JP2007222046A - Method for producing eucalyptus plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for improving a Eucalyptus globules afforestation business into a business having an investment value. <P>SOLUTION: This method for producing Eucalyptus plants comprises afforesting the simultaneous forest of Eucalyptus globules having an identical tree age as a primary test forest, forming cottages from superior trees selected from the forest, making seedlings from the cottages, making a scion garden, making a secondary test forest, selecting predominant trees, and using the seedling of the predominant trees as seedlings of business target. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing Eucalyptus plants suitable for business-scale plantation.

  Eucalyptus plants, in particular Eucalyptus globulus, are currently evaluated as being suitable as chip materials for pulping because of their high growth rate and excellent pulping suitability. Although commercial-scale tree planting is being carried out for commercial use, it is necessary to obtain a fine tree with excellent growth rate and pulping suitability. An elite tree is a specific individual of the Eucalyptus plant that has a gene that can be expected to grow for the purpose of afforestation on a business scale. In conventional tree planting methods using seeds, it is difficult to obtain the original planting effect of Eucalyptus globulus due to the inherent variation of the gene, and the expected effect on the growth rate and pulping suitability cannot be obtained. there were. In order to increase the production of fine trees by seed planting, the fine trees are determined by mating seeds and selecting pure species. This method is not suitable for afforestation on a commercial scale because it requires a minimum period of 10 years for seed collection and an additional period for confirmation work for pure species. Therefore, there is a method in which an elite tree is selected and a cloned seedling of the elite tree is produced and used for commercial plantation.

  As a method for selecting an elite tree, a statistical method such as group selection of elite trees from a wild forest or a seed forest has been implemented (for example, see Non-Patent Document 1). However, Eucalyptus plants are a large variety group that is said to have over 600 species native to Australia. It was extremely inefficient to select elite trees from wild forests with multiple varieties. In addition, even if the selection from the seed forest, because there is a variation in the growth due to the environment of the plantation, such as the effect of soil, the steep slope of the land, the effect of pests, even if the elite tree selected from the seed forest is propagated, At present, it is not always an individual with excellent growth rate and pulping suitability.

  In addition, methods for producing cloned seedlings after selection of elite trees include cutting methods, grafting methods, cutting methods, and tissue culture methods. As a method for producing a clonal seedling by tissue culture, for example, the stems and leaves obtained by aseptically culturing each organ of the Eucalyptus plant are moistened with an artificial liquid medium containing inorganic salts and the like. There is a method for mass production of Eucalyptus plant clone seedlings, which is transplanted to a porous medium support, and is rooted and acclimatized in a non-sterile state under illumination, in the presence of humidity and carbon dioxide ( For example, Patent Documents 1 to 5). However, this tissue culture method is a clone seedling production technique from a research standpoint, and requires special production equipment and advanced technology. There is nothing.

  A cutting method has been studied as a method for producing a clone seedling that is easy to operate and is commercially reasonable. In the cutting method, cutting seedlings of Eucalyptus and Acacia plants are planted in business in Brazil, Europe and Southeast Asia. In the cutting method of Eucalyptus plants, a method is generally used in which cutting is performed at the root, and cutting is performed with the sprouting that grows from the cutting root. That is, a spikelet containing 1 to 4 nodes and 2 to 8 leaves is cut out from a branch sprouting from a stump by cutting or the like, and generally a part of the leaf is cut out to prepare an ear. The cuttings are immersed in a bactericide solution, and then a hormonal powder such as indolebutyric acid as a rooting promoter is attached to the base, or the base is immersed in the hormone solution. After that, insert the ear into the cutting medium with the insertion hole. For cutting cutting soil, materials having appropriate water permeability and water retention properties such as bark, sand, wood chips, peat moss, vermiculite, perlite and mixtures thereof are used. At this time, the balance between the aeration of the soil and the moisture retention determines the success or failure of rooting. Among Eucalyptus plants, Eucalyptus globulus has a low rooting success rate and is known as a species unsuitable for mass production of cloned seedlings. Conventionally, techniques such as mist spray, fine fog, plastic sheet covering, sun cover, bottom heat, etc. are used in combination to optimize the temperature, humidity, and air circulation necessary for rooting, A method of promoting rooting has been taken (for example, Non-Patent Document 2).

