A cultivation method for daylilies resistant to leaf rust

Abstract

This invention relates to the field of daylily cultivation technology, specifically to a method for cultivating daylilies resistant to leaf rust. The invention provides a method for cultivating daylilies resistant to leaf rust, comprising the following steps: Seed treatment: After sterilization, daylily seeds are soaked in a seed treatment agent and then placed at a constant temperature of 35-37℃ for 6-8 days to obtain germinated daylily seeds; Seedling management: The germinated daylily seeds are sown in a seedling substrate and cultivated until germination, obtaining daylily seedlings; Transplanting: The daylily seedlings are transplanted into soil treated with a soil treatment agent. This invention's cultivation method can improve the resistance of daylilies to leaf rust.

Description

Technical Field

[0001] This invention relates to the field of daylily cultivation technology, specifically to a method for cultivating daylilies resistant to leaf rust. Background Technology

[0002] Daylilies, a nutritious vegetable with a unique flavor, are widely popular in the market. However, leaf rust has always been a significant problem in daylily cultivation. Leaf rust not only drastically reduces daylily yield but also severely impacts its quality, causing substantial economic losses for growers.

[0003] Currently, growers typically rely on chemical pesticides to control leaf rust in daylilies. However, long-term use of chemical pesticides not only increases planting costs but may also pose potential harms to the environment and human health. Furthermore, as pathogens develop resistance, the effectiveness of chemical pesticides is gradually diminishing.

[0004] Therefore, providing a more environmentally friendly and effective planting method to improve the resistance of daylilies to leaf rust has broad application prospects and market value. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a method for cultivating daylilies resistant to leaf rust, which not only improves the daylily's resistance to leaf rust, but also reduces the use of chemical pesticides, lowers planting costs, and protects the environment and human health.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a method for cultivating daylilies resistant to leaf rust, the method comprising the following steps:

[0008] Seed treatment: After sterilization, daylily seeds are soaked in a seed treatment agent and then placed at a constant temperature of 35-37℃ for 6-8 days to obtain germinated daylily seeds.

[0009] Seedling management: Germinated daylily seeds are sown in seedling substrate and cultivated until germination, thus obtaining daylily seedlings;

[0010] Seedling transplantation: Transplant daylily seedlings into soil treated with a soil treatment agent.

[0011] Preferably, the seed treatment agent includes daylily vesicles, abscisic acid, and gibberellin.

[0012] Preferably, the seedling substrate includes daylily vesicles, peat moss, and perlite.

[0013] Preferably, the soil treatment agent includes daylily vesicles, vermiculite powder, and weathered coal.

[0014] Preferably, the seed treatment agent comprises, by weight, 0.03-0.05 parts daylily vesicles, 3-5 parts abscisic acid, and 2-6 parts gibberellin.

[0015] Preferably, the seedling substrate comprises, by weight, 2-4 parts daylily vesicles, 32-60 parts peat moss, and 50-80 parts perlite.

[0016] Preferably, the soil treatment agent comprises, by weight, 1-3 parts daylily vesicles, 26-40 parts vermiculite powder, and 21-30 parts weathered coal.

[0017] Secondly, a daylily resistant to leaf rust is provided, which is cultivated according to the planting method described in this invention.

[0018] It should be noted that leaf rust has seriously affected the yield of daylilies and the economic income of farmers in various planting areas of my country. Daylily leaf rust is caused by *Hemerocallis fulva*, primarily affecting the leaves and flower stalks. Initially, blister-like spots appear on the leaves and flower stalks; later, affected plants produce fewer or no flower stalks, the flower stalks turn reddish-brown, the flower buds shrivel and easily fall off, and in severe cases, the entire plant dies. Control of daylily leaf rust should adopt a "prevention-first, control-combined" approach, taking appropriate preventative measures before the disease occurs.

[0019] Thirdly, the present invention provides the application of the planting method described herein in improving the resistance of daylilies to leaf rust.

[0020] Fourthly, a combined planting system for daylilies resistant to leaf rust is provided. The combined planting system includes a seed treatment agent, a seedling substrate, and a soil treatment agent. The seed treatment agent includes daylily vesicles, abscisic acid, and gibberellin. The seedling substrate includes daylily vesicles, peat moss, and perlite. The soil treatment agent includes daylily vesicles, vermiculite powder, and weathered coal.

[0021] Plant exovesicles are nanoscale vesicles secreted by plant cells. They contain 90% of the active ingredients in plants and are the concentrated essence of plant active ingredients. They have a phospholipid bilayer structure and contain substances such as DNA, small RNA and proteins. They can carry these biomolecules to participate in processes such as intercellular communication, material exchange and signal transduction.

[0022] Daylily exovesicles are membranous vesicles released from daylily plant cells into the extracellular environment, typically ranging in diameter from tens to hundreds of nanometers. These vesicles contain abundant bioactive molecules, such as proteins, nucleic acids, and lipids, and can participate in processes such as intercellular communication, substance exchange, and signal transduction.

