JP2010104289A - Method for producing plant belonging to genus eucalyptus, plant belonging to genus eucalyptus, wood chip and pulp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for effectively producing plants belonging to the genus Eucalyptus having a high pulp yield for increasing the productivity of the pulp, especially the method of production suitable for business scale commercial afforestation, and also the Eucalyptus plants produced by the above production method, and wood tips and pulp, produced by using the plants belonging to the genus Eucalyptus. <P>SOLUTION: The method for producing the plants belonging to the genus Eucalyptus is provided by including a process of selecting the plants belonging to the genus Eucalyptus having the high pulp yield from officially approved woods of the plants belonging to the genus Eucalyptus and having a same tree age, a process of preparing clone seedlings by a cutting method from the selected plants belonging to the genus Eucalyptus and a process of planting the clone seedlings. The plants belonging to the genus Eucalyptus produced by the above method, the wood chips produced from the above plants and the pulp produced form the wood chips are also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing Eucalyptus plants represented by Eucalyptus globulus, Eucalyptus plants produced by this production method, and wood chips and pulp produced using the Eucalyptus plants.

  Eucalyptus plants, particularly Eucalyptus globulus, have been evaluated as suitable as a chip material for pulping because of their high growth rate and excellent pulping ability. In order to extract pulp fibers from ordinary trees, an operation called cooking is selected. In this operation, under pressure and heating, wood chips are reacted with chemicals mainly composed of caustic soda and sodium sulfide for a certain period of time to extract cellulose insoluble in these chemicals. By the way, the reactor which performs these reactions is called a digester and has a certain volume. Productivity in pulp production is determined by the volume of this digester. There are two types of digesters, fixed type and continuous type, and there is no difference between which type of productivity is determined by its volume.

  Therefore, in order to improve the productivity of this pulp production, an effort is made to obtain more pulp from a certain wood chip put in a constant volume digester. The percentage of pulp obtained from a given input wood chip is called pulp yield. This varies with the nature of the wood chips. That is, with wood chips having a low pulp yield, the productivity of pulp production decreases. For these reasons, wood chips capable of obtaining a high pulp yield are desired.

  By the way, Eucalyptus plants are produced today by commercial plantations for commercial use. A common method for planting trees is a planting method using seeds, but it is difficult to obtain the expected effect due to the inherent variation of genes. Therefore, a method of producing a clonal seedling having a desired property and using it for commercial plantation has been carried out.

  The technology to improve plantation productivity of Eucalyptus plants has been studied in the technical field of forest tree breeding, selecting high-growth trees and crossing them to create pure-line species, seedling clones Techniques such as conversion have been proposed (see, for example, Non-Patent Document 1). In other words, it is a technique of imparting a genetic trait to a proliferation target through selection and hybridization. However, this technique is a technique for improving only afforestation productivity from the direction of growth, resistance to pests, and the like, and there is nothing that focuses on pulp yield.

  On the other hand, there are many attempts to modify the characteristics of Eucalyptus globulus. The research that has been studied since the oldest is to increase the yield of cellulose by reducing the content of lignin, which is the main component of trees. For example, lignin low-content trees have been created by manipulating genes involved in lignin biosynthesis using genetic recombination technology (see, for example, Non-Patent Document 2). In addition, recently, there is a study for imparting salt tolerance with the intention of effective use of barren land due to salt damage, and a genetically modified eucalyptus in which only a salt tolerance gene is introduced has been created (for example, see Non-patent Document 3). . In addition, a study was conducted on dry and acidic soils, which are problematic as environmental stresses in afforestation environments. Studies have been made to introduce a citrate synthase gene that has been developed (see, for example, Non-Patent Document 4).

  However, these are artificially used to modify genes and contain environmental risks such as preserving biodiversity and spreading unsafe genes into the natural environment. It is not a technique. In addition, this technique focuses only on characteristics such as a decrease in lignin content, salt resistance, and environmental stress resistance.

