• Journal of Plant Biotechnology
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• v.32 no.1
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• pp.51-55
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• 2005

Chinese leymus (Leymus chinensis Trin.) is a perennial grass that is widely distributed at high pH sodic and arid soil in the northeastern Asia. An efficient regeneration system was established through somatic embryogenesis of mature seeds to understand its high adaptability to harsh environmental conditions on the basis of molecular biology. The calli were efficiently induced (about $70\%$) from mature seeds on MS medium supplemented with $1.5\;\cal{mg/L}$ 2,4-D. Somatic embryos were formed from the surface of embryogenic callus on MS medium supplemented with $2.0\;\cal{mg/L}\;kinetin\;and\;0.5\;\cal{mg/L}$ NAA after 3 weeks of culture. Roots were induced from the shoot when transferred to MS medium without plant growth regulator for 1 week. Plant regeneration rate was $36\%$ and regenerated plantlets were grown to normal mature plants in pot. An efficient plant regeneration system in this study will be useful for molecular breeding of L. chinensis.

• Journal of Plant Biotechnology
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• v.2 no.3
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• pp.123-128
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• 2000

To enhance in vitro plantlet regeneration efficiency of soybean through embryogenesis, the culture conditions such as material part and size of immature seed, 2,4-D, pH and solidifying agents for somatic embryogenesis were investigated. Somatic embryogenesis was induced from the immature embryo, immature cotyledon and embryonic axis explants of the immature seed on MS medium supplemented with 2.0 mg/L 2,4-D. The highest rate (up to 22.9%) of somatic embryogenesis was obtained from the immature cotyledon, following embryonic axis and the immature embryo. The rate varied with the developmental stages of seed. The maximum rate (25.4%) of embryogenesis was obtained from 3-4 mm length of the seed (after 25 days of flowering). The optimum concentration of 2,4-D for embryogenesis was 10 mg/L. The optimum pH was at 5.8 and solidifying agent for medium was better with 0.4% gelrite than with agar. For rapid multiplication of shoot tips from the germinating somatic embryos, they were cultured on MS medium containing 2 mg/L indole-3-butyyic acid (IBA) and 1 mg/L 6-benzyladenine (BA). After then somatic embryos with one and three cotyledons were transferred to the growth regulator free medium. The medium exhibited the higher rate (ca. 50%) of development than the multiplication medium.

• 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'.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1737-1746
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• 2013

IbMYB1, a transcription factor (TF) for R2R3-type MYB TFs, is a key regulator of anthocyanin biosynthesis during storage of sweet potatoes. Anthocyanins provide important antioxidants of nutritional value to humans, and also protect plants from oxidative stress. This study aimed to increase transgenic potatoes' (Solanum tuberosum cv. LongShu No.3) tolerance to environmental stress and enhance their nutritional value. Transgenic potato plants expressing IbMYB1 genes under the control of an oxidative stress-inducible peroxidase (SWPA2) promoter (referred to as SM plants) were successfully generated through Agrobacterium-mediated transformation. Two representative transgenic SM5 and SM12 lines were evaluated for enhanced tolerance to salinity, UV-B rays, and drought conditions. Following treatment of 100 mM NaCl, seedlings of SM5 and SM12 lines showed less root damage and more shoot growth than control lines expressing only an empty vector. Transgenic potato plants in pots treated with 400 mM NaCl showed high amounts of secondary metabolites, including phenols, anthocyanins, and flavonoids, compared with control plants. After treatment of 400 mM NaCl, transgenic potato plants also showed high DDPH radical scavenging activity and high PS II photochemical efficiency compared with the control line. Furthermore, following treatment of NaCl, UV-B, and drought stress, the expression levels of IbMYB1 and several structural genes in the flavonoid biosynthesis such as CHS, DFR, and ANS in transgenic plants were found to be correlated with plant phenotype. The results suggest that enhanced IbMYB1 expression affects secondary metabolism, which leads to improved tolerance ability in transgenic potatoes.

• Plant Biotechnology Reports
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• v.4 no.1
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• pp.85-94
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• 2010

In vitro shoot regeneration of gladiolus in three different culture systems, viz., semi-solid agar (AS), membrane raft (MR), and duroplast foam liquid (DF) cultures was evaluated following the kinetics of shoot multiplication and hyperhydricity at optimized growth regulator combinations. Compared to the AS system, matrixsupported liquid cultures enhanced shoot multiplication. The peak of shoot multiplication rate was attained at 18 days of incubation in the MR and DF systems, whereas the maximum rate in the AS system was attained at 21 days. An early decline in acceleration trend was observed in liquid cultures than the AS culture. The hyperhydric status of the regenerated shoots in the different culture systems was assessed in terms of stomatal attributes and antioxidative status. Stomatal behavior appeared to be normal in the AS and MR systems. However, structural anomaly of stomata such as large, round shaped guard cells with damage in bordering regions of stomatal pores was pronounced in the DF system along with a relatively higher $K^+$ ion concentration than in the AS and MR systems. Antioxidative status of regenerated shoots was comparable in the AS and MR systems, while a higher incidence of oxidative damages of lipid membrane as evidenced from malondialdehyde and ascorbate content was observed in the DF system. Higher oxidative stress in the DF system was also apparent by elevated activities of superoxide dismutase, ascorbate peroxidase, and catalase. Among the three culture systems, liquid culture with MR resulted in maximum shoot multiplication with little or no symptoms of hyperhydricity. Shoots in the DF system were more prone to hyperhydricity than those in the AS and MR systems. The use of matrix support such as membrane raft as an interface between liquid medium and propagating tissue could be an effective means for rapid and efficient mass propagation with little or no symptoms of hyperhydricity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.609-614
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• 1997