[0023] Plant exovesicles and plant extracts differ significantly in origin, composition, and function. In terms of origin, plant exovesicles are nanoscale vesicles released by plant cells under specific physiological or pathological conditions. These vesicles are secreted by cells via the endosomal-exocytic pathway and have a double-membrane structure. Plant extracts are substances extracted from plants using physical or chemical methods. In terms of composition, plant exovesicles mainly contain bioactive molecules such as proteins, nucleic acids, and lipids, which play important roles in plant growth and development, stress adaptation, and interactions with other organisms. The composition of plant extracts differs from that of plant exovesicles. Functionally, plant exovesicles participate in processes such as intercellular communication, substance exchange, and signal transduction. The efficacy of plant extracts may be unstable.

[0024] In this invention, the preparation method of daylily exovesicles is as follows:

[0025] Weigh 150-250g of fresh daylily and pour it into a crusher. Add 150-250mL of sterile PBS and crush and homogenize. Centrifuge at 3000-4000×g at 4℃ for 10-20min to remove larger residues. Take the yellow transparent solution in the middle layer and centrifuge at 5000-6000×g at 4℃ for 20-30min. Take the supernatant and centrifuge at 80000-90000×g at 4℃ for 20-30min. Then resuspend the precipitate with 1-3mL of sterile PBS and centrifuge at 90000-110000×g at 4℃ for 30-40min. After centrifugation, resuspend the precipitate with 1-3mL of sterile PBS to obtain the daylily vesicles.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] This invention, after extensive experimental screening, has found that the combined use of the seed treatment agent (comprising daylily vesicles, abscisic acid, and gibberellin), the seedling substrate (comprising daylily vesicles, peat moss, and perlite), and the soil treatment agent (comprising daylily vesicles, vermiculite powder, and weathered coal) can improve the resistance of daylilies to leaf rust, as well as increase their yield and quality. During the experimental screening process, the inventors conducted numerous experiments. They attempted to replace daylily vesicles, abscisic acid, gibberellin, peat moss, perlite, vermiculite powder, and weathered coal with other substances. The results showed that the substituted solutions did not significantly improve the resistance to leaf rust or the yield and quality of daylilies. They also attempted to replace the daylily vesicles with daylily extracts, but the results were also only moderately effective in improving the resistance to leaf rust or the yield and quality of daylilies.

[0028] The inventors hypothesize that, on the one hand, the exovesicles of daylilies, by regulating the activity of abscisic acid and gibberellin, enable seeds to acquire stronger growth vigor and resilience during germination, thus laying the foundation for subsequent growth and resistance to leaf rust. On the other hand, in substrate preparation, the exovesicles of daylilies interact with peat moss and perlite to regulate the soil microenvironment, promote the growth and reproduction of beneficial microorganisms, and enhance soil fertility, providing more favorable conditions for the growth of daylilies and resistance to leaf rust. Furthermore, the exovesicles of daylilies, through their interaction with vermiculite powder and weathered coal, further improve the soil environment and increase soil fertility, thus providing better protection for the growth of daylilies and resistance to leaf rust.

[0029] Furthermore, the exovesicles of daylilies play an important role in daylily cultivation. They may provide active ingredients (daylily exovesicles may contain substances that stimulate the daylily plant's immune system; these substances, upon contact with daylilies, can trigger disease-resistant signaling pathways within the daylily, thereby activating a series of defense responses, such as the production of disease-related proteins and the synthesis of antibacterial substances; these defense responses can effectively inhibit the colonization and spread of *Hemerocallis fulva* rust) and promote nutrient absorption and growth in daylilies (daylily exovesicles may also contain substances that promote daylily growth). The exoves of daylilies provide nutrients for the absorption and growth of daylily plants. By improving the root environment and enhancing root vitality, the exoves of daylilies help daylilies better absorb and utilize nutrients and water from the soil. This not only enhances the resistance of daylilies to leaf rust but also improves the overall growth vigor and yield of daylilies. The exoves also act as a physical barrier (the exoves form a protective layer on the surface of the daylily plant, which may have a certain physical barrier effect; this protective layer can block the direct contact and infection of daylily rust spores, thereby reducing the incidence of leaf rust). Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] This embodiment provides a method for cultivating daylilies resistant to leaf rust, the method comprising the following steps:

[0033] Seed treatment: Select healthy daylily plants that have been planted for 6 years. During the initial flowering period, leave 3-4 robust flower buds on each flower stalk without picking them, allowing them to produce fruit as daylily seeds. Sterilize the daylily seeds. After sterilization, soak the daylily seeds in a seed treatment agent and place them at a constant temperature of 35-37℃ for 6-8 days to obtain germinated daylily seeds.

[0034] Seedling management: Sow the germinated daylily seeds in a seedling substrate with a thickness of 5-6cm and cultivate until seedlings emerge to obtain daylily seedlings; when the daylily seedlings grow to a certain height (e.g., 5-6cm) and have a well-developed root system, transplant them.

[0035] In this embodiment of the invention, a thickness of 5-6 cm can provide better heat preservation and moisture retention performance, while promoting root development; it also ensures good drainage of the seedling substrate to avoid seed rot caused by excessive moisture.

[0036] The cultivation conditions are as follows:

[0037] During the day (6:00-18:00), maintain the temperature at 25-28℃ to promote seedling firmness and enhance stress resistance; at night (18:01-5:59), maintain the temperature at 18-20℃ to help seedlings maintain growth vitality at night and reduce energy consumption.