As mentioned above, it is advantageous to produce Eucalyptus plants with a high pulp yield commercially, but no research has been conducted focusing on the pulp yield from the technical fields of past timber breeding and genetic recombination. .
Written by Kihachiro Ohba, “Forestry Breeding”, first edition, Bunnendo Publishing, September 30, 1991, p. 1-156 “Control of lignin biosynthesis by tobacco transcription factor Ntlim1,” [online], Nippon Paper Group, [Search February 22, 2006], Internet <URL: http://www.np-g.com/about/ research / society / 2001 / publish_ja_035.html> Junko Watanabe, 1 other person, “Development of genetically modified eucalyptus”, Japan Paper Association, Pulp and Paper Technology Association, January 2004, Vol. 8, No. 1, p. 62-66 Satoshi Kawazu, “Development of Environmental Stress-Resistant Eucalyptus and Industrial Plantation”, Japan Paper Association, Pulp and Paper Technology Association, January 2004, Vol. 8, No. 1, p. 55-61

  An object of the present invention relates to a method for producing Eucalyptus plants, and in order to increase the productivity of pulp production, the effect of Eucalyptus plants having a high pulp yield (hereinafter, the pulp yield is referred to as “yield”) is effective. Is to provide a production method. In particular, provide production methods suitable for commercial-scale commercial plantations. Also provided are Eucalyptus plants produced by this production method and wood chips and pulp produced using the Eucalyptus plants.

  As a result of intensive studies to solve the above problems, (1) a step of selecting a eucalyptus plant having a high pulp yield from a certified eucalyptus plant of the same age, (2) a cutting method from the selected eucalyptus plant The production method of the Eucalyptus genus plant including the process of producing a clone seedling by (3) and the process of planting a clone seedling was discovered. Moreover, the eucalyptus genus plant produced by this production method, the wood chip manufactured using this eucalyptus plant, and the pulp manufactured from this wood chip | tip were discovered.

  The effect of the present invention will be described. Until now, in Eucalyptus plants, it was understood that the yield differs for each tree species, but the pulp yield in the tree species was not understood. The present inventor paid attention to the yield change of each plant of the genus Eucalyptus, and conducted an experiment to investigate the variation in yield of each plant after growing in the same-aged simultaneous forest constructed from natural seeds. .

  In this experiment, first, in a simultaneous forest of the same age, which is constructed from natural seeds, chipping materials obtained from each individual after the growth are used for yield measurement. The yield is calculated from (absolute dry weight of unbleached pulp pulp after cooking / absolute dry weight of raw material chips) × 100. The yield of each individual planted from the same-aged simultaneous forest constructed from natural seeds varied widely. For example, in the case of Eucalyptus globulus, the distribution was averaged at about 51.5%. Next, clonal seedlings were grown and planted from the population with this variation, and the yield after matured was re-examined. As a result, it was clarified that clones from individuals with a low parent yield were low, and clones from individuals with high yield were high.

  By the way, branching, tree shape, leaf stem bark and the like are known as genetic traits carried as clones. In addition, it was understood that homogeneity is expressed in these characteristics by cloning. However, although it was not previously understood whether the yield is a genetic trait or not, the above-mentioned experiment revealed that the yield is a genetic trait.

  In addition, it is thought that the phenomenon of a yield change originates in the growth physiology of a plant. In other words, like moss, it stands upright from the ground not only by the ground surface but also by stems, increases the number of leaves by attaching leaves in three dimensions, and tries to use sunlight efficiently. In this case, to increase the number of leaves, it is better to make them taller, but then the stems that support them need to be strong, and the high leaves must be fed with water and nutrients necessary for photosynthesis. . Therefore, the stem that has come to serve both as the support and the path must inevitably become thicker and stronger, and as a result, the thicker stem and trunk now support the tree. It is a tree.

  Another function of the trunk, the passage, has to deliver the water essential for leaf photosynthesis and the delivery of metabolites synthesized in the leaf, which has led to the development of tissues that act as passages and supports. This tissue is called a vascular bundle. Many plants, including trees, are vascular plants, and this vascular part forms the main component of plant biomass. This vascular bundle is divided into a xylem that sends water and a phloem that sends metabolites, and each cell is made of a formation layer inside the bark, and the cells of the xylem are inside the formation layer, the phloem. Cells are formed on the outside. The cells of the xylem form a primary cell wall, and then, as the secondary cell wall begins to form and lignin, the vacuole becomes larger and the inside becomes hollow, resulting in a dead hollow cell. That is, an individual tree is formed of hollow cells, and the thickness of the cell wall varies from individual to individual. The thickness of the cell wall affects the yield change, and it is considered that the yield is high in individuals with thick cell walls.

