particularly relates to a method for increasing the germination rate of hemerocallis fulva seeds. According to the method, the germination rate of the hemerocallis fulva seeds can be increased by harvesting, storing and treating the seeds to break dormancy and accelerating germination, the time is short, the operation is simple, the germination rate can be increased to 86% or above, the technical problem of seed germination in new variety breeding of hemerocallis fulva is thoroughly solved, and a powerful technical guarantee is provided for hemerocallis fulva breeding.

Description

Technical Field

[0001] This invention belongs to the field of plant breeding technology, specifically relating to a method for improving the germination rate of daylily seeds. Background Technology

[0002] Daylilies belong to the Asphodelaceae family and are well-known ornamental and edible flowers. They are perennial herbaceous plants that are valued for their foliage in spring and autumn and their flowers in summer. They are highly adaptable, have low maintenance costs, are easy to manage and propagate. With a wide variety of varieties, long flowering periods, diverse flower shapes and rich colors, they are a rare and excellent material for landscaping.

[0003] Daylilies can be used not only in flower beds, borders, roadside areas, lawns, woodlands, and grassy slopes to create natural landscapes, but also as cut flowers and potted plants to beautify homes, showing broad application prospects.

[0004] Plant breeding techniques include conventional hybridization breeding, mutation breeding, ploidy breeding, and gene editing, among others. Hybridization breeding remains the most important method in daylily breeding. In daylily breeding, because daylily germplasm resources contain diploid, tetraploid, hexaploid, and octaploid forms, many hybridization incompatibilities occur when creating hybrid combinations. Hybridization-compatible combinations will produce fruits and seeds. These seeds are hard-won, making it crucial to improve the germination rate of daylily seeds. Furthermore, the quality of seeds produced by different combinations varies greatly. Even very mature and plump seeds can have significantly different germination rates, indicating substantial differences in dormancy levels and germination rates between different seeds or combinations. Immature sowing techniques often waste hard-won hybrid seeds, hindering the daylily breeding process to some extent.

[0005] Therefore, there is an urgent need to develop a method to improve the germination rate of daylily seeds. Summary of the Invention

[0006] The purpose of this invention is to provide a method for improving the germination rate of daylily seeds. The method provided by this invention is not only simple to operate, but also effectively breaks the dormancy of daylily seeds, with a germination success rate of over 85%, providing strong technical support for daylily hybridization breeding.

[0007] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for improving the germination rate of daylily seeds, comprising the following steps: S1. After daylilies have been hybridized or self-pollinated and set fruit, they should be harvested with the fruit pods attached when the fruit first splits open after turning brown, and then stored in a refrigerator. S2. After removing the seeds, put them back into the refrigerator for cold storage. After storage, select the plump seeds. S3. After screening, the seeds are subjected to germination-promoting treatment, followed by germination-inducing treatment. S4. Sow the pre-germinated seeds in a seed tray filled with substrate.

[0008] Preferably, the daylily fruit is the fruit produced by artificial hybridization of two daylily germplasm resources or the fruit obtained by self-pollination or cross-pollination of daylily germplasm resources through wind or insect pollination.

[0009] Preferably, the refrigerated storage conditions in step S1 are: refrigeration at 4-5℃ for 5-7 days, with one open tissue culture bottle containing 100 ml of water placed on each shelf of the refrigerator.

[0010] Preferably, the refrigerated storage conditions in step S2 are: refrigeration at 4-5℃ for 25 days, with one open tissue culture bottle containing 100 ml of water placed on each shelf of the refrigerator.

[0011] Preferably, the germination-promoting treatment in step S3 is as follows: the seeds are soaked in a 300 ppm gibberellin solution at 25-30℃ for 24-48 h, and then rinsed for 1 min.

[0012] Preferably, the germination process in step S3 is as follows: wrap the seeds in a damp cloth, place them in a container, and germinate them at 25°C. The seeds need to be washed with warm water at 25-30°C every other day. Every 1-2 days, the germinated seeds are screened, and the remaining seeds are sown.

[0013] Preferably, in step S4, the seed tray is a standard seed tray with 50 holes and a depth of 5 cm; the substrate ratio is peat:coconut coir 5:3; the seed sowing depth is 0.5-1.0 cm, and the substrate moisture content is maintained above 85% after sowing.

[0014] This invention also provides the application of the above method in improving the germination rate of daylily seeds.

