How to produce cuttings of conifers

Abstract

To provide a method that can increase the number of ears harvested per conifer and can produce rooted cuttings more efficiently.SOLUTION: The present invention provides a method for producing a conifer rooted cutting, comprising: an ear-harvesting step of harvesting a side branch with a strong core together with part of a node from a mother tree of conifer, such as Cryptomeria and Chamaecyparis plants, as a cutting; a rooting step of rooting the cutting; and a seedling raising step of raising the rooted cutting using the side branch as a main axis.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing cuttings of conifers. [Background technology]

[0002] There are two methods for producing coniferous seedlings: seedlings grown from seeds and cuttings. In the cutting method, broad-leaved trees can be taken from knots, but conifers do not produce new shoots when taken from knots. For this reason, in conifers, a part including the tip of the main axis is selected as the cutting site. For example, Non-Patent Document 1 describes that, as cuttings, branches with an upward growth type that grow close to the tip of the main axis and have a large amount of annual branch growth are preferred. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Ehime Prefecture Forest Tree Breeding Council, "Guide to Producing Cutting Seedlings," published December 28, 2017. https: / / www.pref.ehime.jp / h35700 / 1461 / 5_guide / 5_sashiki.html Summary of the Invention [Problem to be solved by the invention]

[0004] However, when harvesting from the tip of the main stem as in the past, the number of harvested cuttings from one mother tree was limited, making it difficult to raise seedlings efficiently.

[0005] The present invention has been made in view of the above, and aims to provide a method that can increase the number of cuttings taken per coniferous tree and enable more efficient production of cutting seedlings. [Means for solving the problem]

[0006] The present invention provides the following [1] to [6]. [1] A cutting process in which a central branch of a coniferous tree is taken from the mother tree along with a portion of the node as a cutting; A rooting step for rooting the cuttings; and A seedling raising step of raising the rooted cuttings using the lateral branches as the main axis, Methods for producing conifer cuttings. [2] The method according to [1], wherein the length of the nodes contained in the cutting is 2 to 8 cm. [3] A method according to [1] or [2], in which in the cutting collection step, at least a side branch branching from a node located 20 cm or less from the tip of the base branch and a portion of the node are collected as cuttings. [4] The method according to any one of [1] to [3], wherein the length of the lateral branch contained in the cutting is 5 cm or more. [5] The method according to any one of [1] to [4], wherein the coniferous tree is a plant of the genus Cryptomeria or a plant of the genus Chamaecyparis obtusa. [6] A method for producing coniferous trees, comprising cultivating cuttings produced by the method for producing coniferous tree cuttings according to any one of [1] to [5]. [Effects of the Invention]

[0007] According to the present invention, when harvesting cuttings from coniferous trees, the stem-standing lateral branches are left attached to the nodes to be used as cuttings, thereby making it possible to obtain a large number of cuttings that can achieve the same rooting rate and seedling yield rate as in the conventional technology in which the part including the tip of the main axis was used as the cutting, thereby improving the efficiency of coniferous tree cutting seedling production. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the procedure for harvesting. [Figure 2] Figure 2 is a photograph showing an example of a cutting. The left side shows a cutting that includes a stemmed lateral branch and part of a node, and the right side shows a cutting that includes the tip of a stemmed main axis. [Figure 3] Figure 3 is a schematic diagram showing the steps from cutting to raising seedlings. DETAILED DESCRIPTION OF THE INVENTION

[0009] [1. Methods for Producing Coniferous Tree Cuttings] The method for producing cuttings of coniferous trees includes at least a cutting collection step, a rooting step, and a seedling raising step.

[0010] [1.1. Picking process] The cutting collection process is a process of collecting cuttings from a mother tree.

[0011] [Mother tree] The mother tree may be any coniferous tree. Examples of coniferous trees include plants of the cypress family (Taxodiaceae) (plants of the genus Cryptomeria (such as Japanese cedar (Cryptomeria japonica))), plants of the cupressaceae family (plants of the genus Chamaecyparis (such as Chamaecyparis obtusa))), plants of the genus Cunninghamia (such as Cunninghamia lanceolata), plants of the pinaceae family (plants of the genus Pinus (Pinus) (such as Pinus thunbergii)), plants of the genus Larix (such as Larix kaempferi and Larix gmelinii), and plants of the fir genus (Abies) (such as Abies sachalinensis). The mother tree used in the present invention may be any of the above mentioned trees, but is not particularly limited thereto. Preferably, the plant is of the family Cupressaceae or Cupressaceae, more preferably of the genus Cryptomeria or Chamaecyparis, and even more preferably of Cryptomeria japonica or Chamaecyparis obtusa.