  Based on this understanding of natural phenomena and considering the pulp production process, to search for the desired genetic traits, first, a simultaneous forest of natural seeds of the same age is established as a test forest, and this test is performed. By cloning and growing high-yield Eucalyptus plants selected from forest pulp yield distribution, genetic trait differences among individuals can be converged by cloning, and yield can be increased. Is possible. That is, it is possible to grow only individuals having a high yield by using the variation in yield of natural seeds for each individual. According to the present invention, a high-yield Eucalyptus plant can be produced efficiently and is extremely important as a plantation for pulp production.

  In the present invention, it has been found that the production of high-yield wood chips can be achieved by selectively using high-yield individuals for planting, but from the eucalyptus forest established from the existing natural forest, This effect cannot be achieved due to the influence of disturbance factors such as tree age and tree species. This effect can be achieved by planting clone seedlings produced by cutting methods from Eucalyptus plants of individuals selected from a simultaneous forest of Eucalyptus plants of the same age.

<Step (1)>
In the step (1), Eucalyptus plants having a high pulp yield are selected from a test forest of Eucalyptus plants of the same age.

  First, a simultaneous forest of the same age is constructed from natural seeds as a test forest, and the variation in yield of each individual is investigated after the forest is grown. The method is as follows. First, seedlings are prepared. For this, commercially available seeds are used. Commercially available seeds that are generally sold in the area can be used and sowed. In the preparation of seedlings, all generally known media can be applied. For example, vermiculite, peat moss and pine bark. Since germination takes place in about 2 weeks by repeating irrigation after sowing, this is cultured for about 7 months to form a mountain seedling that can be planted. Fertilization and irrigation during this period are in accordance with general methods.

  Next, the produced seedling is planted in the plantation. As a plantation, a land with a uniform and flat soil distribution is selected 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 main work after planting is weeding. This is done as appropriate by observing the state of weeds.

  Subsequently, in a certified forest of the same age, which is constructed from natural seeds, the variation in yield of each individual after the forest growth is investigated. Cut several individuals in the certified forest near the rhizomes, take out the trunk use part of the timber, and peel the whole trunk into chips with a chipper. The chip material is stirred thoroughly and the yield is measured. The yield is determined as the ratio of input chips to unbleached pulp obtained by actually digesting wood chips. That is, the measured pulp yield = the yield of unbleached pulp, and is calculated from (absolute dry weight of unbleached pulp pulp after cooking / absolute dry weight of raw material chips) × 100. From the yield distribution obtained in the survey, a high-yield Eucalyptus plant is selected and grown after step (2). The selection of high-yield Eucalyptus plants indirectly has the effect of improving the efficiency of biomass production per plantation unit area, that is, contributing to the prevention of global warming by increasing the amount of carbon dioxide immobilized. Yes.

<Step (2)>
In the step (2), a cloned seedling is produced from the Eucalyptus plant selected in the step (1) by the cutting method. First, cut seedlings are obtained from the rhizomes that have been cut first. Fell trees at about 15cm from the surface. In consideration of obtaining cut seedlings, logging will be done from autumn to spring. After that, we wait for sprout growth from spring to summer. First, the next spring, when budding begins to come out, arrange edamae etc. in order to get a good cutting.

  In the case of Eucalyptus globulus, the sprouting from the felled tree, that is, the cutting material, is a juvenile leaf without a specific petiole. As an ecological feature of Eucalyptus globulus, leaves change according to their growth. It grows in the state of the above-mentioned juvenile leaves for 2 to 3 years after planting, but thereafter the leaves have petioles, and gradually change into shaped leaves that have transpiration and photosynthetic ability on the front and back. Since cuttings with shaped leaves do not root and are not suitable for cloning, young leaves are extracted as in this procedure, and then cloned by cutting them. Next, the branches and leaves consisting of juvenile leaves brought back from the plantation are cut into one section and the opposite leaves are cut in half. Cut about 2 mm on both sides of the bottom of the inserted cob to expose the formation layer. The cuttings thus produced are collectively sterilized with a disinfectant for about 1 second. Next, attach hormones to the insertion axis of the cutting head and insert them sequentially.

  In order to promote rooting, the plant is managed in a greenhouse at a temperature of 25 to 30 ° C. and a relative humidity of 75 to 85% after cutting. For this reason, sunshine is given for 1.5 to 2 months. The greenhouse is covered with a movable shading net. Open and close this net to adjust daytime temperature and humidity conditions. Leave it to the outside environment almost at night.