[0038] If natural light is insufficient, plant growth lights can be used to supplement the light on cloudy days or during periods of weak light to ensure that seedlings receive enough energy for photosynthesis.

[0039] Starting from the 4th day after sowing, ventilation will be carried out from 8:00 to 17:00 every day in order to better regulate the humidity and carbon dioxide concentration in the seedling shed and promote photosynthesis and gas exchange.

[0040] Adjust the watering frequency and amount according to the weather conditions and the dryness of the substrate to maintain appropriate humidity.

[0041] Seedling transplantation: Transplant daylily seedlings into soil treated with a soil treatment agent.

[0042] Choose loose, fertile, and well-drained soil for transplanting;

[0043] Before transplanting, the soil should be deeply tilled to improve its aeration and water retention; and a soil treatment agent should be used to disinfect and treat the soil to reduce the occurrence of pests and diseases; the soil treatment agent selected in this embodiment of the invention can ensure its friendliness to the soil environment and its safety for the growth of daylily seedlings.

[0044] When transplanting, the seedlings should be carefully removed from the seedling substrate, keeping the root system as intact as possible and avoiding damage to improve the survival rate after transplanting.

[0045] Dig a hole in the prepared soil, the depth and width of which should be slightly larger than the size of the seedling's root system; place the seedling in the hole, gently cover the roots with soil, and gently press it down to ensure that the seedling is in close contact with the soil.

[0046] After transplanting, water should be applied promptly to promote close contact between the seedlings and the soil and to encourage root growth.

[0047] For a period of time after transplanting, apply an appropriate amount of well-rotted farmyard manure or compound fertilizer to provide sufficient nutrition. As the seedlings grow, topdressing should be applied in a timely manner according to their growth and soil fertility.

[0048] Regularly cultivate and weed to improve soil aeration and reduce the impact of weeds on daylily growth. When cultivating, avoid damaging the daylily's root system.

[0049] According to the weight parts, the seed treatment agent includes 0.03 parts daylily exovesicles, 3 parts abscisic acid and 2 parts gibberellin; the seedling substrate includes 2 parts daylily exovesicles, 32 parts peat moss and 50 parts perlite; the soil treatment agent includes 1 part daylily exovesicles, 26 parts vermiculite powder and 21 parts weathered coal.

[0050] Example 2

[0051] This embodiment provides a method for cultivating daylilies resistant to leaf rust, the method comprising the following steps:

[0052] Seed treatment: Select healthy daylily plants that have been planted for 6 years. During the initial flowering period, leave 3-4 robust flower buds on each flower stalk without picking them, allowing them to produce fruit as daylily seeds. Sterilize the daylily seeds. After sterilization, soak the daylily seeds in a seed treatment agent and place them at a constant temperature of 35-37℃ for 6-8 days to obtain germinated daylily seeds.

[0053] Seedling management: Sow the germinated daylily seeds in a seedling substrate with a thickness of 5-6cm and cultivate until seedlings emerge to obtain daylily seedlings; when the daylily seedlings grow to a certain height (e.g., 5-6cm) and have a well-developed root system, transplant them.

[0054] In this embodiment of the invention, a thickness of 5-6 cm can provide better heat preservation and moisture retention performance, while promoting root development; it also ensures good drainage of the seedling substrate to avoid seed rot caused by excessive moisture.

[0055] The cultivation conditions are as follows:

[0056] During the day (6:00-18:00), maintain the temperature at 25-28℃ to promote seedling firmness and enhance stress resistance; at night (18:01-5:59), maintain the temperature at 18-20℃ to help seedlings maintain growth vitality at night and reduce energy consumption.

[0057] If natural light is insufficient, plant growth lights can be used to supplement the light on cloudy days or during periods of weak light to ensure that seedlings receive enough energy for photosynthesis.

[0058] Starting from the 4th day after sowing, ventilation will be carried out from 8:00 to 17:00 every day in order to better regulate the humidity and carbon dioxide concentration in the seedling shed and promote photosynthesis and gas exchange.

[0059] Adjust the watering frequency and amount according to the weather conditions and the dryness of the substrate to maintain appropriate humidity.

[0060] Seedling transplantation: Transplant daylily seedlings into soil treated with a soil treatment agent.

[0061] Choose loose, fertile, and well-drained soil for transplanting;

[0062] Before transplanting, the soil should be deeply tilled to improve its aeration and water retention; and a soil treatment agent should be used to disinfect and treat the soil to reduce the occurrence of pests and diseases; the soil treatment agent selected in this embodiment of the invention can ensure its friendliness to the soil environment and its safety for the growth of daylily seedlings.

[0063] When transplanting, the seedlings should be carefully removed from the seedling substrate, keeping the root system as intact as possible and avoiding damage to improve the survival rate after transplanting.

[0064] Dig a hole in the prepared soil, the depth and width of which should be slightly larger than the size of the seedling's root system; place the seedling in the hole, gently cover the roots with soil, and gently press it down to ensure that the seedling is in close contact with the soil.

[0065] After transplanting, water should be applied promptly to promote close contact between the seedlings and the soil and to encourage root growth.

