Cultivation method and device for improving seed germination rate and seedling survival rate of kandelia candel transplanted in north

Abstract

The invention discloses a cultivation method and device for improving the seed germination rate and the seedling survival rate of kandelia candel transplanted in north, and belongs to the technical field of mangrove forest cultivation. The cultivation device comprises an outer pot body and an in-pot substrate layer, the substrate layer in the pot sequentially comprises a quartz sand substrate layer, a rock wool layer and a biochar layer wrapped by the rock wool layer from top to bottom, and a water outlet is formed in the junction of the two substrates of the outer pot body and used for adjusting the height of the water level. The cultivation method comprises the steps of selecting kandelia candel seeds which are similar in size, complete in cap, full, mature and free of insect pests, preparing a matrix, simulating environmental conditions of a natural water body or a eutrophication water body to ensure seed germination, moving the seeds into a device and recording germination and growth changes, domesticating seedlings after rooting and germination, directionally cultivating kandelia candel seedlings with high tolerance, and conducting seedling cultivation. After the seedlings are matured, the substrate and the kandelia candel seedlings are integrally transplanted into the natural environment for continuous culture, so that the germination rate and the transplanting survival rate of the kandelia candel seeds are effectively increased, and the method is easy to popularize and apply.

Description

Technical Field

[0001] The present invention belongs to the technical field of mangrove cultivation, and in particular relates to a cultivation method and device for improving the seed germination rate and seedling survival rate of northward-migrating Kandelia candel. Background Art

[0002] Kandelia ovata belongs to the genus Kandelia of the Rhizophoraceae family. It is a special type of plant community that grows in tropical and subtropical coastal wetlands. They have extremely strong adaptability and unique ecological functions. Their biological community is a precious tropical evergreen broad-leaved forest. On the one hand, they have a developed root system and active metabolism, and can absorb nutrients and filter pollutants in the water through their roots and stems; on the other hand, they can promote soil formation and enhance coastal protection. They can not only purify coastal water quality and protect the ecology, but also provide habitats for marine animals and contribute to the development of offshore fisheries.

[0003] Kandelia candel has excellent salt and alkali tolerance and is highly adaptable to coastal saline waters. Furthermore, it is the most cold-tolerant mangrove species, providing potential for the northward migration of mangrove ecosystems. Therefore, research on the introduction of Kandelia candel has important theoretical and practical implications, particularly for the development of coastal shelterbelt systems.

[0004] Biochar has the advantages of high adsorption, high strength, renewability, and environmental friendliness. It is beneficial for the attachment of root microorganisms, promoting the symbiosis between plants and microorganisms, and improving the growth environment of the roots. As a solid product obtained through thermochemical conversion under anoxic conditions, this material has the functions of improving soil, increasing resource utilization efficiency, and reducing environmental pollution. Studies have shown that biochar can improve soil properties, provide rich nutrients for seed germination and seedling growth, and play an important role in promoting plant growth. Construction waste materials such as rock wool not only have a loose and porous fiber structure that can effectively improve air permeability and drainage, but also have a certain thermal insulation effect. It can optimize the growth environment of the roots of Kandelia candel and play an important role in improving the cold resistance of Kandelia candel transplants.

[0005] The mangrove plant Kandelia candel has high requirements for its growing environment. Conventional transplants of Kandelia candel have low survival rates and difficulty germinating hypocotyls. Kandelia candel growth is highly sensitive to environmental conditions, particularly water, nutrients, and its adaptability to its habitat. Therefore, finding effective culture media and environmental conditions to promote Kandelia candel seed germination and enhance its environmental tolerance is of great significance for ecological restoration and wetland plant conservation.

[0006] Prior art, such as patent document CN108243859B, discloses a method for rapidly cultivating salt-tolerant Kandelia candel. This method uses a cross-regional seed collection method, where mature Kandelia candel hypocotyls are placed in homemade nutrient soil and grown into seedlings. These are then transplanted into a seedbed and grown into full-grown seedlings. After root removal, the seedlings are then incubated in bags for a period of time before being transported and transplanted for afforestation. However, this technique still suffers from drawbacks such as complex operation, high environmental requirements, and poor adaptability, resulting in unsatisfactory Kandelia survival rates and ecological applications. Therefore, a simple, easy-to-use cultivation device and transplanting strategy that can adapt to diverse environmental conditions is urgently needed. Summary of the Invention

[0007] In view of the problems in the existing technology that the cultivation process of Kandelia ovata is complicated to operate, has high requirements for environmental conditions and poor adaptability, resulting in unsatisfactory survival rate and ecological application effect of Kandelia ovata, the main purpose of the present invention is to provide a cultivation method for improving the germination rate of Kandelia ovata seeds and the survival rate of seedlings migrated northward, which is used to cultivate Kandelia ovata seeds and can adjust the water level height for seed immersion, effectively improving the germination rate and transplanting survival rate of Kandelia ovata seeds, and is easy to promote and apply.