[0015] The beneficial effects of this invention are: 1. This invention breaks the dormancy of daylily seeds and improves the germination rate of daylily seeds by harvesting, storing, treating and germinating hybrid or naturally pollinated daylily fruits, thus providing strong technical support for daylily breeding.

[0016] 2. This invention has low cost, simple operation, high seed germination rate, and low seed loss. The germination rate is as high as 85% or more. The application of this method can promote the development of daylily breeding and contribute to the breeding of new daylily varieties. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of the daylily seed germination process in Example 1; Figure 2 The images show actual germination of seeds after treatment for the four hybrid combinations in Example 1. Detailed Implementation

[0019] This invention provides a method for improving the germination rate of daylily seeds, specifically including the following steps: (1) After daylilies are hybridized or naturally pollinated, they are harvested when the fruit begins to turn brown and just begins to crack. After daylilies are hybridized or naturally pollinated, the fruit gradually swells and the seeds inside the fruit gradually become full. The seam of the pod begins to turn brown and is easy to crack after turning brown. The pod will crack open when you gently squeeze it with your hand. At this time, the seeds are mature and it is the best time to harvest.

[0020] (2) Harvesting with fruit pods: Put the fruit pods into a mesh bag, put in a hybridization label and seal the bag. Place all the mesh bags in the refrigerator at 4℃-5℃ and store them in the refrigerator. Place an open tissue culture bottle containing 100 ml of water on each shelf of the refrigerator.

[0021] (3) After 5-7 days, remove the seeds from the pods and put them back into the refrigerator at 4℃-5℃. Sow all the seeds out of the pods, put the seeds back into the mesh bags, put on the labels and close the openings. Put the mesh bags back into the refrigerator for storage.

[0022] (4) After the seeds are stored for 25 days, they are taken out of the refrigerator and screened. The unsaturated seeds are removed and the saturated seeds are used for pre-sowing treatment. After the seeds are stored for 25 days, it means that the seeds need to be stored at 4℃~5℃ for 30 days from the time they are harvested from the pods to the time they are taken out of the refrigerator for screening. The unsaturated seeds are removed and the saturated and firm seeds are used for pre-sowing treatment.

[0023] (5) Soak the seeds in a 300 ppm gibberellin solution at 25-30℃ for 24-48 h. Specifically, prepare 1000 mL of 300 ppm gibberellin aqueous solution in a 2000 mL beaker, and immerse the entire mesh bag containing the seeds in the aqueous solution for 24-48 h.

[0024] (6) Take out the mesh bag containing the seeds and rinse the mesh bag directly. You can gently rub the mesh bag during the rinsing process. The water temperature should be 25-30℃. Rinse for about 1 minute.

[0025] (7) Wet a square piece of pure cotton cloth with water, do not wring it dry, wrap the seeds directly, place them in a container, and germinate them at around 25°C. The seeds need to be taken out and washed every other day. The water temperature for washing the seeds should be 25-30°C. After washing the gauze, wrap the seeds again, put them back in the container, and continue to germinate them at around 25°C.

[0026] (8) After 7 days of germination, the seeds will begin to sprout. Every 1-2 days, select the sprouted seeds for sowing. Wash the unsprouted seeds and wrap them in cotton cloth to continue germination.

[0027] (9) Fill the seed tray with substrate, sow one seed per hole at a depth of 0.5-1.0 cm, and water thoroughly after sowing. Use a standard 50-hole seed tray with a depth of 5 cm. The substrate ratio is peat moss:coconut coir 5:3. Fill the tray with substrate, ensuring it is level with the top of the tray and loose. Use one end of a pencil to make holes 0.5-1.0 cm deep in the tray. Drop the germinated seeds into the holes, sowing one seed per hole. Gently smooth the substrate over the holes with a scraper, covering them completely. Insert a label recording the hybridization number and sowing time, then water thoroughly. Keep the substrate moist during germination, maintaining a moisture content above 85%.

[0028] (10) After 15 days of germination, the germination rate of the pre-germinated seeds can reach more than 85%. At this time, no further selection is needed, and all seeds are sown directly. When sowing, the germinated seeds can be sown first and the seeds that have not yet sprouted can be sown last. Record the sowing time and the number of seeds that have not yet sprouted on the label so that the overall germination rate can be recorded later.