  In order to promote rooting, a cutting method has been proposed in which cuttings treated with an auxin-containing solution or a talc-diluted auxin-containing powder are rooted under high humidity. However, in order to obtain high humidity, a technique such as mist spraying or a humidifier is required, so it cannot be said that it is a commercially reasonable production method. In addition, a method for producing cloned seedlings by cutting with water as a medium has been proposed (for example, Patent Document 6).

  In addition, the rooting ability of eucalyptus plants or acacia plants that have been harvested is treated with paclobutrazol, a plant growth regulator, or an inhibitor of the gibberellin biosynthetic pathway. Physiology of the cuttings so that the roots can be sufficiently rooted without having to be treated with a plant growth regulator after the cuttings have been collected by growing and inserting the cuttings into the tree soil. Produces a large number of inexpensive clone seedlings by modifying the state in advance and enabling the production of cuttings and seedlings of Eucalyptus and Acacia species that were difficult to produce using conventional cutting techniques Techniques to do this are disclosed. However, with this method, gibberellin's natural dwarfing is promoted, the vital tree is vitalized, the healthy branches and leaves are weak, and the overgrowth of the branches and leaves is extremely weak, so that the purpose of proliferation cannot be achieved (for example, Patent Document 7).

The technical group of selection methods for elite trees and production methods for clone seedlings described above cannot produce Eucalyptus plants that can withstand commercially reasonable plantations.
Bunei-do Publishing “Forestry Breeding” written by Kihachiro Ohba, pages 1 to 156 Eucalyptus Domestication and Breeding (Oxford University Press Inc., New York, 1993), 237-246 JP-A-8-252038 JP-A-6-133657 JP-A-7-31309 JP-A-8-228621 Japanese Patent Laid-Open No. 9-172892 JP-A-6-98630 JP 2001-231355 A

  It is an object of the present invention to provide a method for producing a Eucalyptus plant that maintains a high growth rate suitable for commercial plantation and excellent pulping ability.

The above problems can be solved by the present invention described below.
(1) (a) a process of creating a primary forest of Eucalyptus plants having the same age, and (b) a process of selecting a dominant tree from the primary forest, (c) inserting from the dominant tree A step of collecting ears, (d) a step of producing a clone seedling from the cuttings of the dominant tree by a cutting method, (e) a step of creating a secondary verification forest using the clone seedling of the dominant tree, (f) A step of selecting an elite tree from a secondary verification forest, (g) a step of collecting cuttings from the elite tree, (h) a step of producing a cloned seedling from the cuttings of the elite tree by a cutting method, (i) the step A method for producing Eucalyptus plants, comprising a step of creating a plantation using a clone seedling of an elite tree.
(2) The step (c) includes (c1) a step of rooting from the cuttings in a closed-type rooting greenhouse having a light shielding rate of 40 to 60%. Production method.
(3) A clone obtained by the cutting method from the cuttings collected from the mother tree by producing a mother tree from the clone seedlings of the elite tree obtained in the step (h), and (j) the step (j) The method for producing an Eucalyptus plant according to (1) above, further comprising the step of creating a spike garden and / or plantation using a seedling.
(4) The method of producing a Eucalyptus plant according to (3) above, wherein in the step (j), the age of the mother tree of the head garden is 1 to 3 years.
(5) The method for producing an Eucalyptus plant according to (1) above, wherein, in the step (f), an elite tree is selected from a secondary verification forest having a tree age of 5 to 8 years.

  The method of producing Eucalyptus plants that can withstand commercial plantation is to first clone seedlings that have genes that produce high-growth materials with high growth rate with excellent investment value, excellent pulping ability, etc. This can only be achieved by mass propagation. For this purpose, it is necessary to select an elite tree having a gene that achieves this purpose, and to proliferate it at a commercially reasonable cost and to commercialize afforestation based on this. The present invention provides a comprehensive technique of a method for selecting an elite tree having a gene that produces a high growth material and a method for commercially mass-producing the cloned seedling.

  The first effect of the Eucalyptus genus plant production method (1) of the present invention is that an elite tree can be selected with high probability in a short period of time. In the present invention, (a) a step of creating a simultaneous forest of Eucalyptus plants having the same age as a primary verification forest, (b) a step of selecting a dominant tree from the primary verification forest, (c) from the dominant tree A step of collecting cuttings, (d) a step of producing a clone seedling from the cuttings of the dominant tree by a cutting method, (e) a step of creating a secondary verification forest using the clone seedling of the dominant tree, (f ) Select the elite tree through the process of selecting elite trees from the secondary verification forest. In the conventional method of searching for dominant trees from the wild and testing them in the test forest to determine the genetic traits, it is not only possible to select the dominant tree depending on the age difference, but there are 600 species. It is extremely inefficient and nearly impossible to select wild dominant trees from the Eucalyptus plant group. In the present invention, by selecting a dominant tree from a plantation of a simultaneous forest having the same tree age, variations due to tree age can be ignored.

