Method for increasing seedling rate of seeds of extremely-small-population plant paliurus angustifolius and improving growth state of seedlings

Abstract

The invention relates to a method for increasing the seedling rate of seeds of extremely-small-population plants, i.e., hedyotis diffusa, and improving the growth state of seedlings. The method comprises the steps of collecting and screening the seeds, cleaning and sterilizing the seeds, promoting germination of the seeds, planting, transplanting and managing the seedlings. According to the method, the seedling rate of the seeds and the growth performance of the seedlings are remarkably improved, the seedling rate of normal seeds reaches 96.72%, the seedling rate of small seeds reaches 90.25%, the seedlings can grow to 45.52 cm in one year, the ground diameter can reach 5.04 mm, the seedlings are robust and consistent in growth state, and a seedling foundation, a scientific basis and a technical support can be provided for returning to nature and achieving population reconstruction; and a technical foundation is laid for the aspects of biological protection, ecological restoration, resource development and utilization and the like of the species, and the method has great practical significance for rescuing the endangered tree species.

Description

Technical Field

[0001] The invention relates to the technical field of seedling cultivation, in particular to a method for increasing the seedling rate of extremely small population plant Lepidium angustifolium seeds and improving the growth state of the seedlings. Background Art

[0002] Hopea chinensis Hand.-Mazz., also known as South China Hopea and Narrow-leaved Hopea, belongs to the genus Hopea of ​​Dipterocarpaceae. It grows in the foothills, valleys and hillside forests below 600m above sea level. It is one of the representative tree species of tropical evergreen seasonal rain forests in northern and southern Guangxi, and is of great value in studying the composition, geographical distribution and ecological habits of tropical rain forest flora. At the same time, its wood is hard and extremely resistant to decay, so it is called "millennium wood" and is an excellent special timber species; the resin produced is similar to ramie resin and can be used for paint manufacturing, etc.; the bark has dragon robe-like patterns, so it is also called "dragon robe tree"; the by-product is aromatic oil, which can be used as high-end cosmetics and precious Chinese medicine materials, and is of great value. However, the narrow-leaved sedge is a relict species of the Tertiary period, distributed in the "refuges" formed by local terrain. Due to the destruction of human production activities and the impact of climate change, the number of wild narrow-leaved sedge individuals has decreased sharply in the past 20 years, and the species is threatened with extinction. It has been classified as a national second-level key protected plant, a national extremely small population species, and has been listed as a critically endangered (CR) species by the World Conservation Union (IUCN).

[0003] The study found that the narrow-leaved sedge has few fruits and there is a phenomenon of alternate years. In some years, it even has no fruits. The conversion rate of seeds to seedlings in wild populations is relatively low. Although there are seedlings under the forest, most of the seedlings are in poor growth state. The number of seedlings that can grow into saplings and adult trees is small. Even if the seedlings grow to about 20 cm, they often die in large numbers. Through conservation measures, expanding the population is the most basic condition for saving endangered plants. Research on improving the seed seedling rate and seedling growth performance of narrow-leaved sedge is of great value for the protection and expansion of wild populations of this species, and the relocation and near-site rescue protection of species. So far, there has been no report on the seed seedling technology of narrow-leaved sedge, and it is urgent to carry out systematic seedling technology research. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems that under natural conditions, few narrow-leaved sedge seeds are converted into seedlings and the growth state of the seedlings is poor. Under the condition of a certain number of seeds, more seeds can be converted into seedlings, and the growth state of the seedlings can be improved, thereby providing robust seedlings for the seedlings to settle and return to the wild.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for increasing the seedling rate of a very small population of a plant, Scutellaria angustifolia, and improving the growth state of the seedlings, the main operating steps of which are as follows:

[0007] (1) Seed collection and screening:

[0008] Collect fresh and mature seeds without pests and diseases in the natural population distribution area of ​​Sphaerocephala angustifolia, remove the wings on both sides of the seeds and sort them according to size;

[0009] (2) Seed cleaning and sterilization:

[0010] After washing the seeds with clean water to remove the impurities on the surface of the seeds, wrap the seeds and fine sand with gauze and rub them gently repeatedly, wash off the fine sand with clean water, soak them in a 10 mg / mL aqueous solution of crude extract of leaves and branches of Scutellaria angustifolia for 20 minutes, then stir and soak them in a 0.1% chlorhexidine aqueous solution for 5 minutes, and rinse them with running water for 3 to 5 minutes;

[0011] (3) Seed germination promotion:

[0012] Put the small seeds into a sealed bag with a germination promoter, and then soak them together with normal seeds in warm water at 30-35℃ for 20-30 minutes. Sow the soaked seeds on the treated sand bed, spray to keep the sand bed moist, and use wire to make an arched shed on the sand bed, and cover it with plastic film.

[0013] (4) Planting: After the cotyledons and hypocotyls of the seeds have fully germinated, gently pull the seeds out of the sand bed, rinse off the fine sand with clean water, and plant them in a seedling container cup. When planting, be careful to gently bury the radicle into the soil and be careful not to damage or break the radicle;

[0014] (5) Transplantation: When the seedlings grow to 20 to 30 cm in height, they are transplanted into new cups. When changing cups, the longer roots are trimmed, and then the seedling cups are immersed in the root protection agent for 3 to 5 minutes. After that, the non-woven bag is cut open and the seedlings are transplanted into a larger seedling bag.

[0015] (6) Seedling management: After planting and transplanting, the seedlings need to be placed in an outdoor nursery greenhouse with a shade net and sprayed with water once a day. The light transmittance should be maintained at 40-50% within a week. After a week, the light intensity should be gradually increased. One month after planting and transplanting, the light transmittance should be increased to 80-90%. Nutrient solution should be sprayed every 15-20 days.

