A method for reducing the attachment of macrobenthic diatoms to a young seedling curtain of undaria pinnatifida gametes

Abstract

The application discloses a method for reducing large benthic diatom adhesion on Undaria pinnatifida gametophyte seedling curtain, which comprises the following steps: (1) placing several transparent thin plates on the upper surface of the seedling curtain after Undaria pinnatifida gametophyte is poured into a pool, and the transparent thin plates are uniformly distributed on the seedling curtain; (2) replacing the transparent thin plates when water flows for 48 hours after the gametophyte is poured into the pool, and then replacing the transparent thin plates once a day; (3) removing the transparent thin plates when the Undaria pinnatifida gametophyte seedling emergence rate reaches more than 60%, and then entering normal management until the seedling is delivered out of the warehouse. The transparent thin plates are placed on the upper surface of the seedling curtain after the Undaria pinnatifida gametophyte is poured into the pool, so that the large benthic diatom pollution is prevented. The method is simple in operation, and only needs to place the transparent thin plates on the seedling curtain; the cost is low, and the effect of preventing the large benthic diatom can be achieved by placing the transparent thin plates in the Undaria pinnatifida gametophyte seedling breeding pool.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of Undaria pinnatifida seedling cultivation, and particularly relates to a method for reducing large benthic diatoms adhering to Undaria pinnatifida gametophyte seedling curtains. BACKGROUND

[0002] Undaria pinnatifida is one of the three major economic seaweeds in China. The basic process of the conventional process of Undaria pinnatifida seedling production is as follows: seed algae storage, seed algae release of zoospores, zoospore adhesion to seedling curtains to develop into embryospores, and then develop into gametophytes, release of female and male reproductive cells, fertilization to form young sporophytes, grow into Undaria pinnatifida seedlings, and then be released. In this production process, since the zoospores adhere very firmly to the seedling curtains, the method of washing the seedling curtains can be used to prevent and control the pollution of benthic diatoms on the seedling curtains, and the benthic diatoms have less impact on the gametophytes and young sporophytes. However, the conventional process of seedling cultivation has the disadvantages of long cycle, high cost, easy degradation of germplasm, and season limitation.

[0003] The Undaria pinnatifida gametophyte seedling technology can directly start from the gametophytes, expand the Undaria pinnatifida gametophytes preserved in the germplasm bank, and then convert the gametophytes from the growth state to the development state through short light and weak light culture. Then the gametophytes are broken into small pieces, splashed on the water surface of the seedling pool, and settled on the seedling curtains to develop. After the release of reproductive cells and the process of fertilization, Undaria pinnatifida seedlings are developed. The Undaria pinnatifida gametophyte seedling technology shortens the seedling time, reduces the seedling cost, and has stable germplasm and variety characteristics. In addition, the seedling time is not limited by the seed algae breeding season. Therefore, the Undaria pinnatifida gametophyte seedling technology has many advantages over the conventional process of Undaria pinnatifida seedling production.

[0004] However, the application of the Undaria pinnatifida gametophyte seedling technology is still limited at present, and one of the main limiting factors is the pollution problem of benthic diatoms. In the Undaria pinnatifida gametophyte seedling technology, the small pieces of broken gametophytes are attached to the seedling curtains through the settlement effect, and the adhesion is not firm, and they are easily detached under disturbance. Therefore, after the gametophytes are splashed in the pool, the seedling curtains cannot be prevented and controlled by the conventional methods of rinsing and washing the curtains to prevent the pollution of benthic diatoms during the period before the young sporophytes grow out the roots to firmly grasp the seedling curtains. However, during this period, the benthic diatoms will adhere and multiply on the seedling curtains in large numbers, compete with the Undaria pinnatifida gametophytes and young sporophytes for nutrients and growth space, and shade or cover the Undaria pinnatifida gametophytes and young sporophytes, resulting in insufficient light and sparse seedlings of Undaria pinnatifida, affecting the seedling quality and even leading to the failure of Undaria pinnatifida gametophyte seedling.

