A method for rapid and robust seedling cultivation of Polygonatum multiflorum seeds at low altitudes

Abstract

A method for rapid and robust seedling cultivation of Polygonatum multiflorum seeds at low altitudes is disclosed, comprising the following steps: 1) seed harvesting and treatment; 2) seed germination treatment; 3) site selection and seedbed preparation; 4) sowing and heat and moisture retention; 5) small arched shed construction; 6) seedling management; and 7) transplanting. This method, while ensuring a high germination rate of Polygonatum multiflorum seeds, breaks the dormancy state of the seeds and possesses key technological advantages such as a short cycle, high seedling survival rate, and low environmental requirements. Practical application of Polygonatum multiflorum seed propagation technology in areas such as mother plant treatment, seed harvesting and treatment, germination treatment, site selection and seedbed preparation, sowing and heat and moisture retention, small arched shed construction, seedling management, and transplanting allows for the establishment and improvement of a rapid and robust seedling cultivation system for Polygonatum multiflorum seeds in low-altitude environments, meeting the needs of large-scale production of Polygonatum multiflorum seedlings.

Description

Technical Field

[0001] This invention relates to plant seed seedling cultivation technology, specifically a method for rapid seedling cultivation of Polygonatum odoratum seeds at low altitudes. Background Technology

[0002] Polygonatum, a widely used medicinal and edible herb, has a broad range of applications. First recorded in the *Mingyi Bielu* (Records of Famous Physicians), it is sweet and neutral in nature, possessing the functions of tonifying qi and nourishing yin, strengthening the spleen, moistening the lungs, and benefiting the kidneys. It is used for yin deficiency and lung dryness, insufficient yin and blood, and weakness of the spleen and stomach. The *Pharmacopoeia of the People's Republic of China* (2020 edition, Part I) lists Polygonatum as originating from the dried rhizomes of three species: *Polygonatum sibiricum*, *Polygonatum multiflorum*, and *Polygonatum yunnanense*. Based on their different shapes, it is commonly known as chicken-head Polygonatum, ginger-shaped Polygonatum, and large Polygonatum. Due to its sweet and glutinous taste, *Polygonatum multiflorum* is suitable for processing into health foods and wellness products, such as dried fruit and tea, and is therefore quite popular, with its price rising year by year.

[0003] Currently, the annual market demand for Polygonatum odoratum is 7,000 to 8,000 tons, of which about 20% is used in traditional Chinese medicine clinical practice and the production of pharmaceuticals and extracts, and about 80% is used in the processing of health foods and wellness products, demonstrating the broad prospects for the development of the Polygonatum odoratum industry. However, market demand far exceeds natural production, and coupled with disorderly harvesting, wild resources of Polygonatum odoratum have sharply declined. Therefore, effective protection and artificial cultivation of Polygonatum odoratum resources are imperative. Consequently, artificial cultivation of Polygonatum odoratum has begun in various regions.

[0004] The key to the artificial cultivation of Polygonatum multiflorum lies in seedling technology. Polygonatum multiflorum can be propagated sexually (seed) or asexually (rhizome, tissue culture, cell culture). Rhizome propagation is widely used, but its propagation coefficient is low, and the quality deteriorates significantly after multiple generations. Tissue culture and cell propagation are technically demanding and difficult to mass-produce. While using Polygonatum multiflorum seeds for seedling cultivation can significantly increase the propagation rate, the seeds have a post-embryonic maturation habit, resulting in low germination and seedling rates under natural conditions. It requires two winter dormancy periods before a true leaf emerges. Furthermore, Polygonatum multiflorum has high requirements for altitude, light, and other environmental factors, leading to the slow development of the Polygonatum multiflorum seedling industry. Therefore, while ensuring a high germination rate, establishing and improving a rapid seedling cultivation technology system to address the key issues of long dormancy periods, low seedling rates, long seedling cycles, and high environmental requirements is an urgent problem to be solved in current production. Summary of the Invention

[0005] This invention provides a method for rapid and robust seedling cultivation of Polygonatum odoratum seeds at low altitudes. The purpose is to overcome the shortcomings of existing seedling cultivation techniques for Polygonatum odoratum seeds, which suffer from problems such as long dormancy periods, low seedling rates, long seedling cycles, and high environmental requirements.