  Moreover, even if the elite tree was selected from a simultaneous forest of the same age, the present inventor confirmed for the first time that when planting a clone seedling produced from the dominant tree, the growth varies depending on the environment of the plantation. In other words, high-growth trees, that is, dominant trees selected from the same forest age, are not necessarily fine trees. Based on this, a secondary verification forest was created by using a clone seedling obtained from a primary verification forest, that is, a dominant tree selected from the same-aged simultaneous forest first planted with seedlings. It was found that the elite tree can be produced accurately by selecting the elite tree from.

  The second effect of the Eucalyptus plant production method (1) of the present invention is that selection of an elite tree and production of a Eucalyptus plant using the cloned seedling can be performed in a short period of time. When elite trees are determined by seed breeding, selection of pure-type species, etc., which are general breeding, as a result, ultra-long time of 10 years or more is required.・ A method to create a primary forest by creating a grove forest and making a clone seedling from cuttings based on the dominant tree selected from this forest, and then creating a secondary forest from this clone seedling Since it can be done in a short time from the creation of a simultaneous forest of the same age to the selection of fine trees in the secondary verification forest, it can be said to be a suitable method for afforestation.

  The effect of the Eucalyptus plant production method (2) of the present invention is that the rooting rate is increased by a simple means in the cutting method. That is, in the step (c), (c1) including a step of rooting from the cuttings in a closed-type rooting greenhouse having a light shielding rate of 40 to 60%, such as Eucalyptus globulus species having a low rooting success rate Even for Eucalyptus plants, a high rooting rate can be obtained. With this method, it is possible to manage both the temperature and humidity factors within the optimum range for rooting of Eucalyptus plants by adjusting the shading, which can dramatically increase the rooting rate. It becomes.

  The effect of the Eucalyptus plant production methods (3) and (4) of the present invention is that the elite tree clones are retained for many years, the foundation of the elite tree growth is maintained, and the commercial plantation can be made permanent. . Generally, it is carried out by the method of creating a spike garden, but Eucalyptus plants represented by the Eucalyptus globulus species have problems specific to this species, and it has been difficult to maintain a permanent spike garden. In other words, clonal seedlings rooted by the cutting method are planted in a spike garden to serve as the basis for mass growth, but in the case of eucalyptus and globulus species, the planted mother tree has its tree planted and cut by repeated harvesting. Since the rooting rate of potato was significantly reduced, it was difficult to maintain it permanently. As in the production method (4) for Eucalyptus plants of the present invention, a good rooting rate was always obtained by updating the age of the mother tree for cuttings at the head garden to 3 years. This has always ensured mass growth.

  The Eucalyptus genus production method (5) of the present invention is a method for selecting elite trees in a secondary verification forest with a minimum age of 5 years. Time constraints are important to make afforestation projects commercially feasible. In order to confirm that it is an elite tree, it is necessary to actually plant it in the project area and confirm that it is an elite tree. It was not understood if it could be confirmed that it was a tree. In the secondary verification forest constructed using the clone seedlings obtained from the dominant tree selected from the primary verification forest, variation in growth was recognized for the first 4 years, but the elite tree cannot be determined. It was confirmed that the growth potential was fixed after a growth period of 5 years or more. Based on this phenomenon, it was confirmed that it was possible to accurately select elite trees after 5 years in the secondary verification forest. According to the Eucalyptus plant production method (5) of the present invention, an elite tree can be determined in a short period of time, and therefore this elite tree clone can be applied to commercial large-scale afforestation projects at an early stage.

  Production of seedlings that can withstand commercial plantation can be achieved for the first time by cloning seedlings having genes that produce high-growth materials that are worth investing in plantation projects and mass-producing them. For this purpose, the objective can be achieved only by selecting an elite tree having a gene that achieves this purpose, multiplying it at a commercially reasonable cost, and commercializing afforestation based on this. In the present invention, it is possible to provide a method for selecting a gene that produces a high-growth material having an investment value and a comprehensive technique for commercial mass-production of the seedling. In addition, the widespread use of such afforestation will increase carbon dioxide fixation capacity and contribute to global warming.

