A method for rooting of hard-wood cuttings of a mangrove plant aegiceras corniculatum

Abstract

This invention discloses a method for hardwood cutting propagation of the mangrove plant *Avicennia marina*, comprising: S1: Selection and preparation of cuttings: In early July, select vigorous, healthy, and disease-free superior single plants, collect robust perennial branches, keep them moist after collection, bring them back to the cutting site, and cut them into cuttings on the same day; S2: Pretreatment of cuttings: Disinfect the cuttings obtained in step (1) by soaking them in a 700-fold carbendazim solution for 10 minutes, and then let them air dry naturally; subsequently, quickly dip the cuttings in a 1000 mg / L NAA and IBA hormone solution for 30 seconds, and insert them into the substrate of the seedbed to a depth of 3-4 cm. This method for hardwood cutting propagation of the mangrove plant *Avicennia marina* provides technical support for the industrialized and large-scale production of superior *Avicennia marina* seedlings, and can also ensure the demand for superior seedlings for the ecological restoration of coastal mangroves.

Description

Technical Field

[0001] This invention relates to the field of forest tree growth, development and propagation technology, specifically a method for rooting hardwood cuttings of the mangrove plant Avicennia marina. Background Technology

[0002] Avicennia marina, also known as Mangrove spp., is a shrub or small tree belonging to the Verbenaceae family. It is a common mangrove plant in mangrove forests and a pioneer species in community succession. In China, it is mainly distributed in Fujian, Guangdong, Hainan, and Taiwan. Because Avicennia marina can grow on bare beaches where other mangrove plants are difficult to grow, it provides a good habitat for later-stage mangrove succession species and has become a priority species for artificial afforestation in coastal wetlands.

[0003] As one of the most productive marine ecosystems in the tropical and subtropical coastal ecotones, mangroves play a vital role in purifying seawater, preventing wind and waves, maintaining biodiversity, and sequestering carbon. However, due to activities such as land reclamation, aquaculture, and firewood harvesting, mangrove communities have become fragmented, and their area has drastically decreased. To reverse this trend and comprehensively strengthen mangrove protection and restoration efforts, improving the quality and stability of mangrove ecosystems, the Ministry of Natural Resources and the National Forestry and Grassland Administration have formulated the "Special Action Plan for Mangrove Protection and Restoration (2020-2025)." This plan requires the creation of mangrove forests in suitable restoration areas, the implementation of tending and quality improvement in degraded areas, the expansion of mangrove area, and the enhancement of mangrove ecosystem quality and function. By 2025, 18,800 hectares of mangrove forests will be created and restored, including 9,050 hectares of newly created mangrove forests and 9,750 hectares of restored existing mangrove forests. High-quality seedlings are indispensable for mangrove ecological restoration projects; therefore, conducting research on mangrove seedling propagation techniques and ensuring the supply of mangrove seedlings is of significant practical importance.

[0004] Avicennia marina is a cryptovivilous plant. Its seeds are harvested during the seed maturation period, and the larger seeds are selected for seedling cultivation. In my country, Avicennia marina flowers and fruits once a year, with flowering from March to May and fruiting from mid-May to mid-September.

[0005] Currently, the production of Avicennia marina seedlings for afforestation relies primarily on seed propagation, which results in significant variability in offspring. Cutting propagation is a highly efficient asexual reproduction technique that shortens seedling breeding time and, while maintaining the superior traits of the parent plants, allows for the large-scale production of high-quality cuttings for industrial applications. However, Avicennia marina is notoriously difficult to root, belonging to the category of plants that struggle to root from cuttings. To date, there has been no research on cutting propagation techniques for Avicennia marina. The inability to perform cutting propagation hinders the industrialized, large-scale production of Avicennia marina seedlings, severely limiting the demand for high-quality seedlings in mangrove ecological restoration projects. Summary of the Invention