[0006] A method for rapid and robust seedling cultivation of Polygonatum multiflorum seeds at low altitudes includes the following steps: 1) Seed harvesting and treatment: Harvest Polygonatum multiflorum seeds from mature Polygonatum multiflorum fruits, and soften the seed coat to obtain clean seeds; 2) Seed germination treatment: Soak Polygonatum multiflorum seeds in warm water and then perform germination treatment; 3) Site selection and seedbed preparation: Select land plots at an altitude of 100-150m as seedbeds. These seedbeds should be sheltered from the wind, sunny, and near a water source. The nursery should be located in a dry, well-drained mountain valley or farmland with convenient irrigation and drainage, and should be in loose, fertile, and well-drained loam or sandy loam soil. Apply 1.5-2 tons of well-rotted organic fertilizer per acre as base fertilizer, then deep plow to 20cm, harrow and level it, and create raised beds 15-20cm high and 0.8-1.0m wide. Cover the raised beds evenly with about 2cm of loose, raw loess soil to form the seedbed. 4) Sowing and heat / moisture retention: Sow around February of the following year. Water the seedbed thoroughly one day before sowing. Use seeds of Polygonatum odoratum for sowing. (Many have already grown into small bulbs with roots) Sow evenly on the seedbed along with peat moss. Cover the seedbed with a mulch, controlling the thickness to 2-3cm, and water it thoroughly. Then, cover the mulch with a layer of white plastic film and a layer of shade netting for heat and moisture retention. 5) Construct small arched sheds: Around late February, erect small arched sheds about 30-40cm high on each seedbed, and remove the original layer of white plastic film and shade netting from the mulch. Cover the seedlings with a small arched shed; 6) Seedling management: In early March, after the seedlings of Polygonatum odoratum emerge one after another, as the temperature warms up, remove one layer of white mulch and leave only one layer of shade netting; spray foliar fertilizer for the first time after the seedlings emerge until the leaves unfold, and then spray once every 15 days or so. Apply fertilizer 3 to 4 times in total, depending on the growth of the seedlings; 7) Transplanting: When the diameter of the rhizome of the two-year-old seedlings reaches more than 2cm and the single rhizome weighs more than 20 to 25g, transplant them after the seedlings fall back in November of the second year or during the dormant period before the beginning of spring in the third year.

[0007] Furthermore, before step 1), it is necessary to perform treatment on the mother plant of Polygonatum multiflorum: select healthy, disease-free Polygonatum multiflorum plants that are 2 to 3 years old as mother plants for seed collection, and perform pre-harvest treatment on the mother plants for seed collection.

[0008] Furthermore, step 2) employs a five-step method for germinating Polygonatum odoratum seeds. First, soak the seeds in warm water for 22-26 hours and then drain. Second, soak the peat moss thoroughly in a 1 / 10 MS solution of macronutrients for 25-35 minutes, then squeeze out the excess water until it clumps together when grasped. Third, mix the seeds and peat moss evenly in a 1:3 ratio and pack them into a foam box. Fourth, cover the storage substrate with 3-4 layers of thoroughly moistened newspaper, then cover with a foam lid for storage. Fifth, place the foam box indoors at 20-22℃ for seed germination, ensuring the newspaper remains moist.

[0009] As can be seen from the above description of the present invention, compared with the prior art, the advantages of the present invention are as follows: This method, while ensuring a high germination rate of Polygonatum odoratum seeds, breaks the dormancy state of Polygonatum odoratum seeds, and has key technical advantages such as short cycle, high seedling rate, and low environmental requirements. It carries out operational practice of Polygonatum odoratum seed propagation technology in aspects such as treatment of Polygonatum odoratum mother plants, seed harvesting and treatment, germination treatment, site selection and seedbed preparation, sowing and heat preservation and moisture retention, small arched shed construction, seedling management and transplanting. It can establish and improve the technical system for rapid seedling cultivation and strong seedlings of Polygonatum odoratum in low-altitude environments, and can meet the needs of large-scale production of Polygonatum odoratum seedlings. Attached Figure Description

[0010] Figure 1 This is a rendering of the mature fruit of Polygonatum multiflorum in this embodiment.