The present invention will be described in detail below.
(A) Step of creating a primary forest of Eucalyptus plants having the same tree age as a primary verification forest In the present invention, first, a simultaneous forest at the same age is established as a primary verification forest. First, seedlings are prepared. Use commercially available seeds. Commercial seeds are commonly sold in the area and are sown. All commonly known media are applicable. For example, vermiculite, peat moss and pine bark. The seedlings are sprouting in about 2 weeks by repeating irrigation after sowing, so that they are cultured for about 7 months to make a seedling that can be planted. Fertilization and irrigation during this period are in accordance with general methods.

  Plant the seedlings that have been produced. For the plantation, choose a land with uniform and flat soil distribution so that uniform growth conditions can be obtained. In order to obtain a normal planting effect during planting, weeding, such as weeding, removing foreign matter, and plowing. Planting is done during the rainy season when sufficient soil moisture is secured. After planting, apply 3 elements fertilizer of nitrogen, phosphorus and potassium. The time and amount of fertilization may be a method applied to general afforestation methods.

  The only work after planting is weeding. This is done as appropriate by observing the state of weeds. Thus, a simultaneous forest plantation with the same age to select candidate trees is established as the primary verification forest.

(B) Step of selecting dominant tree from primary verification forest The selection standard when selecting the dominant tree from the primary verification forest is based on the breast height diameter standard. In addition to the breast high diameter standard, factors such as straightness, branching, and perfection are added as general selection criteria. The superior tree is selected by comparing it with the surrounding five dominant trees on the basis of the breast height diameter, which is superior to the surrounding five dominant trees. Specifically, search for forests that are the same age as the primary verification forest, especially those that are thick, excellent in shape, that is, straight trunks that do not twist, those that have few branches, A tree that is as thin and dense as possible and that has a small difference in diameter between the root and the trunk of the end is selected and used as a candidate tree.

  Next, five (= periphery 5 dominant trees) are selected next to candidate trees around 20 m. The chest height diameter is measured, the average value of the candidate tree and the surrounding five dominant trees is compared, and the larger the difference is positioned as a superior candidate tree, that is, the dominant tree. This work is done to confirm that excellent growth is not the result of the environment but is unique to the individual.

(C) The process of collecting cuttings from the dominant tree Cutting the dominant tree selected in the primary verification forest from autumn to spring. Fell trees at about 15cm from the surface. The cut surface should be flat. At that time, it should be slightly inclined so that rain dew stays on the stump surface and does not rot. In addition, unnecessary vegetation around the dominant tree stumps will be arranged to ensure sunshine. All of these operations are necessary for the preservation of the stump surface and vigorous budding. After that, we wait for sprout growth from spring to summer. In order to obtain early and vigorous cuttings in the next spring, it was confirmed by cutting experiments in autumn, winter, and spring that trees cut in autumn were preferable.

  If it begins to sprout in the spring, organize it. This is an operation necessary to collect more preferable cuttings. The main point of arrangement is to prevent the chief. When the main trunk branches that have sprouted become approximately 1 m, the top buds are cut off to help the branches grow. This side branch is mainly used for collecting cuttings. This is because the side branch has the conditions necessary for cutting. In other words, cutting requires a quantity, but a side branch can expect a considerable quantity.

  The cuttings need to be moderately firm with moderate lignination. The sprouting from the felled tree, that is, the cutting material, is a juvenile leaf without a petiole characteristic of Eucalyptus plants. Moderate firmness is necessary to support the cuttings during the rooting culture that lasts for two months. On the other hand, those that are too stiff or too thick are not suitable for rooting because their growth has progressed too much.

  Cut out 3-4 node branches and leaves as cutting material. When cutting cutting material, pay attention to the soundness and solidity of the branches and leaves, especially the shaft stiffness. In addition to this, the thickness of the shaft is also judged at the same time, and in addition, the branch cutting operation including pruning is performed while considering the next harvest. In particular, select a root that is as close as possible to the root that is likely to be rooted. Collected branches and leaves should avoid sunshine, be hydrated, keep cool, and be transported promptly.

(D) Process for producing cloned seedlings from cuttings of dominant trees by cutting method The cutting material brought back from the primary verification forest is excised so that the opposite leaf is halved in one node. Cut about 2 mm on both sides at the bottom of the inserted cob to expose the formation layer. The cuttings thus prepared are sterilized with a bactericide for about 1 second. Next, a hormone is applied to the insertion shaft of the cutting head, and it is sequentially inserted into the medium.

