Seeding propagation method for ottelia acuminata

Abstract

The invention discloses an ottelia acuminata sowing propagation method which comprises the following steps: selecting hard and full seeds, sterilizing and killing a sowing seedbed and arranging an insect-proof net, sowing in March-June or September-November, covering thin-layer fine soil after sowing, and managing after sowing and paying attention to keeping water depth and sterilizing and killing in time. According to the method, through comprehensive measures such as seed screening, seeding seedbed preparation and disinfection, seeding operation and later-period management, emergence and settlement of ottelia acuminata seedlings are promoted, and biological hazards are effectively prevented. Researches show that the germination rate of the ottelia acuminata seeds sown by the method reaches 88.5-100%, the emergence rate reaches 75.5-91.8%, and the growth requirements are met. In a word, the method overcomes the problems that seedlings germinated by ottelia acuminata seeds are difficult to emerge from soil and settle, prevents harm of organisms such as fish, snails and insects, improves the germination rate and the emergence rate of sowing propagation, and provides a scientific and effective new method for ottelia acuminata propagation.

Description

Technical Field

[0001] The invention belongs to the technical field of seedling propagation of rare and endangered plant Lagenaria japonica, and in particular relates to a sowing and propagation method of Lagenaria japonica. Background Art

[0002] Ottelia acuminata (Gagnep.) Dandy is a perennial large submerged herb belonging to the genus Ottelia of the family Hydrocharitaceae. It is endemic to China and is listed in the 2021 edition of the National List of Key Protected Wild Plants. Ottelia acuminata has extremely high ornamental, nutritional and medicinal value, and also plays an important role in water purification and soil and water conservation. It is usually used as a landscape resource, green vegetable, feed, traditional Chinese medicine and water ecological restoration. After the 1980s, due to multiple factors such as water pollution, wetland destruction, the introduction of herbivorous fish and excessive human collection, the population of Ottelia acuminata has decreased sharply and has become extinct in many places. In order to meet people's production and living needs and protect wild resources, it is urgent to vigorously develop the artificial cultivation of Ottelia acuminata. However, due to the lack of economical and efficient breeding technology, there is a shortage of Ottelia acuminata seedlings in the market, which has seriously restricted the development of the Ottelia acuminata industry.

[0003] The leaves, flowers and pedicels of sea lettuce are all rich in nutrition, and are crisp and tender and delicious. The protein content of the whole plant is 24.16% on average, which is only slightly lower than the protein content of ordinary broad beans (25.80%), and it is very easy to be harmed by fish, snails, snails and various insects. The seeds of sea lettuce are relatively small, and the energy and nutrition stored are limited, and the ability of the seedlings formed by germination to penetrate the soil layer is very weak. At the same time, the germination process of sea lettuce seeds is that the cotyledons grow about 10 days, and the root system just begins to grow, and the whole process all needs to be carried out in water, and this germination feature is not conducive to the settlement of seedlings and causes survival difficulties. Therefore, how to overcome these unfavorable factors and improve the sowing and propagation effect of sea lettuce is a problem that needs to be solved urgently in the prosperous sea lettuce market. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a scientific, reasonable and effective method for sowing and propagating sea lettuce, which overcomes the problems of difficulty in germination and emergence of sea lettuce seedlings, and prevents biological damage such as fish, snails and insects, thereby improving the germination rate and emergence rate of sowing and propagation.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The method of sowing and propagation of sea lettuce is to choose hard and full seeds, disinfect the sowing seedbed and set up insect-proof nets, sow in March-June or September-November, cover with a thin layer of fine soil after sowing, and pay attention to maintaining water depth and timely disinfection after sowing.

[0007] The above-mentioned method for propagating sea lettuce by sowing comprises the following steps:

[0008] (1) Seed screening: Select hard and full seeds, wash and set aside;

[0009] (2) Seeding bed: Crush the soil and mix it with medium sand, spread it into a seedling bed, and use insect-proof nets to fence around the seedling field;

[0010] (3) Seedbed disinfection: Use metaldehyde and ivermectin to disinfect the seedbed;

[0011] (4) Sowing: In March-June or September-November, mix the seeds with medium sand and stir evenly, then spread them on the disinfected seedbed and cover with a thin layer of fine soil;

[0012] (5) Management: From sowing to the beginning of leaf tips emerging from the soil, the water depth of the seedbed should be maintained at 1-10 cm. The water depth should be adjusted according to the weather and seedling growth conditions, and ivermectin should be used to disinfect the seedling field.

