JP4687028B2 - Cutting plant seedling production method of Eucalyptus plant - Google Patents

Description

  The present invention relates to a method for producing a eucalyptus plant clone seedling by a cutting method.

  Eucalyptus is a woody plant that belongs to the subfamily of the Angiosperm genus Moleen, the subfamily of the subfamily Pleuromyidae, and the origin of the Oceania region centering on the Australian continent. Many species of trees with excellent characteristics such as disease and insect resistance are included in this Eucalyptus genus.

For this reason, Eucalyptus is widely cultivated not only in the Oceania region where it originates, but also in South Africa, South America, Asia, the Mediterranean coast, the west coast of the United States, etc. It is used for. Above all, from increasing in recent years of environmental awareness, Eucalyptus has attracted attention as a raw material for papermaking pulp, Eucalyptus globulus (Eucalyptus globulus (hereinafter, E. Abbreviated as globulus.)), Eucalyptus Nitensu (Eucalyptus nitens (below ), Eucalyptus citriodora (hereinafter abbreviated as E. citriodora )), Eucalyptus grandis (hereinafter abbreviated as E. grandis , Eucalyptus and Eucalyptus).・Europhylla ( Eucalyprus europhylla (hereinafter abbreviated as E. Eurofila )), Eucalyptus Camaldrensis ( Eu Calyptus camaldulensis (hereinafter abbreviated as E. camaldulensis )) or Eucalyptus hybrids having these as one parent have been actively planted in Australia, Brazil, Chile, South Africa, and the like. Therefore, as a most suitable method for producing and supplying a large amount of seedlings having uniform properties, the production of seedlings by cutting method is being studied.

  Cutting is a traditional vegetative propagation method in which an artificially cut plant tissue (cutting head) is cut into the root bed and rooted in the root bed to create an independent plant body. It is. This method is widely used as a method for producing and propagating a large number of individuals having the same genetic characteristics as the parent plant, that is, from herbaceous plants to woody plants. However, not all plants can be propagated this way. Even if this method is used, the cuttings do not root at all, or the rooting rate is extremely low, and there are many species and varieties that cannot be propagated. Except for some species such as camaldrensis, it is known that the rooting is generally poor.

  Therefore, in Eucalyptus, improving rooting ability from cuttings is an important issue in considering mass production. In order to solve such a problem, the present inventors first used a liquid medium that does not contain a carbon source, and cultured the cuttings in a culture vessel while maintaining the carbon dioxide concentration within a certain range. A method for rooting was proposed (Patent Document 1).

          JP2001-186814

  According to the said method, even when it applies to a hard-to-root tree species, the rooting rate from the cutting head is greatly improved.

  However, the rooting ability from the cutting head is greatly influenced by the ability of the cutting head itself. For this reason, in particular, in a hard-to-root tree species such as Eucalyptus, it is necessary to obtain cuttings with excellent rooting ability in order to improve rooting from the cuttings.

  From the above viewpoint, the present invention obtains a eucalyptus cutting with excellent rooting ability, and thereby improves rooting from the cutting, thereby enabling efficient cutting production of the eucalyptus. The challenge was to enable mass production using cuttings of the genus Eucalyptus.

  As a result of diligent research, the present inventors have focused on the size of the cutting head and found that the cutting head having a size equal to or greater than a certain standard value has excellent rooting ability. The present invention has been completed.

That is, in the present invention, when cuttings are collected from a mother tree and then the cuttings are rooted to produce cuttings, the ratio of the axial length (T) to the maximum diameter (R) as cuttings. (T / R) is 0.9 or more , axial length (T) is 20 mm or more and 35 mm or less, and fresh weight is 100 mg or more and 200 mg or less .

  According to the present invention, it is possible to easily select and obtain Eucalyptus cuttings excellent in rooting ability.

  Therefore, according to this invention, the rooting property from the cutting head of the Eucalyptus genus can be improved, and the efficient cuttings seedling production becomes possible.

  Furthermore, according to the present invention, it is possible to mass-produce eucalyptus tree species that have excellent properties and have been difficult to multiply by cuttings by cuttings, which opens the way for industrial use.

  The cutting seedling production method of the present invention can be applied without particular limitation as long as it is a Eucalyptus plant. Representative species of Eucalyptus plants include, for example, E. coli. Globus, E.G. Nitens, E.M. Citriodora, E.I. Grandis, E.G. Eurofila and E. Although camaldrensis and the like are known, the present invention can be applied to species other than these and even interspecific hybrids. However, the present invention exerts its effect even more by applying it to hard-to-root species among Eucalyptus.

