Sandwich type sargassum fusiforme proliferation seedling cultivation method based on ulva lactuca

Abstract

The invention relates to the field of seaweed seedling breeding technology research, in particular to an ulva-based sandwich type sargassum fusiforme proliferation seedling breeding method which comprises the following steps: 1, setting a seedling breeding pond, laying yarn silk to collect fertilized eggs in a centralized manner, and adjusting the height of seawater in the seedling breeding pond after the fertilized eggs are attached to an attachment substrate; 2, crushing the ulva lactuca, counting the quantity of ulva lactuca spores, controlling the total quantity and attachment time of the ulva lactuca spores, and adjusting the seawater height of the nursery pond again after the ulva lactuca spores are attached to the attachment substrate; 3, after the ulva spores are attached, collecting mature and fertilized sargassum fusiforme female algae for the second time, and after fertilized eggs are attached to the attachment base again, adjusting the height of the seawater in the nursery pond for the third time; and 4, carrying out indoor cultivation on the substratum in the nursery pond, and after more than two leaves appear on the sargassum fusiforme seedlings and the ulva lactuca seedlings, completing the cultivation of the proliferation seedlings of the sargassum fusiforme. Effective cultivation of the sargassum fusiforme proliferation seedlings is achieved, and the seedling breeding efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of seaweed seedling propagation technology research, specifically to a method for cultivating sandwich-type Sargassum fusiforme seedlings based on Ulva prolifera. Background Technology

[0002] Sargassum fusiforme is a newly emerging cultured seaweed species in recent years. Originally from the Bohai Sea, it is now cultivated on a large scale in the Yellow Sea and East China Sea, becoming a specialty aquaculture species in some nearshore waters. Given its well-developed rhizoids, large thallus, and perennial nature, Sargassum fusiforme also has certain advantages as a propagation tool for seaweed farm construction.

[0003] Currently, the cultivation of Sargassum fusiforme seedlings mainly involves collecting fertilized eggs and placing them on a substrate for attachment. Sargassum fusiforme seedlings grow relatively slowly, gradually developing from an individual leaf, two leaves, and eventually multiple fully expanded leaves, a process that takes 30-50 days. The formation of upright branches takes even longer. Sargassum fusiforme cultivation in nursery ponds is inevitably affected by floating silt, and the spores of other algae in the seawater also attach to the substrate, thus impacting the cultivation of Sargassum fusiforme seedlings. The settling of floating silt affects the attachment of Sargassum fusiforme seedlings, while the attachment of other algae competes for nutrients, leading to easy seedling detachment and weak algae, thereby affecting the overall progress of seaweed farm construction. Sargassum fusiforme seedlings can only effectively resist external influencing factors, especially floating silt and other algae, after developing multiple fully expanded leaves. Therefore, it is necessary to take proactive measures during the period when Sargassum fusiforme seedlings grow to the stage of having multiple fully expanded leaves.

[0004] After attaching to the plant, Ulva seedlings can quickly develop relatively flat, leaf-like leaves, and they can quickly fall off when the temperature or light conditions are right. Therefore, Ulva is considered as an auxiliary species for the propagation and cultivation of Sargassum seedlings to effectively cope with the effects of floating mud and miscellaneous algae. Summary of the Invention

[0005] In view of the problems encountered in the cultivation of Sargassum fusiforme seedlings in the existing technology, the purpose of this invention is to provide a method for cultivating Sargassum fusiforme seedlings using Ulva as an auxiliary species, so as to effectively deal with the influence of floating mud and miscellaneous algae.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: a method for cultivating sandwich-type Sargassum fusiforme seedlings based on Ulva lactuca, comprising the following steps: Step 1: Set up a seedling pond, collect mature and fertilized female Sargassum fusiforme thalli, collect fertilized eggs by laying gauze in the seedling area, use measuring tools to count the number of fertilized eggs, control the total number of fertilized eggs and attachment time in the seedling pond, after the fertilized eggs have attached to the attachment substrate, adjust the seawater level in the seedling pond and replace it with fresh seawater. Step 2: Crush the Ulva prolifera and release it. Use a measuring tool to count the number of Ulva prolifera spores. After the Sargassum fusiforme fertilized eggs have completed attachment, release the Ulva prolifera spores. Control the total amount of Ulva prolifera spores released and the attachment time. After the Ulva prolifera spores have attached to the attachment substrate, readjust the seawater level in the seedling pond and replace it with fresh seawater. Step 3: After the Ulva spores have completed attachment, collect mature and fertilized female Sargassum fusiforme thallus a second time, use measuring tools to count the number of fertilized eggs, control the total number of fertilized eggs and attachment time in the seedling pond, and after the fertilized eggs have reattached to the attachment substrate, adjust the seawater level in the seedling pond for the third time and replace it with fresh seawater. Step 4: The attachment substrate containing Sargassum fusiforme fertilized eggs and Ulva spores is placed in the seedling pond for indoor cultivation. The water flow rate is adjusted according to the cultivation time. The Sargassum fusiforme seedlings are cultivated after they have two or more leaves.

