JPH0630669A - Raising seedling method for dwarfed plant belonging to saintpaulia - Google Patents

Abstract

PURPOSE:To provide a raising seedling method for dwarfed plant belonging to Saintpaulia. CONSTITUTION:A completely differentiated sterile plant belonging to Saintpaulia obtained by tissue culture is planted in a solid medium with a specific synthetic medium reduced in inorganic salt concentration as the basal medium followed by dripping a dikegulac solution onto one or both of the leaves and apical buds, thus accomplishing the objective raising seedling. With this method, such a plant can be dwarfed to a form suitable for in-vessel raising.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for raising dwarfing plants of the genus Saintpaulia, and more specifically to complete differentiation obtained by culturing tissue of the plant of the genus Saintpaulia. The germ-free plant was cultivated under a specific culture condition using a specific seedling induction and growth solid medium, and treated with a specific dwarfing agent to obtain a hybrid that has been popular in the past. In this case, the plant shape is large, and it is difficult to obtain a plant with a proper plant shape, but it is possible to dwarf a plant of the genus Saintpaulia into a proper plant shape suitable for cultivation in a container, and to proliferate in a high yield. The present invention relates to a method for raising seedlings of dwarfed plants of the genus Saintpaulia in a container by possible tissue culture.

[0002]

2. Description of the Related Art Conventionally, adventitious buds, adventitious roots, flower buds, calli, etc. are induced, formed and grown by aseptically culturing a section of a plant tissue on a medium to propagate the plant. , The growth method by tissue culture of the plant,
Studies have been conducted on various plants, and various techniques have been developed so far.

With the development of such plant tissue culture technology, various plant production methods and growth methods have been developed using the technology, and specific medium composition, culture conditions, etc. suitable for each plant are specific. Some of them have already been put into practical use as production methods for virus-free strains, large-scale breeding methods, etc., and for example, regeneration of disease-free solids by shoot apical tissue culture (growth point culture) of dahlia and potato, orchid (cymbidium). Reproduction of protocomb-like body (original mass-like tissue mass PLB) by shoot apical tissue culture (genus), and various technologies such as mass-propagation technology of genetically uniform seedlings by division growth have been developed and put into practical use. ing.

At present, such tissue culture technology is being applied in various fields from plants such as flowers and vegetables to woody plants such as fruit trees, flowers and trees.
Especially in Japan, orchids, carnations, chrysanthemums, lilies,
The seedling production technology of horticultural crops such as gypsophila, Saintpaulia, gerbera, cyclamen, strawberry, etc. is becoming established.

However, such a tissue culture technique for plants is not a technique that has been completed yet, there are many unknown fields, and there are many places that should be awaited for future research. With regard to vegetative propagation, except for Cymbidium, which is being researched, the medium composition and culture technology have not yet been completed to the extent that they are generalized. The growth system by tissue culture has not been established.

[0006] Regarding general flowers and ornamental plants, research and development such as formation of multiple buds by liquid shaking culture of proliferating tissue, induction of multiple buds in medium supplemented with hormones, mass multiplication of seedlings, etc. are actively conducted. However, there are many problems to be solved in the future, such as the extremely high risk of mutation.

[0007] In addition, cyclamen, primula and the like, which are bred and seeded in bulbs and perennials, are genetically separated, resulting in lack of homogeneity of the product, and a small amount of harvest, resulting in shortage of excellent seeds. Therefore, attempts have been made to grow excellent solids by tissue culture.

Further, storage maintenance and the seed for the mother strains, that the seed propagation and F ₁ solid productive vegetables, F ₁ solid flowers, grown by tissue culture, supplied as seedlings vegetative propagation system Although such attempts have been made, the conventional technique of vegetative growth using such a seed breeding system is only partially put into practical use. In this way, plant tissue culture technology,
As a method for inducing, producing, and propagating various plants, induction and proliferation techniques by tissue culture of various ornamental plants have been proposed.

That is, for example, the shoot apex of a useful annual plant is extracted, and this is transplanted to an artificial medium containing an inorganic salt composition and a plant growth hormone, which is 0.5 to 10 rpm.
A method for mass-proliferating useful annual plants has been proposed, which comprises rotating and cultivating shoot primordia at a rotation number of 10 and then statically culturing the resulting shoot primordia to form seedlings (Japanese Patent Laid-Open No. Sho-06-1999). 59-
No. 132823). However, this method mainly uses shoot-primitives (Sho-ot primordia) to artificially mass-produce useful substances consisting of secondary metabolites such as plastids, vacuoles, oil bodies, and stored substances. And, regarding the growth of ornamental plants, it only refers to petunia, morning glory, and the like.