[0029] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0030] Unless otherwise specified, the production processes, experimental methods, or testing methods involved in the embodiments of this invention are all conventional methods in the prior art, and their names and / or abbreviations are all conventional names in the field, which are very clear and distinct in the relevant application areas. Those skilled in the art can understand the conventional process steps based on the names and apply the corresponding equipment, and implement them according to conventional conditions or the conditions recommended by the manufacturer.

[0031] The various instruments, equipment, raw materials or reagents used in the embodiments of this invention are not subject to any special restrictions on their source. They are all conventional products that can be purchased through regular commercial channels and can be prepared according to conventional methods known to those skilled in the art.

[0032] Example 1: Method for improving the germination rate of daylily seeds Using the new hybrid line "20213706" as the female parent and the horticultural variety "Aixin Baobei" as the male parent for cross-pollination, the fruits gradually matured after swelling, and the pods began to turn brown in some areas. When they cracked open with a gentle squeeze, the fruits were harvested and placed in a mesh bag. After harvesting with the fruit pods intact, the fruits were stored in a refrigerator at 4℃-5℃, with an open tissue culture bottle containing 100 mL of water placed in the refrigerator compartment. After 5 days, the seeds were removed from the fruit pods and placed in a mesh bag. The mesh bag containing 252 seeds was then returned to the refrigerator at 4℃-5℃ for storage. After 25 days of seed storage, the seeds were removed from the refrigerator and screened. The unripe seeds were discarded, and the plump seeds were used for sowing experiments.

[0033] Soak the seeds in a 300 ppm gibberellin solution at 30℃ for 24 hours. Remove the seeds and rinse them at 30℃ for about 1 minute. Wrap the mesh bag containing the seeds in a completely wet cotton cloth and place it in a beaker at about 25℃ to germinate. Take the seeds out and wash them once every other day.

[0034] Seeds are germinated. Starting from the 7th day of germination, seeds that meet the sowing criteria are screened and selected periodically (e.g., every 1 to 2 days). The sowing criteria are: the radicle of the seed breaks through the seed coat (showing white), or primary roots less than 1 cm in length have grown. Seeds that meet the criteria are sown immediately, while those that do not continue germination until further screening. For sowing, peat moss and coconut coir are mixed in a 5:3 volume ratio to create a substrate, which is then filled into 50-cell trays, ensuring the substrate surface is level with the top edge of the tray. One selected seed is sown in each cell, maintaining a sowing depth between 0.5 and 1.0 cm. The substrate is gently smoothed with a scraper, and the soil is thoroughly watered immediately after sowing.

[0035] Continue germination until day 15. When the cumulative germination rate of the seeds reaches 86%, perform the final sowing: first sow all the seeds that have sprouted white, then sow all the remaining ungerminated seeds as a batch on the same day; no further germination treatment will be performed thereafter.

[0036] This embodiment addresses the issue of improving the germination rate of hybrid daylily seeds. Through the harvesting, storage, treatment, and germination of hybrid fruits, the seed germination rate reached 86%, which is relatively high with minimal seed loss, providing strong technical support for the breeding of new and superior daylily varieties.

[0037] Example 2 Using Hemerocallis Y202011 as the female parent and a mixture of pollen from 'Love Baby', 'Pretty Girl', 'Cherry Valentine's Day', and 'Bella' as the male parent, hybrid pollination was performed. After the fruit swelled and gradually matured, the pods began to turn brown in some areas and cracked open with a gentle squeeze. The fruits were then harvested and placed in a mesh bag. After harvesting with the fruit pods intact, the fruits were stored in a refrigerator at 4℃-5℃, along with an open tissue culture bottle containing 100 mL of water in the refrigerator compartment. After 7 days, the seeds were removed from the fruit pods and placed in a mesh bag. The mesh bag containing 120 seeds was then returned to the refrigerator at 4℃-5℃ for storage. After 25 days of seed storage, the seeds were removed from the refrigerator and screened. Incomplete seeds were discarded, and the full seeds were used for sowing experiments.

[0038] Soak the seeds in a 300 ppm gibberellin solution at 30℃ for 24 hours. After soaking, rinse the seeds at 30℃ for about 1 minute. Wrap the mesh bag containing the seeds in a completely wet cotton cloth and place it in a beaker at about 25℃ to germinate. Take out the seeds and wash them every other day. Germination begins on the 7th day. Select seeds every 1-2 days. On the 9th and 12th days, select seeds for sowing. The remaining seeds continue to germinate.