[0016] Preferably, the collection of fresh, mature seeds free of pests and diseases in step (1) above includes collecting seeds from trees and picking up fallen seeds; the sign of mature seeds refers to seeds whose seed coats are all yellow-green and whose seed wings are dark yellow or brown; the basis for judging fresh seeds free of pests and diseases is that there are no insect bites on the surface of the seeds, the seed coat has not yet wilted and wrinkled, and the seed wings have not yet dehydrated and dried up; the method of screening and classifying by size is to use a sieve with a diameter of 43 cm and a pore size of 10 mm to filter the seeds, and seeds with a diameter ≥10 mm are classified as normal seeds, and seeds with a diameter of <10 mm are classified as small seeds.

[0017] Preferably, the method for preparing the crude extract of branches and leaves of Scutellaria baicalensis in the above step (2) is to collect the branches and leaves of Scutellaria baicalensis, dry them in a drying oven at 50°C, crush them, and soak them in a methanol solution with a volume 5 times that of their mass for 48 hours to obtain the extract.

[0018] Preferably, the sprout promoter in step (3) above consists of 1.0-1.5 mg / L IAA + 0.8-1.0 mg / L GA3 + 50-100 mg / L KH2PO3 + 200-300 mg / L NH4NO3 + 100-200 mg / L CaCl2.

[0019] Preferably, the sowing method in the above step (3) is to lightly press the seeds into shallow pits, with a spacing of 3 to 5 cm between the seeds, and then sprinkle a thin layer of sand with a sand covering thickness of ≤0.5 mm but ensuring that the seeds are completely covered without being exposed; the spraying refers to spraying water with a sprayable container, and it is important to avoid excessive water volume that causes the seeds to be exposed on the sand.

[0020] Preferably, the seedling container cup in step (4) above is a non-woven cup with a diameter of 8 cm and a height of 12 cm, the matrix is ​​a coconut bran: red heart soil: vermiculite with a volume ratio of 5:3:1, and after the matrix is ​​placed in the seedling container, it is soaked with a 3% FeSO4 aqueous solution.

[0021] Preferably, the root protection nutrient agent in step (5) above is 0.5-1.0 mg / L GGR + 50-100 mg / L KH2PO3 + 800-1000 mg / L KNO3.

[0022] Preferably, the larger seedling bag described in the above step (5) refers to a non-woven cup with a diameter of 20 cm and a height of 24 cm. The matrix is ​​placed in layers in the seedling bag. The upper matrix is ​​made of red heart soil: peat soil: mushroom residue with a volume ratio of 5:2:1, and the bottom matrix is ​​made of coconut bran: river sand: vermiculite in a ratio of 4:4:1. The volume ratio of the upper matrix to the bottom matrix is ​​2:1.

[0023] Preferably, the nutrient solution in step (6) above is 30-50 mg / L KH2PO3+400-500 mg / L KNO3, and the spraying method is to spray the leaves with a spray so that the substrate is soaked with the nutrient solution.

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

[0025] 1. The present invention systematically proposes a series of detailed schemes from seed collection and germination promotion to seedling growth. In particular, it innovatively proposes to use different germination promotion schemes for seeds of different sizes, use different seedling containers and substrates for seedlings at different developmental stages, soak the roots in root protection nutrients when changing cups and transplanting, and spray the seedlings with specific nutrient solution, which significantly improves the seed seedling rate and the growth performance of seedlings, so that the normal seed seedling rate reaches 96.72%, and the small seed seedling rate reaches 90.25%. The seedlings can grow to 45.52 cm in height and 5.04 mm in ground diameter in one year. The seedlings are strong and have a consistent growth state, which provides a seedling foundation, scientific basis and technical support for their return to nature and population reconstruction.

[0026] 2. When treating seeds in the present invention, the seed wings are firstly peeled off, which can not only avoid wasting more seedling raising space due to longer seed wings, but also improve the germination efficiency. Longer seed wings will make it impossible for seeds to be in close contact with the matrix and absorb water and other substances to promote germination. In addition, the seed wings have a significant inhibitory effect on seed germination. Peeling off the seed wings plays an important role in promoting seed germination. Afterwards, fine sand wrapped in gauze is rubbed with the seeds to increase friction, batch process the seed coat, and reduce the inhibition of the seed coat on seed germination.

[0027] 3. The seed sterilization scheme proposed in the present invention innovatively adds the step of soaking the seeds in an aqueous solution of the crude extract of Scutellaria baicalensis, which can utilize the antibacterial activity of the crude extract itself without causing any harm to the seeds, thereby improving the sterilization success rate without damaging the vitality of the seeds, thereby achieving an ideal effect.

[0028] 4. The germination promotion scheme proposed in the present invention adopts warm water immersion to promote germination, and seeds of different sizes are classified. Smaller seeds are soaked in warm water and germination promoters are added at the same time, so that the germination rate of seeds with lower germination rate in natural state is significantly improved, and the relatively scarce germplasm resources are fully utilized. Under the condition of a certain number of seeds, more seeds are promoted to be transformed into seedlings, which lays a technical foundation for the research on conservation biology, restoration ecology and development and utilization of resources of this species.

[0029] 5. In the germination promotion scheme proposed in the present invention, after the sand bed is treated with potassium permanganate disinfection, the temperature of the sand bed can be appropriately increased by soaking the sand bed with warm water at 35-40°C. The seeds of Scutellaria sphenanthera mature in December and January when the temperature is relatively low. Since its seeds are typical stubborn seeds, they cannot be stored and can only be sown immediately after being harvested. The lower temperature is not conducive to seed germination. After the seeds are soaked in warm water and then sown on a sand bed with a more suitable temperature, the seed germination effect is significantly improved.