[0012] The mother tree may be derived from either a seedling or a cutting. The age of the mother tree is preferably 15 years or less, more preferably 10 years or less, even more preferably 7 years or less, or even more preferably 6 years or less.

[0013] [Gleaning part] The cuttings are taken from lateral branches with nodes attached. That is, the lateral branches are taken as cuttings together with some of the nodes. It is preferable to select lateral branches that are oriented to the center. This allows for a good rooting rate and seedling yield rate, and allows for cuttings with excellent growth. As used herein, "oriented to the center" means that the branch is growing upward against gravity, i.e., the tip of the branch is not drooping due to gravity. Typically, first-year lateral branches (branches grown in the previous year) are oriented to the center. As long as they have a terminal bud, lateral branches may be green branches, mature branches, or sprouting branches. A cutting must contain at least one lateral branch, and may contain two or more lateral branches. In the case of cuttings containing two or more lateral branches, it is preferable to prune them after rooting, leaving one lateral branch.

[0014] The cutting sites will be described below with reference to Figure 1. Figure 1 is a diagram that schematically illustrates the cutting procedure. In cutting (left side of Figure 1), when cutting from a mother tree 1, a main stem 12 with attached lateral branches 11 is cut along dotted lines at nodes 13a including lateral branches 11a, 13b including 11b, and 13c including 11c, to obtain multiple cuttings 2 (center of Figure 1: cuttings 2a, 2b, 2c, etc.). Each cutting 2 is composed of a lateral branch 11 and a node 13 connected to it. Note that in Figure 1, node 13, which is the base of the lateral branch, is part of the main stem 12, but the node may be part of a branch other than the main stem as long as the lateral branch is branched. An example of a cutting obtained by the method of the present invention is shown in Figure 2. While conventional cuttings (right side of Figure 2) use only the tip of the main stem, cuttings obtained by the method of the present invention (left side of Figure 2) are not limited to the tip of the main stem, as long as they include at least one main stem and a portion of one node.

[0015] There are no particular restrictions on which part of the mother tree to harvest cuttings from, but it is preferable to include at least the lateral branches (including the node) that branch off from a node where the distance T from the tip of the base branch from which the lateral branches branch off is preferably 20 cm or less, more preferably 22 cm or less, and even more preferably 25 cm or less. This makes it possible to obtain many cuttings from branches at the bottom of the mother tree that could not be used in the past, enabling efficient seedling cultivation. Note that lateral branches that branch off from nodes where the distance T is less than 20 cm may also be included in the cuttings to be harvested.

[0016] [Cutting size] The length L1 of the lateral branches contained in the cutting is not particularly limited, but is usually 5 cm or more, preferably 10 cm or more, more preferably 12 cm or more, and even more preferably 13 cm or more or 15 cm or more. The upper limit is usually 45 cm or less, preferably 40 cm or less, more preferably 35 cm or less, and even more preferably 30 cm or less. This prevents the cutting from tipping over during planting. Therefore, the length L1 of the lateral branches contained in the cutting is usually 5 to 45 cm, preferably 10 to 40 cm, more preferably 12 to 35 cm, and even more preferably 13 to 35 cm, 13 to 30 cm, 15 to 35 cm, or 15 to 30 cm.

[0017] The length L2 of the node contained in the cutting is not particularly limited, but is usually 2 cm or more, preferably 2.5 cm or more, more preferably 3 cm or more, and even more preferably 4 cm or more. This ensures that the length of the base to be attached to the cutting bed during cutting is secured. The upper limit is usually 8 cm or less, preferably 7 cm or less, more preferably 6 cm or less, and even more preferably 5 cm or less. Therefore, the length of the node is preferably 2 to 8 cm, more preferably 2.5 to 8 cm, even more preferably 3 to 7 cm, and even more preferably 4 to 6 cm.