[0066] For a period of time after transplanting, apply an appropriate amount of well-rotted farmyard manure or compound fertilizer to provide sufficient nutrition. As the seedlings grow, topdressing should be applied in a timely manner according to their growth and soil fertility.

[0067] Regularly cultivate and weed to improve soil aeration and reduce the impact of weeds on daylily growth. When cultivating, avoid damaging the daylily's root system.

[0068] According to the weight parts, the seed treatment agent includes 0.05 parts daylily exovesicles, 5 parts abscisic acid and 6 parts gibberellin; the seedling substrate includes 4 parts daylily exovesicles, 60 parts peat moss and 80 parts perlite; the soil treatment agent includes 3 parts daylily exovesicles, 40 parts vermiculite powder and 30 parts weathered coal.

[0069] Example 3

[0070] This embodiment provides a method for cultivating daylilies resistant to leaf rust, the method comprising the following steps:

[0071] Seed treatment: Select healthy daylily plants that have been planted for 6 years. During the initial flowering period, leave 3-4 robust flower buds on each flower stalk without picking them, allowing them to produce fruit as daylily seeds. Sterilize the daylily seeds. After sterilization, soak the daylily seeds in a seed treatment agent and place them at a constant temperature of 35-37℃ for 6-8 days to obtain germinated daylily seeds.

[0072] Seedling management: Sow the germinated daylily seeds in a seedling substrate with a thickness of 5-6cm and cultivate until seedlings emerge to obtain daylily seedlings; when the daylily seedlings grow to a certain height (e.g., 5-6cm) and have a well-developed root system, transplant them.

[0073] In this embodiment of the invention, a thickness of 5-6 cm can provide better heat preservation and moisture retention performance, while promoting root development; it also ensures good drainage of the seedling substrate to avoid seed rot caused by excessive moisture.

[0074] The cultivation conditions are as follows:

[0075] During the day (6:00-18:00), maintain the temperature at 25-28℃ to promote seedling firmness and enhance stress resistance; at night (18:01-5:59), maintain the temperature at 18-20℃ to help seedlings maintain growth vitality at night and reduce energy consumption.

[0076] If natural light is insufficient, plant growth lights can be used to supplement the light on cloudy days or during periods of weak light to ensure that seedlings receive enough energy for photosynthesis.

[0077] Starting from the 4th day after sowing, ventilation will be carried out from 8:00 to 17:00 every day in order to better regulate the humidity and carbon dioxide concentration in the seedling shed and promote photosynthesis and gas exchange.

[0078] Adjust the watering frequency and amount according to the weather conditions and the dryness of the substrate to maintain appropriate humidity.

[0079] Seedling transplantation: Transplant daylily seedlings into soil treated with a soil treatment agent.

[0080] Choose loose, fertile, and well-drained soil for transplanting;

[0081] Before transplanting, the soil should be deeply tilled to improve its aeration and water retention; and a soil treatment agent should be used to disinfect and treat the soil to reduce the occurrence of pests and diseases; the soil treatment agent selected in this embodiment of the invention can ensure its friendliness to the soil environment and its safety for the growth of daylily seedlings.

[0082] When transplanting, the seedlings should be carefully removed from the seedling substrate, keeping the root system as intact as possible and avoiding damage to improve the survival rate after transplanting.

[0083] Dig a hole in the prepared soil, the depth and width of which should be slightly larger than the size of the seedling's root system; place the seedling in the hole, gently cover the roots with soil, and gently press it down to ensure that the seedling is in close contact with the soil.

[0084] After transplanting, water should be applied promptly to promote close contact between the seedlings and the soil and to encourage root growth.

[0085] For a period of time after transplanting, apply an appropriate amount of well-rotted farmyard manure or compound fertilizer to provide sufficient nutrition. As the seedlings grow, topdressing should be applied in a timely manner according to their growth and soil fertility.

[0086] Regularly cultivate and weed to improve soil aeration and reduce the impact of weeds on daylily growth. When cultivating, avoid damaging the daylily's root system.

[0087] According to the weight parts, the seed treatment agent includes 0.05 parts daylily exovesicles, 4 parts abscisic acid and 3 parts gibberellin; the seedling substrate includes 3 parts daylily exovesicles, 50 parts peat moss and 60 parts perlite; the soil treatment agent includes 2 parts daylily exovesicles, 30 parts vermiculite powder and 26 parts weathered coal.

[0088] Comparative Example 1

[0089] This comparative example provides a method for cultivating daylilies resistant to leaf rust, the method comprising the following steps:

[0090] Seed treatment: Select healthy daylily plants that have been planted for 6 years. During the initial flowering period, leave 3-4 robust flower buds on each flower stalk without picking them, allowing them to produce fruit as daylily seeds. Sterilize the daylily seeds. After sterilization, soak the daylily seeds in a seed treatment agent and place them at a constant temperature of 35-37℃ for 6-8 days to obtain germinated daylily seeds.

[0091] Seedling management: Sow the germinated daylily seeds in a seedling substrate with a thickness of 5-6cm and cultivate until seedlings emerge to obtain daylily seedlings; when the daylily seedlings grow to a certain height (e.g., 5-6cm) and have a well-developed root system, transplant them.