[0013] In step (1): the hard and plump seeds are collected from March to June and September to November, and their seed coats are black or yellowish brown. The surface of the capsule of the sea lettuce is usually attached with some snails, insects and eggs, etc., which should be cleaned before peeling the peel to reduce the harm of these organisms to the seedlings. The seed coat of the normally mature seeds of the sea lettuce is black. This type of seed is of good quality and strong vitality. However, under natural conditions, before the seeds of the sea lettuce reach maturity, their capsules or fruit stalks will rot and fall off or be eaten, making it difficult to obtain seeds. The inventor's experiments have proved that the germination rate of hard and plump seeds with yellowish brown or blackened seed coats can also reach 70%, which can be used for sowing and propagation.

[0014] In step (2), soil and medium sand are mixed in a volume ratio of 2-3:1, the seedbed is 8-12 cm thick, the insect-proof net is 80-100 mesh (the lower end of the insect-proof net is buried about 10 cm below the soil and compacted with soil without gaps), and the fence is 80-100 cm high. Sea lettuce is rich in nutrition, tender in texture, and tastes good. It is very susceptible to snails, snails, slugs and various insects. Using insect-proof nets to fence around the seedling field can effectively block snails, snails, slugs and various crawling pests.

[0015] The soil is pond mud, field mud, garden soil or river silt, and the medium sand is river sand or machine-beaten sand. Sea lettuce grows fast and has large plants, so it needs to absorb a lot of nutrients. The roots of sea lettuce are fleshy and require loose and breathable sandy soil. Pond mud, field mud, garden soil or river silt are rich in nutrients, and river sand or machine-beaten sand can improve the structure of pure soil. According to the growth and root characteristics of sea lettuce, a scientific ratio of mixed soil and sand is beneficial to the growth and development of sea lettuce.

[0016] In step (3): first use 6% metaldehyde granules to disinfect snails, snails, slugs, etc. in the entire seedling field, then use 1.5% ivermectin solution to disinfect, 4-5 days later, put 20-30cm deep water in the seedling field, and drain the water after 1 day. The specific dosage and application method of the drug shall be operated according to the product instructions.

[0017] In step (4): seeds and medium sand are mixed at a volume ratio of 5-6:1, and a thin layer of fine soil is 0.5-1.0 cm thick. The seeds of sea lettuce are small, and the energy and nutrition stored are limited. The ability of the germinating seedlings to penetrate the soil layer is very weak. At the same time, the germination process of sea lettuce seeds is about 10 days after the cotyledons grow out, and the root system begins to grow, and the whole process requires a certain depth of water. Covering with a thin layer of fine soil after sowing can help the seedlings settle, balance the growth ability of the seedlings, and prevent the cotyledons from dying due to the soil being too thick and unable to penetrate the soil layer.

[0018] In step (4): October is the best time for sowing. Sea lettuce can bloom all year round, and seeds can be collected all year round, but there are great differences in seed quality and quantity in different seasons, and the environment and water temperature during sowing can seriously affect the germination and growth of sea lettuce seeds. Through the detection of sea lettuce seed quality and vitality and sowing verification in different months, the inventors determined that seeds collected from March to June and September to November and sown in this period can achieve better seedling raising results.

[0019] In step (5): the water depth of the seedling bed from sowing to the beginning of leaf tip emergence is 1-2 cm in March or November, 8-10 cm in June, and the water depth at other times is determined according to weather conditions; the water entering the seedling field must be filtered with an 80-100 mesh insect-proof net. In March and November, the temperature is relatively low, and the shallow water depth of the seedling bed from sowing to the beginning of leaf tip emergence is conducive to sunlight exposure to increase the temperature of the seedling bed and water, promote seed germination and growth, and the shallow water level is also conducive to the settlement of seedlings; in June, the ambient temperature is relatively high, and the seedling bed needs a deeper water level to stabilize the sowing environment and promote seed germination, but too deep a water level is not conducive to the settlement of seedlings.

[0020] Sea lettuce is sensitive to most pesticides, so pests need to be eliminated before sowing, and fresh water that has been filtered out of pests should be used to remove residual pesticides. During the growth of sea lettuce seedlings, it is also necessary to prevent and eliminate various pests in a timely manner. Studies have found that snails, snails, slugs and other pests that eat sea lettuce have a pattern of harm, and they need to be eliminated regularly.