[0018] As shown in the center of Figure 1 and Figure 2, it is preferable that the length L1 of the lateral branch of the cutting 2 is longer than the length L2 of the node. This allows the cutting 2 to have a size suitable for raising seedlings using the lateral branch as the main axis. If the length L2 of the node is longer, it is preferable to prune the cutting 2 during the raising process.

[0019] Harvesting methods include, for example, harvesting at least one lateral branch along with its base branch and adjusting it to an appropriate size as needed (for example, along the dotted line in Figure 1), or preparing the basal branch by directly cutting it at each node (for example, cutting it along the dotted line in Figure 1).

[0020] -Harvesting period- The harvesting period is usually from autumn to spring, preferably from November to May or from February to April, but the harvesting may also be done in winter and stored in a cool, dark place.

[0021] [1.2. Rooting process] The rooting step is a step of causing roots to grow from the cuttings.

[0022] Rooting from cuttings can be performed by conventional methods. For example, cuttings can be placed on a support and allowed to root. The support may contain additives as needed. The support may also be stored in a culture vessel.

[0023] -Insertion period- The timing of the cuttings may be simultaneous with the collection of the scion or an appropriate time after the collection of the scion (for example, within 6 months, 5 months, 4 months, 3 months, or 2 months after the collection of the scion). Of these, simultaneous with the collection of the scion is preferred. When cuttings are to be planted at an appropriate time after harvesting, it is preferable to store the cuttings in a refrigerator (for example, at 4°C or below) until planting, as this allows the cuttings to maintain their rooting ability.

[0024] -Support- The support may be any support capable of supporting (holding) the cuttings and the culture medium. Among these, conventional supports that are water-absorbent and breathable and allow the cuttings to efficiently absorb additives can be used. Examples of the support include natural soil and artificial soil. Examples of natural soil include Akadama soil and Kanuma soil, and examples of artificial soil include peat moss, coconut fiber, perlite, and vermiculite. Of these, natural soil is preferred, and Akadama soil is more preferred.

[0025] -Culture medium- Examples of media include known media for plant tissue culture and aqueous solvents (e.g., water). Among these, aqueous solvents are preferred, and water is more preferred. Examples of media for plant tissue culture include MS medium, Linsmeyer-Skoog medium, White medium, Gamborg's B-5 medium, and Nitsch-Nitsch medium. Among these, MS medium and Gamborg's B-5 medium are preferred. These media can be used by diluting them appropriately as needed. The medium may be either a liquid medium or a solid medium. However, liquid medium is preferred in terms of work efficiency and less damage to roots during transplantation. Liquid medium can be prepared by mixing the medium components and used as is. Solid medium can be prepared by mixing the medium components in the same way as liquid medium and solidifying it with a solidifying agent (e.g., agar, gellan gum) at the same time as or after preparation. The amount of solidifying agent added can be appropriately determined depending on conditions such as the type of solidifying agent and the composition of the medium. The amount of agar added to the medium is preferably 0.5 to 1% by weight, and the amount of gellan gum added to the medium is preferably 0.2 to 0.3% by weight.

[0026] -Additives- The additive may be any additive used for rooting cuttings, such as fertilizers (e.g., inorganic components, silver ions, antioxidants, carbon sources, vitamins, amino acids, and plant hormones) and other rooting promoters (e.g., agents described in WO 2011 / 136285, JP 2012-232907 A, JP 2013-95664 A, and the like). The form of each component is not particularly limited and may be either a solid (e.g., powder, granules) or a liquid (e.g., liquid fertilizer). The components constituting the additive may be mixed with, absorbed into, or sprayed on a support, or may be directly sprayed, coated, or sprayed on at least a portion of the cutting.

[0027] The additives may be incorporated into the support either as a mixture or at least partially separately, or may be added to a known medium or aqueous solvent (e.g., water) for plant tissue culture and incorporated into the support, or may be applied directly to the cutting (preferably the base).