[0005] Patent CN112956413B discloses a method for preventing and treating benthic diatom pollution in the production of Undaria pinnatifida gametophytes. The method comprises pre-developing Undaria pinnatifida gametophytes in sterilized seawater without benthic diatoms, and then splashing the pond after development reaches a certain degree. Therefore, the Undaria pinnatifida gametophytes have an advantage in the competition with bottom-dwelling diatoms, and can effectively prevent and treat the pollution of various benthic diatoms. However, the Undaria pinnatifida gametophyte pre-development process is highly technical, requiring accurate grasp of the appropriate degree and conditions of development, and requiring large-scale and intense lighting conditions and pre-development facilities and venues. Application in large-scale production is still subject to certain restrictions. A simple and effective method for preventing and treating large-scale benthic diatom pollution is urgently needed in the production of Undaria pinnatifida gametophytes. Summary of the Invention

[0006] In view of the above-mentioned prior art, the object of the present invention is to provide a method for reducing the attachment of large benthic diatoms to the Undaria pinnatifida gametophyte seedling curtain.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for reducing the attachment of large benthic diatoms to a Undaria pinnatifida gametophyte seedling curtain, comprising the following steps:

[0009] (1) After the gametophytes of Undaria pinnatifida are poured into the pond, several transparent thin plates are placed on the upper surface of the seed curtain, and the transparent thin plates are evenly distributed on the seed curtain;

[0010] (2) Replace the transparent sheet when the gametophyte pool is running for 48 hours, and then replace it once a day;

[0011] (3) When the emergence rate of kelp gametophyte seedlings reaches more than 60%, remove the transparent sheet and enter normal management until the seedlings are shipped out.

[0012] Preferably, in step (1), the transparent sheet is placed 6-12 hours after the Undaria pinnatifida gametophytes are poured into the pond.

[0013] Preferably, in step (1), the total area of ​​the transparent thin plate is 1 / 50-1 / 10 of the area of ​​the seedling curtain, and the thickness is 0.5-1.5 mm.

[0014] More preferably, the transparent thin plate is a transparent glass plate or a transparent plastic plate.

[0015] Preferably, in step (1), the illumination is 400-600 lx, and the daily illumination time is 8-12 h.

[0016] Preferably, in step (2), the flow rate of the running water is 4-6 cm / s, and the time is 2-4 hours; 72 hours after the gametophytes are poured into the pool, the illumination is adjusted to 900-1100 lx, and the daily illumination time is 8-14 hours.

[0017] As preferred, in step (3), the normal management light is 3000-4500lx, and the daily light time is 8-14h.

[0018] In the production of Undaria pinnatifida gametophyte, the benthic diatom of fouling organism competes with Undaria pinnatifida gametophyte and young sporophyte for living space and light. There are many kinds of benthic diatom, and the cell size is quite different. In the production of Undaria pinnatifida gametophyte, the small size benthic diatom with the length of several microns likes weak light and grows slowly, and has weak competitiveness, and can survive and reproduce under the Undaria pinnatifida young body. In the early production of Undaria pinnatifida gametophyte, the small size benthic diatom exists in the gap between the strands of Undaria pinnatifida gametophyte seed rope, and has little harm to the Undaria pinnatifida gametophyte seed production. The large size benthic diatom has strong phototaxis and likes strong light, and has more competitiveness when competing with Undaria pinnatifida gametophyte and young sporophyte for nutrition and light, and has great harm. If the pollution of large size benthic diatom can be controlled, the pollution problem of benthic diatom in the production of Undaria pinnatifida gametophyte can be basically solved.

[0019] After the Undaria pinnatifida gametophyte is poured into a pool, the benthic diatom is deposited, covered and attached to the upper surface of the seed rope. The upper surface of the seed rope is occupied by the gametophyte, which is not the ideal attachment place of the large size benthic diatom in the water body. And the lower surface of the seed rope is weak in light, which is also not the ideal place for the large size benthic diatom to attach. Therefore, the seed curtain after the Undaria pinnatifida gametophyte is poured is not the ideal place for the large size benthic diatom to attach. The large size benthic diatom has a certain swimming ability, and providing ideal attachment materials such as thin glass sheets or plastic sheets for the large size benthic diatom can easily attract the large size benthic diatom to attach, so as to effectively reduce the attachment of the large size benthic diatom on the Undaria pinnatifida seed curtain, and thus protect the Undaria pinnatifida gametophyte from the harm of the large size benthic diatom pollution.