[0011] Figure 2 This is a diagram showing the effect of harvesting and processing Polygonatum multiflorum seeds in Example 1 of this invention.

[0012] Figure 3 This is a diagram showing the germination of Polygonatum multiflorum seeds in peat soil in Example 1 of this embodiment.

[0013] Figure 4 This is a diagram showing the seedling emergence of Polygonatum multiflorum in the second year of this embodiment.

[0014] Figure 5 This is a schematic diagram of the foam box in this embodiment.

[0015] Figure 6 This is a schematic diagram of another type of foam box in this embodiment.

[0016] Figure 7 This is a schematic diagram of the foam box in this embodiment three.

[0017] Figure 8 This is a schematic diagram of the foam box in Embodiment 4. Detailed Implementation

[0018] Example 1

[0019] Reference manual attached Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 A method for rapid and vigorous seedling cultivation of Polygonatum multiflorum seeds at low altitudes, comprising the following steps:

[0020] 1) Treatment of Polygonatum multiflorum mother plants: Select robust, disease-free Polygonatum multiflorum plants that are 2-3 years old as seed-producing mother plants, and perform pre-harvest treatment on these mother plants. Specifically, the pre-harvest treatment method is as follows: During the stem-elongation and leaf-expanding stage in mid-to-late March, depending on the plant height (if the mother plant is too tall), remove the tail section, with the tail section being about 1 / 3 of the total plant height. The purpose is to ensure that the fruiting branches have sufficient nutrition. During the flowering and fruiting stages of the seed-producing mother plants, apply phosphorus and potassium fertilizer to promote robust seed development, full grains, and mature fruiting. For details, please refer to the instruction manual. Figure 1 .

[0021] 2) Seed Harvesting and Processing: Harvest the seeds of Polygonatum multiflorum from mature fruits, and soften the seed coat to obtain clean seeds. (Specifically: harvest when the fruit coat gradually turns from green to dark green, depending on the maturity of the seeds (harvesting period is generally between late October and mid-November). Pack the collected fruits into woven bags and place them in a cool, ventilated place for composting, keeping the compost pile thickness below 10cm (to avoid overheating). Once the seed coat softens and is free of mold (composting time is generally controlled at 10-15 days), transfer them to a cold storage for refrigeration (temperature controlled at -8℃ to -10℃) for half a month. Finally, wash and extract the seeds with clean water for later use. Note that moldy fruits should be discarded. For details, please refer to the attached instructions. Figure 2 .

[0022] 3) Seed germination treatment: A five-step method is used to germinate Polygonatum cyrtonema seeds. First, soak the seeds in warm water for 22-26 hours (optimal time is 24 hours), then drain. Second, soak peat moss in a 1 / 10 MS macronutrient solution for 25-35 minutes, then squeeze dry until it clumps together when grasped. Third, store the Polygonatum cyrtonema seeds in peat moss (using medium-coarse peat moss, 20-40mm thick), mixing the seeds and peat moss in a 1:3 ratio. Store this mixture in an insulated container (e.g., a foam box 1). The mixture 2 should be less than 15cm thick within the container. Fourth, cover the top with approximately 2cm thick damp newspaper 3 to maintain moisture, then cover with a foam lid for final storage. Step 5: Insert a thermometer (e.g., a soil thermometer 4) to monitor the temperature of the mixture. Place the insulated container in an environment of approximately 20℃ for static germination. Sow the seeds when the radicles are 2-5cm long and there are about 2-3 radicles. Static germination takes about 30-45 days. During this period, check the damp newspaper to prevent it from drying out. If it dries out, spray it with water to keep it moist. For details on seed germination in peat moss, please refer to the instruction manual. Figure 3 and Figure 5 .