[0028] Examples of inorganic components include elements such as nitrogen, phosphorus, potassium, sulfur, calcium, magnesium, iron, manganese, zinc, boron, molybdenum, chlorine, iodine, and cobalt, as well as inorganic salts containing these elements. Examples of inorganic salts include potassium nitrate, ammonium nitrate, ammonium chloride, sodium nitrate, potassium monohydrogen phosphate, sodium dihydrogen phosphate, potassium chloride, potassium sulfate, ammonium sulfate, magnesium sulfate, ferrous sulfate, ferric sulfate, manganese sulfate, zinc sulfate, copper sulfate, sodium sulfate, calcium chloride, magnesium chloride, boric acid, molybdenum trioxide, sodium molybdate, potassium iodide, and cobalt chloride, as well as hydrates thereof. Among these, the inorganic component preferably includes at least one selected from nitrogen, phosphorus, potassium, inorganic salts containing nitrogen, inorganic salts containing phosphorus, and inorganic salts containing potassium. The inorganic component may be used alone or in combination of two or more. When one inorganic component is contained in the above-mentioned known medium, the amount in the medium is preferably 0.1 μM to 100 mM, more preferably 1 μM to 100 mM. When two or more components are contained in combination, the amount of each component in the medium is preferably 0.1 μM to 100 mM, more preferably 1 μM to 100 mM.

[0029] Examples of silver ions include silver compounds (silver ion sources) such as silver thiosulfate (STS, AgSO) and silver nitrate. Among these, STS is preferred. STS is presumed to take the form of silver thiosulfate ions in the culture medium and to be negatively charged. Therefore, it can contribute to promoting healthy root development and growth. The silver ions may be of one type alone or in combination of two or more types. When silver ions are added to the culture medium, the amount of the silver ion source in the culture medium is preferably 0.5 μM to 6 μM, more preferably 2 μM to 6 μM.

[0030] Examples of antioxidants include ascorbic acid and sulfites. Ascorbic acid has low residual properties in the medium, and therefore can prevent environmental pollution. Therefore, ascorbic acid is preferred as the antioxidant. One antioxidant may be used alone, or two or more antioxidants may be used in combination. When an antioxidant is contained in the medium, the amount is preferably 5 mg / L to 200 mg / L, and more preferably 20 mg / L to 100 mg / L.

[0031] Examples of carbon sources include carbohydrates such as sucrose and their derivatives; organic acids such as fatty acids; and primary alcohols such as ethanol. The carbon source may be a single type or a combination of two or more types. When a carbon source is contained in the medium, the amount is preferably 1 g / L to 100 g / L, and more preferably 10 g / L to 100 g / L. When rooting culture is performed with the supply of carbon dioxide, the rooting medium does not need to contain a carbon source, and preferably does not. Organic compounds that can serve as carbon sources, such as sucrose, also serve as carbon sources for microorganisms, so when using a rooting medium containing these compounds, cultivation must be performed in a sterile environment. However, by performing rooting culture with the supply of carbon dioxide, the addition of a carbon source to the rooting medium can be omitted, allowing cultivation in a non-sterile environment.

[0032] Examples of vitamins include biotin, thiamine (vitamin B1), pyridoxine (vitamin B4), pyridoxal, pyridoxamine, calcium pantothenate, inositol, nicotinic acid, nicotinamide, and riboflavin (vitamin B2). Vitamins may be used alone or in combination of two or more. When adding one vitamin to the medium, the amount is preferably 0.01 mg / L to 200 mg / L, more preferably 0.02 mg / L to 100 mg / L. When adding a combination of two or more vitamins, the amount of each vitamin is preferably 0.01 mg / L to 150 mg / L, more preferably 0.02 mg / L to 100 mg / L.

[0033] Examples of amino acids include glycine, alanine, glutamic acid, cysteine, phenylalanine, and lysine. The amino acids may be used alone or in combination of two or more. When adding one amino acid to the medium, the amount is preferably 0.1 mg / L to 1000 mg / L. When adding a combination of two or more amino acids, the amount of each amino acid in the medium is preferably 0.2 mg / L to 1000 mg / L.

[0034] Examples of plant hormones include root-stimulating agents such as auxin and cytokinin. The plant hormone may be a single type or a combination of two or more types. Among these, auxin or a combination of auxin and cytokinin is preferred. Examples of auxins include naphthaleneacetic acid (NAA), indoleacetic acid (IAA), p-chlorophenoxyacetic acid, 2,4-dichlorophenoxyacetic acid (2,4D), indolebutyric acid (IBA), and derivatives thereof. The auxin may be one of these or a combination of two or more of them. Examples of cytokinins include benzyladenine (BA), kinetin, zeatin, and derivatives thereof. The cytokinin may be one of these or a combination of two or more of them.