  After cutting to obtain rooting, sunshine is applied for 1.5 to 2 months at a temperature of 25 to 30 ° C. and a relative humidity of 75 to 85%. The greenhouse for this purpose is referred to as the root greenhouse. The rooting greenhouse preferably adjusts the sunshine using a light-shielding net. The environmental conditions during the day are always adjusted artificially by opening and closing the shading net. At night, it depends on the external environment. When the aperture ratio of the light-shielding net is 40 to 60%, it can be managed in the above temperature and humidity range.

  As a work in the rooting greenhouse, there is an anti-leaf treatment. The opposite leaves attached at the time of cutting are started to root, and when the shoots grow from the buds, they end their photosynthesis role and die. The dead leaves (old leaves) are removed. The general growth process of cuttings is (i) callus formation at the cutting shaft, (ii) rooting, and (iii) sprout formation-surface extension.

  It takes about two months for rooting in the rooting greenhouse. After rooting, take it out of the greenhouse and move to a seedling process to create cloned seedlings. Cloned seedlings that have passed 1.5 months after cuttings have a ground surface height of about 10 cm. In the seedling process, acclimation to the open air and seedling growth are promoted while fertilizing and irrigating. This period is about 10 months in total. The period of this seedling process is divided into the following three periods, and the contents of fertilization are changed to grow seedlings.

  (Rooting promotion period) No fertilizer is applied during the period from cutting to rooting. It is only environmental maintenance such as temperature, humidity, sunshine. The reason why fertilization is not performed during this period is to prevent unwanted germs from growing due to the fertilization and damaging the cutting part.

  (Post-emergence budding period) After rooting, cuttings start their own budding. Early fertilization is performed at this time. During this time, fertilizer with high phosphorus value (nitrogen: phosphorus: potassium = 9: 45: 15) is applied in consideration of sufficient root elongation.

  (Cultivation period for mother tree and seedling seedling) Once the plant is completed, a culture period is set up to make it into a mother tree or seedling seedling. During this period, fertilizers with high nitrogen levels are given to enhance leaf and stem growth. The clone seedling by the cutting method from the primary verification forest is completed.

(E) The process of creating a secondary verification forest using dominant seedling clones Cloned seedlings are almost completed at the end of winter. Next, a secondary verification forest is constructed using this clone seedling.
In the construction of the secondary verification forest, the planting of clone seedlings, planting intervals, fertilization, weeding, etc. are carried out in the same way as normal project planting. Growing up for a predetermined period by these methods, it will be a secondary verification forest. The test measures the growth at regular intervals and obtains data for determining the elite tree.

  Evaluation of growth is performed by measuring both tree height and breast height diameter and calculating volume. The growth order of volume calculated in this way is determined in about 5 years. Since this order does not change until the subsequent harvesting period, it is possible to determine an elite tree by evaluating the volume by evaluating the volume up to 5 years. Even if a similar plantation is performed by changing the location of the plantation, clones that obtain a high ranking in any plantation can be confirmed and determined as a fine tree.

(F) A step of selecting an elite tree from the secondary test forest, (g) A step of collecting cuttings from the elite tree, (h) A step of producing clone seedlings from the cuttings of the elite tree by cutting method (f) step Is performed in accordance with (b), and a fine tree is selected. Further, the step of collecting cuttings from the elite tree is performed by the same method as the step (c), and the step of producing clone seedlings from the cuttings of the elite tree is performed by the same method as the step (d).

(I) Process for creating a plantation using a clone seedling of an elite tree A plant seedling of an elite tree is planted and grown in a predetermined plantation. When an elite tree is selected through a secondary verification forest, Eucalyptus plants having a high growth rate and a suitable pulping ability can be produced regardless of the environment of the plantation.