  In the present invention, tissue culture seedlings, cutting seedlings, grafted seedlings or seedling seedlings can be used as a mother tree for collecting cuttings (hereinafter also referred to as a cutting tree collecting mother tree). Among these, the cutting seedlings may be cutting seedlings obtained by the cutting seedling production method of the present invention. These seedlings can be obtained by a conventional method.

  By the way, a method of obtaining Eucalyptus tissue culture seedlings via multi-buds or shoot primordia is well known. For example, in order to obtain a tissue culture seedling via a multi-bud, it may be performed generally as follows.

  First, the current year branch or sprout branch is collected from an individual as a material, cut into an appropriate size, and immersed in 0.1 to 5.0% hypochlorous acid for 5 to 30 minutes for sterilization. At this time, as a material, a new treetop developed by grafting the branch of the current year as a graft can also be used. The material after sterilization is washed with sterilized water and then cut into sections, sucrose 1 to 5% by weight, benzylaminopurine (hereinafter abbreviated as BAP) as a plant hormone 0.01 to 0.5 mg / l. , Placed on Murashige Sukug (hereinafter abbreviated as MS) medium (pH 6.0-7.0) containing 0.2-0.25% by weight of gellan gum, and at 20-30 ° C. using a fluorescent lamp for plant culture While irradiating light of 2000 to 20000 lux for 18 hours / day, the buds are developed by culturing for several weeks. In addition to BAP, Kinetin (hereinafter abbreviated as K) and naphthalene acetic acid (hereinafter abbreviated as NAA) are used as plant hormones in the above medium or medium under the same temperature and light conditions as above. When a subculture is performed at intervals of 3 to 4 weeks using a medium supplemented with sucrose, a multi-bud is formed. By cutting and rooting adventitious buds extending from the multi-bud, tissue culture is performed. A seedling is obtained. At this time, rooting is MS plant (diluted 2-32 times) containing 0.1-10 mg / l of indolebutyric acid (hereinafter abbreviated as IBA) or indoleacetic acid (hereinafter abbreviated as IAA) as a plant hormone. pH 5.7 to 5.8) was used as a rooting medium, and porous substrates such as river sand, garden glass fiber, garden urethane resin, and garden foamed phenol resin were wetted with this rooting medium. The base of adventitious buds obtained from multi-buds is inserted into the cultivated body, and the culture is performed for 3 to 4 weeks under the same temperature and light conditions as above while controlling the carbon dioxide concentration in the culture environment to 300 to 1500 ppm. To do so. In addition, the multi-buds after cutting out adventitious buds can be maintained and proliferated if they are appropriately divided and cultured in a medium having the same composition as the medium used for forming the multi-buds.

  As the cuttings of the present invention, shoots or stems and leaves produced by the elongation of the buds can be collected from the mother tree for cuttings collection and used. For this purpose, it is advisable to cultivate the mother tree for collecting cuttings by excising the top buds. By cultivating in this way, a lot of buds are produced, so that the number of cuttings obtained per mother tree is also increased.

  In addition, it is preferable to use what the above-ground part height after excising a top bud as mentioned above is 5-60 cm, especially 10-30 cm as a mother tree for cutting ear collection. If a seedling with such a height above the ground is used as the cutting head mother tree, cuttings having high rooting ability and capable of forming healthy roots can be efficiently obtained.

  In the case of Eucalyptus plants, usually about 1 to 16 nodes are used for seedlings with a height of 5 to 60 cm after excision of the top buds, and about 3 to 10 nodes for seedlings of 10 to 30 cm. If you have buds and buds arise from this section. Therefore, if the above-ground height after excision of the top bud is less than 5 cm, the number of cuttings obtained per mother tree becomes extremely small, which is not preferable. On the other hand, even if the above-ground height is larger than 60 cm, the axillary buds are produced only from the upper nodes, and the resulting axillary buds tend to be inferior in the ability to root as cuttings and to form healthy roots. Therefore, it is not preferable. In addition, in order to obtain cuttings for collecting cuttings with a head height of more than 60 cm, it is necessary to cultivate over that period, so the efficiency is poor, and the mother tree itself can be damaged by scratches, microorganisms, etc. This is also not preferable from this point.