[0092] In this embodiment of the invention, a thickness of 5-6 cm can provide better heat preservation and moisture retention performance, while promoting root development; it also ensures good drainage of the seedling substrate to avoid seed rot caused by excessive moisture.

[0093] The cultivation conditions are as follows:

[0094] During the day (6:00-18:00), maintain the temperature at 25-28℃ to promote seedling firmness and enhance stress resistance; at night (18:01-5:59), maintain the temperature at 18-20℃ to help seedlings maintain growth vitality at night and reduce energy consumption.

[0095] If natural light is insufficient, plant growth lights can be used to supplement the light on cloudy days or during periods of weak light to ensure that seedlings receive enough energy for photosynthesis.

[0096] Starting from the 4th day after sowing, ventilation will be carried out from 8:00 to 17:00 every day in order to better regulate the humidity and carbon dioxide concentration in the seedling shed and promote photosynthesis and gas exchange.

[0097] Adjust the watering frequency and amount according to the weather conditions and the dryness of the substrate to maintain appropriate humidity.

[0098] Seedling transplantation: Transplant daylily seedlings into soil treated with a soil treatment agent.

[0099] Choose loose, fertile, and well-drained soil for transplanting;

[0100] Before transplanting, the soil should be deeply tilled to improve its aeration and water retention; and a soil treatment agent should be used to disinfect and treat the soil to reduce the occurrence of pests and diseases; the soil treatment agent selected in this embodiment of the invention can ensure its friendliness to the soil environment and its safety for the growth of daylily seedlings.

[0101] When transplanting, the seedlings should be carefully removed from the seedling substrate, keeping the root system as intact as possible and avoiding damage to improve the survival rate after transplanting.

[0102] Dig a hole in the prepared soil, the depth and width of which should be slightly larger than the size of the seedling's root system; place the seedling in the hole, gently cover the roots with soil, and gently press it down to ensure that the seedling is in close contact with the soil.

[0103] After transplanting, water should be applied promptly to promote close contact between the seedlings and the soil and to encourage root growth.

[0104] For a period of time after transplanting, apply an appropriate amount of well-rotted farmyard manure or compound fertilizer to provide sufficient nutrition. As the seedlings grow, topdressing should be applied in a timely manner according to their growth and soil fertility.

[0105] Regularly cultivate and weed to improve soil aeration and reduce the impact of weeds on daylily growth. When cultivating, avoid damaging the daylily's root system.

[0106] According to the weight parts, the seed treatment agent includes 4 parts abscisic acid and 3 parts gibberellin; the seedling substrate includes 3 parts daylily vesicles, 50 parts peat moss and 60 parts perlite; the soil treatment agent includes 2 parts daylily vesicles, 30 parts vermiculite powder and 26 parts weathered coal.

[0107] Comparative Example 2

[0108] This comparative example provides a method for cultivating daylilies resistant to leaf rust, the method comprising the following steps:

[0109] Seed treatment: Select healthy daylily plants that have been planted for 6 years. During the initial flowering period, leave 3-4 robust flower buds on each flower stalk without picking them, allowing them to produce fruit as daylily seeds. Sterilize the daylily seeds. After sterilization, soak the daylily seeds in a seed treatment agent and place them at a constant temperature of 35-37℃ for 6-8 days to obtain germinated daylily seeds.

[0110] Seedling management: Sow the germinated daylily seeds in a seedling substrate with a thickness of 5-6cm and cultivate until seedlings emerge to obtain daylily seedlings; when the daylily seedlings grow to a certain height (e.g., 5-6cm) and have a well-developed root system, transplant them.

[0111] In this embodiment of the invention, a thickness of 5-6 cm can provide better heat preservation and moisture retention performance, while promoting root development; it also ensures good drainage of the seedling substrate to avoid seed rot caused by excessive moisture.

[0112] The cultivation conditions are as follows:

[0113] During the day (6:00-18:00), maintain the temperature at 25-28℃ to promote seedling firmness and enhance stress resistance; at night (18:01-5:59), maintain the temperature at 18-20℃ to help seedlings maintain growth vitality at night and reduce energy consumption.

[0114] If natural light is insufficient, plant growth lights can be used to supplement the light on cloudy days or during periods of weak light to ensure that seedlings receive enough energy for photosynthesis.

[0115] Starting from the 4th day after sowing, ventilation will be carried out from 8:00 to 17:00 every day in order to better regulate the humidity and carbon dioxide concentration in the seedling shed and promote photosynthesis and gas exchange.

[0116] Adjust the watering frequency and amount according to the weather conditions and the dryness of the substrate to maintain appropriate humidity.

[0117] Seedling transplantation: Transplant daylily seedlings into soil treated with a soil treatment agent.

[0118] Choose loose, fertile, and well-drained soil for transplanting;

[0119] Before transplanting, the soil should be deeply tilled to improve its aeration and water retention; and a soil treatment agent should be used to disinfect and treat the soil to reduce the occurrence of pests and diseases; the soil treatment agent selected in this embodiment of the invention can ensure its friendliness to the soil environment and its safety for the growth of daylily seedlings.