[0030] 6. Among the germination promoters screened and designed for small seeds in the present invention, IAA and GA3 act as growth regulators to promote the secretion of endogenous plant hormones in seeds and increase the activity of amylase, etc., to accelerate seed metabolism and improve seed germination ability. On the one hand, these salt ions CaCl2, NH4NO3, and KH2PO3 are indispensable nutrients in the process of plant growth and can maintain the metabolic stability inside the seeds. On the other hand, they can also act as an osmotic medium to regulate the rate at which water enters the seeds, and can also enter the embryonic cells of the seeds to affect the pre-germination metabolism of the seeds. The two synergistic effects improve the germination rate of small seeds.

[0031] 7. The present invention improves the survival rate of seedling transplanting by soaking the seedlings in root protection nutrients during re-cup transplanting. The GGR in the root protection nutrients can promote root regeneration, and KH2PO3 and KNO3 provide rich nitrogen, phosphorus, potassium and other nutrients for the growth of the plants, so that the survival rate of narrow-leaved sedge seedlings after re-cup transplanting reaches 97.37%.

[0032] 8. The present invention adopts different seedling raising matrices at different development stages, which can significantly improve the seed seedling rate and seedling growth performance of narrow-leaved sedge, and the annual seedling mortality rate can be as low as 2.71%. In the germination and seedling stage, the volume ratio of coconut bran: red heart soil: vermiculite is 5:3:1, mainly coconut bran, and vermiculite has good water and fertilizer adsorption performance, which has good water retention and good air permeability, and can fully meet the most critical moisture in the seedling stage; in the seedling growth stage, a layered matrix is ​​used, and the upper layer uses red heart soil: peat soil: mushroom residue with a volume ratio of 5:2:1, which is the nutrient layer matrix, ensuring the nutrition required for seedling growth, and the bottom layer uses coconut bran: river sand: vermiculite 4:4:1, which increases the air permeability of the bottom, avoiding rotting due to airtight roots, thereby affecting the growth state of seedlings and even death.

[0033] 9. The present invention manages seedlings by spraying nutrient solution. Compared with the ordinary method of spreading fertilizer on the surface of the substrate, liquid nutrition is more conducive to absorption. The nitrogen, phosphorus and potassium ratio of the selected and prepared nutrient solution is precisely suitable for the growth and development of narrow-leaved sedge seed seedlings, which significantly improves the growth state of the seedlings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a picture of fresh and ripe seeds of Scutellaria angustifolia.

[0035] Figure 2 This is a picture of the seeds of Scutellaria baicalensis after sterilization.

[0036] Figure 3 This is a picture of narrow-leaved Sedum seeds sown on a sand bed to promote germination.

[0037] Figure 4 After sowing the narrow-leaved sedge seeds, sprinkle them with a thin layer of sand to cover them.

[0038] Figure 5 This is a picture of the germination seeds of Sphaerocephalum angustifolia.

[0039] Figure 6 This is a picture of the cup seedlings of narrow-leaved slope barrier seeds germinating.

[0040] Figure 7 This is a picture of the seed seedlings of narrow-leaved sedge that survived transplanting.

[0041] Figure 8 This is a picture of the seeds and seedlings of the annual narrow-leaved Sphagnum opulus. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0043] Seedling rate (%) = number of seeds that can be planted after germination / total number of seeds sown × 100;

[0044] Transplant survival rate (%) = number of transplanted surviving seedlings / total number of transplants × 100;

[0045] Mortality rate (%) = number of dead seedlings / total number of transplanted surviving seedlings × 100;

[0046] Germination lag: the number of days required for the first seed in the test seeds to germinate;

[0047] Germination period: the difference in germination time between the first seed and the last seed in the test.

[0048] Embodiment 1:

[0049] A method for increasing the seedling rate of a very small population plant, Scutellaria angustifolia, and improving the growth state of the seedlings, the operating steps are as follows:

[0050] (1) Seed collection and screening:

[0051] In the distribution area of ​​the natural population of S. angustifolia, seeds from trees are collected and fresh mature seeds that have fallen and are free of pests and diseases are picked up. The sign of mature seeds refers to seeds with yellow-green seed coats and dark yellow or brown seed wings. Fresh seeds without pests and diseases are judged based on the absence of insect bites on the surface of the seeds, the seed coat has not yet wilted and wrinkled, and the seed wings have not yet dehydrated and dried. After peeling off the seed wings on both sides, the seeds are sorted and classified according to size; the method of sorting and classifying by size is to use a sieve with a diameter of 43cm and a pore size of 10mm to filter the seeds. Seeds with a diameter of ≥10mm are classified as normal seeds, and seeds with a diameter of <10mm are classified as small seeds.

[0052] (2) Seed cleaning and sterilization:

[0053] After washing the debris on the surface of the seeds with clean water, the seeds and fine sand were wrapped with gauze and rubbed gently repeatedly, the fine sand was washed off with clean water, and the seeds were soaked in an aqueous solution of crude extract of branches and leaves of Scutellaria sutchuenensis with a mass fraction of 10 mg / mL for 20 minutes. The preparation method of the crude extract of branches and leaves of Scutellaria sutchuenensis is to collect the branches and leaves of Scutellaria sutchuenensis, dry them in a drying oven at 50°C, and then crush them, soak them in a methanol solution with a volume of 5 times the mass of the solution for 48 hours, and then stir and soak them in a 0.1% chlorhexidine aqueous solution for 5 minutes, and rinse them with running water for 3 to 5 minutes;

[0054] (3) Seed germination promotion:

[0055] Put the small seeds into a sealed bag containing a germination promoter, which is composed of 1.5mg / L IAA+0.8mg / L GA3+100mg / LKH2PO3+200mg / L NH4NO3+200mg / L CaCl2. Then soak them in 35℃ warm water for 30min together with normal seeds. After the sand bed is soaked with 0.5% potassium permanganate aqueous solution in advance, soak it with 40℃ warm water every 1h, repeat 3 to 5 times, and then sow the soaked seeds on the treated sand bed. When sowing, press the seeds lightly into shallow pits. The spacing between seeds is 5cm, and then sprinkle a thin layer of sand. The thickness of the sand coverage is ≤0.5mm, but make sure that the seeds are completely covered without being exposed. Use a spray container to spray to keep the sand bed moist, and avoid too much water that exposes the seeds on the sand. Then use wire to make an arched shed on the sand bed, and cover it with plastic film.