[0021] In view of the problems existing in the current breeding of sea lettuce, the inventor has established a method for sowing and propagating sea lettuce, selecting hard and full seeds, disinfecting the sowing seedling bed and setting up an insect-proof net, sowing in March-June or September-November, covering a thin layer of fine soil after sowing, and paying attention to maintaining water depth and timely disinfection after sowing. The method promotes the emergence and settlement of sea lettuce seedlings through comprehensive measures such as seed screening, sowing seedling bed preparation and disinfection, sowing operation and post-management, and effectively prevents biological hazards. Studies have shown that the germination rate of seeds sown with the method of the present invention reaches 88.5-100%, and the emergence rate reaches 75.5-91.8%, which meets the growth requirements. In short, the present invention overcomes the problem of difficulty in emergence and settlement of sea lettuce seed germination seedlings, and prevents biological hazards such as fish, snails, and insects, improves the germination rate and emergence rate of sowing and propagation, and provides a scientific and effective new method for the breeding of sea lettuce. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is an observation diagram of the suspension state of the sea lettuce seedlings that were not covered with soil after sowing in Example 3.

[0023] Figure 2 This is an observation diagram of the biological damage to the sea lettuce in the late sowing period without disinfection of the seedbed in Example 4.

[0024] Figure 3 This is an observation diagram of the germination and growth of sea lettuce treated with garden soil in Example 5. DETAILED DESCRIPTION

[0025] Example 1 Study on germination of sea lettuce seeds in different states

[0026] (1) In October, the seeds of sea lettuce in different states were collected, cleaned and set aside.

[0027] (2) Crush the garden soil and mix it with medium sand in a volume ratio of 2:1. Stir evenly and spread it into a seedbed 8-12 cm thick in a white plastic bucket with specifications of 71×50×42 cm.

[0028] (3) The seedbed soil was disinfected with 6% metaldehyde granules and 1.5% ivermectin solution, and then rinsed twice with filtered water.

[0029] (4) Mix the seeds and medium sand in a volume ratio of 5:1, stir evenly, and sow them on the sterilized seedbed, covering with 0.5-1.0 cm of fine soil. Sow 50 seeds per bucket.

[0030] (5) After sowing, add water to the seedbed to a depth of 1-2 cm. After the cotyledons emerge, keep the water depth to cover the leaves. See Table 1 for germination rate and seedling growth.

[0031] Table 1 Germination effect of sea lettuce seeds in different states

[0032] Seed Status Germination rate / % Seedling rate / % Growth The seed coat is black, hard and full 96.5 88.6 Strong seedlings, good growth The seed coat is black, and the seeds are shriveled and not full. 55.5 30.9 Weak seedlings and poor growth The seed coat is yellow-brown, hard and full 82.7 75.2 Strong seedlings, good growth The seed coat is white, hard and full 6.4 1.5 Weak seedlings and poor growth

[0033] Results: The germination rate and seedling rate of seeds with black or yellowish brown hard and full seed coats after sowing were 96.5%, 82.7% and 88.6%, 75.2%, respectively, and the seedlings grew strong. The germination rate and seedling rate of seeds with black seed coats but shriveled and less full, and hard and full seeds with white seed coats were lower. The hard and full seeds of sea lettuce with black or yellowish brown seed coats had better effect after sowing and could be used for sowing and propagation of sea lettuce.

[0034] Example 2 Study on the sowing and germination of sea lettuce seeds in different months

[0035] (1) From January to December, hard and plump sea lettuce seeds with black seed coats were collected, cleaned and set aside.

[0036] (2) Crush the garden soil and mix it with medium sand in a volume ratio of 2:1. Stir evenly and spread it into a seedbed 8-12 cm thick in a white plastic bucket with specifications of 71×50×42 cm.

[0037] (3) The seedbed soil was disinfected with 6% metaldehyde granules and 1.5% ivermectin solution, and then rinsed twice with filtered water.

[0038] (4) Mix the seeds and medium sand in a volume ratio of 5:1, stir evenly, and sow them on the sterilized seedbed, covering with 0.5-1.0 cm of fine soil. Sow 50 seeds per bucket.

[0039] (5) Add water to the seedbed after sowing. From sowing to the beginning of leaf tips emerging from the soil, the water depth is 1-2 cm in January-March and November-December, 8-10 cm in June-September, and 3-6 cm in April-May and October. After the cotyledons emerge from the soil, the water depth is kept above 10 cm in June-September, and the water depth is kept above the leaves at other times. See Table 2 for germination rate and seedling growth.