In general, cuttings having a high rooting ability and forming healthy roots are obtained from a mother tree for collecting cuttings. Therefore, it is preferable to cultivate the mother tree for cutting cutting itself under appropriate nutritional conditions and environmental conditions. For example, the water supply is preferably performed about once a day and fertilization is performed about once a week so that the culture soil where the mother tree for cuttings is collected is not extremely dried. Commercial fertilizers such as “Hyponex” can also be used as the fertilizer. In that case, what diluted the stock solution about 500 to 2000 times should just be given. The temperature is preferably maintained at 15 to 40 ° C, particularly 20 to 30 ° C during the day. Since Eucalyptus prefers a relatively warm climate, care must be taken so that the minimum daily temperature does not fall below 5 ° C. The humidity is preferably maintained at a relative humidity of 50% or more, but usually it is not necessary to specifically manage the humidity. However, an environment where a relative humidity of 30% or less continues for many days is not preferable. Light amount, 50~1200μmol / S / ^{m 2,} it is preferable that particularly 200~1000μmol / S / ^{m 2,} if grown in normal greenhouse, which also need not be specially managed. However, an environment in which the amount of light is 2000 μmol / S / m ² over several hours of the day is not preferable.

  Thus, in order to efficiently cultivate the cuttings for collecting cuttings while maintaining appropriate nutritional conditions and environmental conditions, each of these cuttings is collected in a seedling pot, etc. It is good to grow as. Pot seedlings are easy to manage such as water supply and fertilization, and can be moved from the greenhouse to the outdoors or from the outdoors to the greenhouse, depending on the growth state and season, for example. Therefore, management of temperature, humidity, light quantity, etc. is easy. In addition, when multiple cuttings are harvested at the same time, even if an infectious disorder such as illness or mold occurs in one of the cuttings, it is possible to collect other cuttings. The entire mother tree can be easily protected from infection.

  In this case, it is preferable that the pot for planting the mother tree for cutting cutting is 50 to 2000 ml, particularly 70 to 350 ml. If a pot with a capacity smaller than 50 ml is used, the culture soil in the pot cannot hold water and liquid fertilizer sufficiently, so it is easy to dry. It is difficult to obtain a cutting tree for collecting cuttings, and thus, a cutting root having high rooting ability and forming a healthy root. On the other hand, pots with a capacity of more than 2000 ml have a poor workability because they are considerably heavier when culture soil is added thereto. In addition, planting one individual cutting head tree in such a large pot also increases the occupied area, water supply amount, fertilization amount, etc., per cutting head collecting mother tree, and thus the economic efficiency deteriorates. .

  In the present invention, a cutting head having a ratio (T / R) of the axial length (T) to the maximum diameter (R) of 0.9 or more is used. This is because cuttings having such a T / R ratio have a high rooting ability and a high possibility of forming healthy roots. In addition, if the T / R ratio is 0.9 or more, R is 15 mm or more, or T is 20 mm or more and the raw weight (W) is 100 mg or more, this possibility becomes very high. . However, it is preferable that T is 35 mm or less and W is 200 mg or less. In order to obtain cuttings with a larger T or W from the mother tree for harvesting the head, the buds and stems and leaves of the mother tree for harvesting the cutting must be grown for a long period of time. This is because spikes are not necessarily high in rooting ability and healthy root formation ability. In the present invention, R, T and W all mean the maximum diameter, the axial length and the weight of the cuttings immediately after being collected from the cutting tree for collecting cuttings (for R and T, (See FIG. 1).

  The cuttings having such T, R, and W may be obtained by collecting shoots or foliage from the mother tree for collecting cuttings and selecting them as described above. At this time, it is preferable to use one having two or more cutting spikes, preferably 4 to 6 leaves. This is because such cuttings show even better rooting ability and healthy root forming ability.

  The cuttings thus obtained can be rooted by a conventional method to form seedlings. For example, as a culture medium, a 2-32-fold diluted MS medium (pH 5, 7-5.8) containing IBA 0.1-20 mg / l is used. Inserting the cutting base into a porous substrate such as resin, and cultivating while supplying carbon dioxide as a carbon source so that the concentration in the culture environment is 300 to 1500 ppm, rooting, can do. However, at this time, a solid medium obtained by adding agar or gellan gum to the medium components and solidifying the medium may be used. In this case, there is no need to use a porous substrate such as a urethane resin for gardening or a foamed phenol resin for gardening. Moreover, you may use what added sucrose to the said culture medium component instead of using a carbon dioxide gas as a carbon source. In this case, it is not necessary to supply carbon dioxide in the culture environment, but it is necessary to perform the culture in a sterile environment.

  In addition, the cuttings are made of red soil (red crust), river sand, mountain sand, Hinata soil, Kanuma soil, vermiculite, perlite, peat moss, etc. It can also be rooted and made into a seedling by inserting and culturing with the base portion inserted into a liquid fertilizer that has been wetted.