[0056] (4) Planting: After the cotyledons and hypocotyls of the seeds have fully sprouted, the seeds are gently pulled out from the sand bed, the fine sand is washed off with clean water, and the seeds are planted in a seedling container cup. The seedling container cup is a non-woven cup with a diameter of 8 cm and a height of 12 cm. The substrate is a coconut bran: red heart soil: vermiculite with a volume ratio of 5:3:1. After the substrate is placed in the seedling container, it is soaked with a 3% FeSO4 aqueous solution. When planting, pay attention to gently bury the radicle in the soil and do not damage or break the radicle;

[0057] (5) Transplantation: When the seedlings grow to 20 cm in height, they are transplanted to new cups. When changing cups, the longer roots are trimmed. Then, the seedling cups are immersed in a root protection nutrient agent for 5 min. The root protection nutrient agent is composed of 0.5 mg / L GGR+50 mg / L KH2PO3+1000 mg / L KNO3. Then, the non-woven bag is cut open and the seedlings are planted in a larger seedling bag. The larger seedling bag refers to a non-woven cup with a diameter of 20 cm and a height of 24 cm. The substrate is placed in layers in the seedling bag. The upper substrate is made of red heart soil: peat soil: mushroom residue in a volume ratio of 5:2:1, and the bottom substrate is made of coconut bran: river sand: vermiculite in a volume ratio of 4:4:1. The volume ratio of the upper substrate to the bottom substrate is 2:1.

[0058] (6) Seedling management: After planting and transplanting, the seedlings need to be placed in an outdoor nursery greenhouse with a shade net and sprayed with water once a day. The light transmittance should be maintained at 40-50% within one week. After one week, the light transmittance should be gradually increased. One month after planting and transplanting, the light transmittance should be increased to 80-90%. The nutrient solution should be sprayed every 15 days. The nutrient solution is 50 mg / L KH2PO3 + 400 mg / L KNO3. The spraying method is to spray the leaves with a spray and soak the substrate with the nutrient solution.

[0059] Embodiment 2:

[0060] A method for increasing the seedling rate of a very small population plant, Scutellaria angustifolia, and improving the growth state of the seedlings, the operating steps are as follows:

[0061] (1) Seed collection and screening:

[0062] In the distribution area of ​​the natural population of S. angustifolia, seeds from trees are collected and fresh mature seeds that have fallen and are free of pests and diseases are picked up. The sign of mature seeds refers to seeds with yellow-green seed coats and dark yellow or brown seed wings. Fresh seeds without pests and diseases are judged based on the absence of insect bites on the surface of the seeds, the seed coat has not yet wilted and wrinkled, and the seed wings have not yet dehydrated and dried. After peeling off the seed wings on both sides, the seeds are sorted and classified according to size; the method of sorting and classifying by size is to use a sieve with a diameter of 43cm and a pore size of 10mm to filter the seeds. Seeds with a diameter of ≥10mm are classified as normal seeds, and seeds with a diameter of <10mm are classified as small seeds.

[0063] (2) Seed cleaning and sterilization:

[0064] After washing the debris on the surface of the seeds with clean water, the seeds and fine sand were wrapped with gauze and rubbed gently repeatedly, the fine sand was washed off with clean water, and the seeds were soaked in an aqueous solution of crude extract of branches and leaves of Scutellaria sutchuenensis with a mass fraction of 10 mg / mL for 20 minutes. The preparation method of the crude extract of branches and leaves of Scutellaria sutchuenensis is to collect the branches and leaves of Scutellaria sutchuenensis, dry them in a drying oven at 50°C, and then crush them, soak them in a methanol solution with a volume of 5 times the mass of the solution for 48 hours, and then stir and soak them in a 0.1% chlorhexidine aqueous solution for 5 minutes, and rinse them with running water for 3 to 5 minutes;

[0065] (3) Seed germination promotion:

[0066] Put the small seeds into a sealed bag containing a germination promoter, which is composed of 1.0mg / L IAA+1.0mg / L GA3+50mg / LKH2PO3+200mg / L NH4NO3+100mg / L CaCl2. Then soak them in 30℃ warm water together with normal seeds for 20 minutes. After the sand bed is soaked with 0.5% potassium permanganate aqueous solution in advance, soak it with 35℃ warm water every 1 hour, repeat 3 to 5 times, and then sow the soaked seeds on the treated sand bed. When sowing, press the seeds lightly into shallow pits. The spacing between seeds is 3cm, and then sprinkle a thin layer of sand. The thickness of the sand covering is ≤0.5mm, but make sure that the seeds are completely covered without being exposed. Use a spray container to spray to keep the sand bed moist, and avoid too much water that exposes the seeds on the sand. Then use wire to make an arched shed on the sand bed, and cover it with plastic film.