[0020] Before the large size benthic diatom multiplies a lot on the transparent sheet, the transparent sheet is replaced to control the amount and spread of the large size benthic diatom in the water body, and at the same time, the large size benthic diatom newly added to the water body is attracted to attach. When the Undaria pinnatifida gametophyte grows into young sporophyte, the young sporophyte grows rapidly, and a small amount of large size benthic diatom has no substantial threat to the young sporophyte, and at this time, the transparent sheet can not be used any more. After the young sporophyte grows out the rhizoids and is firmly attached to the seed curtain, the large size benthic diatom can be effectively prevented and controlled by rinsing the curtain and flushing the curtain.

[0021] The beneficial effects of the present application are as follows:

[0022] The present application places a transparent sheet on the upper surface of the seed curtain after the Undaria pinnatifida gametophyte is poured into a pool, so as to prevent and control the pollution of the large size benthic diatom. The present application is simple to operate, and only needs to place the transparent sheet on the seed curtain. The cost is low, and the effect of preventing and controlling the large size benthic diatom can be achieved by placing the transparent sheet in the Undaria pinnatifida gametophyte seed production pool. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 : transparent glass plate is placed in the example, and no transparent glass plate is placed in the comparative example;

[0024] Figure 2 : large benthic diatom attached to the surface of the transparent glass plate after 2h in the example, indicated by the arrow;

[0025] Figure 3 : large benthic diatom attached to the surface of the transparent glass plate after 18h in the example, indicated by the arrow;

[0026] Figure 4 : seedling screen obtained in the example;

[0027] Figure 5 : seedling screen obtained in the comparative example. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0029] As described in the background, the technical process of the gametophyte pre-development of Undaria pinnatifida is technically difficult, and requires accurate understanding of the suitable degree and conditions of development, and large-scale and strong lighting conditions and pre-development facilities and sites. Its application in large-scale production is still limited to a certain extent.

[0030] Based on this, the present application provides a method for reducing the attachment of large benthic diatoms on the Undaria pinnatifida gametophyte seedling screen, comprising the following steps:

[0031] (1) 6-12h after the Undaria pinnatifida gametophyte is poured into a pool, a plurality of transparent thin plates are placed on the upper surface of the seedling screen, and the transparent thin plates are uniformly distributed on the seedling screen; the total area of the transparent thin plates is 1 / 50-1 / 10 of the area of the seedling screen, and the thickness is 0.5-1.5mm; the transparent thin plates are glass sheets or transparent plastic sheets; the light intensity is 400-600lx, and the daily light time is 8-12h.

[0032] (2) The transparent thin plates are replaced when the gametophytes are poured into the pool for 48h, and then replaced once a day; the flow rate of the flowing water is 4-6cm / s, and the time is 2-4 hours; after the gametophytes are poured for 72h, the light intensity is adjusted to 900-1100lx, and the daily light time is 8-14h.

[0033] (3) When the Undaria pinnatifida gametophyte seedling emergence rate reaches more than 60%, the transparent thin plates are no longer placed, and the normal management is entered, the light intensity is 3000-4500lx, and the daily light time is 8-14h. Until the seedlings are delivered out of the warehouse.

[0034] In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in conjunction with specific embodiments.

[0035] The test materials used in the embodiments of the present application are all conventional test materials in the art and can be purchased through commercial channels.

[0036] Embodiment

[0037] An adjustable height fluorescent tube is hung above a 0.9 m x 0.9 m x 0.4 m PVC tank, so that the light at the overflow plane of the tank can reach 500-5000 lx. Two female gametophyte seedling curtains of Undaria pinnatifida are hung in the tank, each with a size of 0.68 m x 0.34 m. The vertical distance between the seedling curtain and the overflow plane of the tank is 10 cm. The tank is filled with sand-filtered seawater.