[0006] The purpose of this invention is to provide a method for rooting hardwood cuttings of the mangrove plant *Avicennia marina*, thereby addressing the problem mentioned in the background art that, to date, there has been no technical research on the propagation of *Avicennia marina* by cuttings, making it impossible to carry out propagation of *Avicennia marina* by cuttings, hindering the industrialized and large-scale production of *Avicennia marina* seedlings, and failing to meet the demand for high-quality *Avicennia marina* seedlings in mangrove ecological restoration projects. To achieve the above objective, this invention provides the following technical solution: A method for rooting hardwood cuttings of the mangrove plant *Avicennia marina*:

[0007] S1: In early July, select vigorous, healthy, and disease-free superior single plants, collect robust perennial branches, keep them moist after collection, bring them back to the cutting site, and cut them into cuttings on the same day.

[0008] S2: Disinfect the cuttings obtained in step (1) by soaking them in a 700-fold carbendazim solution for 10 minutes, then remove them and let them air dry naturally; then dip the cuttings in a 1000 mg / L NAA and IBA hormone solution for 30 seconds, and insert them into the substrate of the seedbed at a depth of 3-4 cm.

[0009] S3: Spray immediately after cutting to leave a water film on the leaf surface, and then carry out post-cutting management.

[0010] Furthermore, in step (1), when preparing the cuttings, the upper cut is a flat cut, 0.5-1.0 cm from the axillary bud, and the lower cut is a slanted cut, 0.5-2.0 cm from the axillary bud.

[0011] Furthermore, in step (1), the cutting is 7-10 cm long and has 2-3 leaves.

[0012] The rooting medium is a key factor affecting the rooting of Avicennia marina cuttings. Waterlogged or poorly permeable substrates can easily cause cuttings to rot, hindering rooting and seedling development. Based on preliminary experiments, this invention ultimately selected perlite as the rooting medium. Perlite has good water absorption and aeration, making it a suitable substrate for Avicennia marina cuttings.

[0013] Furthermore, in step (2), the substrate is perlite, which is disinfected with 700 times the amount of carbendazim before being placed on the tray.

[0014] Furthermore, in step (2), the substrate is filled into the seedling tray, and the seedling tray is placed inside the arched plastic shed.

[0015] Furthermore, in step (2), when inserting the cuttings, first use a bamboo stick slightly thicker than the cutting to make a hole in the seed tray, then insert the lower end of the cutting into the substrate along the hole, and use your fingers to compact the substrate of the cutting part so that its base is in full contact with the substrate.

[0016] Furthermore, in step (3), the post-insertion management includes: spraying water periodically to ensure that the air humidity inside the greenhouse is around 70-80% and the temperature is the natural room temperature of 25-35℃.

[0017] Furthermore, in step (3), the post-insertion management includes: after the cuttings are inserted, a 45W LED full-spectrum plant light is installed above the plastic arched shed, with the photoperiod maintained at 16-18 hours. The method of the present invention is used to carry out the cutting propagation of Avicennia marina, which provides technical support for the industrialized and large-scale production of Avicennia marina seedlings and also provides a guarantee for the demand for superior seedlings in the ecological restoration of coastal mangroves.

[0018] Furthermore, the post-insertion management also includes: spraying the substrate and cuttings with a 700-fold carbendazim solution or a 0.1% potassium permanganate solution every 7-10 days after cutting, and watering once every one or two days depending on the moisture level of the substrate.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The method for hardwood cutting propagation of the mangrove plant Avicennia marina: This invention directly collects hardwood cuttings of superior Avicennia marina germplasm, prunes them, and uses them as cuttings. The cuttings are then cultivated and managed in a simple plastic greenhouse. The operation is simple and easy to promote.