[0067] (4) Planting: After the cotyledons and hypocotyls of the seeds have fully sprouted, the seeds are gently pulled out from the sand bed, the fine sand is washed off with clean water, and the seeds are planted in a seedling container cup. The seedling container cup is a non-woven cup with a diameter of 8 cm and a height of 12 cm. The substrate is a coconut bran: red heart soil: vermiculite with a volume ratio of 5:3:1. After the substrate is placed in the seedling container, it is soaked with a 3% FeSO4 aqueous solution. When planting, pay attention to gently bury the radicle in the soil and do not damage or break the radicle;

[0068] (5) Transplantation: When the seedlings grow to 30 cm in height, they are transplanted to new cups. When changing cups, the longer roots are trimmed. Then, the seedling cups are immersed in a root protection nutrient for 3 min. The root protection nutrient is composed of 1.0 mg / L GGR + 100 mg / L KH2PO3 + 800 mg / L KNO3. Then, the non-woven bag is cut open and the seedlings are planted in a larger seedling bag. The larger seedling bag is a non-woven cup with a diameter of 20 cm and a height of 24 cm. The substrate is placed in layers in the seedling bag. The upper substrate is made of red heart soil: peat soil: mushroom residue in a volume ratio of 5:2:1, and the bottom substrate is made of coconut bran: river sand: vermiculite in a volume ratio of 4:4:1. The volume ratio of the upper substrate to the bottom substrate is 2:1.

[0069] (6) Seedling management: After planting and transplanting, the seedlings need to be placed in an outdoor nursery greenhouse with a shade net and sprayed with water once a day. The light transmittance should be maintained at 40-50% within one week. After one week, the light transmittance should be gradually increased. One month after planting and transplanting, the light transmittance should be increased to 80-90%. The seedlings should be sprayed with nutrient solution every 20 days. The nutrient solution is 30 mg / L KH2PO3 + 500 mg / L KNO3. The spraying method is to spray the leaves with a spray and soak the substrate with nutrient solution.

[0070] Embodiment 3:

[0071] A method for increasing the seedling rate of a very small population plant, Scutellaria angustifolia, and improving the growth state of the seedlings, the operating steps are as follows:

[0072] (1) Seed collection and screening:

[0073] In the distribution area of ​​the natural population of S. angustifolia, seeds from trees are collected and fresh mature seeds that have fallen and are free of pests and diseases are picked up. The sign of mature seeds refers to seeds with yellow-green seed coats and dark yellow or brown seed wings. Fresh seeds without pests and diseases are judged based on the absence of insect bites on the surface of the seeds, the seed coat has not yet wilted and wrinkled, and the seed wings have not yet dehydrated and dried. After peeling off the seed wings on both sides, the seeds are sorted and classified according to size; the method of sorting and classifying by size is to use a sieve with a diameter of 43cm and a pore size of 10mm to filter the seeds. Seeds with a diameter of ≥10mm are classified as normal seeds, and seeds with a diameter of <10mm are classified as small seeds.

[0074] (2) Seed cleaning and sterilization:

[0075] After washing the debris on the surface of the seeds with clean water, the seeds and fine sand were wrapped with gauze and rubbed gently repeatedly, the fine sand was washed off with clean water, and the seeds were soaked in an aqueous solution of crude extract of branches and leaves of Scutellaria sutchuenensis with a mass fraction of 10 mg / mL for 20 minutes. The preparation method of the crude extract of branches and leaves of Scutellaria sutchuenensis is to collect the branches and leaves of Scutellaria sutchuenensis, dry them in a drying oven at 50°C, and then crush them, soak them in a methanol solution with a volume of 5 times the mass of the solution for 48 hours, and then stir and soak them in a 0.1% chlorhexidine aqueous solution for 5 minutes, and rinse them with running water for 3 to 5 minutes;

[0076] (3) Seed germination promotion:

[0077] Put the small seeds into a sealed bag containing a germination promoter, which is composed of 1.0mg / L IAA+1.0mg / L GA3+100mg / LKH2PO3+300mg / L NH4NO3+200mg / L CaCl2. Then soak them in 30℃ warm water together with normal seeds for 25 minutes. After the sand bed is soaked with 0.5% potassium permanganate aqueous solution in advance, soak it with 35℃ warm water every 1h, repeat 3 to 5 times, and then sow the soaked seeds on the treated sand bed. When sowing, press the seeds lightly into shallow pits. The spacing between seeds is 5cm, and then sprinkle a thin layer of sand. The thickness of the sand coverage is ≤0.5mm, but make sure that the seeds are completely covered without being exposed. Use a spray container to spray to keep the sand bed moist, and avoid too much water that exposes the seeds on the sand. Then use wire to make an arched shed on the sand bed, covered with plastic film.

[0078] (4) Planting: After the cotyledons and hypocotyls of the seeds have fully sprouted, the seeds are gently pulled out from the sand bed, the fine sand is washed off with clean water, and the seeds are planted in a seedling container cup. The seedling container cup is a non-woven cup with a diameter of 8 cm and a height of 12 cm. The substrate is a coconut bran: red heart soil: vermiculite with a volume ratio of 5:3:1. After the substrate is placed in the seedling container, it is soaked with a 3% FeSO4 aqueous solution. When planting, pay attention to gently bury the radicle in the soil and do not damage or break the radicle;

[0079] (5) Transplantation: When the seedlings grow to 20 cm in height, they are transplanted to new cups. When changing cups, the longer roots are trimmed. Then, the seedling cups are immersed in a root protection nutrient agent for 3 min. The root protection nutrient agent is composed of 0.5 mg / L GGR+50 mg / L KH2PO3+900 mg / L KNO3. Then, the non-woven bag is cut open and the seedlings are planted in a larger seedling bag. The larger seedling bag refers to a non-woven cup with a diameter of 20 cm and a height of 24 cm. The substrate is placed in layers in the seedling bag. The upper substrate is made of red heart soil: peat soil: mushroom residue in a volume ratio of 5:2:1, and the bottom substrate is made of coconut bran: river sand: vermiculite in a volume ratio of 4:4:1. The volume ratio of the upper substrate to the bottom substrate is 2:1.