Further, a method of redifferentiating a plant which germinates and roots from callus under light irradiation from a tissue piece of the plant, and a growth medium therefor, as a growth medium, 0.1 to 10 ppm of cytokinins, which are plant hormones, And an MS medium containing 0.01 to 10 ppm of auxins have been proposed (JP-A-3-139224). However,
This is an examination of a specific medium composition, culture conditions, etc. for Asteraceae plants suitable for obtaining a large number of Asteraceae plants in a short period of time.

A method for regenerating a plant, which comprises inducing callus from a tissue piece of a plant, culturing the callus to differentiate adventitious buds, and then culturing the adventitious buds to obtain seedlings , And a method for multiplying seeds and seedlings thereof have been proposed (Japanese Patent Laid-Open No. 4-45730). However, this method utilizes differentiated adventitious buds, and is intended for plants of the genus Astragalus.

Further, a tissue section of a flowering plant or a tissue section of a regenerated plant obtained by culturing the same is cultured in a medium to be redifferentiated to obtain a regenerated plant, and then the regenerated plant is regenerated. A method for culturing flowering plants has been proposed in which a flowering plant is cultured by culturing in a medium having a composition different from that at the time of differentiation (JP-A-4-30733). However, this method is an examination of the medium composition of the medium used for the redifferentiation culture, and the medium used for the flowering culture, and the target plant is a plant belonging to the family Echinacea, Caryophyllaceae, and Solanaceae, especially the genus Torenia. The plants are only illustrated.

Recently, however, there has been proposed a technique related to in-container flowering, in which a plant is cultivated in a hermetically-sealed container to cause it to flower, and the flower can be viewed as it is.

As an example of such a proposal, for example, a stem section of a plant is cultivated aseptically in a primary basal medium to form adventitious buds, which are then brought to a specific inorganic salt concentration and dwarfed. A cultivation method has been proposed in which the culture medium is placed on a secondary basal medium containing an agent and irradiated with a natural daylight color fluorescent lamp for a short day to carry out closed culture (JP-A-60-22210). However, this method utilizes adventitious buds, and the target plant is also limited to Torenia (Japanese name Hanaurikusa).

In addition, a specific dwarfing agent 2 to 10 is used as a dwarfing agent in a container in which the whole plant of a sterile seedling of Citrus can be seen through.
A method for cultivating dwarf citrus (Japanese Patent Application Laid-Open No. 2-190113), which comprises planting in an MS medium supplemented with ml / l, intermittently irradiating light for a long period of time, and aseptically performing closed culture (JP-A-2-190113). Cultivation method comprising planting the whole plant of a sterile seedling in an MS medium to which a specific component is added as a dwarfing agent in a transparent container, and irradiating light intermittently for a long time and aseptically hermetically culturing (Japanese Patent Laid-Open No. 2-200121
Gazette), etc. have been proposed.

Further, as a dwarfing agent in a container in which a germ-free seedling of a lotus root, the whole plant, can be used as a dwarfing agent.
2 to 1.0 g / l was added to MS modified medium,
A method for cultivating dwarf balconies characterized by irradiating light intermittently for a long period of time and performing aseptic closed culture (JP-A-3-28).
5618 gazette), a dwarfing technique for such plant bodies, and a technique for cultivation in a container have been proposed. However, these are all those that studied the dwarfing conditions and the like in a closed container for a specific plant body, and those that have been studied with regard to St. Paulia spp.
I can't find it.

As described above, in order to establish an in-container cultivation technique in which a plant is cultivated in a closed container and can be viewed as it is, a technique of growing the plant in a closed container in a stable and high yield, It is premised to develop and establish a dwarfing technique for growing into a proper form in a closed container, a flowering technique for differentiating flower buds, and flowering, but in the first place, cultivate a plant in a closed container, It is very difficult to make it bloom, and so far, there have been reported examples of flowering in a sealed container of dwarf Torenia, cultivation of dwarf tomato, sennichouko, flowering in a sealed container of balsam, etc. Though
Currently, most of the practically used ornamental plants that grow dwarf plants in a closed container and are used for ornamental purposes do not have flowers.