[0120] When transplanting, the seedlings should be carefully removed from the seedling substrate, keeping the root system as intact as possible and avoiding damage to improve the survival rate after transplanting.

[0121] Dig a hole in the prepared soil, the depth and width of which should be slightly larger than the size of the seedling's root system; place the seedling in the hole, gently cover the roots with soil, and gently press it down to ensure that the seedling is in close contact with the soil.

[0122] After transplanting, water should be applied promptly to promote close contact between the seedlings and the soil and to encourage root growth.

[0123] For a period of time after transplanting, apply an appropriate amount of well-rotted farmyard manure or compound fertilizer to provide sufficient nutrition. As the seedlings grow, topdressing should be applied in a timely manner according to their growth and soil fertility.

[0124] Regularly cultivate and weed to improve soil aeration and reduce the impact of weeds on daylily growth. When cultivating, avoid damaging the daylily's root system.

[0125] According to the weight parts, the seed treatment agent includes 0.05 parts daylily exovesicles, 4 parts abscisic acid and 3 parts gibberellin; the seedling substrate includes 50 parts peat moss and 60 parts perlite; the soil treatment agent includes 2 parts daylily exovesicles, 30 parts vermiculite powder and 26 parts weathered coal.

[0126] Comparative Example 3

[0127] This comparative example provides a method for cultivating daylilies resistant to leaf rust, the method comprising the following steps:

[0128] Seed treatment: Select healthy daylily plants that have been planted for 6 years. During the initial flowering period, leave 3-4 robust flower buds on each flower stalk without picking them, allowing them to produce fruit as daylily seeds. Sterilize the daylily seeds. After sterilization, soak the daylily seeds in a seed treatment agent and place them at a constant temperature of 35-37℃ for 6-8 days to obtain germinated daylily seeds.

[0129] Seedling management: Sow the germinated daylily seeds in a seedling substrate with a thickness of 5-6cm and cultivate until seedlings emerge to obtain daylily seedlings; when the daylily seedlings grow to a certain height (e.g., 5-6cm) and have a well-developed root system, transplant them.

[0130] In this embodiment of the invention, a thickness of 5-6 cm can provide better heat preservation and moisture retention performance, while promoting root development; it also ensures good drainage of the seedling substrate to avoid seed rot caused by excessive moisture.

[0131] The cultivation conditions are as follows:

[0132] During the day (6:00-18:00), maintain the temperature at 25-28℃ to promote seedling firmness and enhance stress resistance; at night (18:01-5:59), maintain the temperature at 18-20℃ to help seedlings maintain growth vitality at night and reduce energy consumption.

[0133] If natural light is insufficient, plant growth lights can be used to supplement the light on cloudy days or during periods of weak light to ensure that seedlings receive enough energy for photosynthesis.

[0134] Starting from the 4th day after sowing, ventilation will be carried out from 8:00 to 17:00 every day in order to better regulate the humidity and carbon dioxide concentration in the seedling shed and promote photosynthesis and gas exchange.

[0135] Adjust the watering frequency and amount according to the weather conditions and the dryness of the substrate to maintain appropriate humidity.

[0136] Seedling transplantation: Transplant daylily seedlings into soil treated with a soil treatment agent.

[0137] Choose loose, fertile, and well-drained soil for transplanting;

[0138] Before transplanting, the soil should be deeply tilled to improve its aeration and water retention; and a soil treatment agent should be used to disinfect and treat the soil to reduce the occurrence of pests and diseases; the soil treatment agent selected in this embodiment of the invention can ensure its friendliness to the soil environment and its safety for the growth of daylily seedlings.

[0139] When transplanting, the seedlings should be carefully removed from the seedling substrate, keeping the root system as intact as possible and avoiding damage to improve the survival rate after transplanting.

[0140] Dig a hole in the prepared soil, the depth and width of which should be slightly larger than the size of the seedling's root system; place the seedling in the hole, gently cover the roots with soil, and gently press it down to ensure that the seedling is in close contact with the soil.

[0141] After transplanting, water should be applied promptly to promote close contact between the seedlings and the soil and to encourage root growth.

[0142] For a period of time after transplanting, apply an appropriate amount of well-rotted farmyard manure or compound fertilizer to provide sufficient nutrition. As the seedlings grow, topdressing should be applied in a timely manner according to their growth and soil fertility.

[0143] Regularly cultivate and weed to improve soil aeration and reduce the impact of weeds on daylily growth. When cultivating, avoid damaging the daylily's root system.

[0144] According to the weight parts, the seed treatment agent includes 0.05 parts daylily vesicles, 4 parts abscisic acid and 3 parts gibberellin; the seedling substrate includes 3 parts daylily vesicles, 50 parts peat moss and 60 parts perlite; the soil treatment agent includes 30 parts vermiculite powder and 26 parts weathered coal.

[0145] Comparative Example 4

[0146] This comparative example provides a method for cultivating daylilies resistant to leaf rust, the method comprising the following steps:

[0147] Seed treatment: Select healthy daylily plants that have been planted for 6 years. During the initial flowering period, leave 3-4 robust flower buds on each flower stalk without picking them, allowing them to produce fruit as daylily seeds. Sterilize the daylily seeds. After sterilization, soak the daylily seeds in a seed treatment agent and place them at a constant temperature of 35-37℃ for 6-8 days to obtain germinated daylily seeds.