[0080] (6) Seedling management: After planting and transplanting, the seedlings need to be placed in an outdoor nursery greenhouse with a shade net and sprayed with water once a day. The light transmittance should be maintained at 40-50% within one week. After one week, the light transmittance should be gradually increased. One month after planting and transplanting, the light transmittance should be increased to 80-90%. The seedlings should be sprayed with nutrient solution every 15 days. The nutrient solution is 50 mg / L KH2PO3 + 500 mg / L KNO3. The spraying method is to spray the leaves with a spray and soak the substrate with nutrient solution.

[0081] Comparative Example 1:

[0082] A method for seedling of narrow-leaved sedge, which is basically the same as the steps of Example 1, except that in step (3), when promoting germination of seeds, small seeds are not treated with germination promoters, but are directly placed in warm water at 30-35°C and soaked for 20 minutes like normal seeds. Comparative Example 2:

[0083] A method for seedling of narrow-leaved sedge, which is basically the same as the steps of Example 1, except that in step (3), the warm water at 30-35°C is adjusted to room temperature water when promoting seed germination, and the warm water at 35-40°C is adjusted to room temperature water when treating the sand bed. Comparative Example 3:

[0084] A method for growing seedlings of narrow-leaved sedge, which is basically the same as the step process of Example 1, except that in step (5), no root protection nutrient is used to soak the pruned roots during transplanting, and the roots are directly transplanted after being pruned.

[0085] Comparative Example 4:

[0086] A method for growing seedlings of narrow-leaved sedge, which is basically the same as the step process of Example 1, except that the seedling medium selected for transplanting in step (5) is different. The seedling medium selected in comparative example 5-1 is still the seedling medium used in step (4), that is, the volume ratio of coconut bran: red heart soil: vermiculite is 5:3:1, and the seedling medium selected in comparative example 5-2 is red heart soil.

[0087] Comparative Example 5:

[0088] A method for growing narrow-leaved sedge seeds into seedlings is basically the same as the step process of Example 1, except that in step (6) seedling management, the nutrient solution to be sprayed is adjusted to apply a commercially available general compound fertilizer, that is, a compound fertilizer with N:P:K=15:15:15 is selected and evenly spread on the surface of the substrate.

[0089] Implementation effect:

[0090] The treatment methods of Examples 1 to 3 and Comparative Examples 1 to 5 within the protection scope of the present invention were respectively used to cultivate seed seedlings of Scutellaria baicalensis, and the seedling formation effects and seedling growth states of the seeds with different treatments were statistically compared.

[0091] Table 1: Seedling rate and seedling growth status of Scutellaria baicalensis seeds in Examples 1 to 3

[0092]

[0093] The seedling rates and seedling growth states of the three embodiments of the narrow-leaved sedge are shown in Table 1. As can be seen from Table 1, embodiment 1 is the optimal embodiment, with the highest seedling rates, transplant survival rates, one-year-old seedling heights, and ground diameters of seeds of different sizes, the lowest one-year-old seedling mortality rate, the best seedling performance, and uniform seedling health. Embodiments 2 and 3 are second, but the seedling rates are all above 90%, and the one-year-old seedling mortality rate is less than 4%, which is much greater than the seedling rate and seedling growth state of the narrow-leaved sedge seeds under natural conditions without artificial interference, and therefore are also within the protection scope of the present invention.

[0094] Table 2: Comparison of germination and seedling effect between comparative examples 1 to 2 and example 1

[0095]

[0096] Comparative Example 1 mainly investigates whether the germination promoter has a promoting effect on the germination of relatively small seeds. Whether seeds can germinate smoothly and become seedlings is an important factor related to plant growth and reproduction. Under natural conditions, the seeds of endangered plants often make it difficult to germinate and become seedlings due to their own biological characteristics, and the time for germination and seedling formation varies. In the case of shortage of seed resources, the use of artificial intervention to maximize the use of various types of seeds to promote their germination and seedling formation is of great significance for the renewal of endangered plant seedlings and population recovery. Therefore, the present invention screened and studied germination promoters for relatively small seeds with a low germination rate under natural conditions. The comparison of the use effect of the germination promoter can be learned from the experimental data analysis of Comparative Example 1 and Example 1. As shown in Table 2, compared with Example 1, the germination time lag and germination duration of relatively small seeds in Comparative Example 1 were extended by 0.82 days and 9.97 days respectively, and the seedling rate was reduced by 11.81%, indicating that the germination promoter can promote the rapid germination of relatively small seeds, and can improve the uniformity of relatively small seed germination within a certain range, and also improve the seedling rate of relatively small seeds, and the germination promoter has a significant promoting effect on the germination of relatively small seeds. The germination promoter screened by the present invention is composed of plant growth regulators (IAA and GA3) and inorganic salts (KH2PO3, NH4NO3 and CaCl2), and the plant growth regulator can affect the physiological and biochemical processes related to seed germination. Inorganic salts are not only indispensable nutrients in the process of plant growth, but also maintain the metabolic stability of the inside of the seed, and can also be used as an osmotic substance to regulate the rate of water entering the seed, and can also enter the embryonic cell of the seed to affect the pre-germination metabolism of the seed. However, they all need suitable concentrations when they play their promoting effect in a coordinated manner, and too high or too low concentrations may achieve counterproductive effects. The germination-promoting agent obtained by screening a large number of experiments is suitable for the small seeds of Scutellaria serrata and achieves a relatively ideal effect. It is of great significance for making full use of the small seeds and improving the seedling rate of seeds under the condition of shortage of seed resources.