[0021] 2. The method for rooting hardwood cuttings of the mangrove plant Avicennia marina: Using the rooting method provided by this invention, the rooting rate of hardwood cuttings of Avicennia marina reaches more than 50%, providing a technical basis for propagating superior seedlings of Avicennia marina through cuttings;

[0022] 3. The method for hardwood cutting propagation of the mangrove plant Avicennia marina provides technical support for the industrialized and large-scale production of high-quality Avicennia marina seedlings and ensures the supply of high-quality seedlings for the ecological restoration of coastal mangroves. Attached Figure Description

[0023] Figure 1 Images of hardwood cuttings;

[0024] Figure 2 Rooting status of NAA-treated cuttings after 30 days;

[0025] Figure 3 Rooting status of NAA-treated cuttings after 60 days;

[0026] Figure 4 Rooting status of IBA-treated cuttings after 30 days;

[0027] Figure 5 Rooting status of IBA-treated cuttings after 60 days. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Please see Figure 1-5 The present invention provides a technical solution: a method for rooting hardwood cuttings of the mangrove plant Avicennia marina, comprising the following steps.

[0030] In this embodiment:

[0031] As introduced in the background section, Avicennia marina is a "cryptorvegetative" fruit, and seedlings are mainly propagated by seed. However, its offspring are differentiated and cannot maintain the superior biological characteristics of the parent plant. Cuttings are relatively easy to operate and produce a large number of seedlings in a short period of time. However, because Avicennia marina is difficult to root, there are currently no reports on the propagation of Avicennia marina by cuttings.

[0032] Greenwood cuttings and hardwood cuttings are two different methods of propagation. Greenwood cuttings use immature, leafy new shoots that are semi-lignified and grown in the current year. However, in specific experiments, it was found that the branches of Avicennia marina grow slowly, and the part of the semi-lignified new shoots that are grown in the current year is very easy to rot in the substrate, while the part exposed outside the substrate is easy to lose water and dry out.

[0033] Based on this, the purpose of this invention is to provide a method for rooting hardwood cuttings of Avicennia marina. By optimizing the propagation conditions for cuttings, the method effectively overcomes the problem of difficult rooting of Avicennia marina cuttings, laying a technical foundation for the breeding of superior varieties of Avicennia marina.

[0034] In one embodiment of the present invention, a method for rooting hardwood cuttings of Avicennia marina is provided, comprising the following steps:

[0035] (1) Selection and preparation of cuttings:

[0036] In early July, select healthy, disease-free Avicennia marina plants and collect robust perennial branches to prepare cuttings 7-10 cm long with 2-3 opposite leaves.

[0037] (2) Seedbed preparation and cutting substrate:

[0038] The cutting bed is a 4×8-cell tray with a depth of 11cm. The cutting substrate is perlite. The substrate is disinfected with 700 times diluted carbendazim before being filled into the trays.

[0039] (3) Pretreatment of cuttings:

[0040] Disinfect the cuttings by soaking the base in a 700-fold carbendazim solution for 10 minutes, then remove and air dry naturally. Subsequently, quickly dip the cuttings in a 1000 mg / L NAA and IBA hormone solution for 30 seconds.

[0041] (4) Cuttings:

[0042] When propagating by cuttings, first make holes in the seedling tray with a wooden stick slightly thicker than the cuttings, then insert the lower end of the cuttings into the substrate along the holes. The cutting depth is 3-4 cm. Insert 2 cuttings into each hole in the seedling tray, and then gently compact the substrate. After cutting, spray water immediately to leave a layer of water film on the leaf surface.

[0043] (5) Post-insertion management:

[0044] After cutting, place the seedling trays in an arched plastic greenhouse. Depending on the weather, spray the greenhouse periodically to ensure that the humidity inside is around 70-80% and the temperature is at room temperature of 25-35℃.

[0045] After cutting, use a 45W LED full-spectrum plant light at a height of 60cm above the seedbed to provide light, with a photoperiod of 16-18 hours.

[0046] After cutting, spray the substrate and cuttings with a 700-fold dilution of carbendazim solution or a 0.1% potassium permanganate solution every 7-10 days to sterilize them, and water the substrate every one or two days depending on the moisture content of the substrate.