[0148] Seedling management: Sow the germinated daylily seeds in a seedling substrate with a thickness of 5-6cm and cultivate until seedlings emerge to obtain daylily seedlings; when the daylily seedlings grow to a certain height (e.g., 5-6cm) and have a well-developed root system, transplant them.

[0149] In this embodiment of the invention, a thickness of 5-6 cm can provide better heat preservation and moisture retention performance, while promoting root development; it also ensures good drainage of the seedling substrate to avoid seed rot caused by excessive moisture.

[0150] The cultivation conditions are as follows:

[0151] During the day (6:00-18:00), maintain the temperature at 25-28℃ to promote seedling firmness and enhance stress resistance; at night (18:01-5:59), maintain the temperature at 18-20℃ to help seedlings maintain growth vitality at night and reduce energy consumption.

[0152] If natural light is insufficient, plant growth lights can be used to supplement the light on cloudy days or during periods of weak light to ensure that seedlings receive enough energy for photosynthesis.

[0153] Starting from the 4th day after sowing, ventilation will be carried out from 8:00 to 17:00 every day in order to better regulate the humidity and carbon dioxide concentration in the seedling shed and promote photosynthesis and gas exchange.

[0154] Adjust the watering frequency and amount according to the weather conditions and the dryness of the substrate to maintain appropriate humidity.

[0155] Seedling transplantation: Transplant daylily seedlings into soil treated with a soil treatment agent.

[0156] Choose loose, fertile, and well-drained soil for transplanting;

[0157] Before transplanting, the soil should be deeply tilled to improve its aeration and water retention; and a soil treatment agent should be used to disinfect and treat the soil to reduce the occurrence of pests and diseases; the soil treatment agent selected in this embodiment of the invention can ensure its friendliness to the soil environment and its safety for the growth of daylily seedlings.

[0158] When transplanting, the seedlings should be carefully removed from the seedling substrate, keeping the root system as intact as possible and avoiding damage to improve the survival rate after transplanting.

[0159] Dig a hole in the prepared soil, the depth and width of which should be slightly larger than the size of the seedling's root system; place the seedling in the hole, gently cover the roots with soil, and gently press it down to ensure that the seedling is in close contact with the soil.

[0160] After transplanting, water should be applied promptly to promote close contact between the seedlings and the soil and to encourage root growth.

[0161] For a period of time after transplanting, apply an appropriate amount of well-rotted farmyard manure or compound fertilizer to provide sufficient nutrition. As the seedlings grow, topdressing should be applied in a timely manner according to their growth and soil fertility.

[0162] Regularly cultivate and weed to improve soil aeration and reduce the impact of weeds on daylily growth. When cultivating, avoid damaging the daylily's root system.

[0163] According to the weight parts, the seed treatment agent includes 0.05 parts daylily extract, 4 parts abscisic acid and 3 parts gibberellin; the seedling substrate includes 3 parts daylily exovesicles, 50 parts peat moss and 60 parts perlite; the soil treatment agent includes 2 parts daylily exovesicles, 30 parts vermiculite powder and 26 parts weathered coal.

[0164] The preparation method of daylily extract is as follows: soak daylily in ethanol and stir to dissolve the target component in ethanol to obtain daylily extract.

[0165] Effect verification

[0166] Experimental Methods: The experimental site was a daylily planting base in Wennan Town, Xintai City, Shandong Province; the daylily variety used was April Flower; the experiment included seven treatments: Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4. Fertilizer and water management were good. A plot-based experimental method was used, with each plot covering an area of ​​8m². 2 Twenty plants were planted in each plot, with a plant spacing of 30cm×40cm and a row spacing of 1m, arranged in a randomized block. When the seedlings were 30-45cm tall, with stems 0.6-0.8cm thick and 15-20 leaves, the severity of daylily leaf rust was recorded, and the incidence rate of each leaf on the plant was calculated to obtain the average incidence rate for each plant.

[0167] The resistance level of daylilies was identified according to the grading standards shown in Table 1, and the experimental results are shown in Table 2.

[0168] Table 1 Grading Standards for Daylily Leaf Rust

[0169]

[0170] Table 2. Incidence of leaf rust in daylily plants

[0171] Processing group Incidence rate Incidence level Example 1 Disease incidence rate of the entire plant is less than 5%. China Anti Example 2 Disease incidence rate of the entire plant is less than 5%. China Anti Example 3 0% of the entire plant was disease-free. High resistance Comparative Example 1 Disease incidence rate ≥40% in the entire plant High Sensitivity (HS) Comparative Example 2 Disease incidence rate ≥40% in the entire plant High Sensitivity (HS) Comparative Example 3 Disease incidence rate ≥35% in the whole plant High Sensitivity (HS) Comparative Example 4 Disease incidence rate ≥30% in the whole plant High Sensitivity (HS)

[0172] Table 2 shows that the leaf rust incidence rate of daylily plants grown using the leaf rust-resistant daylily cultivation method of this invention is 0-5%. Among them, daylily plants grown using the leaf rust-resistant daylily cultivation method of Example 3 exhibit extremely high resistance to leaf rust, with the disease almost never occurring. In contrast, daylily plants grown without the leaf rust-resistant daylily cultivation method of this invention show extremely poor resistance to leaf rust, with the disease easily occurring and developing rapidly, usually severely impacting yield or quality, and are therefore unsuitable for cultivating leaf rust-resistant daylilies.