[0018] As described above, generally, with the development and widespread use of techniques for propagating various plants by tissue culture, individual culture conditions suitable for various plants have been studied, developed, and are being established. However, there are not many that have reached the level of practical use, let alone cultivate the plant in a closed container or an air permeable container to differentiate flower buds to flower, and to watch as it is in the container container There are few cases of research on this, and it is in a situation where it has not been practically used.

[0019]

In such a situation, the present inventors have cultivated a plant in a container to differentiate flower buds, make them bloom, and then to view the plant as it is. With the goal of establishing a breeding technology, the basic technology that is the basis of that technology, that is, a method for growing a plant in a stable and high yield, dwarfing conditions for dwarfing properly, and stable flower buds We started the basic research in order to investigate various cultivation conditions for differentiating and flowering for a long time.

According to the research conducted by the present inventors and the findings to date, in order to establish such a plant growing technique, the above-mentioned various plant growth techniques and dwarfing techniques, which are the technical bases, are established. Needless to say, the development of basic technologies such as flowering technology is a major prerequisite, but each of these technologies is, in fact, completely different depending on the type of individual plant. Also, for citrus, citrus cortex, spinach, spinach, etc., it is almost impossible to achieve the intended purpose even if the cultivation method and conditions are diverted to other plants as they are. Accordingly, it is necessary to develop and establish individual cultivation methods and cultivation conditions.

On the premise of such knowledge, the present inventors have found that among the various plants, the conventional hybrids have a large grass shape, and therefore, a suitable grass shape suitable for cultivation in a container is obtained. Focusing on the plant of the genus Saintpaulia, for which plant production has been strongly requested, and developing a method for growing a dwarfed plant suitable for cultivation in a container by growing it in a container in high yield. As a result of earnest research,
The inventors have found that the intended purpose can be achieved by combining a specific dwarfing process, a specific medium composition, and culture conditions, and have completed the present invention.

That is, the present invention provides a method for growing and dwarfing a plant of the genus Saintpaulia, which had a large grass shape in the case of a hybrid, and then raising the dwarfed plant in a container. It is intended.

Further, the present invention utilizes a completely differentiated sterile plant body obtained by tissue-culturing a tissue section of a sterile plant body of a Saintpaulia sp. The purpose is to provide a method for raising seedlings in a container.

Further, the present invention provides a method for raising seedlings in a container of a plant of the genus Saintpaulia aseptically cultivated in a container to differentiate flower buds, allow them to flower, and then watch them in the container as they are. The purpose is to do.

Furthermore, according to the present invention, a plant of the genus Saintpaulia is grown in a high yield under a specific medium composition, a specific culture condition, and a specific treatment condition to obtain a suitable grass-shaped plant in a container. It is intended to provide a method for dwarfing growth.

[0026]

The constitution for achieving the object of the present invention comprises the following technical means (1) to (4). (1) A completely differentiated aseptic plant of a Saintpaulia genus plant obtained by tissue culture contains a carbon source, is pH-adjusted, and the inorganic salt concentration is adjusted to 1/1 to 1/5. After being planted in a solid medium having a reduced synthetic medium as a basic medium, a dikegrac solution is added dropwise to one or both of the leaf surface, the apical bud, and a dwarfing plant of a St. genus plant characterized by growing seedlings. How to raise seedlings.

(2) Containing 1% by weight of sucrose and having a pH of 5.
8. A method for raising dwarfing plants of the genus Saintpaulia according to (1) above, wherein a solid medium having a basic medium of a synthetic medium adjusted to 8 and having an inorganic salt concentration adjusted to 1/2 is used.

(3) The method for raising dwarfed plants of St. Paulia spp. According to the above (1), characterized in that a dikegrac solution having a component concentration of 20 to 200 mg / l is used.

(4) The method for raising dwarfed plants of St. Paulia spp. Described in (1) above, wherein the synthetic medium is an MS modified medium.