[0007] In the above-mentioned method for cultivating sandwich-type Sargassum fusiforme seedlings based on Ulva prolifera, in step 1, the seedling pond is 500cm long and 200cm wide, and the water depth is adjusted to 60cm; the light conditions require 2,000-3,000lx, the seawater is sand-filtered seawater that has been settled for no less than 24 hours, the mesh number of the gauze is 120, and the attachment substrate is an artificial reef.

[0008] In the above-mentioned method for cultivating Sargassum fusiforme seedlings using a sandwich-type method based on Ulva prolifera, in step 1, the total number of Sargassum fusiforme fertilized eggs collected is 2,000,000-3,000,000. The number of attached seedlings is checked 12 hours after attachment to ensure that the attachment density of Sargassum fusiforme fertilized eggs is not less than 20 plants / cm². 2 The attachment time of Sargassum fusiforme fertilized eggs is 70-74 hours.

[0009] In the above-mentioned method for cultivating sandwich-type Sargassum fusiforme seedlings based on Ulva prolifera, in step 2, the Ulva prolifera seeds are collected from naturally distributed wild populations, pulverized using a food processor at a speed of 3000 R / min for 5 minutes, and then released into a separate plastic steel tank for 12 hours. The total number of Ulva prolifera spores is 100,000-200,000. After 12 hours of seedling attachment, the seedling attachment density is checked, and the spore attachment density is not less than 1 plant / cm². 2 The attachment time of Ulva spores is 46-50 hours.

[0010] In the above-mentioned method for cultivating Sargassum fusiforme seedlings using a sandwich-type method based on Ulva prolifera, in step 3, the total number of Sargassum fusiforme fertilized eggs collected is 1,000,000-2,000,000. The number of attached seedlings is checked 12 hours after attachment to ensure that the secondary attachment density of Sargassum fusiforme fertilized eggs is not less than 10 plants / cm². 2 The attachment time of Sargassum fusiforme fertilized eggs is 46-50 hours.

[0011] In the above-mentioned method for cultivating Sargassum fusiforme propagation seedlings based on Ulva prolifera, in step 4, the water flow rate is 0.15-0.25 m / s for the first five days of cultivation, and then the water flow rate is controlled at 0.35-0.45 m / s. After 30 days of indoor cultivation, Sargassum fusiforme seedlings will have 2-3 primary leaves, and the cultivation of Sargassum fusiforme propagation seedlings will be completed.

[0012] In the above-mentioned method for cultivating sandwich-type Sargassum fusiforme seedlings based on Ulva prolifera, in step 1, when adjusting the seawater level in the seedling tank, half of the seawater in the seedling tank is drained and replaced with fresh seawater; in step 2, when adjusting the seawater level in the seedling tank again, one-third of the seawater in the seedling tank is drained and replaced with fresh seawater; and in step 3, when adjusting the seawater level in the seedling tank for the third time, one-third of the seawater in the seedling tank is drained and replaced with fresh seawater.

[0013] The beneficial effects of the sandwich-type Sargassum fusiforme propagation seedling cultivation method based on Ulva are as follows: By using a manually controlled, phased "sandwich-type" seedling collection method, the relatively slow-growing Sargassum fusiforme seedlings can rely on the rapidly growing Ulva fusiforme with its expanded leaves to resist external influencing factors, especially floating mud and miscellaneous algae, during the growth process. This achieves effective cultivation of Sargassum fusiforme propagation seedlings, improves seedling propagation efficiency, reduces labor intensity during seedling cultivation, and is conducive to obtaining high-density, large-sized Sargassum fusiforme propagation seedlings. Detailed Implementation

[0014] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described below in conjunction with specific embodiments.

[0015] Example 1 A method for cultivating sandwich-type Sargassum fusiforme seedlings based on Ulva lactuca includes the following steps: Step 1: Set up a seedling pond, collect mature and fertilized female Sargassum fusiforme thalli, collect fertilized eggs by laying gauze in the seedling area, use measuring tools to count the number of fertilized eggs, control the total number of fertilized eggs and attachment time in the seedling pond, after the fertilized eggs have attached to the attachment substrate, adjust the seawater level in the seedling pond and replace it with fresh seawater.

