• Plant Biotechnology Reports
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• v.5 no.4
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• pp.345-352
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• 2011

The rheological and diffusion properties of blends of agar/guar gum, agar/Phytagel and Phytagel/guar gum were analysed and compared to those properties of agar or Phytagel applied alone at two different gelling concentrations. Moreover, their effects on the shoot multiplication of the apple scion Galaxy and two black locust clones (SF63, SF82) were studied, and their cost benefits over agar were calculated. Elastic hydrogel formation was demonstrated for each blend by rheological measurements, but the gel strength depended on the types and concentrations of the applied gelling agents and blends. Guar gum was able to speed the diffusion in the different blends, and diffusion was independent of gel strength. The rate of shoot multiplication increased (to 8.9 shoots per explant) and the percent of hyperhydrated shoots decreased (to 12%) when the blend of agar/guar gum was used for the shoot multiplication of apple. Similarly, the highest multiplication rates of black locust clones (between 3.9 and 4.1) were obtained on media solidified by blends containing guar gum. The best shoot performance with the lowest percent of hyperhydrated shoots (11-12% in SF63 and 2-23% in SF82) was achieved using agar alone or the agar/guar gum blend. The shoot multiplication was improved of both species and the production cost was reduced by 42% by using the agar/guar gum blend.

• Plant Biotechnology Reports
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• v.4 no.2
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• pp.101-107
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• 2010

An efficient plant regeneration system has been developed for figleaf gourd (Cucurbita ficifolia Bouch$\'{e}$), which is exclusively used as a rootstock for cucumber. The protocol is based on results obtained from a series of culture experiments involving different parts of the cotyledons and various media. The culture of cotyledon explants was critical for the enhancement of shoot regeneration frequency. The lower parts of the cotyledon excised at the plumule base were found to display a markedly enhanced production of adventitious shoots compared to other cotyledon regions. Culture in silver nitrate-supplemented Murashige and Skoog (MS) medium was not beneficial for shoot regeneration and suppressed root regeneration. Efficient shoot regeneration was obtained on MS medium containing 1.0 $mg\;l^{-1}$ zeatin and 0.1 $mg\;l^{-1}$ indole-3-acetic acid. Regenerated shoots successfully elongated and rooted in medium containing 0.1 $mg\;l^{-1}$ 1-naphthalene-acetic acid after 10-15 days of subculturing. The plantlets were satisfactorily acclimatized in a greenhouse and grew into normal plants without any morphological alterations.

• Plant Biotechnology Reports
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• v.2 no.3
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• pp.219-226
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• 2008

Transgenic plants with the herbicide-resistance gene (bar gene) were obtained via organogenesis from isolated mesophyll protoplasts of Nierembergia repens after applying electroporation. Transient ${\beta}-glucuronidase$ (GUS) activity of electroporated protoplasts assayed 2 days after applying an electric pulse showed that optimum condition (transient GUS activity 319 pmol 4 MU/mg per min and plating efficiency 2.43%) for electroporation was 0.5 kV/cm in field strength and $100{\mu}F$ in capacitance. The protoplasts electroporated with the bar gene at this condition initiated formation of microcolonies on medium after 2 weeks. After 4 weeks of culture, equal volume of fresh 1/2-strength Murashige and Skoog (MS) medium containing 0.2 mg/l bialaphos was added for selection of transformed colonies. After 6 weeks of culture, growing colonies were transferred onto regeneration medium containing 1.0 mg/l bialaphos, on which they formed adventitious shoots 1-2 months after electroporation. The adventitious shoots rooted easily after transfer onto MS medium with bialaphos lacking plant-growth regulators. Transformation of these regenerants with the bar gene was confirmed by Southern analysis. Some of the transformants showed strong resistance to the application of bialaphos solution at 10.0 mg/l.