[0173] The efficacy verification experiments show that the combined use of the seed treatment agent of this invention, which includes daylily vesicles, abscisic acid, and gibberellin; the seedling substrate, which includes daylily vesicles, peat moss, and perlite; and the soil treatment agent, which includes daylily vesicles, vermiculite powder, and weathered coal, in this combined planting system can improve the resistance of daylilies to leaf rust, as well as increase the yield and quality of daylilies. During the experimental screening process, the inventors conducted extensive screening experiments. They tried replacing daylily vesicles, abscisic acid, gibberellin, peat moss, perlite, vermiculite powder, and weathered coal with other substances. They found that the replaced technical solutions did not significantly improve the resistance of daylilies to leaf rust or the yield and quality of daylilies. They also tried replacing cherry vesicles with cherry extract, and found that the replaced technical solutions also had only moderate effects on improving the resistance of daylilies to leaf rust or the yield and quality of daylilies.

[0174] This is because: Firstly, daylily vesicles regulate the activity of abscisic acid and gibberellin, enabling seeds to acquire stronger growth vigor and resilience during germination, thus laying the foundation for subsequent growth and resistance to leaf rust. Secondly, in substrate preparation, daylily vesicles interact with peat moss and perlite to regulate the soil microenvironment, promote the growth and reproduction of beneficial microorganisms, and enhance soil fertility, providing more favorable conditions for daylily growth and resistance to leaf rust. Thirdly, daylily vesicles further improve the soil environment and increase soil fertility through interaction with vermiculite powder and weathered coal, thus providing better protection for daylily growth and resistance to leaf rust.

[0175] Furthermore, the exovesicles of daylilies play an important role in daylily cultivation. They may provide active ingredients (daylily exovesicles may contain substances that stimulate the daylily plant's immune system; these substances, upon contact with daylilies, can trigger disease-resistant signaling pathways within the daylily, thereby activating a series of defense responses, such as the production of disease-related proteins and the synthesis of antibacterial substances; these defense responses can effectively inhibit the colonization and spread of *Hemerocallis fulva* rust) and promote nutrient absorption and growth in daylilies (daylily exovesicles may also contain substances that promote daylily growth). The exoves of daylilies provide nutrients for the absorption and growth of daylily plants. By improving the root environment and enhancing root vitality, the exoves of daylilies help daylilies better absorb and utilize nutrients and water from the soil. This not only enhances the resistance of daylilies to leaf rust but also improves the overall growth vigor and yield of daylilies. The exoves also act as a physical barrier (the exoves form a protective layer on the surface of the daylily plant, which may have a certain physical barrier effect; this protective layer can block the direct contact and infection of daylily rust spores, thereby reducing the incidence of leaf rust).

[0176] The embodiments described above are only some, not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art through related deductions and substitutions based on the inventive concept, without inventive effort, are within the scope of protection of the present invention.

Claims

1. A method for cultivating daylilies resistant to leaf rust, characterized in that, The planting method includes the following steps: Seed treatment: After sterilization, daylily seeds are soaked in seed treatment agent and then placed at a constant temperature of 35-37℃ for 6-8 days to obtain germinated daylily seeds. Seedling management: Germinated daylily seeds are sown in seedling substrate and cultivated until germination, thus obtaining daylily seedlings; Seedling transplantation: Transplant daylily seedlings into soil treated with a soil treatment agent; According to the weight percentages, the seed treatment agent comprises 0.03-0.05 parts of daylily exovesicles, 3-5 parts of abscisic acid and 2-6 parts of gibberellin; According to the weight proportions, the seedling substrate includes 2-4 parts daylily vesicles, 32-60 parts peat moss and 50-80 parts perlite; According to the weight proportions, the soil treatment agent comprises 1-3 parts daylily exovesicles, 26-40 parts vermiculite powder, and 21-30 parts weathered coal; The leaf rust disease mentioned is caused by *Hemerocallis fulva*. The daylily exovesicles are natural nanoscale vesicles directly extracted from daylily plants by differential centrifugation. The preparation method of the daylily exovesicles is as follows: Weigh 150-250g of fresh daylily and pour it into a crusher. Add 150-250mL of sterile PBS and crush and homogenize. Centrifuge at 3000-4000×g, 4°C for 10-20min to remove larger residues. Take the yellow transparent solution in the middle layer and centrifuge at 5000-6000×g, 4°C for 20-30min. Take the supernatant and ultracentrifuge at 80000-90000×g, 4°C for 20-30min. Then resuspend the precipitate with 1-3mL of sterile PBS and ultracentrifuge at 90000-110000×g, 4°C for 30-40min. After centrifugation, resuspend the precipitate with 1-3mL of sterile PBS to obtain the daylily exovesicles.

2. The application of the planting method described in claim 1 in improving the resistance of daylilies to leaf rust.

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