(J) Process: (h) Using a cloned seedling obtained from the cuttings obtained from the cuttings collected from the mother tree by producing mother trees from the cloned seedlings of the elite tree obtained in the process (h) Further, the process of creating a spike garden and / or a plantation site (h) The clone seedling of the elite tree obtained in the process is planted in the spike garden in addition to the process (i). The management operation of the hot-house is the key to continuous production of elite tree clone seedlings. As described above, cutting work is performed in the summer, so it takes about half a year to root them and turn them into seedlings. In other words, cloned seedlings do not become cutting material in the same year, and it is necessary to fatten and grow them. This requires regular planting in a spike garden or potted plant, which is implemented during the winter season. A clonal seedling is planted at an interval of about 70 cm in the head garden. After planting, irrigation fertilization is performed. Irrigation is done by observing the weather and looking at the dryness of the surface. Apply fertilizer by adjusting the three major fertilizers of nitrogen, phosphorus and potassium while observing the growth of seedlings. Thus, the clonal seedlings of elite trees are cultivated and grown by the regular planting of the head garden, and in the summer of the following year, the branch grows and grows. The plant that has been grown for another year after planting is used as the mother tree. Since the tree grows sufficiently large enough to withstand the heading after this one year, the heading is started. The new branch of this mother tree will be used as cutting material for the following year. Cutting methods such as cutting method and rooting method are the same as described above. This material has sufficient rooting ability and is suitable as a cutting material. Furthermore, once the cuttings have been collected, the mother tree can be used for the next year if it is grown. However, even if the tree vigor gradually declines and continues to grow, the branches and leaves obtained from them lose their rooting ability and are not suitable as a material for ears. This mother tree is updated with a new clone seedling after it has been used for a predetermined period. The age of the mother tree is preferably 1 to 3 years in order to maintain the rooting ability of the cuttings.

  Hereinafter, the present invention will be described in more detail with reference to examples.

First, seedlings of Eucalyptus globulus are prepared. In production, commercially available seeds are sown. All commonly known media are applicable. For example, vermiculite, peat moss and pine bark. The seedlings are sprouting in about 2 weeks by repeating irrigation after sowing, so that they are cultured for about 7 months to make a seedling that can be planted. Fertilization and irrigation during this period are in accordance with general methods. Next, the seedlings that have been produced are planted on a flat land with a uniform soil distribution. In order to obtain a normal planting effect during planting, weeding, such as weeding, removing foreign matter, and plowing. Planting is done during the rainy season when sufficient soil moisture is secured. After planting, apply 3 elements fertilizer of nitrogen, phosphorus and potassium. The time and amount of fertilization may be a method applied to general afforestation methods.
The work after planting is only weeding, but in some cases, work such as sterilization and insect removal is additionally performed. Observe the state of weeds and implement as appropriate. Thus, a simultaneous forest plantation with the same age to select candidate trees is established as the primary verification forest.

  The primary test forest constructed as described above, that is, the dominant tree collected from the Eucalyptus and Grobles simultaneous forests of the same age, is selected, cut off, and the clone seedling of the dominant tree using the sprout obtained from it as a material A secondary verification forest was established. Table 1 is a comparison of the growth of the three clones planted in this secondary verification forest after 12 years of rearing.

  The volume factor for non-selected seedlings is explained as follows. In other words, for the establishment of the secondary verification forest, Eucalyptus globulus seedlings made from commercially available seeds and three clone seedlings from the dominant tree made from the primary verification forest were grown for 12 years and their volume was compared. did. I also saw whether it was a reproducible result of planting in different plantations. The comparison is expressed as the ratio of each clone when the volume of normal seedlings planted at the same time is 1. It can be understood from Table 1 that clone No1 shows almost twice as much growth in any of the different plantations as compared to normal seedlings. However, clone No3 shows only the same growth compared to normal seedlings. Not all of the clonal seedlings of the primary certified forests showed high growth rates.

  In order to produce a cloned seedling from the cuttings of the dominant tree in the primary verification forest by cutting, first the branches and leaves cut out from the mother tree are cut into one section and the opposite leaves are cut in half. Open the formation layer about 2mm on both sides of the lower part of the insertion cob. The cuttings thus prepared are collectively sterilized with a bactericide for about 1 second. Next, the hormone is attached to the insertion axis of the cutting head and then inserted sequentially. A 96-well styroblock was used, and the cutting medium was a mixture of two equivalents of peat moss and vermiculite. Thoroughly irrigate these media prior to cutting. Talc powder mixed with 8000 ppm indole butyric acid was used as a rooting promoting hormone attached at the time of cutting.