[0039] Mix peat moss and coconut coir in a 5:3 volume ratio to prepare a substrate, and fill it into 50-cell seed trays, ensuring the substrate surface is flush with the top edge of the tray. Sow one selected seed in each cell, controlling the sowing depth to between 0.5 and 1.0 cm. Gently smooth the substrate with a scraper, and water thoroughly immediately after sowing.

[0040] When the germination rate of the pre-germinated seeds reaches 87.7% on the 15th day of cultivation, the final sowing is carried out: first, all the seeds that have sprouted are sown, and then all the remaining ungerminated seeds are sown as a batch on the same day; no further pre-germination treatment is carried out.

[0041] This embodiment addresses the issue of improving the germination rate of hybrid daylily seeds. Through the harvesting, storage, treatment, and germination of hybrid fruits, the seed germination rate reached 87.7%, which is relatively high with minimal seed loss, providing strong technical support for the breeding of new and superior daylily varieties.

[0042] Verification Example 1 In 2025, the seeds of four hybrid combinations with large seed collection volumes prepared in 2025 were subjected to seed germination treatment using this invention.

[0043] The results are as follows Figure 2 As shown in Table 1, the germination rate is also very high, all above 89%.

[0044] Table 1. Statistical analysis of seed treatment results for the four hybrid combinations

[0045] Comparative Example 1 In 2025, in order to overcome the daylily seed sowing technology, the inventors, in addition to using the germination method in this invention, also used daylily seed soaking in hot water, gibberellin treatment combined with hot water soaking and low-temperature storage treatment, and treated the seeds immediately after harvesting without low-temperature storage, and compared the results, which are shown in Table 2.

[0046] Table 2

[0047] As can be seen from the table above, the daylily germination method of the present invention has better germination effect and germination rate than the germination methods of the other 6 daylily varieties. Moreover, it is simple to operate and suitable for all daylily hybrids or self-pollinated varieties.

[0048] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method of increasing the germination rate of Hemerocallis seed, characterized by, It comprises the following steps: S1, after the Hemerocallis citrina Baroni fruits are set by crossing or self-pollination, the fruits are collected when they are brown and initially cracked, and are placed in a refrigerator for cold storage; S2, the seeds are taken out and placed in the refrigerator for cold storage again, and after the storage is completed, the full seeds are screened; S3, the screened seeds are subjected to germination promotion treatment, and after the germination promotion treatment, germination acceleration treatment is performed; S4, the seeds after the germination acceleration treatment are sown in a plug tray filled with a substrate.

2. The method of claim 1, wherein, The fruits of the Hemerocallis citrina Baroni are fruits produced after two Hemerocallis citrina Baroni germplasm resources are artificially crossed and grouped, or are fruits obtained by self-pollination or cross-pollination of the Hemerocallis citrina Baroni germplasm resources through wind or insect pollination.

3. The method of claim 1, wherein, The cold storage conditions in step S1 are 4-5℃ cold storage for 5-7 d, and a bottle of open culture bottle filled with 100 ml of water is placed in each layer of the refrigerator.

4. The method of claim 1, wherein, The cold storage conditions in step S2 are 4-5℃ cold storage for 25 d, and a bottle of open culture bottle filled with 100 ml of water is placed in each layer of the refrigerator.

5. The method of claim 1, wherein, The process of the germination promotion treatment in step S3 is that the seeds are soaked in a 300 ppm gibberellin solution at 25-30℃, and after soaking for 24-48 h, the seeds are taken out and rinsed for 1 min.

6. The method of claim 1, wherein, The process of the germination acceleration treatment in step S3 is that the seeds are wrapped with a wet cloth and placed in a container, and germination acceleration is performed under the condition of 25℃, and the seeds need to be cleaned with 25-30℃ warm water every other day; every 1-2 d, screening is performed, the germinated seeds are sown, and the remaining seeds continue to be subjected to germination acceleration.

7. The method of claim 1 wherein, In step S4, the plug tray is a standard plug tray with 50 holes and a depth of 5 cm; the substrate is mixed at a ratio of 5:3 of peat soil:coconut husk; the sowing depth of the seeds is 0.5-1.0 cm, and after sowing, the water content of the substrate is maintained at more than 85%.

8. Application of the method of claim 1 in improving the germination rate of Hemerocallis citrina Baroni seeds.

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