[0016] Step 2: Crush the Ulva prolifera and release it. Use a measuring tool to count the number of Ulva prolifera spores. After the Sargassum fusiforme fertilized eggs have completed attachment, release the Ulva prolifera spores. Control the total amount of Ulva prolifera spores released and the attachment time. After the Ulva prolifera spores have attached to the attachment substrate, readjust the seawater level in the seedling pond and replace it with fresh seawater.

[0017] Step 3: After the Ulva spores have completed attachment, collect mature and fertilized female Sargassum fusiforme thalli a second time, use measuring tools to count the number of fertilized eggs, control the total number of fertilized eggs and attachment time in the seedling pond, and after the fertilized eggs have reattached to the attachment substrate, adjust the seawater level in the seedling pond for the third time and replace it with fresh seawater.

[0018] Step 4: The attachment substrate containing Sargassum fusiforme fertilized eggs and Ulva spores is placed in the seedling pond for indoor cultivation. The water flow rate is adjusted according to the cultivation time. The Sargassum fusiforme seedlings are cultivated after they have two or more leaves.

[0019] Example 2 The propagation of Sargassum fusiforme seedlings is generally carried out in May, and its main steps include substrate preparation, seed collection, spore release, and seedling attachment.

[0020] A method for cultivating sandwich-type Sargassum fusiforme seedlings based on Ulva lactuca includes the following steps: Step 1: Prepare the seedling pond. Select a seedling pond with a length of 500cm and a width of 200cm, so that the bottom area of ​​the seedling pond is 10,000cm2. Adjust the water depth to 60cm. The light conditions require 2,000-3,000lx, and the seawater must be sand-filtered seawater that has been settled for more than 24 hours.

[0021] Step 2: Collect mature, fertilized female Sargassum fusiforme thalli and collect them in a fertilized egg collection pool. The fertilized egg collection pool can be a Sargassum fusiforme seedling pool or a separate plastic steel water tank. Lay down gauze for centralized collection of fertilized eggs, with a gauze mesh of 120 mesh.

[0022] The collection of Sargassum fusiforme can be carried out using either artificially cultivated or wild populations. The main targets for collecting both wild and artificially cultivated Sargassum fusiforme resources should be vigorous wild algae that have reproductive receptacles and a body length of more than 30cm. In this embodiment, the artificially cultivated population is used as the target for collection.

[0023] After the Sargassum fusiforme seeds are collected, they are clamped with seedling ropes and placed in the aquaculture area to promote maturity at sea. The maturity of the reproductive receptacles is checked regularly. Once the seedlings meet the collection requirements, they are promptly transported back to the seedling workshop for spore release and seedling attachment.

[0024] Step 3: Collect Sargassum fusiforme fertilized eggs for the first collection of Sargassum fusiforme seedlings. Use a measuring cup to count the number of fertilized eggs, strictly control the total number of fertilized eggs and attachment time in a single Sargassum fusiforme seedling pond. The total number of fertilized eggs collected is 2,000,000-3,000,000. Check the attachment quantity 12 hours after attachment to ensure that the attachment quantity meets the minimum requirement, that is, the minimum density of Sargassum fusiforme fertilized eggs collected for the first time is 20-30 plants / cm2. The attachment time of Sargassum fusiforme fertilized eggs is 72 hours, with an error of ±2 hours. After attachment on the attachment substrate is completed, drain half of the seawater in the seedling pond by adjusting the height of the drainage pipe and replace it with fresh seawater.

[0025] The attachment substrate mainly uses artificial reefs in the form of round or square shapes made of cement. The following description uses a 10cm×10cm square reef as an example. The preparation of the attachment substrate mainly includes pretreatment after the substrate is made, including air drying, fresh water soaking, sun drying, seawater soaking, and rinsing. After treatment, the attachment substrate can be used for the attachment of Sargassum fusiforme and Ulva procumbens seedlings.

[0026] Step 4: Collect mature wild Ulva plants, pulverize them using a food processor at 3,000 RPM for 5 minutes, and then place them in a separate plastic-steel water tank for 12 hours. The Ulva plants collected for cultivation utilize naturally distributed wild populations. The main targets for collecting wild Ulva plants are those with a dark green color, well-developed leaves, and a leaf width exceeding 3 cm.