  In order to obtain rooting, desired sunshine is applied for 1.5 to 2 months at a temperature of 25 degrees and a relative humidity of 85% after cutting. For this purpose, the greenhouse was the root greenhouse. An open-and-close shading net is installed above the greenhouse. The environmental conditions during the day are always adjusted artificially by opening and closing the shading net. At night, it depends on the external environment. In this way, cuttings were managed under a greenhouse for approximately 1.5 months. The effect on the rooting rate was investigated by changing the aperture ratio of the light-shielding net installed in the rooting greenhouse from 0% to 100% (no cover). As a result, at 0,100%, it was impossible to control the temperature and humidity, and cutting roots could not be obtained. At 20% and 80%, the fluctuation of the temperature and humidity adjustment results were too large, but rooting was obtained, but it was an insufficient result, and it was found that it could not be used as a commercial rooting device. It was understood that the results with the aperture ratios of 40% and 60% were suitable as a rooting device for business with a sufficient rooting rate. The results are shown in Table 2.

  A secondary verification forest was constructed from clone seedlings made from candidate trees selected in the primary verification forest. In the test, the volume growth was measured at regular intervals, and the data for determining the elite tree was obtained. Table 3 shows the growth of each of the 5 clones every year. In each clone seedling, the volume growth rank varies until the fourth year of the tree, but the rank after the fifth year is fixed and the rank does not vary. In other words, by observing the results of the fifth year, it is possible to determine a higher-growth clone, that is, an elite tree.

  A head garden was constructed from a clone of a fine tree. Seedlings are planted at intervals of about 70 cm in the head garden. After planting, irrigation fertilization is performed. Irrigation is performed by observing the weather and looking at the dryness of the surface. Apply fertilizer by adjusting the three major fertilizers of nitrogen, phosphorus and potassium while observing the growth of seedlings. The plant that has been grown for another year after planting is used as a mother tree. Since this year's growing, the tree becomes large enough to withstand the harvesting, so we start harvesting. The cutting time is in midsummer when the branches and leaves are sufficiently stretched. The cutting method has been described above. Thereafter, cuttings were made each year from this mother tree, and the results shown in Table 4 were obtained in the rooting rate. The rooting rate decreases as the age of the mother tree increases, and from 4 years onwards it will fall below the rooting rate that can withstand business growth. From this, it was confirmed that the mother tree can always secure a sufficient rooting rate by updating every three years.

  From the above results, it takes less than 10 years from the creation of the primary verification forest to the establishment of the plantation from the clone seedlings of the elite tree, and the production method that propagates the elite tree by the establishment of the afforestation area using conventional seeds It was possible to produce Eucalyptus plants in a shorter period of time.

  In order to produce seedlings that can withstand commercial plantation, it is first possible to clone seedlings having genes that produce high-quality, high-growth materials that are worth investing as a plantation project, and can only be achieved by mass propagation. For this purpose, it is possible to achieve the purpose only by selecting an elite tree having a gene that achieves this purpose, and by proliferating in large quantities at a cost commensurate with its commercial value and commercializing afforestation. According to the present invention, it is possible to provide a method for selecting genes that produce high-quality materials with high growth that have an investment value, and a comprehensive technique for commercial mass-production of the seedlings. The present invention is applicable to the afforestation field conducted as such a commercial business.

Claims (5)

  (A) A process of creating a primary forest of Eucalyptus plants of the same age, making it a primary verification forest, (b) selecting a dominant tree from the primary verification forest, (c) collecting cuttings from the dominant tree (D) a step of producing a clone seedling by cutting method from the cutting head of the dominant tree, (e) a step of creating a secondary verification forest using the clone seedling of the dominant tree, (f) a secondary verification A step of selecting an elite tree from the forest, (g) a step of collecting cuttings from the elite tree, (h) a step of producing a clone seedling from the eaves of the elite tree by a cutting method, (i) A method for producing Eucalyptus plants, comprising a step of creating a plantation using a clone seedling.   The method of producing a Eucalyptus plant according to claim 1, wherein the step (c) includes a step of (c1) rooting from the cuttings in an enclosed rooting greenhouse having a light shielding rate of 40 to 60%.   (J) The process produces a mother tree from the cloned seedlings of the elite tree obtained in the process (h), replants the head garden, and uses the cloned seedling obtained by the cutting method from the cuttings collected from the mother tree. And the production method of the Eucalyptus genus plant of Claim 1 including the process of creating a head garden and / or a plantation place further.   The method of producing a Eucalyptus plant according to claim 3, wherein in the step (j), the age of the mother tree of the hot garden is 1 to 3 years.   The method of producing Eucalyptus plants according to claim 1, wherein in the step (f), an elite tree is selected from a secondary verification forest having a tree age of 5 to 8 years.