[0008] Another object of the present invention is to provide a cultivation device for improving the seed germination rate and seedling survival rate of northward-migrated Kandelia candel. The device features manually adjustable flooding height, simulating the flooded environment of Kandelia candel's native habitat to the greatest extent possible, thereby increasing the survival rate of Kandelia candel seedlings transplanted to a different location. Furthermore, combining biochar with construction waste materials promotes the complementary physical, chemical, and biological properties of the two materials, creating a synergistic effect. This device provides a suitable growth environment for Kandelia candel roots, improves the survival rate of northward-migrated Kandelia candel seedlings, and promotes ecological restoration of coastal wetland environments.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a cultivation device for improving the seed germination rate and seedling survival rate of northward-migrating Kandelia candel, which uses a mixed matrix of quartz sand, rock wool, and biochar, and includes an outer pot body and an inner pot matrix layer;

[0011] The matrix layer in the basin includes a quartz sand matrix layer, a rock wool layer and a biochar layer wrapped by the rock wool layer from top to bottom. The outer basin body is provided with a drainage port at the junction of the two matrices to adjust the water level in the device according to actual conditions.

[0012] Preferably, the height ratio of the quartz sand matrix layer to the biochar layer is 1:1-3.

[0013] Preferably, the height ratio of the quartz sand matrix layer to the biochar layer is 1:2.

[0014] The cultivation device for improving the seed germination rate and seedling survival rate of northward-migrated Kandelia candela can simulate the water level changes in the native habitat of Kandelia candela to the greatest extent and promote the germination of the hypocotyl.

[0015] A second aspect of the present invention provides a cultivation method for improving the seed germination rate and seedling survival rate of northward-migrating Kandelia candel, which is implemented by the cultivation device for improving the seed germination rate and seedling survival rate of northward-migrating Kandelia candel, and includes the following steps:

[0016] (1) Seed selection: Select Kandelia candel seeds of similar size, intact caps, plump, mature, and free of insect pests;

[0017] (2) Matrix preparation: The matrix includes a surface matrix and a plant root layer matrix from top to bottom;

[0018] The plant root layer matrix is ​​quartz sand with an average particle size of 6 to 9 mm. The particle size is relatively large, and the air permeability and drainage are good, which has a good support capacity for plants.

[0019] The plant root layer matrix is ​​biochar wrapped in rock wool, with an average particle size of 4 to 6 mm. Due to its highly porous structure, biochar can effectively store water and air, which helps the root system to breathe and absorb nutrients. The rock wool has a certain thermal insulation effect, which reduces the temperature stress on the Kandelia candel. On the other hand, it plays a role in fixing the biochar, preventing it from loosening and spreading.

[0020] Biochar and quartz sand were mixed in a volume ratio of 1:1 to form a matrix for water filterability and water level regulation;

[0021] (3) Simulated environment: The most suitable temperature for Kandelia candel seed germination is 25-30°C, the most suitable salinity is low to medium salt, the light duration is 12-14 h per day, and the pH value is 6.5-8.5. During the seed germination process, the environmental conditions of natural water bodies or eutrophic water bodies, including temperature, humidity, and light, are simulated according to actual conditions to ensure seed germination;

[0022] (4) Seed germination: Place Kandelia candel seeds of similar size in several cultivation devices for improving the seed germination rate and seedling survival rate of northward-migrated Kandelia candel, and record the changes in their germination and growth process;

[0023] (5) Transplantation: After the Kandelia candel seeds take root and germinate, water is added to the cultivation device according to different environmental conditions to acclimate the seedlings, observe their growth conditions and survival rates, and cultivate Kandelia candel seedlings with strong tolerance. After the seedlings grow and mature, the substrate and Kandelia candel seedlings are transplanted as a whole to the natural environment for further cultivation.

[0024] Preferably, in step (1), the embryonic axis height of the Kandelia candel seeds is 16 to 20 cm.

[0025] Preferably, in step (3), the most suitable salinity is 5‰ to 15‰.

[0026] Preferably, the biochar is coconut shell charcoal.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. Improve ecological adaptability: Innovatively combine quartz sand, rock wool and biochar, and utilize their excellent water filtration and heat preservation properties to simulate the native environment of Kandelia candel, effectively cultivate highly tolerant Kandelia candel seedlings, and enhance their environmental adaptability when transplanted to other places.