[0097] Comparative Example 2 mainly investigates whether warm water has a promoting effect on seed germination. Another important factor affecting seed germination is temperature. The physiological changes in the seed germination process are completed under the catalysis of related enzymes, and the enzymatic reaction is closely related to temperature. If the temperature is too low, the activity of related enzymes will decrease, which is not conducive to seed germination. Only suitable temperature can enhance enzyme activity, promote material and energy conversion, and improve germination effect. The effect of temperature on the germination effect of narrow-leaved sedge seeds can be known from the experimental data comparison of Comparative Example 2 and Example 1. Compared with Example 1, the germination lag and germination period of small seeds in Comparative Example 2 were extended by 0.67 days and 3.07 days, respectively, and the seedling rate was reduced by 8.83%. The germination lag and germination period of normal seeds were extended by 1.42 days and 3.03 days, respectively, and the seedling rate was reduced by 6.54%. Therefore, the warm water temperature screened by the present invention is conducive to the germination of narrow-leaved sedge seeds, and the operation of increasing the warm water to soak the seeds and treating the sand bed with warm water significantly improves the seedling rate of narrow-leaved sedge seeds.

[0098] Table 3: Comparison of survival of seedlings transplanted in comparative example 3 and example 1

[0099] deal with Transplant survival rate (%) Example 1 97.37 Comparative Example 3 92.43

[0100] Comparative Example 3 mainly investigates whether the root protection nutrient agent screened for use has an effect on improving the survival rate of transplanting. According to the growth stage of the seedlings, transplanting and replacing different seedling containers is more conducive to the growth of seedlings. During transplanting, the death of seedlings is usually caused by damage to the root system. How to protect the roots during transplanting to improve the survival rate of transplanting is of great significance. Compared with Example 1, the transplanting survival rate of Comparative Example 3 decreased by 4.94%, indicating that the root protection nutrient agent of the present invention has a promoting effect on the transplanting survival of narrow-leaved sedge. The root protection nutrient agent screened by the present invention is composed of plant growth regulator GGR and inorganic salts (KH2PO3 and KNO3). GGR is an innovative green product after chemical fertilizers, micro-fertilizers, hormones, and yield-increasing bacteria. It can significantly improve the survival rate of seedlings. It is better than a single auxin in promoting rooting. At the same time, the added inorganic salts (KH2PO3 and KNO3) can provide sufficient nutrition for rooting metabolism.

[0101] Table 4: Comparison of the growth status of one-year-old seedlings in Comparative Examples 4 to 5 and Example 1

[0102] deal with mortality rate(%) Seedling height (cm) Ground diameter (mm) Seedling performance Example 1 2.71 45.52 5.04 Green and strong leaves, consistent growth of seedlings Comparative Example 4-1 2.87 21.14 2.22 Leaves are slightly yellow, seedlings are of different heights, and are thin and weak. Comparative Example 4-2 5.94 18.29 1.48 Leaves are slightly curled and yellow, seedlings are thin and weak, and yellow tops appear Comparative Example 5 6.79 20.57 3.47 Yellow-green leaves, small leaves

[0103] Comparative Example 4 mainly investigates whether the seedling medium screened for transplanting has a promoting effect on improving the growth state of seedlings. The seedling medium can provide a basic source of nutrition for the growth of seedlings, and the quality of the seedling medium is crucial to the growth and development of seedlings. High-quality nutrient soil should have the following characteristics: rich in organic matter and good air permeability and drainage. Comparative Example 4-1 investigates whether the same seedling medium can be used throughout the development stage of narrow-leaved sedge seeds. As can be seen from Table 4, the mortality rate of the seedling medium used for planting after transplanting and changing cups is not significantly affected, and it is only increased by 0.16%, but the growth state of the seedlings is significantly different. Compared with Example 1, the seedling height of Comparative Example 4-1 is reduced by 24.38cm, the ground diameter is reduced by 2.82mm, and the leaves appear slightly yellow, the growth of the seedlings is inconsistent, and the growth state is poor. The seedling medium used in Comparative Example 4-2 is red heart soil, which is generally recognized to have a good effect. Compared with Example 1, the mortality rate of Comparative Example 4-2 increased by 3.23%, the seedling height decreased by 27.23cm, the ground diameter decreased by 3.56mm, and the leaves were slightly curled and slightly yellow, the seedlings were thin and weak, and yellow tops appeared, and the growth state was the worst. This shows that the nutritional requirements of narrow-leaved sedge in different growth periods are quite different. Only by selecting a more suitable seed seedling medium in different periods can the growth state of seedlings be improved. The seedling medium selected by the present invention is suitable for the growth requirements of narrow-leaved sedge seed seedlings, and significantly improves the growth state of seedlings.

[0104] Comparative Example 5 mainly examines whether the nutrient solution screened for spraying is more suitable for the growth of narrow-leaved sedge seed seedlings. One of the important factors affecting plant growth and development is fertilization. What fertilizer to use and how to apply it are crucial. Comparative Example 5 applied a general compound fertilizer, which was used in the form of solids sprinkled on the surface. Compared with Example 1, the mortality rate of Comparative Example 5 increased by 4.08%, the seedling height decreased by 24.95cm, the ground diameter decreased by 1.57mm, and the leaves were yellow-green and smaller, and the growth state was worse than that of Example 1. It can be seen that the nutrient solution formula screened by the present invention is suitable for the growth and survival of narrow-leaved sedge seed seedlings, and the application by spraying is more conducive to the absorption of the seedlings, which is of great significance for improving the growth state of the seedlings.