• The Korean Journal of Ecology
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• v.14 no.3
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• pp.305-316
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• 1991

Growth hadit and demograph in a mature population of polygonatum and polygonatum humile in kanghwa island were studied for two growing seasons. Shoots of two species emerged early spring from the growing apices of the underdground rhizomes which had persisted for up to 1~5 year.after flowering, the ramets produced two rhizome buds at the shoot base. Bacause of the apical dominance in the rhizome system, a new rhizome was developed from only one bud, an actual bud,and the other latent buds were suppressed sothat remained dormant. The latent dud produced a new rhizome only when the actual dud was severed by the herbivores or by the physical obstacles. Therefore, the ramet number is not increased by the new rhizome from the latent bud. however, new ramets dould sometimes grow from latent buds which had been produced more than a year ago. Production of these ramets was main means increasing the ramet numbew and widening the potential zone of exploitation. Changes in size class of each ramet were noyiceable after a tear in small size-classes. Small ramets replaced themselves with larger-sized ramet, while large ramets with similar-sized or smallar-sized ramets. ramet numbers were average 0.82and 1.14 times of those fromthe previous year inp. involucratum and p. humile, though there was between-site variation. Almost all the ramets in the quadrats were alive during the growing season. when the entire rhizome systems were excavater next spring, there were many rhizomesegments without shoots, especially in p. involucratum. therefore, the drcrease of ramet number in p. involucratum in probably due to the climatic factors of winter.

• Journal of Plant Biotechnology
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• v.7 no.2
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• pp.135-141
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• 2005

Protocols for in vitro conservation was developed for Coleus forskohlii. Plants maintained both in field served as explant source. Shoot tips and single node cuttings were used to optimize protocols for in vitro multiplication. MS basal medium supplemented with $0.54\;{\mu}M$ naphthalene acetic acid (NAA) and $8.87\;{\mu}M$ benzy-ladenine (BA) induced multiple shoots in shoot tips and nodes. Shoot multiplication was amplified with a gradual decrease of BA concentration, leading to its final omission after 4 months. Concomitant rooting on multiplication media enabled successful establishment extra vitrum. For in vitro conservation studies, experiments were carried out with 2-3 week maintained in vitro plants under standard and reduced culture conditions (SCC, RCC). In vitro plants could be successfully conserved in full strength MS medium (FMS) under SCC for 6 months without subculture with full potential to regenerate, producing viable shoots and nodes. The root production remained unaffected due to conservation, showing high rooting activity in mannitol and low temperature treatments. Preset low temperature (15 and $10^{\circ}C$) and reduction in media constituents does not appear to favour conservation, although the former accomplished conservation levels equal to (FMS) under SCC.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.273-277
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• 2005

Adventitious shoots were directly induced from leaf explants of R. glutinosa, an important medicinal plant. Proliferating shoot cultures were obtained by culturing leaf discs on Murashige and Skoog(MS) medium alone or combination with auxins and cytokinins. MS medium supplemented with 1 $mg/{\ell}\;BA\;and\;2\;mg/{\ell}$ IAA was the most effective, providing high shoot bud formation frequency without formation of intervening callus. The effect of leaf age on adventitious shoot formation was also investigated. The maximum shoot bud production (93.4%) was achived using 3rd leaf from apex of 6 weeks old plantlets after seed germination. Plantlet were rooted on an half-strength MS (1/2MS) medium containing 0.1 $mg/{\ell}\;IBA$. This prtocol is useful for clonal propagation and Agrobacterium-mediated transforamtion in R. glutinosa.

• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.189-195
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• 2007

Helicteres isora is medicinally important plant effective against asthma, diabetes, hypolipidemia, HIV, besides a good source of diosgenin. Seed dormancy and low rate of natural fruit production make this plant a perfect candidate for developing an in vitro method useful for its clonal propagation and further biotechnological developments. This is the first report on in vitro production of this plant. Nodal explants obtained from aseptically germinated seedlings were cultured on MS medium (Murashige and Skoog 1962) fortified with indole-3-acetic acid (IAA) ($0.57-22.83\;{\mu}M$), indole-3-butyric acid (IBA) ($0.41-16.58\;{\mu}M$), 6-benzylaminopurine (BA) ($0.44-17.75\;{\mu}M$) and kinetin (Kin) ($0.46-13.94\;{\mu}M$) either singly or in combinations of IAA + BA, IAA + Kin and BA + Kin. Combinations of cytokinins (BA and Kin) were most suitable for multiple shoot induction and $13.94\;{\mu}M\;Kin\;+\;13.31\;{\mu}M\;BA$ was optimum (79% frequency) associated with high number of microshoots (7.1 shoots per explant) after 20 days of culture. Maximum shoot elongation and proliferation (10 shoots per explant with 4.8 cm average height) was achieved on MS media containing $2.32\;{\mu}M\;Kin\;+\;2.22\;{\mu}M\;BA\;+\;2.85\;{\mu}M\;IAA$. High rooting frequency (70%) was achieved on MS medium (1/2 basal strength) fortified with $4.14\;{\mu}M$ IBA, while activated charcoal showed inhibitory effects on rooting. Hardening was done with 76% survival rate and these plants were growing without any visual defects and morphologically mimicking the naturally growing plants.