[0047] To address the difficulty of rooting Avicennia marina cuttings, this invention optimizes aspects such as cutting selection, seedbed preparation, optimal selection of cutting substrate, cutting pretreatment, cutting methods, and post-cutting management. Through the synergistic effect of each cutting step, the invention effectively overcomes the difficulty of rooting hardwood cuttings of Avicennia marina, realizing the feasibility of propagating and cultivating superior seedlings through cuttings.

[0048] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0049] The test materials used in the embodiments of the present invention, unless otherwise specified, are all conventional test materials in the art and can be purchased through commercial channels.

[0050] Example 1:

[0051] We selected healthy, disease-free, mature Avicennia marina trees from the mangrove forest community along the Guanhai Corridor in Xiashan District, Zhanjiang City, Guangdong Province. Cuttings were taken from these trees for hardwood cutting rooting research, as detailed below:

[0052] (1) In early July, collect the annual branches of excellent single plants of Avicennia marina to make cuttings.

[0053] (2) Take the collected perennial branches and cut them into cuttings with 2-3 leaves and a length of 7-10cm. The upper cut of the cutting is flat and 0.5-1.0cm away from the axillary bud, and the lower cut is oblique and 0.5-2.0cm away from the axillary bud.

[0054] (3) Pretreatment of cuttings:

[0055] The cuttings were disinfected by soaking in a 700-fold dilution of carbendazim solution for 10 minutes, then removed and air-dried naturally. They were then quickly dipped in a 1000 mg / L NAA solution for 30 seconds, ensuring the lower cut was completely submerged. Thirty cuttings were treated, and the treatment was repeated three times.

[0056] (4) Cuttings:

[0057] The cutting bed is a 4×8-cell tray with a depth of 11cm. The cutting substrate is perlite. The substrate is disinfected with 700 times diluted carbendazim before being filled into the trays.

[0058] When propagating by cuttings, first make holes in the seedling tray with a wooden stick slightly thicker than the cuttings, then insert the lower end of the cuttings into the substrate along the holes. The cutting depth is 3-4 cm. Insert 2 cuttings into each hole in the seedling tray, and then gently compact the substrate. After cutting, spray water immediately to leave a layer of water film on the leaf surface.

[0059] (5) Post-insertion management:

[0060] After cutting, place the seedling trays in an arched plastic greenhouse. Depending on the weather, spray the greenhouse periodically to ensure that the humidity inside is around 70-80% and the temperature is at room temperature of 25-35℃.

[0061] After cutting, use a 45W LED full-spectrum plant light at a height of 60cm above the seedbed to provide light, with a photoperiod of 16-18 hours.

[0062] After cutting, spray the substrate and cuttings with a 700-fold dilution of carbendazim solution or 0.1% potassium permanganate every 7-10 days to sterilize them, and water the substrate every one or two days depending on the moisture content of the substrate.

[0063] The rooting results were analyzed 60 days after cutting. The average rooting rate of cuttings treated with 1000 mg / L NAA for 30 seconds was 66%, with an average of 1-2 roots per cutting and an average root length of 1.16 cm.

[0064] Example 2:

[0065] We selected healthy, disease-free, and mature Avicennia marina trees (also known as white mangroves) from the mangrove forest community along the Guanhai Corridor in Xiashan District, Zhanjiang City, Guangdong Province. Cuttings were taken from these trees and used for hardwood cutting rooting research. Details are as follows:

[0066] (1) In early July, collect the annual branches of excellent single plants of Avicennia marina to make cuttings.

[0067] (2) Take the collected perennial branches and cut them into cuttings with 2-3 leaves and a length of 7-10cm. The upper cut of the cutting is flat and 0.5-1.0cm away from the axillary bud, and the lower cut is oblique and 0.5-2.0cm away from the axillary bud.