Next, the structure of the present invention will be described in detail. In general, the genus Saintpaulia is a perennial belonging to the genus Tobacco, Tanzania,
It is known as an ornamental horticultural plant that was bred mainly from two species of the same genus that grow naturally in southern Kenya. Circular succulent leaves with soft hairs are arranged at the end of petioles of about 10 cm, and a large number of five-valve flowers resembling violets open in the flower inflorescences at the same height as the flowers. Progenitor S-aintpa
Many varieties are made from 21 species such as ulia ionantha and Saintpaulia confusa. There are many varieties of flower colors such as purple, crimson, and white, and representative varieties such as Little Sapphire, Happy Teen, Blue Boy, Sailor Boy, and Ruby.

Tissue culture of these tissue sections of the plants of the genus St.paulia leads to the induction of completely differentiated sterile plants. As the tissue section of the plant, a tissue section of an appropriate organ of a normal plant is sterilized, or a sterile seedling germinated by aseptically seeding a disinfected seed, and the seedling is grown. Plant shoot apex,
Leaf, petioles, and the like are preferably used.

Tissue sections of such aseptic plants of the genus Saintpaulia were prepared using MS medium (Murashige and Skoog's basic inorganic salt medium) as a synthetic medium as a base.
A pH-adjusted MS-modified medium containing a carbon source was used as a basic medium (A), a phytohormone consisting of auxins and cytokinins was added to the medium, and the medium was placed on a solid medium containing the same, followed by specific culture conditions. Cultivate under to differentiate the shoots.

The MS-modified medium is based on a normal MS medium and contains about 0.5% by weight of folic acid and about 0.05% of biotin.
The one added by weight% is preferably used, and as the carbon source, for example, 2% by weight of sucrose is added, and the pH is 5.0 to 5.0.
It is adjusted to 6.0, preferably pH 5.8, and used as the basal medium (A).

As described above, as the basic medium (A), the above-mentioned MS-modified medium and sucrose as a carbon source are preferably used, but the basic medium (A) is not limited to this, or the composition equivalent to this or It goes without saying that other synthetic media having the same effect can be similarly used as long as they are the components. Other synthetic mediums having the same effect include MS medium, B5 medium, N-
The medium of itsch (1965) is mentioned.

As the plant hormone added to the basic medium (A), naphthalene acetic acid 0.1 to 1.0 mg /
1 and benzyladenine 0.1 to 1.0 mg / l are preferably used, but not limited thereto, and other auxins and cytokinins having the same physiological activity as these are similarly used in combination. it can. Other auxins include:
Indole acetic acid, indole butyric acid, 2,4-dichlorophenoxyacetic acid, etc., and cytokinins include kinetin, zeatin, 2-isopentenylaminopurine, etc., respectively.

As a supporting material, for example, about 0.7% by weight of agar is added to a medium containing such components,
After adjusting the pH to the above range and sterilizing by a conventional method,
Aseptically dispense into a suitable container and solidify to prepare a solid medium. The support material is not limited to agar, and any suitable material such as gellan gum can be used as long as it has the same effect.

[0039] The above-mentioned aseptic plant tissue section of a plant of the genus Saintpaulia is placed on the solid medium and cultured to differentiate buds and germinate. In this case, 22 to 27 ° C is preferable. Temperature condition of 25 ℃ ± 1 ℃,
And, by culturing for about 30 to 40 days under a light irradiation condition of 14 to 17 hours day length, preferably 16 hours day length, the buds can be differentiated and germinated.

Then, the sprouted seedlings obtained in the above step are adjusted to pH containing a carbon source and the inorganic salt concentration is 1/1 or less, preferably 1/2 to 1/5.
The MS modified medium in which the concentration of the inorganic salt is reduced is planted and cultured in a seedling induction and growth solid medium which is the basic medium (B).

As the seedling induction and growth solid medium, for example, 1% by weight of sucrose is used as a carbon source,
The pH was adjusted to 5.8 and the inorganic salt concentration was adjusted to 1/2.
The S-modified medium was used as the basic medium (B), and further, activated carbon powder was added in an amount of 0.1% in order to promote normal rooting and stabilize the plant.
Additions of 01 to 1% by weight, preferably 0.1 to 0.3% by weight are preferably used. The basic medium (B)
Needless to say, is not limited to this, and any synthetic medium having the same effect as described above can be similarly used.