[0029] 2. Enhanced Planting Stability: A composite design of biochar and rock wool creates a stable matrix support system. The rock wool tightly wraps the biochar particles, providing insulation while effectively preventing the matrix from loosening or shifting, enhancing root attachment. Combined with the porosity of biochar, this further optimizes water and nutrient distribution, reducing the risk of seedling lodging and providing a long-lasting, stable physical support environment for Kandelia root growth, significantly improving its resistance to disturbance after transplanting. Furthermore, the combination of biochar and quartz sand filters water and regulates water levels, closely simulating Kandelia's native habitat and promoting seed germination.

[0030] 3. Enhance tolerance to sediment pollution: Quartz sand and biochar have strong adsorption capacity for nitrogen, phosphorus and other pollutants. On the one hand, they can enrich the nutrients needed for the roots of Kandelia candel. On the other hand, they can slow down the eutrophication of coastal waters to a certain extent and purify the water.

[0031] 4. Broad application prospects: Combining mangrove plant seed germination, northward migration and introduction cultivation, ecological restoration and water purification, a set of cultivation techniques is formed to improve the seed germination rate and seedling survival rate of northward migrated Kandelia ovata. This is conducive to improving the tolerance of Kandelia ovata seedlings to various environments and reducing the environmental sensitivity during the transplanting process. It has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic cross-section of a cultivation device for improving the germination rate of northward-migrating Kandelia candel seeds and the survival rate of seedlings in an embodiment; 1 is a quartz sand matrix layer; 2 is a rock wool layer; 3 is a biochar layer; and 4 is a drainage outlet.

[0033] Figure 2 Schematic diagram of the structure of a cultivation device for improving the germination rate of northward-migrating Kandelia candel seeds and the survival rate of seedlings in an embodiment; 1 is a quartz sand matrix layer; 2 is a rock wool layer; 3 is a biochar layer; and 5 is a natural matrix layer. DETAILED DESCRIPTION

[0034] In order to more fully understand and demonstrate the technical solutions, objectives, and advantages of the present invention, the technical effects produced by the present invention are further described in detail and completely in conjunction with specific embodiments. Obviously, the embodiments described are only some of the embodiments of the present invention, and not all of them. It should be pointed out that for those skilled in the art, other embodiments obtained without departing from the concept of the present invention are all within the scope of protection of the present invention.

[0035] like Figure 1 and 2 As shown, the following embodiment proposes a cultivation device for improving the seed germination rate and seedling survival rate of northward migrating Kandelia ovata, which adopts a mixed matrix of quartz sand-rock wool-biochar, including an outer basin body and an inner basin matrix layer. The inner basin matrix layer includes, from top to bottom, a quartz sand matrix layer 1, a rock wool layer 2 and a biochar layer 3 wrapped by the rock wool layer 2. The outer basin body is provided with a drainage port 4 at the junction of the two matrices, and the water level in the device is adjusted according to actual conditions.

[0036] In some embodiments, the height ratio of the quartz sand matrix layer to the biochar layer is 1:1-3.

[0037] In some embodiments, the height ratio of the quartz sand matrix layer to the biochar layer is 1:2.

[0038] In some embodiments, the cultivation device includes a surface matrix and a plant root layer matrix from top to bottom. The surface matrix is ​​paved with quartz sand and biochar, and the plant root layer is paved with biochar wrapped in rock wool. The quartz sand plays a role in drainage and support; the biochar provides rich nutrients for the plants, and the rock wool plays a certain role in insulation.

[0039] In some embodiments, the cultivation device includes a drainage outlet located at the junction of the two layers of substrate, which can effectively regulate the water level. The water level height can be adjusted according to actual conditions, simulating the water level changes in the natural habitat of Kandelia candel, and facilitating water changes.

[0040] Through the design of the above-mentioned device, the embryonic axis of Kandelia can be supported to the greatest extent, its root growth and germination can be promoted, and after the seedlings mature, the Kandelia candel and the substrate can be transplanted as a whole to a natural environment.

[0041] The present invention will be further described below with reference to the embodiments.

[0042] Example 1

[0043] This embodiment proposes a mixed biochar matrix cultivation method that can improve the germination rate and transplant survival rate of Kandelia candel seeds. The method is implemented using the above-mentioned cultivation device, and the steps are as follows:

[0044] (1) Seed selection: Select Kandelia candel seeds that are similar in size (hypocotyl height is 18 ± 2 cm), have intact caps, are plump and mature, and are free of insect pests.