[0035] The method for adding plant hormones can be according to the instructions of the commercially available product, for example, by directly applying a plant hormone powder (e.g., auxin) to the base of the cutting (e.g., the cut ends of both ends of the node) before cutting, or by adding it to the support. When the plant hormone is applied directly to the base of the cutting, the amount of the plant hormone powder is preferably 0.001 mg to 10 mg, more preferably 5 to 10 mg. When adding one plant hormone to the medium, the amount is preferably 0.001 mg / L to 10 mg / L, more preferably 0.01 mg / L to 10 mg / L. When adding a combination of two or more plant hormones, the amount of each is preferably 0.001 mg / L to 10 mg / L, more preferably 0.01 mg / L to 10 mg / L.

[0036] The timing of adding the rooting medium is not particularly limited. For example, it can be added at the start of rooting culture or during culture. The method of addition depends on the type of ingredients, but examples include spraying, wetting, and spraying. The number of additions is not particularly limited, and may be once (at the start of culture) or twice or more (at the start and during culture). In addition, the components constituting the rooting medium may be added together or separately, or may be replaced or replenished as appropriate during culture.

[0037] -Culture container- Storing the support in a culture vessel allows for smooth rooting of cuttings. The culture vessel preferably has a water passage (mesh, pores), allowing for use in bottom watering. Examples include seedling boxes, containers (e.g., the containers described in JP 2017-079706 A, multi-cavity containers (JFA-150, JFA-300), etc.), cell trays, seedling pots, planters, and trays (box-shaped containers with mesh openings on the bottom or side). The culture vessel may be a type in which one cutting is planted per container, or a type in which two or more cuttings are planted per container. These culture vessels are preferably placed on a seedling shelf. The material of the culture vessel is not particularly limited, and examples include resin, glass, and wood.

[0038] -Putting cuttings- The method for inserting the cutting into the support may be appropriately selected depending on conditions such as the type of support, the environment, the type of cutting, etc. For example, a method may be used in which a portion of the cutting including the base (for example, 1 cm to 5 cm from the base) is inserted into the support.

[0039] By base of the cutting is meant the area at one end of the cutting where roots form (opposite the end where leaves form).

[0040] The cutting procedure will be described with reference to Figure 3. Figure 3 is a schematic diagram showing the procedure from cutting to raising seedlings. The cuttings are inserted into the support 31 so that the nodes 13 (the cut portions form the bases 14a, 14b) are hidden and the lateral branches 11 extend from the support 31 and face upward, forming an environment 3 for the rooted seedlings (left side of Figure 3). Note that in the example of Figure 3, multiple cuttings are inserted into a container that houses one support, but the cuttings may be inserted one by one into separate containers or partitioned spaces (for example, seedling raising containers, cell trays).

[0041] When inserting, physical stimulation may be applied to the cutting (e.g., by making a wound at the base). This can improve the rooting rate. The size (e.g., size and shape) of the wound made at the base is not particularly limited. For example, a cross-shaped wound can be made at the base (the cut surface described above) of the multiple shoot that is the cutting. Examples of tools used for making the wound include scissors and knives. It is preferable to remove the leaves at the base of the cutting that will be inserted into the support.

[0042] -Irrigation- The watering method for rooting may be, for example, overhead watering or bottom watering. Of these, bottom watering is preferred. For example, a culture vessel (equipped with a water inlet) containing a support with a cutting inserted therein may be immersed in water.

[0043] The amount of water to be applied is not particularly limited as long as the cuttings are substantially moistened. In the rooting and culturing process, the cuttings may be irrigated through a water-absorbing member. That is, water is supplied to the water-absorbing member, and moisture is supplied to the cuttings through the contact area between the medium and the water-absorbing member. It is preferable to supply water to the water-absorbing member so that the medium is moistened and / or so that the water-absorbing member absorbs water uniformly. This allows the moisture environment of the medium to be maintained at an appropriate level, constant, and uniform. The irrigation process may be performed by hand or with an automatic irrigation device.