The sprouted seedlings are transplanted to the solid medium aseptically dispensed in an appropriate container, and then the dikegrak solution is dropped on one or both of the leaf surface of the seedlings, the apical shoots,
For example, seedlings are grown under a light irradiation condition of about 25 ° C. and a photoperiod of 16 hours. The dike black solution has a component concentration of 20 to 2
The amount used is 00 mg / l, and about 1 ml is dripped on the leaf surface and / or the apical bud. Outside of the component concentration range, it is impossible to obtain a plant body in a proper form.

As the container, a test tube, an Erlenmeyer flask, a glass bottle, a plastic container or the like is preferably used, but any suitable container can be used as long as it has sufficient light transmittance. The raising of seedlings is carried out under the condition that light is intermittently irradiated for a long period of time, that is, under the light irradiation condition of 14 to 17 hours day length, preferably 16 hours day length, and the temperature condition is
22 to 27 ° C, particularly 25 ° C ± 1 ° C is preferable.

By accurately controlling the culture environment such as the temperature and the sunshine duration, the plant can be grown with high reproducibility. Especially, the temperature condition of the culture is an important requirement. The temperature condition of ℃ ± 1 ℃ is particularly preferable because the plant can be uniformly and stably regenerated and grown. Then, it was confirmed that the growth slowed down when the temperature condition of the culture was lowered to, for example, 20 ° C. or lower.

As described above, the present invention requires the above-mentioned culture process, medium composition, culture conditions, and treatment conditions as essential requirements, and a plant of the genus Saintpaulia is cultivated in a container without any of these. It cannot be dwarfed in a suitable manner, and the intended purpose of the invention cannot be achieved. And, such culture process, medium composition, culture conditions, treatment conditions are peculiar to the plant of the genus St.paulia, these are tissue culture techniques of various plants, or the above-mentioned torenia, citrus, garlic perilla, balsam, etc. Even with the conventionally known matters such as the cultivation technique in the closed container, it is impossible to predict at all.

Next, a test example will be shown to verify the effect peculiar to the present invention. Test Example 1 (Induction of Differentiated Plant) As a plant of the genus Saintpaulia, a differentiated plant was induced using a red flower species, a white flower species, etc. of Optimara cultivars. 5 mm to 10 m from those obtained by sterilizing the leaves of plants obtained by greenhouse cultivation by a conventional method
About m of material was collected and a section was prepared.

As the medium, an MS-modified medium was used as the basic medium (A), and naphthalene acetic acid and benzyl adenine were added to the medium at predetermined concentrations. As the basal medium (A), an MS-modified medium modified by adding 0.05% by weight of biotin and 0.5% by weight of folic acid to MS medium was used, and 2% by weight of sucrose and 0% of agar were used. .7% by weight
Was added to adjust the pH to 5.8 and used as the medium. A basal medium that has been sterilized under pressure by a conventional method has a diameter of 2
20 ml was dispensed into a 5 mm test tube.

Then, the leaf section of the plant of the genus Saintpaulia was placed on the basal medium in the test tube at room temperature of 25.
1 by natural daylight fluorescent lamp of 4,000 lux at ℃
The buds were differentiated by culturing for 30 days under the irradiation condition of 6-hour photoperiod.

(In-container seedling raising test) Next, 1% by weight of sucrose and 0.7% by weight of agar were added to adjust pH to 5.8 and inorganic salt concentration to 1/2, and activated carbon powder 0.1%. Into the MS-modified medium in which 100% was added and dispersed, 50 ml of a medium sterilized under pressure steam by a conventional method was poured into a heat-resistant glass flask container having a volume of 200 ml.

The seedlings differentiated and sprouted as described above are
The plate was placed on a solid medium in a flask, and then 1 ml of a Dikegrac solution (produced by Sankyo Co., Ltd., registered trademark Atrinal) having a predetermined component concentration was dropped on the leaf surface of the seedling, and the room temperature was 25 ± 1
The dwarfing state of the plants was observed by static culture at 16 ° C. under irradiation with a 4,000 Lux natural daylight fluorescent lamp for 16 hours photoperiod. The results of the concentration test of the Dikeglac solution are shown in Table 1.