[0038] Take 6 g of Undaria pinnatifida J56 female and male gametophytes, respectively, add 10℃ sterilized seawater, and crush to 1-6 cells under the condition of 16000 rpm. After mixing, evenly sprinkle on the water surface of the tank and allow to settle freely. The water temperature is 20℃.

[0039] When the gametophytes are sprinkled for 8h, evenly place 8 pieces of transparent glass plates with a size of 7.5 cm x 2.5 cm x 0.1 mm on the surface of the seedling curtain in the tank. The light is 500 lx, 12h per day. As shown in the left tank in Figure 1 , the transparent glass plates are connected with ropes for easy replacement, Figure 1 and the connection between the transparent glass plates and the ropes is indicated by the red arrow.

[0040] When the gametophytes are sprinkled for 48h, gently remove the transparent glass plates with tweezers, and there are large benthic diatoms attached to the transparent glass plates. Replace the same number of new transparent glass plates on the seedling curtain with a water flow rate of 5 cm / s for 3 hours.

[0041] After the gametophytes are sprinkled for 72h, adjust the light to 1000 lx, and the light time is 12h per day. Replace the new transparent glass plates before flowing water.

[0042] The same operation is continued to the seventh day of gametophyte sprinkling, 91% of the female gametophytes develop into sporophytes, the transparent glass plates are stopped, the light is adjusted to 3000-4500 lx, and the light is 12h per day. Continue to cultivate for 25d, and the Undaria pinnatifida seedlings reach 1 cm.

[0043] The seedlings of the embodiment have a body length of ≥0.5 cm, a seedling density of 21 seedlings / cm, a seedling loss rate of 3.0%, and a seedling deficiency rate of 0.3%. The seedling curtain is shown in Figure 4 , and the Undaria pinnatifida seedlings are dense.

[0044] Comparative Example

[0045] In this comparative example, no transparent glass plate is placed on the seedling curtain, and the rest is the same as in the embodiment. Figure 1 Shown in the sink on the right.

[0046] The seedlings in the control group were ≥0.5 cm in length and the seedling density was 9 plants / cm, the seedling loss rate was 3.2%, the seedling loss rate was 3.4%, and the seedling curtain was Figure 5 As shown, the kelp seedlings are sparse and missing.

[0047] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for reducing the attachment of large benthic diatoms to the gametophyte seedling curtain of Undaria pinnatifida, characterized in that: The following steps are involved: (1) After the gametophytes of Undaria pinnatifida are poured into the pond, several transparent thin plates are placed on the upper surface of the seed curtain, and the transparent thin plates are evenly distributed on the seed curtain; (2) Replace the transparent sheet when the gametophyte pool is running for 48 hours and then replace it daily; (3) When the emergence rate of Undaria pinnatifida gametophyte seedlings reaches more than 60%, remove the transparent sheet and enter normal management until the seedlings are shipped out; The transparent thin plate is a transparent glass plate or a transparent plastic plate; In step (1), the total area of ​​the transparent thin plate is 1 / 50-1 / 10 of the area of ​​the seedling curtain, and the thickness is 0.5-1.5 mm.

2. The method for reducing the attachment of large benthic diatoms to the Undaria pinnatifida gametophyte seedling curtain according to claim 1, characterized in that: In step (1), the transparent sheet is placed 6-12 hours after the gametophytes of the Undaria pinnatifida are poured into the pond.

3. The method for reducing the attachment of large benthic diatoms to the Undaria pinnatifida gametophyte seedling curtain according to claim 1, characterized in that: In step (1), the light intensity is 400-600 lx, and the daily light exposure time is 8-12 hours.

4. The method for reducing the attachment of large benthic diatoms to the Undaria pinnatifida gametophyte seedling curtain according to claim 1, characterized in that: In step (2), the flow rate of the flowing water is 4-6 cm / s, and the time is 2-4 hours; 72 hours after the gametophytes are poured into the pool, the light intensity is adjusted to 900-1100 lx, and the daily light duration is 8-14 hours.

5. The method for reducing the attachment of large benthic diatoms to the Undaria pinnatifida gametophyte seedling curtain according to claim 1, characterized in that: In step (3), the normal managed light intensity is 3000-4500 lx, and the daily light exposure time is 8-14 hours.

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