[Action]
In rooting of cuttings, it is necessary that starch as an energy source and plant hormones that promote cell differentiation / proliferation are present in a certain amount or more in the cuttings. Therefore, it is considered that cuttings having a certain size and not having a certain weight are inferior in rooting ability and are difficult to form healthy roots.

  However, large and heavy cuttings do not necessarily have high rooting ability and form healthy roots. Plant hormones are synthesized near the top buds of plants, and starch is mainly synthesized in leaves. Therefore, when the cuttings grow large, it takes time for these components to reach the rooting site, that is, the base of the cuttings. In addition, even if it reaches this rooting site, it is not possible to secure a sufficient amount for rooting.Moreover, since large and heavy cuttings have a large amount of metabolism and transpiration, moisture from the cutting head This is thought to be due to the fact that the absorption of nutrients and nutrients cannot catch up.

  Therefore, the present inventors have studied various selection criteria for cuttings excellent in rooting ability and healthy root formation ability, and as a result, grasped cuttings by the maximum diameter and axial length, When these elements satisfy a certain relationship, it has been found that there is a high possibility that the cutting head has the above two abilities, and the present invention has been completed.

  Hereinafter, the present invention will be described in more detail by way of examples.

[Example 1]
Chilean E. coli selected by viability Tissue culture seedlings obtained from globulas Ch-1 via polyblasts are transplanted and acclimatized to culture soil placed in wedge-shaped vinyl pots, water supply once a day, liquid fertilizer once a week After raising the seedlings for 3-6 months while feeding, the top buds were excised so that the above-ground height was 25 cm, and this was used as a mother tree for ear collection, and used for the following experiments. At this time, the capacity of the vinyl pot was 150 ml, and the culture soil was prepared by mixing and mixing red jade soil: Hyuga soil: Kanuma soil at a ratio of 1: 1: 1.

  While dividing the 30 cutting tree harvesting mother trees obtained as described above into groups of A to G by 5 pieces, while performing water supply once a day and fertilization once a week for each group, further Continued cultivation. And about the mother tree for cutting head collection of A group, when the bud grew to about 1.0 cm of axial length, this was extract | collected, and 60 cuttings of axial length 1.0cm were obtained. Similarly, 50 cuttings with an axial length of 1.5 cm are taken from the cutting tree harvesting parent tree of group B, and 48 cm cuttings with an axial length of 2.0 cm are taken from the cutting tree collecting mother tree of group C. From the cutting tree harvesting mother tree of group D, 55 cuttings with an axial length of 3.0 cm, from the cutting tree harvesting group E group of 50 cuttings with an axial length of 5.0 cm, 30 cuttings with an axial length of 7.0 cm can be obtained from the F-group cutting harvesting mother tree, and 4 cuttings with an axial length of 10 cm can be obtained from the G-group cutting spike collecting mother tree. It was.

  These bases were inserted into a horticultural foamed phenolic resin moistened with 8-fold diluted MS medium containing 1.5 mg / l of IBA, and the base was inserted. In the culture room, using a fluorescent lamp for plant culture, cultivated while irradiating light of 2000 (lower side) to 20000 (upper side) lux for 18 hours / day, and after 1 month, determine the rooting rate for each group. investigated.

  The results are shown in Table 1.

  As apparent from Table 1, in the BF groups, many cuttings could be collected, and the collected cuttings showed a rooting rate of 30% or more. On the other hand, in group A, many cuttings could be collected, but these cuttings did not root at all. In Group G, the number of cuttings that could be collected was small, and the rooting rate was low.

[Example 2]
Chilean E. coli selected by viability A tissue culture seedling obtained from the Globus line Ch-10 via the multi-bud was acclimatized and raised in the same manner as in Example 1 to obtain a mother tree for cutting cutting.

  After cultivating the obtained mother tree for collecting cuttings for 2 to 4 weeks while supplying water once a day and fertilizing once a week, the buds were collected randomly and promptly one by one. After measuring one axial length (T), maximum diameter (R), and fresh weight (W), these cuttings were cultured in the same manner as in Example 1, and after 3 weeks, The presence or absence was investigated. 2 to 4 are graphs showing the results in relation to T, R, and W. FIG. One point in the graph corresponds to one insertion head.

  As apparent from FIGS. 2 to 4, all the cuttings in which rooting was observed had a T / R ratio of 0.9 or more (FIG. 2), while the cuttings in which rooting was not observed. Among them, there was almost no R of 15 mm or more and W of 100 mg or more, or T of 20 mm or more and W of 100 mg or more (FIGS. 3 and 4). Therefore, cuttings having a T / R ratio of 0.9 or more are highly likely to have excellent rooting ability, and in particular, the T / R ratio is 0.9 or more and R is 15 mm or more, or T is It is considered that there is an extremely high possibility that the cutting head is 20 mm or more and the raw weight (W) is 100 mg or more.