  After rooting in the rooting greenhouse (approximately 2 months in the meantime), it goes out of the greenhouse and shifts to the acclimatization process. It is a clone seedling that has passed 1.5 months after cutting, and the surface part is about 10 cm. While fertilizing and irrigating, acclimate outside air and grow seedlings. This period is about 10 months in total. This period is divided into the following three periods to grow seedlings. Fertilization in the three periods is as follows.

(Rooting promotion period)
No fertilizer is applied during the period from cutting to rooting. temperature humidity. Improve the environment such as sunshine.

(Emergence period)
After rooting, the cuttings start budding themselves. Early fertilization is performed at this time. During this time, fertilizer having a high phosphorus value (nitrogen: phosphorus: potassium = 9: 45: 15) is applied in consideration of sufficient root elongation.

(Mountain seedling culture period)
Once the plant has buds, leaves, stems, and roots, a long period of time is provided for tailoring the seedlings. During this period, fertilizers with high nitrogen levels are given to enhance leaf and stem growth. The cloned seedling is thus completed.

<Step (3)>
In step (3), the cloned seedling obtained in step (2) is planted. Afforestation can be performed by the method described in the step (1). After planting, normal planting management such as fertilization and weeding is performed. In this way, afforestation from which a high-yield Eucalyptus genus plant can be harvested by an operation of planting from the selected high-yield clone seedling, cutting and harvesting becomes possible.

<Chip formation>
Chipping is performed in order to allow the chemicals to penetrate into the wood evenly during cooking. The device consists of a receiving blade and a cutting knife, and wood is thrown obliquely with respect to the knife. By this cutting operation, the wood is cut to a thickness of 4 to 10 mm and a width of about 25 mm, that is, a length of 15 to 35 mm in the fiber direction. The cutting angle is generally 30 to 60 °. After this chip formation, a screen is provided to adjust the chip size.

<Pulping>
There are various pulping methods. Here, the kraft method in which a digester is provided will be described. The craft method is premised on the recovery and reuse of cooking chemicals from pulp waste liquid (black liquor) and the recovery and utilization of heat. Pulp is made through a reaction called cooking. The cooking is an operation in which chips are put into a reaction vessel and cellulose is extracted by eluting the lignin in the wood chips with a reaction liquid called white liquor generally consisting of caustic soda and sodium sulfide. The reaction is performed at 160 to 180 ° C. for 2 to 3 hours. The cellulose separated after the reaction is taken out and washed to be pulped.

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

<Step (1)>
First, commercially available natural seeds of Eucalyptus globulus were sown in a crushed pine bark medium. In general, commercially available seeds have not undergone selection or purification such as gene modification or breeding. After sowing, irrigation was repeated three times in the morning, noon, and evening in an outdoor nursery bed equipped with a light-shielding net. The dried state of the culture medium was observed, and watering was carried out so as to keep it always moist. A shading net was set up until germination and indirect sunshine was used. Fertilization was not performed. Thereby, it germinated in about 2 weeks. Thereafter, this was cultured for about 7 months to obtain a mountain seedling that could be planted. During this period, fertilization and irrigation are performed by a general method, but in this example, the method described below was performed.

(Emergence promotion period)
When the seeds start germination, the initial fertilization is performed. During this period, fertilizer having a high phosphorus value (nitrogen: phosphorus: potassium = 9: 45: 15) was applied to allow sufficient root elongation.
(Mountain seedling culture period)
After growing as a plant having buds, leaves, stems, and roots, a long-term growth period is provided for tailoring the seedlings. During this period, fertilizers with high nitrogen values (nitrogen: phosphorus: potassium = 40: 45: 15) were given to enhance the growth of leaves and stems. Irrigation during this period was performed according to a general method.

Next, seedlings were planted in the plantation. As a plantation, a land with a uniform and flat soil distribution was selected so that uniform growth conditions were obtained. In planting, we prepared ground such as weeding, removing foreign matter, and plowing so that a normal afforestation effect was obtained. Planting was done during the rainy season when sufficient soil moisture was secured. Although the planting area may be a general method, it was planted at an area interval of 6 m ² . After planting, a three element fertilizer of nitrogen, phosphorus and potassium was applied. The amount of fertilizer may be an amount applied to a general afforestation method. In this example, the amount of fertilizer was about 150 g per plant with a three-element fertilizer. After planting, we weeded appropriately according to the condition of the forest.