[0045] (2) Matrix preparation: The matrix layer includes the surface matrix and the plant root layer matrix from top to bottom. Biochar and quartz sand are mixed in a volume ratio of 1:1 to form a matrix with water filtration and water level regulation. The surface matrix is ​​quartz sand (particle size is 6-9 mm), which has a relatively large particle size and good air permeability and drainage, and has a good support capacity for plants; the plant root layer matrix is ​​biochar wrapped in rock wool (particle size is 4-6 mm). Due to its highly porous structure, biochar can effectively store water and air, which helps the root system to breathe and absorb nutrients; rock wool has a certain insulation effect on the one hand, reducing the temperature stress on the autumn candel, and on the other hand, it plays a role in fixing the biochar, preventing the biochar from loosening and spreading.

[0046] (3) Simulated environment: The optimum temperature for Kandelia candel seed germination is 25-30°C, the optimum salinity is low to medium (5-15‰), the daylight duration is 12-14 h per day, and the pH range is 6.5-8.5. During the seed germination process, the environmental conditions of natural water bodies or eutrophic water bodies are simulated according to the actual situation to ensure that the seeds germinate under conditions of suitable temperature, humidity, and light.

[0047] (4) Seed germination: Kandelia candel seeds of similar individual sizes were placed in multiple cultivation devices, and their germination and growth changes were recorded.

[0048] (5) Transplantation: After the seeds have taken root and germinated, the water bodies with different environmental conditions are transferred to the cultivation device to acclimate the seedlings, observe their growth status and survival rate, and cultivate the candela seedlings with strong tolerance. After the seedlings have grown to maturity, the substrate layer and the candela seedlings are transplanted as a whole to the corresponding natural environment and continue to cultivate them. This effectively cultivates the candela seedlings with high tolerance and enhances their ability to adapt to the environment when transplanted to a different location.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A cultivation device for improving the seed germination rate and seedling survival rate of northward-migrating Kandelia candel, characterized in that: A mixed matrix of quartz sand, rock wool and biochar is used, including an outer basin body and an inner basin matrix layer; The matrix layer in the basin includes a quartz sand matrix layer, a rock wool layer and a biochar layer wrapped by the rock wool layer from top to bottom. The outer basin body is provided with a drainage port at the junction of the two matrices to adjust the water level in the device according to actual conditions.

2. The cultivation device for improving the seed germination rate and seedling survival rate of northward-migrating Kandelia candel according to claim 1, characterized in that: The height ratio of the quartz sand matrix layer to the biochar layer is 1:1-3.

3. The cultivation device for improving the seed germination rate and seedling survival rate of northward-migrating Kandelia candel according to claim 1, characterized in that: The height ratio of the quartz sand matrix layer to the biochar layer is 1:

2.

4. A cultivation method for improving the seed germination rate and seedling survival rate of northward-migrating Kandelia candel, characterized in that: The cultivation device for improving the seed germination rate and seedling survival rate of northward-migrating Kandelia candel according to any one of claims 1 to 3 is implemented, comprising the following steps: (1) Seed selection: Select Kandelia candel seeds of similar size, intact caps, plump, mature, and free of insect pests; (2) Matrix preparation: The matrix includes a surface matrix and a plant root layer matrix from top to bottom; Wherein, the plant root layer matrix is ​​quartz sand with an average particle size of 6 to 9 mm; The plant root layer matrix is ​​biochar wrapped in rock wool, with an average particle size of 4 to 6 mm; (3) Simulated environment: The most suitable temperature for Kandelia candel seed germination is 25-30°C, the most suitable salinity is low to medium salt, the light duration is 12-14 h per day, and the pH value is 6.5-8.

5. During the seed germination process, the environmental conditions of natural water bodies or eutrophic water bodies are simulated to meet the above conditions to ensure seed germination; (4) Seed germination: Kandelia candel seeds of similar size were placed in several cultivation devices, and changes in their germination and growth processes were recorded; (5) Transplantation: After the Kandelia candel seeds take root and germinate, water is added to the cultivation device according to different environmental conditions to acclimate the seedlings, observe their growth conditions and survival rates, and cultivate Kandelia candel seedlings with strong tolerance. After the seedlings grow and mature, the substrate and Kandelia candel seedlings are transplanted as a whole to the natural environment for further cultivation.

5. The cultivation method for improving the seed germination rate and seedling survival rate of Kandelia candelii according to claim 4, characterized in that: In step (1), the embryonic axis height of the Kandelia candel seeds is 16 to 20 cm.

6. The cultivation method for improving the seed germination rate and seedling survival rate of Kandelia candelii according to claim 4, characterized in that: In step (3), the most suitable salinity is 5‰ to 15‰.

7. The cultivation method for improving the seed germination rate and seedling survival rate of Kandelia candelii according to claim 4, characterized in that: The biochar is coconut shell charcoal.

8. The cultivation method for improving the seed germination rate and seedling survival rate of Kandelia candelii according to claim 4, characterized in that: The biochar and quartz sand are mixed in a volume ratio of 1:1 to form a matrix for water filterability and water level regulation.

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