[0040] Table 2 Effects of sowing sea lettuce at different times

[0041] Sowing time January February March April May June July August September October November December Number of buds / plant 30 25 38 45 41 42 21 15 39 50 45 33 Germination rate / % 60 50 76 90 82 84 42 30 78 100 90 66 Bud emergence difficulty Disaster Disaster easy easy easy easy Disaster Disaster easy easy easy generally Bud growth rate slow slow quick quick quick quick quick quick quick quick quick slow Pests and diseases few few few More More many serious serious More few few few

[0042] Results: Due to high temperature in July and August, the germination rate of sea lettuce seeds was low, pests and diseases were serious, and the sowing effect was the worst. After the seeds germinated in January-February and December, the temperature was too low, and the seedlings were not easy to emerge and grow. From March to June and September to November, the seed germination rate was 76-100%, and the overall growth was good. Among them, October had a high germination rate, fast growth, few pests and diseases, and strong seedlings, which was the best sowing time.

[0043] Example 3 Study on the effect of soil cover thickness after sowing on the germination effect of sea lettuce

[0044] (1) In October, collect hard and plump sea lettuce seeds with black seed coat, clean them and set aside.

[0045] (2) Crush the garden soil and mix it with medium sand in a volume ratio of 2:1. Stir evenly and spread it into a seedbed 8-12 cm thick in a white plastic bucket with specifications of 71×50×42 cm.

[0046] (3) The seedbed soil was disinfected with 6% metaldehyde granules and 1.5% ivermectin solution, and then rinsed twice with filtered water.

[0047] (4) Mix the seeds with medium sand in a volume ratio of 5:1, stir evenly, and sow them on the sterilized seedbed, covering with 0, 0.5, 1.0, 2.0, and 4.0 cm thick fine soil. Sow 50 seeds per bucket.

[0048] (5) After sowing, add water to the seedbed to a depth of 1-2 cm. After the cotyledons emerge, keep the water depth to cover the leaves. See Table 3 for germination rate and seedling growth.

[0049] Table 3 Germination effect of sea lettuce seeds with different covering thickness

[0050] Covering thickness / cm 0 0.5 1.0 2.0 4.0 Number of seedlings floating on the water surface 30 7 5 0 0 Number of buds emerging from soil / plant (including seedlings floating on the water surface) 46 40 43 25 12 Number of seedlings / plant 21 45 48 23 11

[0051] Results: After sowing, the seedlings formed by the germination of the sea lettuce seeds without soil cover basically floated on the water surface (such as Figure 1 The number of seedlings from the sea lettuce seeds covered with 2.0-4.0cm soil was 11-23, while the number of seedlings from 0.5-1.0cm soil was 45-48, which was the best.

[0052] Example 4 Study on the preventive effect of metaldehyde and ivermectin on diseases and insect pests of sea lettuce seedlings

[0053] (1) Collect hard and plump sea lettuce seeds with black seed coat in April, clean them and set aside.

[0054] (2) Crush the garden soil and mix it with medium sand at a volume ratio of 2:1. Stir evenly. Spread it flat in the test field to form a seedbed 8-12 cm thick. Use 80-100 mesh insect-proof nets to build a fence 80-100 cm high around the seedling field.

[0055] (3) Treat the seedbed soil according to the method in Table 4, and then rinse it twice with filtered water.

[0056] (4) Mix the seeds and medium sand in a volume ratio of 5:1, stir evenly, sow on the seedbed, and cover with 0.5-1.0 cm thick fine soil. Sow 1000 seeds per treatment.

[0057] (5) After sowing, add water to the seedbed to a depth of 3-5 cm. After the cotyledons emerge, keep the water depth to cover the leaves. See Table 4 for germination rate and seedling growth.

[0058] Table 4 Effects of different seedbed treatments on the germination of sea lettuce seeds

[0059]

[0060] Results: Although the germination rate of sea lettuce sown directly without soil treatment was as high as 97.0%, the seedlings were seriously damaged by snails, snails, insects and other organisms, with a large number of petioles broken or leaves incomplete (such as Figure 2 As shown). After the seedbed soil was disinfected with 6% metaldehyde or 1.5% ivermectin, the degree of damage to the seedlings by snails, snails, insects and other organisms was greatly reduced. After the combination of 6% metaldehyde and 1.5% ivermectin, the seedling rate of sea rapeseed sowing reached 95.0%, and the plants grew well.

[0061] Example 5 Study on the germination of sea rapeseed seeds in different seedbeds

[0062] (1) In October, collect hard and plump sea lettuce seeds with black seed coat, clean them and set aside.