[Example 3]
Chilean E. coli selected by viability Tissue culture seedlings obtained from globula strain Ch-5 via multi-buds were acclimatized in the same manner as in Example 1, and then divided into groups of 3 to 3 once a day. Water supply, fertilization once a week, and for group A, raise the seedlings for 0.8 months, so that the height of the top part after excision of the top buds is 10 cm. . By raising seedlings for 6 months, the height of the above-ground part after excision of the apical buds is increased by raising a seedling-collecting mother tree having a height of 15 cm after excision of the apical buds for 3 months. Raise the 35 cm cutting head mother tree for 4 months for group D, and raise the cutting tree head tree height of 45 cm after excision of apical bud for 5 months for group E Due to this, the above-ground height after excision of apical bud is 65 For the F group, raise the m cuttings for 6 months, and for the F group, grow the cuttings for 80 m above the shoot, and for the G group, for 8 months. As a result, a harvesting mother tree for cuttings having an above-ground height of 100 cm after excision of the apex was obtained. At this time, seedling pots with a capacity of 200 ml were used for groups A to D, and those with a capacity of 1000 ml were used for groups E to G. As the culture soil, the same one as in Example 1 was used.

  Each of the three cutting tree harvesting mother trees of groups A to G obtained as described above was cultivated while performing water supply once a day and fertilization once a week, and after that cultivation for 3 weeks. During the 7th week from the eyes, axillary buds having an axial length of about 3.5 cm were inserted and collected as ears. Table 2 shows the number of cuttings having an axial length of 3.5 cm, which could be collected within the above period, as an average value for each group as the number per cutting tree for cuttings.

  As is apparent from Table 2, in any of the groups A to G, an average of 5 or more cuttings can be collected per cutting head collecting mother tree, and the number of cuttings collected is as follows. , E group was the most. In the F and G group cuttings for collecting cuttings, the sprouts that can become cuttings are concentrated between 10 and 20 cm from the top, so that the above-ground height is high, but so many cuttings cannot be collected. . Moreover, since it takes a long time to raise a seedling for harvesting cuttings having a high height above the ground, it is not efficient to use such a mother tree for collecting cuttings. Therefore, as the cutting tree harvesting mother tree, from the viewpoint of the number of cuttings obtained per one and the period required to obtain the mother tree, those of the A to E groups, particularly the B and C groups It is considered preferable.

    It is a figure which shows the maximum diameter (R) and axial direction length (T) of an cutting head, (A) is the schematic diagram which looked at the cutting ear from the side, (B) is the schematic diagram which saw the cutting ear from right above It is.     It is a graph which shows the relationship between T / R ratio and W of a cutting head, and the presence or absence of rooting of the cutting head.     It is a graph which shows the relationship between R and W of cuttings, and the presence or absence of rooting of the cuttings.     It is a graph which shows the relationship between T and W of cuttings, and the presence or absence of rooting of the cuttings.

Claims (5)

A method for producing cuttings and seedlings of Eucalyptus plants by collecting cuttings from a mother tree and then rooting the cuttings, where the ratio of the axial length (T) to the maximum diameter (R) ( A eucalyptus plant having a T / R) of 0.9 or more , an axial length (T) of 20 mm or more and 35 mm or less, and a fresh weight of 100 mg or more and 200 mg or less . Cutting seedling production method. As cuttings, further, the maximum diameter (R) is characterized by using those on 15mm or more, cuttings production method of Eucalyptus plant of claim 1. Cutting plant seedling production of Eucalyptus plants according to claim 1 or 2 , characterized in that the height of the above-ground part after excision of the top bud is 5 to 60 cm as a mother tree for collecting cuttings. Method. The method for producing cuttings seedlings of Eucalyptus plants according to claim 1, 2 or 3 , wherein tissue culture seedlings, cutting seedlings, grafted seedlings or seedling seedlings are used as mother trees for collecting cuttings. . Eucalyptus globulus, Eucalyptus nitens (Eucalyptus nitalus), Eucalyptus citriodora, Eucalyptus citriodora, Eucalyptus citriodora, Eucalyptus citrus The method for producing cuttings and seedlings of Eucalyptus plants according to claim 1, 2, 3 or 4 , characterized in that it is cis (Eucalyptus camaldulensis) or a hybrid of Eucalyptus having these as one parent. .

Images