[0023] Additionally, the foam box 1 may be equipped with partitions 11 arranged at intervals, so that the foam box 1 has two accommodating cavities 10, one at the front and one at the back. These two accommodating cavities 10 can hold heat sources (such as heat containers) that slowly release heat into the insulation box 1. For details, please refer to the appendix of the instruction manual. Figure 6 .

[0024] 4) Site selection and seedbed preparation: Select a plot of land at an altitude of 100-150m as the seedbed. The seedbed should be a dry land or farmland in a mountain valley that is sheltered from the wind, sunny, close to a water source and with convenient irrigation and drainage. The soil should be loose, fertile and well-drained loam or sandy loam. Apply 1.5-2 tons of decomposed organic fertilizer per mu as base fertilizer, then plow to a depth of 20cm, rake and level it, and make beds 15cm-20cm high and 0.8m-1.0m wide. Cover the beds evenly with about 2cm of loose raw loess to make the seedbed.

[0025] 5) Sowing and heat and moisture retention: Sow around January of the following year. Water the seedbed thoroughly one day before sowing. When sowing, evenly scatter the seeds of Polygonatum multiflorum (many of which have already grown into small bulbs with roots) along with peat moss (i.e., the mixture) onto the seedbed. The spacing between the rows and plants of Polygonatum multiflorum should be about 1-1.5cm x 1-1.5cm. Cover the surface of the seedbed with a mulch material (such as wood, bamboo shavings, or rice husks) with a humidity of 70%-80% (the optimal humidity is 75%). The mulch thickness should be controlled at 2-3cm. Water the mulch material thoroughly. Cover the mulch material with a layer of white mulch film and a layer of 75% shade netting for heat and moisture retention. Growers need to check the moisture level of the seedbed frequently to avoid excessive dryness. Generally, no additional watering is required.

[0026] 6) Small arched shed construction: Around late February, erect small arched sheds about 30-40cm high for each seedbed, and remove the original layer of white mulch and 75% shade netting from the covering material and cover the small arched sheds with them; spray water 1-2 times a day for half a month to keep the soil moist.

[0027] 7) Seedling Management: In early March, after the Polygonatum odoratum seedlings emerge, as the temperature warms up, remove one layer of white mulch and leave only one layer of 75% shade netting. Apply foliar fertilizer for the first time after emergence until the leaves unfold, and then spray every 15 days or so, for a total of 3-4 applications depending on the seedling growth. The foliar fertilizer used is 0.2% potassium dihydrogen phosphate plus 0.3% urea. In addition, cultivate, weed, fertilize, and mound soil once each in April, June, and August. For details on the emergence of Polygonatum odoratum in the second year, please refer to the instruction manual. Figure 4 .

[0028] 8) Transplanting: When the rhizome diameter of the two-year-old seedlings reaches 2cm or more, and the weight of a single rhizome is 20-25g or more, transplant them in November of the second year after the seedlings have died or during the dormant period before the beginning of spring in the third year. Take care to protect the root system of the seedlings during transplanting to improve the survival rate. For details on the two-year-old seedlings of *Polygonatum odoratum*, please refer to the attached instructions. Figure 5 .

[0029] Example 2

[0030] This embodiment is basically the same as Embodiment 1 in its implementation, except that: in step 3) of the method for rapid seedling cultivation of Polygonatum odoratum seeds at low altitudes, the insulated container is placed in an environment of about 22°C for static germination. A row of light bulbs 12 can also be installed on the lid of the foam box 1 to ensure a constant temperature inside the insulated box; this also further improves the germination rate of Polygonatum odoratum seeds. For details, please refer to the attached instruction manual. Figure 7 .