[0063] (2) Crush the dry pond mud, field mud, river silt and garden soil, mix them with medium sand at a volume ratio of 2:1, stir evenly, and spread them into a seedbed 8-12 cm thick. Use 80-100 mesh insect-proof nets to build 80-100 cm high fences around the seedling field.

[0064] (3) First, use 6% metaldehyde granules to disinfect snails, snails, slugs, etc. in the entire nursery field, and then use 1.5% ivermectin solution to disinfect them. After 4-5 days, put 20-30 cm deep filtered clean water in the nursery field, and drain the water after 1 day. Repeat twice to clean the nursery bed.

[0065] (4) Mix the seeds and medium sand in a volume ratio of 5:1, stir evenly, sow on the disinfected seedbed, and cover with 0.5-1.0 cm thick fine soil.

[0066] (5) After sowing, add water to the seedbed to a depth of 1-2 cm. After the cotyledons emerge, keep the water depth to cover the leaves. See Table 5 for germination rate and seedling growth.

[0067] Table 5. Germination results of sea lettuce seeds

[0068] Soil source Germination rate / % Seedling rate / % Growth pond scum 90.5 80.0 Plants grow well Field mud 88.5 91.8 Plants grow well River silt 95.6 75.5 Plants grow well Garden Soil 100 89.6 Plants grow well

[0069] Results: Different soil sources had little effect on the germination of sea lettuce seeds, and all of them could meet the requirements for sowing and seedling raising. The germination rate in pond mud, field mud, river silt and garden soil was 88.5-100%, with the highest being 100% in garden soil and the lowest being 88.5% in field mud; the emergence rate was 75.5-91.8%, with the highest being 91.8% in field mud and the lowest being 75.5% in river silt.

Claims

1. A method for sowing and propagating sea lettuce, characterized in that: Choose hard and full seeds, disinfect the seedbed and set up insect-proof nets, sow in March-June or September-November, cover with a thin layer of fine soil after sowing, and pay attention to maintaining water depth and timely disinfection after sowing.

2. The method for sowing and propagating sea lettuce according to claim 1, characterized in that The following steps are involved: (1) Seed screening: Select hard and full seeds, wash and set aside; (2) Seeding bed: Crush the soil and mix it with medium sand, spread it evenly into a seedling bed, and use insect-proof nets to fence around the seedling field; (3) Seedbed disinfection: Use metaldehyde and ivermectin to disinfect the seedbed; (4) Sowing: In March-June or September-November, mix the seeds with medium sand and stir evenly, then spread them on the disinfected seedbed and cover with a thin layer of fine soil; (5) Management: From sowing to the beginning of leaf tips emerging from the soil, the water depth in the seedbed should be maintained at 1-10 cm. The water depth should be adjusted according to the weather and seedling growth conditions, and ivermectin should be used to disinfect the seedling field.

3. The method for sowing and propagating sea lettuce according to claim 2, characterized in that In step (1): the hard and plump seeds are collected from March to June and September to November, and their seed coats are black or yellowish brown.

4. The method for sowing and propagating sea lettuce according to claim 2, characterized in that In step (2), the soil blocks and medium sand are mixed in a volume ratio of 2-3:1, the seedbed is 8-12 cm thick, the insect-proof net is 80-100 mesh, and the fence is 80-100 cm high.

5. The method for sowing and propagating sea lettuce according to claim 4, characterized in that: The soil blocks are pond mud, field mud, garden soil or river silt, and the medium sand is river sand or machine-beaten sand.

6. The method for sowing and propagating sea lettuce according to claim 2, characterized in that In step (3): firstly, snails, snails, slugs, etc. in the entire seedling field are disinfected with 6% metaldehyde granules, and then disinfected with 1.5% ivermectin solution. After 4-5 days, 20-30 cm deep water is added to the seedling field, and the water is drained after 1 day.

7. The method for sowing and propagating sea lettuce according to claim 2, characterized in that In step (4): the seeds are mixed with medium sand in a volume ratio of 5-6:1, and a thin layer of fine soil is 0.5-1.0 cm thick.

8. The method for sowing and propagating sea lettuce according to claim 2, characterized in that In step (4): the sowing time is October.

9. The method for sowing and propagating sea lettuce according to claim 2, characterized in that In step (5): the water depth of the seedling bed from sowing to the time when the leaf tips begin to emerge from the soil is 1-2 cm in March or November, 8-10 cm in June, and the water depth at other times is determined according to weather conditions; the water entering the seedling field must be filtered with an 80-100 mesh insect-proof net.

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