  In this way, a test forest of the same age is constructed from natural seeds, and after the forest is grown, the yield value for each individual is investigated. Generally, it takes about 8 to 12 years to grow up, but here we investigated after 12 years. Each individual was cut down and chipped with a chipper after peeling. The wood was cut to a thickness of 4 to 10 mm and a width of about 25 mm, that is, a length of 15 to 35 mm in the fiber direction. The cutting angle was 30-60 °. After forming the chip, a screen was provided to adjust the chip size.

  The pulping was carried out by the kraft method with a digester. In cooking, chips were put into a reaction vessel, and lignin in wood chips was eluted with white liquor composed of caustic soda and sodium sulfide to extract cellulose. The reaction was performed at 160 to 180 ° C. for 2 to 3 hours. The cellulose separated after this reaction was taken out, washed and pulped. When the yield was calculated, the distribution shown in Table 1 could be grasped. As a high-yield individual, a eucalyptus globulus individual with the highest yield falling within the range of 53.5 to 54% was selected.

<Step (2)>
A method for obtaining a cloned seedling by cutting from the rhizome of the individual with the highest yield used to investigate the yield is described. The felling was about 15cm from the surface. Logging was done from autumn to spring. In the next spring, when budding began to appear, we arranged the long branches in order to get a good cutting. The sprouting from this felled tree is a young leaf without a petiole characteristic of Eucalyptus globulus, and this was used as a material for the ear.

  The branches and leaves brought back from the plantation were cut into one section and the opposite leaves were cut in half. About 2 mm on both sides of the lower part of the inserted cob was cut open to expose the formation layer. The cuttings thus prepared were roughly sterilized with a disinfectant for about 1 second. Next, a hormone was attached to the insertion axis of the cutting head, and inserted sequentially.

  In order to obtain rooting, sunshine was applied for 1.5 to 2 months after cutting at a temperature of 25 ° C. and a relative humidity of 85%. Using a greenhouse, covered with a movable shading net. The net was opened and closed to adjust daytime environmental conditions. I left it to the outside environment almost at night. Rooting was observed in the greenhouse (almost 2 months in the meantime), and it went out of the greenhouse and shifted to the acclimatization process. A clone seedling passed about 1.5 months after cutting, and the surface part was about 10 cm. While fertilizing and irrigating, acclimation to the open air and seedling growth were promoted. The total period was about 10 months. This period was divided into three periods (rooting promotion period), (emergence period), and (mountain seedling culture period), and seedlings were grown. Fertilization was carried out with different contents at each stage of growth.

(Rooting promotion period)
No fertilizer was applied during the period from cutting to rooting. Only environmental maintenance such as temperature, humidity, and sunshine was performed.

(Emergence period)
After rooting, the cuttings started budding themselves. Furthermore, in order to promote sufficient root elongation, fertilizer having a high phosphorus value (nitrogen: phosphorus: potassium = 9: 45: 15) was applied at this time.

(Mountain seedling culture period)
Once the plant has buds, leaves, stems, and roots, a long period of time is provided for tailoring the seedlings. During this period, fertilizers with high nitrogen values (nitrogen: phosphorus: potassium = 40: 45: 15) were given to enhance the growth of leaves and stems.

  A clone seedling was prepared as described above.

<Step (3)>
After planting the cloned seedlings obtained in the step (2), normal planting management such as fertilization and weeding was performed in the same manner as in the step (1). Trees were cut 12 years after planting, and the yield was investigated in the same manner as when a high-yield Eucalyptus plant was selected, and the yield distribution is shown in Table 2. In addition, the results in Table 1 which are the yield distribution of natural seeds in the same age forest (natural seed forest) and the results in Table 2 which is the yield distribution in the same age forest of clone seedlings with high yield (clonal forest) are combined. This is shown in FIG.

  It was confirmed that the Eucalyptus plant obtained by the production method including the steps (1) to (3) has a high yield.

Yield distribution in the same age forest obtained from natural seeds and clonal seedlings with high pulp yield.

Claims (4)

  (1) a step of selecting a eucalyptus plant having a high pulp yield from a test forest of Eucalyptus plants of the same age, (2) a step of producing a clone seedling from the selected eucalyptus plant by a cutting method, (3) a clone A method for producing Eucalyptus plants, including a step of planting seedlings.   A Eucalyptus plant produced by the production method according to claim 1.   A wood chip manufactured from the Eucalyptus plant according to claim 2.   A pulp produced from the wood chip according to claim 3.

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