[0027] The number of Ulva spores was counted using a measuring cup. Ulva spores were released after the first collection of Sargassum fusiforme fertilized eggs had completed attachment. The total number of Ulva spores and attachment time in a single nursery were strictly controlled. The total number of Ulva spores was 100,000-200,000. The number of attached spores was checked 12 hours after attachment to ensure that the minimum density requirement was met, i.e., a minimum density of 1-2 spores / cm². The attachment time was 48 hours, with an error margin of ±2 hours. After attachment, one-third of the seawater in the nursery was drained by adjusting the height of the drainage pipe and replaced with fresh seawater.

[0028] Step 5: Conduct a second collection of Sargassum seedlings using the same method as in Step 3, after the Ulva spores have completed attachment. Strictly control the total number of fertilized eggs and the attachment time in a single Sargassum seedling pond. The total number of fertilized eggs collected is 1,000,000-2,000,000. Check the number of attached seedlings 12 hours after attachment to ensure that the number of attached seedlings meets the minimum density requirement, i.e., the minimum density of Sargassum fertilized eggs collected in the second time is 10-20 plants / cm2. The attachment time of Sargassum fertilized eggs is 48 hours, with an error of ±2 hours. After attachment is completed, drain 1 / 3 of the seawater in the seedling pond by adjusting the height of the drainage pipe and replace it with fresh seawater.

[0029] After the second collection of Sargassum fusiforme seedlings, the attachment substrates containing Sargassum fusiforme and Ulva prolifera were cultured in a seedling pond. A slight water flow was maintained during cultivation. For the first 5 days, the water flow rate was controlled at 0.2 m / s, with an error margin of ±0.05 m / s; thereafter, the water flow rate was controlled at 0.4 m / s, with an error margin of ±0.05 m / s. After 15 days of indoor cultivation, Sargassum fusiforme seedlings developed two primary leaves, with a maximum leaf length of over 2 mm; Ulva prolifera seedlings developed into flat leaves, with a maximum leaf length of over 1 mm. After 30 days of indoor cultivation, Sargassum fusiforme seedlings could develop up to three primary leaves, with a maximum leaf length of over 5 mm; Ulva prolifera seedlings had flat leaves with a maximum leaf length of over 3 mm.

[0030] Because the seedlings of Ulva prolifera grow rapidly with their flat leaves and occupy a relatively large area of ​​the substrate, they can effectively resist the influence of floating mud and miscellaneous algae, ensuring the overall progress of Ulva prolifera seedling cultivation in indoor seedling cultivation, and playing a positive protective role in the rapid growth of Ulva prolifera seedlings after propagation.

[0031] Furthermore, Ulva seedlings can quickly develop relatively expansive leaf-like structures after attachment, and can quickly detach when the temperature or light conditions reach a certain level. Therefore, it is considered to use Ulva as an auxiliary species for the propagation and cultivation of Sargassum seedlings to effectively cope with the influence of floating mud and miscellaneous algae.

[0032] At this point, the cultivation of Sargassum fusiforme seedlings is complete.

[0033] In this embodiment, the cultivation of Sargassum fusiforme propagation seedlings and Ulva proliferatore seedlings is mainly achieved by artificially controlling the staged "sandwich" seedling collection method, which quantitatively mixes and controls the attachment time of Sargassum fusiforme propagation seedlings.

[0034] The aforementioned artificially controlled phased "sandwich" seedling harvesting method refers to artificially controlling the harvesting of Sargassum fusiforme seedlings in two batches at certain intervals after they mature, while harvesting Ulva prolifera seedlings in between, thus completing a "sandwich" seedling harvesting process of two Sargassum fusiforme seedling harvestings and one Ulva prolifera seedling harvesting.

[0035] The aforementioned control of the quantitative collection ratio of Sargassum fusiforme and Ulva prostrata seedlings refers to strictly controlling the minimum density of Sargassum fusiforme seedlings collected for the first time to be 20-30 seedlings / cm2, strictly controlling the minimum density of Sargassum fusiforme seedlings collected for the second time to be 10-20 seedlings / cm2, and strictly controlling the density of Ulva prostrata seedlings collected to be 1-2 seedlings / cm2.

[0036] The aforementioned control of the attachment time of Sargassum fusiforme and Ulva prostrata seedlings refers to strictly controlling the attachment time of Sargassum fusiforme seedlings during the first collection to 72 hours, strictly controlling the attachment time of Sargassum fusiforme seedlings during the second collection to 48 hours, strictly controlling the attachment time of Ulva prostrata seedlings to 48 hours, and the time interval between the two collections of Sargassum fusiforme seedlings attachment to 72 hours.