[0068] (3) Pretreatment of cuttings:

[0069] Disinfect the cuttings by soaking them in a 700-fold dilution of carbendazim solution for 10 minutes, then remove and air dry naturally. Next, dip them in a 1000 mg / L IBA solution for 30 seconds. During treatment, the lower cut end should be completely submerged in the solution. Treat 30 cuttings and repeat 3 times.

[0070] (4) Cuttings:

[0071] The cutting bed is a 4×8-cell tray with a depth of 11cm. The cutting substrate is perlite. The substrate is disinfected with 700 times diluted carbendazim before being filled into the trays.

[0072] When propagating by cuttings, first make holes in the seedling tray with a wooden stick slightly thicker than the cuttings, then insert the lower end of the cuttings into the substrate along the holes. The cutting depth is 3-4 cm. Insert 2 cuttings into each hole in the seedling tray, and then gently compact the substrate. After cutting, spray water immediately to leave a layer of water film on the leaf surface.

[0073] (5) Post-insertion management:

[0074] After cutting, place the seedling trays in an arched plastic greenhouse. Depending on the weather, spray the greenhouse periodically to ensure that the humidity inside is around 70-80% and the temperature is at room temperature of 25-35℃.

[0075] After cutting, use a 45W LED full-spectrum plant light at a height of 60cm above the seedbed to provide light, with a photoperiod of 16-18 hours.

[0076] After cutting, spray the substrate and cuttings with a 700-fold dilution of carbendazim solution or 0.1% potassium permanganate every 7-10 days to sterilize them, and water the substrate every one or two days depending on the moisture content of the substrate.

[0077] The rooting results were counted 60 days after cutting. The average rooting rate of cuttings treated with 1000 mg / L IBA for 30 seconds was 50%, with an average of 1-2 roots per cutting and an average root length of 3.5 cm.

[0078] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for rooting hardwood cuttings of the mangrove plant *Avicennia marina*, characterized in that: Includes the following steps: S1: Selection and preparation of cuttings: In early July, select vigorous, healthy, and pest-free superior individual trees, collect robust perennial branches, keep them moist after collection, bring them back to the cutting site, and cut them into cuttings on the same day. S2: Cutting pretreatment: Disinfect the cuttings obtained in step (1) by soaking them in a 700-fold carbendazim solution for 10 minutes, then remove them and let them air dry naturally. Then, quickly dip the cuttings in a 1000 mg / L NAA and IBA hormone solution for 30 seconds and insert them into the substrate of the seedbed at a depth of 3-4 cm. S3: Post-insertion management: Spray immediately after cutting to leave a film of water on the leaf surface, and then carry out post-cutting management; In step (1), when preparing the cuttings, the upper cut is a flat cut, 0.5-1.0 cm from the axillary bud, and the lower cut is a slanted cut, 0.5-2.0 cm from the axillary bud; In step (1), the cutting is 7-10cm long and has 2-3 leaves; In step (2), the substrate is perlite, which is disinfected with 700 times carbendazim before being placed on the tray; In step (2), the substrate is filled into the seedling tray and the seedling tray is placed in the arched plastic shed; In step (2), when inserting the cuttings, first use a bamboo stick slightly thicker than the cutting to make a hole in the seed tray, then insert the lower end of the cutting into the substrate along the hole, and use your fingers to press the substrate of the cutting part firmly so that its base is in full contact with the substrate. In step (3), the post-planting management includes: spraying water periodically to ensure that the air humidity inside the greenhouse is 70-80% and the temperature is the natural room temperature of 25-35℃; In step (3), the post-insertion management includes: after the cuttings are inserted, a 45W LED full-spectrum plant light is installed above the plastic archway, and the photoperiod is maintained at 16-18 hours.

2. The method for rooting hardwood cuttings of mangrove plant Avicennia marina according to claim 1, characterized in that: The post-planting management also includes: spraying the substrate and cuttings with a 700-fold carbendazim solution or a 0.1% potassium permanganate solution every 7-10 days after planting to kill bacteria, and watering once every one or two days depending on the moisture level of the substrate.

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