• Applied Biological Chemistry
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• v.41 no.4
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• pp.228-234
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• 1998

An adaptive measure of photosynthetic cells to a condition identified with a reduction of cellular energy charge, caused by water deficit-induced impairment of photosynthetic ATP production, was investigated using hydroponically cultured rice seedlings. Water stress treatment of the seedlings resulted in a marked decrease in cellular ATP level, a significant increase in the content of NAD(H) and concurrent decrease in that of NADP(H) in shoots, which accompanied a decrease in the activity of NAD kinase (EC 2.7.1.23) that specifically converts NAD(H) to NADP(H). The decline in the enzyme activity was particularly evident in the $Ca^{2+}/calmodulin-dependent$ kinase, the major form of NAD kinase in plants, whereas the level of active calmodulin remained unchanged during water deficit. The ratio of $NADP^+$ to NADPH was maintained nearly constant and no increases were seen in the level of $H_2O_2$ and the activities of $superoxide/H_2O_2-detoxifying$ enzymes in shoots stress-treated for two days. Based on these results, it may be suggested that rice plants take a strategy to cope with an adverse situation of limited photophosphorylation created by water deficit in that cells facilitate ATP production through glycolysis and oxidative phosphorylation; in doing so, rice cells suppress NAD kinase activity, consequently up-sizing the NAD(H) pool at the expense of the NADP(H) pool. Several parameters associated with the stress symptoms are also of implicative that there is no overproduction of superoxide radical or the related active oxygen at least in rice seedlings.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.145-150
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• 1994

This study was conducted to determine the effects of 3 cytokinins (BA,2iP and kinetin) and their concentrations (0, 0.1, 0.5, 1.0, and 2.0 mg/L) on multiple shoot production of Citrus spp. 'Sambokam' and 'Byungkyool' by nodal culture. Nodal explants were obtained from in vitro germinated seedlings of both cultivars. 'Sambokam' produced more multiple shoots than did 'Byungkyool' by nodal culture. Among the 3 cytokinins tested in this study BA supplemented in semi-solid MS basal medium was the most effective stimulator for multiple shoot production, and an optimal concentration was determined to be 1.0 mg/L. Shoot elongation and root formation were inhibited by increasing cytokinin concentration, regardless of cytokinin types. BA at 1.0 mg/L produced the most multiple shoots and the highest number of leaves in 'Sambokam', whereas any cytokinin and concentration studied in this experiment did not affect any scored variables such as shoot and leaf numbers, etc. in 'Byungkyool'.

• Korean Journal of Medicinal Crop Science
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• v.28 no.2
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• pp.136-141
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• 2020

Background: The leaves of the goji berry (Lycium chinense Mill.) are used as raw materials in processing and by replace fruits to some extent. The reason is that the leaves are cheaper, however, betaine content is higher than in the fruits. These experiments were conducted to determine the planting density and cutting height for producing a large number of leaves. Methods and Results: The cultivar 'Myeongan' with many branches was used. When the shoot height reached 50 cm - 70 cm, harvesting was possible four times a year. The time to next harvest was approximately 38 days after regeneration of new shoots. Leaf quantity was in the order of 1st > 2nd > 4th > 3rd harvest. Insect damage occurred during the third harvest in late July and early August, therefore, eco-friendly control was necessary. The total yield was higher at the planting density 60 cm × 30 cm than that of 60 cm × 20 cm or 60 cm × 40 cm. The yield at cutting for shoot height of 60 cm was increased by 6.3 percent compared to that of 50 cm, At the cutting height of 70 cm, harvest was difficult owing to hardening of stems and thorns. Betaine content, an indicator component of goji berry, was not significantly different according to planting densities and cutting height. Conclusions: The ideal cutting period to produce leaves of goji berry for processing is when the shoots grow to approximately 60 cm, and the leaves can be harvested 4 times a year. The dried-leaf yield was highest at the planting density of 60 cm × 30 cm.