[0037] The above embodiments are merely illustrative of the structural concept and features of the present invention, intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for cultivating sandwich-type Sargassum fusiforme seedlings based on Ulva lactuca, characterized in that, Includes the following steps: Step 1: Set up a seedling pond, collect mature and fertilized female Sargassum fusiforme thalli, collect fertilized eggs by laying gauze in the seedling area, use measuring tools to count the number of fertilized eggs, control the total number of fertilized eggs and attachment time in the seedling pond, after the fertilized eggs have attached to the attachment substrate, adjust the seawater level in the seedling pond and replace it with fresh seawater. Step 2: Crush the Ulva prolifera and release it. Use a measuring tool to count the number of Ulva prolifera spores. After the Sargassum fusiforme fertilized eggs have completed attachment, release the Ulva prolifera spores. Control the total amount of Ulva prolifera spores released and the attachment time. After the Ulva prolifera spores have attached to the attachment substrate, readjust the seawater level in the seedling pond and replace it with fresh seawater. Step 3: After the Ulva spores have completed attachment, collect mature and fertilized female Sargassum fusiforme thallus a second time, use measuring tools to count the number of fertilized eggs, control the total number of fertilized eggs and attachment time in the seedling pond, and after the fertilized eggs have reattached to the attachment substrate, adjust the seawater level in the seedling pond for the third time and replace it with fresh seawater. Step 4: The attachment substrate containing Sargassum fusiforme fertilized eggs and Ulva spores is placed in the seedling pond for indoor cultivation. The water flow rate is adjusted according to the cultivation time. The Sargassum fusiforme seedlings are cultivated after they have two or more leaves.

2. The method for cultivating sandwich-type Sargassum fusiforme propagation seedlings based on Ulva as described in claim 1, characterized in that, In step 1, the seedling pond is 500cm long and 200cm wide, and the water depth is adjusted to 60cm; the light conditions require 2,000-3,000 lx, the seawater is sand-filtered seawater that has been settled for no less than 24 hours, the mesh number of the gauze is 120 mesh, and the attachment substrate is an artificial reef.

3. The method for cultivating sandwich-type Sargassum fusiforme seedlings based on Ulva as described in claim 1, characterized in that, In step 1, the total number of Sargassum fusiforme fertilized eggs collected is 2,000,000-3,000,000. The number of attached seedlings is checked 12 hours after attachment to ensure that the attachment density of Sargassum fusiforme fertilized eggs is not less than 20 plants / cm². 2 The attachment time of Sargassum fusiforme fertilized eggs is 70-74 hours.

4. The method for cultivating sandwich-type Sargassum fusiforme propagation seedlings based on Ulva as described in claim 1, characterized in that, In step 2, the *Ulva prostrata* seedlings are collected from naturally distributed wild populations. They are pulverized using a food processor at 3000 RPM for 5 minutes, then placed in a separate plastic-steel water tank for 12 hours. The total number of *Ulva prostrata* spores is 100,000-200,000. After 12 hours of attachment, the number of attached seedlings is checked, and the spore density is not less than 1 seedling / cm². 2 The attachment time of Ulva spores is 46-50 hours.

5. The method for cultivating sandwich-type Sargassum fusiforme propagation seedlings based on Ulva as described in claim 1, characterized in that, In step 3, the total number of Sargassum fusiforme fertilized eggs collected is 1,000,000-2,000,000. The number of fertilized eggs is checked 12 hours after attachment to ensure that the secondary attachment density is not less than 10 plants / cm². 2 The attachment time of Sargassum fusiforme fertilized eggs is 46-50 hours.

6. The method for cultivating sandwich-type Sargassum fusiforme propagation seedlings based on Ulva as described in claim 1, characterized in that, In step 4, the water flow rate is 0.15-0.25 m / s for the first five days of cultivation, and then the water flow rate is controlled at 0.35-0.45 m / s. After 30 days of indoor cultivation, the Sargassum seedlings will have 2-3 primary leaves, and the Sargassum propagation seedling cultivation is completed.

7. The method for cultivating sandwich-type Sargassum fusiforme propagation seedlings based on Ulva as described in claim 1, characterized in that, In step 1, when adjusting the seawater level in the seedling tank, drain half of the seawater and replace it with fresh seawater. In step 2, when adjusting the seawater level in the seedling tank again, drain one-third of the seawater and replace it with fresh seawater. In step 3, when adjusting the seawater level in the seedling tank for the third time, drain one-third of the seawater and replace it with fresh seawater.