[0044] -Rooting culture period- The rooting culture period for rooting cuttings varies depending on the tree species. However, it is sufficient to continue at least until rooting is observed, and preferably until the roots are fully developed. The period is usually 2 weeks to 10 months, preferably 4 weeks to 8 months, and more preferably 1 month to 6 months.

[0045] -Other conditions for rooting- Conditions for rooting other than those mentioned above (e.g., temperature, light, carbon dioxide concentration, humidity, location) can be determined appropriately depending on the tree species, part, size, type of additive, etc. of the cutting. For example, they are as follows. The temperature is more preferably 23 to 28°C. The light irradiated to the cuttings may be natural light or light whose intensity has been artificially adjusted. Examples of artificial adjustment methods include adjusting the light intensity, adjusting the wavelength components, and shading. Light intensity (photosynthetically active photon flux density) is 10 μmol / m 2 / s~1000μmol / m 2 / s is preferred, and 50 μmol / m 2 / s~500μmol / m 2 / s is more preferred. The light to be irradiated preferably contains a wavelength component of 650 nm to 670 nm and a wavelength component of 450 nm to 470 nm, and the ratio of the two is preferably 9:1 to 7:3, more preferably 9:1 to 8:2. When light is blocked, the light blocking rate is preferably 30 to 70%, more preferably 40 to 60%.

[0046] The carbon dioxide concentration during rooting is usually 300 to 2000 ppm, preferably 800 to 1500 ppm. The carbon dioxide concentration can be adjusted to the above range by using a culture vessel equipped with a carbon dioxide-permeable membrane (for example, by placing the vessel in a facility such as an artificial climate chamber).

[0047] The humidity is preferably 60% or higher, and more preferably 80% or higher, which can promote root growth from the plant. There is no particular upper limit. The culture vessel is preferably placed in a greenhouse, which makes it easier to control conditions such as humidity and temperature.

[0048] The location for rooting and culturing is not particularly limited, and may be either a closed space (eg, in a vinyl house, in an artificial sunlight room, in a greenhouse, indoors) or an open space (eg, outdoors).

[0049] [1.3. Seedling raising process] The seedling raising process is a process of raising the cuttings after rooting. The seedling raising is carried out using the lateral branches of the cuttings as the main axis. In this specification, raising the seedlings using the lateral branches as the main axis means planting and raising the seedlings with the lateral branches above ground so that the rooted parts (usually the nodes) are hidden in the culture soil.

[0050] -Support- Examples of supports used in the seedling raising step are the same as those used in the rooting step. The support is not particularly limited, and the same supports as those used in the rooting step may be used, but a combination of natural soil and artificial soil is preferred, and a combination of Akadama soil granules and peat moss is more preferred.

[0051] -Seedling container- The seedling cultivation containers used in the seedling cultivation process are the same as those used in the rooting process described above, but the seedlings may be transplanted to a nursery or cultivated directly in the rooting cultivation container. When using a cultivation container that can accommodate two or more plants for root cultivation, it is preferable to transplant them into a container that can be planted individually (e.g., a cultivation container). For example, as shown in Figure 3, the seedlings 41 after rooting can be transferred to a cultivation container 42 and cultivated as container seedlings 4.

[0052] - Seedling raising period - Seedlings may be raised until they reach a size large enough to be transplanted into forests. Once the seedlings have grown to a certain size (for example, a height of 15 cm or more and a root diameter of 3 mm or more), they can be used for planting or other purposes. The period varies depending on the plant species and is not particularly limited, but is usually 4 months to 1.5 years, preferably 5 months to 1 year and 3 months, and more preferably 6 months to 1 year. The timing of the seedling raising period is not particularly limited, and may begin immediately after the rooting period has ended.

[0053] -Seedling raising place- The seedling raising location is the same as the example of the rooting culture location described above. It may be continued in the same location as the rooting culture, or it may be moved. The soil for the seedling raising process may be, for example, the natural soil or artificial soil described above, and the support used for the rooting culture may be used as is.

[0054] -Fertilization- The fertilization method is not particularly limited, and the fertilization conditions (fertilization interval, amount, and method) should be appropriate for the fertilizer used. Examples of fertilizer components are the same as those of the fertilizer given to the mother tree.