[0049]

[Table 1]

[0050]

EXAMPLES Next, the present invention will be specifically described based on Examples. Example 1 Raising seedlings of Saintpaulia little sapphire and Saintpaulia optimara white flower seeds The petioles of the above Saintpaulia spp.
After sterilization for 5 minutes, it was washed several times with sterile water. Next, the petiole part was cut into small pieces, and the petiole section was cut with 2% by weight of sucrose, 0.05% by weight of biotin and 0.5% by weight of folic acid.
MS-modified medium containing pH of 5.8 was used as the basic medium (A), and naphthalene acetic acid 0.1 mg /
1, benzyladenine 1.0 mg / l were added, and further plated on a solid medium containing 0.7% by weight of agar, and
16 at 4,000 Lux natural daylight fluorescent at 5 ° C
The cells were cultured for 1 month under the light irradiation condition of time and day length.

Next, the seedlings differentiated and sprouted as described above are placed on a seedling induction and growth solid medium which is aseptically dispensed into a container, and a dikegrac solution having a component concentration of 100 mg / l is added to the seedlings. 1 ml was dropped on the leaf surface, and seedlings were grown at 25 ° C. under the light irradiation condition of a natural daylight color fluorescent lamp of 4,000 Lux for a 16-day photoperiod to grow seedlings.

As the seedling induction and growth solid medium, 1% by weight of sucrose and 0.7% by weight of agar were added to adjust the pH.
The MS-modified medium adjusted to 5.8 and the inorganic salt concentration adjusted to 1/2 was used as a basic medium, and 0.1% by weight of activated carbon powder was added and dispersed to sterilize by a conventional method to obtain a volume of 200.
What was formed by dispensing in a glass flask container of ml was used. Roots grow 30 to 40 days after the start of seedling raising,
The leaves and petioles grew, the rooting condition was good, and the plants with good leaf and petiole morphology and grass appearance were obtained.

[0053]

INDUSTRIAL APPLICABILITY As described in detail above, the present invention utilizes a completely differentiated aseptic plant obtained by tissue-culturing a tissue section of a plant of the genus Saintpaulia to produce a plant of the genus Saintpaulia. Propagation is to raise a dwarfed plant body in a grass form suitable for cultivation in a container, whereby the present invention, in a conventional hybrid, has a large grass form and is cultivated in a container. Which was difficult to do,
It has an effect that it can be easily propagated, dwarfed, and raised in a container.

Since many axillary buds, which cannot be seen in conventional hybrids, come out, a grass-shaped plant of the genus Saintpaulia that does not exist in the actual environment is produced, and only the excellent strain is selectively selected. It has the effect that it can be proliferated, dwarfed, and raised in a container.

Furthermore, the method for raising a dwarfed plant according to the present invention is aseptically cultivated from the collection of the material to the growth of the plant. Therefore, it is genetically identical to the parental plant. It is possible to stably grow the plant in a virus-free state, and in the past, it was possible to easily and in large quantity dwarf the excellent mating species that had been difficult to grow in the container. Its industrial utility is extremely high because it can be made to grow by chemical growth.

Furthermore, according to the present invention, since the water, nutrients and the like necessary for the growth of the plant are added to the solid medium, it is possible to grow the plant without special fertilizer. Therefore, according to the seedling raising technique of the present invention,
There is an effect that a plant body in a grass shape suitable for cultivation in a container can be easily obtained in a large amount without requiring special management.

Claims (4)

[Claims] 1. A completely differentiated aseptic plant of a plant of the genus Saintpaulia obtained by tissue culture, containing a carbon source, p
H adjustment, the inorganic salt concentration is adjusted to 1/1 to 1/5,
After planting in a solid medium having a basic medium of a synthetic medium in which the concentration of the inorganic salt is reduced, a dikegrac solution is added dropwise to one or both of the leaf surface, the apical shoots, and dwarfing a St. Paulia plant characterized by raising seedlings. Method for raising seedlings of fossilized plants. 2. A solid medium comprising a synthetic medium containing 1% by weight of sucrose, adjusted to pH 5.8 and having an inorganic salt concentration adjusted to ½ as a basic medium. 1. The method for raising a dwarfed plant of the plant of the genus Saintpaulia according to 1. 3. The method for raising dwarfed plants of the genus Saintpaulia according to claim 1, wherein a dikegrac solution having a component concentration of 20 to 200 mg / l is used. 4. The method for raising dwarfed plants of St. Paulia spp. According to claim 1, wherein the synthetic medium is an MS modified medium.