Claims

1. A method for increasing the seedling rate of a very small population of a plant, Scutellaria angustifolia, and improving the growth state of the seedlings, characterized in that: It includes seed collection and screening, seed cleaning and sterilization, seed germination promotion, planting, transplanting, and seedling management; the main operating steps are as follows: (1) Seed collection and screening: Collect fresh and mature seeds without pests and diseases in the natural population distribution area of ​​Sphaerocephala angustifolia, remove the wings on both sides of the seeds and sort them according to size; (2) Seed cleaning and sterilization: After washing the seeds with clean water to remove the impurities on the surface of the seeds, wrap the seeds and fine sand with gauze and rub them gently repeatedly, wash off the fine sand with clean water, soak them in a 10 mg / mL aqueous solution of crude extract of leaves and branches of Scutellaria angustifolia for 20 minutes, then stir and soak them in a 0.1% chlorhexidine aqueous solution for 5 minutes, and rinse them with running water for 3 to 5 minutes; (3) Seed germination promotion: Put the small seeds into a sealed bag with a germination promoter, and then soak them in 30-35℃ warm water together with normal seeds for 20-30 minutes. At the same time, soak the sand bed with 0.5% potassium permanganate aqueous solution in advance, and then soak it with 35-40℃ warm water every 1 hour, repeat 3-5 times, sow the soaked seeds on the treated sand bed, spray to keep the sand bed moist, use iron wire to make an arched shed on the sand bed, and cover it with plastic film; (4) Planting: After the cotyledons and hypocotyls of the seeds have fully germinated, gently pull the seeds out of the sand bed, rinse off the fine sand with clean water, and plant them in a seedling container cup. When planting, be careful to gently bury the radicle into the soil and be careful not to damage or break the radicle; (5) Transplantation: When the seedlings grow to 20 to 30 cm in height, they are transplanted into new cups. When changing cups, the longer roots are trimmed, and then the seedling cups are immersed in the root protection agent for 3 to 5 minutes. After that, the non-woven bag is cut open and the seedlings are transplanted into a larger seedling bag. (6) Seedling management: After planting and transplanting, the seedlings need to be placed in an outdoor nursery greenhouse with a shade net and sprayed with water once a day. The light transmittance should be maintained at 40-50% within a week. After a week, the light intensity should be gradually increased. One month after planting and transplanting, the light transmittance should be increased to 80-90%. Nutrient solution should be sprayed every 15-20 days.

2. The method for increasing the seedling establishment rate of the extremely small population plant Lepidium angustifolium and improving the growth state of the seedlings according to claim 1, characterized in that: The step (1) of collecting fresh, mature seeds free of pests and diseases includes collecting seeds from trees and picking up fallen seeds. The sign of mature seeds refers to seeds with yellow-green seed coats and dark yellow or brown seed wings. The basis for judging fresh seeds free of pests and diseases is that there are no insect bites on the surface of the seeds, the seed coat has not yet wilted and wrinkled, and the seed wings have not yet dehydrated and dried up. The size screening and classification method is to use a sieve with a diameter of 43 cm and a pore size of 10 mm to filter the seeds. Seeds with a diameter of ≥10 mm are classified as normal seeds, and seeds with a diameter of <10 mm are classified as small seeds.

3. The method for increasing the seedling establishment rate of the extremely small population plant Lepidium angustifolium and improving the growth state of the seedlings according to claim 1, characterized in that: The method for preparing the crude extract of branches and leaves of Scutellaria baicalensis in step (2) is to collect the branches and leaves of Scutellaria baicalensis, dry them in a drying oven at 50°C, crush them, and soak them in a methanol solution with a volume 5 times that of their mass for 48 hours to obtain the crude extract.

4. The method for increasing the seedling establishment rate of the extremely small population plant Lepidium angustifolium and improving the growth state of the seedlings according to claim 1, characterized in that: The germination promoter in step (3) is composed of 1.0-1.5 mg / L IAA + 0.8-1.0 mg / L GA3 + 50-100 mg / L KH2PO3 + 200-300 mg / L NH4NO3 + 100-200 mg / L CaCl2.

5. The method for increasing the seedling establishment rate of the extremely small population plant Lepidium angustifolium and improving the growth state of the seedlings according to claim 1, characterized in that: The sowing method in step (3) is to lightly press the seeds into shallow pits, with a spacing of 3 to 5 cm between the seeds, and then sprinkle a thin layer of sand with a sand covering thickness of ≤0.5 mm, but ensure that the seeds are completely covered without being exposed; the spraying refers to spraying water with a sprayable container, and it is important to avoid excessive water that causes the seeds to be exposed on the sand.

6. The method for increasing the seedling establishment rate of the extremely small population plant Lepidium angustifolium and improving the growth state of the seedlings according to claim 1, characterized in that: The seedling container cup of step (4) is a non-woven cup with a diameter of 8 cm and a height of 12 cm. The matrix is ​​a coconut bran: red heart soil: vermiculite with a volume ratio of 5:3:

1. After the matrix is ​​placed in the seedling container, it is soaked with a 3% FeSO4 aqueous solution.

7. The method for increasing the seedling establishment rate of the extremely small population plant Lepidium angustifolium and improving the growth state of the seedlings according to claim 1, characterized in that: The root protection nutrient in step (5) is 0.5-1.0 mg / L GGR + 50-100 mg / L KH2PO3 + 800-1000 mg / L KNO3.

8. The method for increasing the seedling establishment rate of the extremely small population plant Lepidium angustifolium and improving the growth state of the seedlings according to claim 1, characterized in that: The larger seedling bag described in step (5) refers to a non-woven cup with a diameter of 20 cm and a height of 24 cm. The matrix is ​​placed in layers in the seedling bag. The upper matrix is ​​made of red heart soil: peat soil: mushroom residue with a volume ratio of 5:2:1, and the bottom matrix is ​​made of coconut bran: river sand: vermiculite with a volume ratio of 4:4:

1. The volume ratio of the upper matrix to the bottom matrix is ​​2:

1.

9. The method for increasing the seedling establishment rate of the extremely small population plant Lepidium angustifolium and improving the growth state of the seedlings according to claim 1, characterized in that: The nutrient solution in step (6) is 30-50 mg / L KH2PO3+400-500 mg / L KNO3, and the spraying method is to spray the leaves with a spray so that the substrate is soaked with the nutrient solution.

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