[0055] -Other seedling raising conditions- The conditions for raising seedlings (e.g., temperature, humidity, light irradiation, watering conditions, and location for raising seedlings) can be determined appropriately. The conditions may be the same as those used for rooting culture, or may be different conditions.

[0056] For cuttings with multiple lateral branches, it is preferable to remove all but one lateral branch during the seedling raising process. The lateral branch to be left on the cutting should be one that has a good center and grows upward. This allows the cutting to be grown using the lateral branch as the main branch.

[0057] [2. Tree production methods] The conifer seedlings produced by the above-described method for producing cuttings can be used for tree production. As described above, the method for producing cuttings of coniferous trees of the present invention allows many cuttings to be obtained from a single mother tree, enabling efficient production of seedlings. In other words, a sufficient number of seedlings for use in forestry can be secured. Therefore, by using the cuttings, it is possible to efficiently produce large quantities of coniferous trees, which is expected to increase the productivity of wood resources that can be used for various purposes.

[0058] The process of cultivating seedlings is not particularly limited. For example, seedlings that have grown to a certain extent may be transported to a silvicultural site and planted there. The silvicultural site may be changed as appropriate depending on the tree species. When planting seedlings, a tree shelter or the like may be used to prevent damage from wild rabbits and the like. [Example]

[0059] The present invention will be described below with reference to examples, which are not intended to limit the scope of the present invention.

[0060] (Example 1: Raising seedlings from cuttings consisting of lateral branches and parts of nodes of Japanese cedar) On April 1, 2021, branches (main axes) were harvested from a 5-year-old mother cedar tree. The cuttings were cut into a shape with one or two lateral branches attached to the nodes of the main axis (nodes: 4-6 cm, lateral branches: 15-30 cm), and each was prepared as a cutting. Lateral branches growing upward against gravity (not drooping downward due to gravity) were considered to be "main-standing" (same as in Example 2). Akadama soil (manufactured by Yanashima Shoji Co., Ltd.) was filled into seedling box B (510 cm long x 360 cm wide x 105 cm high, same as in Example 2) to prepare a cutting bed. 5-10 mg of LUTON (registered trademark) powder (manufactured by Ishihara Biosciences Co., Ltd., white powder containing the plant hormone NAA, NAA concentration 0.4%) was applied to the base of the cuttings prepared as described above (the lower cut surface of the cut node), and the cuttings were then placed in a cutting bed approximately 5 cm from the base. The seedling boxes with the cuttings placed in them were placed on an outdoor seedling shelf and rooted for two months while watering once a day. After that, the cuttings were removed from the cutting bed and those that had roots visible to the naked eye were counted to calculate the rooting rate. From June 2021 onwards, cuttings that were confirmed to have rooted were replanted into seedling containers. A 1:1 mixture of Akadama soil (Yanagishima Shoji Co., Ltd.) and peat moss (Toho Corporation) was filled into the seedling containers to create the seedling soil. The cuttings were transplanted into the soil so that the nodes of the cuttings were hidden by the soil and the lateral branches were the main axis. When replanting, cuttings with two lateral branches were pruned, leaving only one lateral branch that had a good center and was growing upward. The cedar seedlings replanted in the seedling containers were placed on outdoor seedling shelves and continued to be managed by overhead irrigation and once a week by applying a 1:1000 diluted liquid fertilizer, Hyponex (Hyponex Japan Co., Ltd.). The growth of cedar seedlings was measured on November 1, 2021, and the seedling yield rate was calculated as the number of seedlings that met the No. 6 standard (seedling height of 15 cm or more, base diameter of 3 mm or more) specified in the Standard Specifications for Major Seedlings for Forests notified by the Director-General of the Forestry Agency.

[0061] (Comparative Example 1: Seedlings grown from cuttings, which are the main stems (tips) of cedar trees) The procedure was the same as in Example 1, except that approximately 30 cm from the tip of the main axis was prepared as a cutting.

[0062] [Table 1]

[0063] In comparison with Comparative Example 1, in which the tip of the main stem was used as a cutting, Example 1, in which the tip of the main stem was used as a cutting, yielded a larger number of cuttings per mother tree, resulting in a larger number of seedlings. Furthermore, the rooting rate and seedling yield rate of Example 1 were as good as those of Comparative Example 1.