[0031] Example 3

[0032] This embodiment is basically the same as the first embodiment in terms of implementation, except that: in the method for rapid seedling cultivation of Polygonatum odoratum seeds at low altitudes, in step 3), the inner bottom surface 13 of the foam box 1 is an arched surface that is low around the edges and high in the middle; and the inner bottom surface 13 is provided with shallow grooves 14 around its perimeter, which have channels for draining excess water. These channels are provided with openable covers 15. In use, a layer of non-woven fabric 16 is laid on the inner bottom surface of the foam box 1. For details, please refer to the attached instruction manual. Figure 8 .

[0033] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. A method for rapid and vigorous seedling cultivation of Polygonatum multiflorum seeds at low altitudes, characterized in that, It includes the following steps: 1) Seed Harvesting and Processing: Seeds of *Polygonatum cyrtonema* are harvested from mature fruits. The seed coat is softened to obtain clean seeds. Specifically, harvesting is done when the fruit coat gradually changes from green to dark green, depending on the seed maturity. The harvested fruits are placed in woven bags and piled in a cool, ventilated place for composting, with the pile thickness controlled below 10cm. Once the seed coat softens and is free of mold, it can be transferred to a cold storage facility at -8℃ to -10℃ for half a month. Finally, the seeds are washed and rinsed with clean water for later use. 2) Seed Germination Treatment: *Polygonatum cyrtonema* seeds are soaked in warm water before germination treatment. A five-step method is used to germinate the seeds. Seed germination treatment: First, soak the Polygonatum cyrtonema seeds in warm water for 22-26 hours and then drain. Second, soak the peat moss thoroughly in a 1 / 10 MS macronutrient solution for 25-35 minutes, then squeeze dry until it can be formed into a clump when squeezed by hand. Third, mix the Polygonatum cyrtonema seeds and peat moss evenly in a 1:3 ratio and pack them into a foam box. Fourth, cover the storage substrate with 3-4 layers of fully moistened newspaper, then cover with a foam lid for storage. Fifth, place the foam box in a room at 20-22℃ for Polygonatum cyrtonema seed germination, paying attention to maintaining the moisture of the newspaper. The foam box lid is equipped with a row of light bulbs. 3) Site selection and seedbed preparation: Select a plot of land at an altitude of 100-150m as the seedbed. For the seedbed, the nursery site should be a sheltered, sunny, and well-drained dry land or farmland in a mountain valley, near a water source. The soil should be loose, fertile, and well-drained loam or sandy loam. Apply 1.5-2 tons of well-rotted organic fertilizer per acre as base fertilizer, then deep plow to 20cm, rake and level it, and make raised beds 15-20cm high and 0.8-1.0m wide. Cover the raised beds evenly with 2cm of loose, raw loess to form the seedbed. 4) Sowing and heat / moisture retention: Sow in February of the following year. Water the seedbed thoroughly one day before sowing. When sowing, evenly scatter the Polygonatum odoratum seeds along with peat moss onto the seedbed. Cover the seedbed with a 2-3cm thick covering material, and water the covering material thoroughly. Then, layer on top of the covering material. 5) Small arched shed construction: In late February, erect small arched sheds 30-40cm high for each seedbed, and remove the original layer of white mulch and shade netting, and cover the small arched sheds with them; 6) Seedling management: In early March, after the Polygonatum odoratum seedlings emerge one after another, as the temperature warms up, remove one layer of white mulch and leave only one layer of shade netting; apply foliar fertilizer for the first time after emergence until the leaves unfold, and then spray once every 15 days, and apply fertilizer 3-4 times in total according to the growth of the seedlings; 7) Transplanting: When the diameter of the rhizome of the two-year-old seedlings reaches more than 2cm and the single rhizome weighs more than 20-25g, transplant them after the seedlings die back in November of the second year or during the dormant period before the beginning of spring in the third year.

2. The method for rapid seedling cultivation of Polygonatum multiflorum seeds at low altitudes as described in claim 1, characterized in that: Before step 1), it is necessary to perform treatment on the mother plants of Polygonatum multiflorum: select healthy, disease-free Polygonatum multiflorum plants that are 2 to 3 years old as mother plants for seed collection, and perform pre-harvest treatment on the mother plants for seed collection.

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