[0064] (Example 2: Raising seedlings from cuttings consisting of cypress lateral branches and parts of nodes) On April 1, 2021, branches (main axes) were harvested from two-year-old cypress mother trees. Cuttings were then cut into sections with one or two lateral branches (nodes: 4-6 cm, lateral branches: 15-30 cm) attached to the main axis. Each cutting was then prepared as a cutting bed. Akadama soil (manufactured by Yanashima Shoji Co., Ltd.) was filled into seedling box B to serve as a cutting bed. 5-10 mg of Luton (registered trademark) powder (manufactured by Ishihara Biosciences Co., Ltd., white powder containing the plant hormone NAA, NAA concentration: 0.4%) was applied to the base of the cuttings prepared as described above (the lower cut surface of the node). The cuttings were then inserted into the cutting bed approximately 5 cm from the base. The seedling boxes with the cuttings were placed on outdoor seedling shelves and watered once a day for two months to cultivate the roots. After that, the cuttings were removed from the cutting beds and those that had roots visible to the naked eye were counted to calculate the rooting rate. From June 2021 onwards, cuttings that were confirmed to have rooted were transplanted into seedling containers. A 1:1 mixture of Akadama soil (Yanagishima Shoji Co., Ltd.) and peat moss (Toho Corporation) was filled into the seedling containers to create the seedling soil. The cuttings were transplanted into the soil so that the nodes of the cuttings were hidden by the soil and the lateral branches of the cuttings formed the main axis. When transplanting, cuttings with two lateral branches were pruned, leaving only one lateral branch that had a good center and was growing upward. The cypress seedlings transplanted into the seedling containers were placed on outdoor seedling shelves and continued to be managed by overhead irrigation and once a week by applying a 1:1000 diluted liquid fertilizer, Hyponex (Hyponex Japan Co., Ltd.). The growth of cedar seedlings was measured on November 1, 2021, and the seedling yield rate was calculated as the number of seedlings that met the No. 6 standard (seedling height of 15 cm or more, base diameter of 3 mm or more) specified in the Standard Specifications for Major Seedlings for Forests notified by the Director-General of the Forestry Agency.

[0065] (Comparative Example 2: Tip of Hinoki cypress main stem) The procedure was the same as in Example 2, except that approximately 30 cm from the tip of the main axis was prepared as a cutting.

[0066] [Table 2]

[0067] In comparison with Comparative Example 2, in which the tips of the cored main stems were used as cuttings, Example 2, in which the cored lateral branches were harvested with nodes attached and used as cuttings, yielded a larger number of cuttings per mother tree, and as a result, a larger number of seedlings. Furthermore, the rooting rate and seedling yield rate of Example 2 were as good as those of Comparative Example 1.

[0068] These results show that the method of the present invention makes it possible to obtain a larger number of cuttings from conifers that have a good rooting rate and seedling yield, thereby realizing efficient production of cutting seedlings. [Explanation of symbols]

[0069] 1 mother tree 11 Side branches 12 spindle Verse 13 14 Base 2 Cuttings 3 Rooting environment 31 Support 4 Container seedlings 41 Seedlings after rooting 42 containers

Claims

1. a harvesting step of harvesting a lateral branch having a terminal bud and a core from a mother coniferous tree as a cutting together with a part of a node at the base of the lateral branch; A rooting step for rooting the cuttings; and A seedling raising step of raising the rooted cuttings using the lateral branches as the main axis, The length of the lateral branches included in the cuttings is 10 cm or more, The length of the nodes contained in the cuttings is 8 cm or less. Methods for producing conifer cuttings.

2. 2. The method of claim 1, wherein the length of the nodes contained in the cutting is 2 to 8 cm.

3. 3. The method according to claim 1 or 2, wherein in the step of collecting cuttings, at least a lateral branch branching from a node located 20 cm or less from the tip of the basal branch and a part of the node are collected as cuttings.

4. The method according to any one of claims 1 to 3, wherein the length of the lateral branches contained in the cutting is 15 cm or more.

5. The method according to any one of claims 1 to 4, wherein the coniferous tree is a plant of the genus Cryptomeria or Chamaecyparis obtusa.

6. A method for producing coniferous trees, comprising cultivating cuttings produced by the method for producing coniferous tree cuttings according to any one of claims 1 to 5.

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