C-MH(Choline salt of maleic hydrazide, 39％) has been applied on peanut(Arachis hypogaea L.) plant in 1994∼1995 on three different times of 24 days after flowering (DAF), 28 DAF and 31 DAF and on three different levels of 0.2, 0.1. 0.067％, respectively. Main stem length was noticeably retarded by 38∼44％ compared to that of non-treatment. Branch numbers were not changed by C-MH treatments. Ratio of flowering inhibition was 38％ in 0.2％ concentration and 22％ in 0.067％ at 28 days after flowering treatment compared to that of control. Ratio of pure seed was slightly enhanced by 3％ in 28 DAF treatments. Yield productivity was increased by 7％ in 0.1％, at 28 DAF treatment compared to that of non-treatment (3.2MT /ha).

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.143-148
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• 2008

This study was conducted to investigate the effects of BA, a growth regulator on enhancing propagation efficiency, and physical treatment on promotion of axillary bud generation in three hosta cultivars, 'Ellerbroek', 'Francee', and 'Halcyon'. These are cultivars suitable for cut foliage production among Hosta spp. because of their diverse leaf patterns and long vase life of cut foliage. The degree of axillary bud generation by treatment time and concentration of BA has not been proven to be extraordinarily effective as compared to not treated control. As a physical treatment, base wounding was more effective than stem cutting. In 'Ellerbroek', increase of axillary bud generation among treatment methods was not great. However, in 'Halcyon', base wounding had four more axillary buds per plant than not treated control. In addition, although number of axillary buds increased per plant by BA treatment and stem cutting was 2 and 1.8, respectively, it was 6.1 by base wounding, indicating the greatest effect on promotion of axillary bud generation among all treatments.

• Korean Journal of Pharmacognosy
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• v.51 no.4
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• pp.302-309
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• 2020

The objective of this study was to optimize the condition for induction and proliferation of callus from Rhus chinensis Mill. and investigate the skin-brightening effect of Rhus chinensis callus (RCC). It was confirmed that the most proper plant growth regulator (PGR) for callus induction is 1.0 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D). The most optimal condition of PGR, medium and additives for callus proliferation were 2,4-D (1.0 mg/L), MS medium and citric acid, respectively. Inhibitory activities of tyrosinase were higher at 50 and 100 ㎍/mL of RCC extracts (41.86 and 75.56%, respectively) than arbutin (27.32%). As the results of measuring melanin inhibition in B16F1 melanocyte and B16F10 melanoma cell, RCC extracts increased its inhibitory activities concentration-dependently, and were found to have higher whitening effect than arbutin at a concentration of 100 ㎍/mL. Therefore, it is suggested that RCC can be used as an effective material for skin-brightening cosmetics.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.72-77
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• 2017

This study was conducted to examine the effect by application method and concentration of plant growth regulator (PGR) on the growth and runner production of strawberry (Fragaria ${\times}$ ananassa Duch. cv. Maehyang) in a velno-type greenhouse. The seedlings of strawberry were transplanted in pot ($64{\times}27{\times}18cm$) filled with commercial mixed medium (Tosilee) on February 22nd, 2016. The 6-benzylaminopurine (6-BAP) was applied with foliar spray or drench, respectively as 900, 1,200 or $1,500mg{\cdot}L^{-1}$ (50 mL per plant) at 3 weeks after transplanting. Nutrient solution was sufficiently supplied by the drip irrigation as EC $0.65dS{\cdot}m^{-1}$ for rooting during 7 days. After rooting, the 450 mL nutrient solution supplied per pot twice a day (10 min). Plant height and crown diameter of 'Maehyang' mother plant appeared no significantly difference. The other growth characteristics, such as root length, number of primary roots, leaf length, leaf width, leaf area and fresh and dry weights of the shoot or root, were significantly the greatest in the control. And, the SPAD value of strawberry was the highest as 44.2 in the drench with $900mg{\cdot}L^{-1}$. The foiler spray was more effective in runner production than drench, and the number of runners appeared high values at the 900 and $1,500mg{\cdot}L^{-1}$. Whereas, the number of strawberry plantlets was effective in the drench. The results indicate that both growth and the number of runners of strawberry plant were the best achieved by foliar spray application at the $900mg{\cdot}L^{-1}$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.3
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• pp.283-287
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• 1992

This experiment was carried in order to compare some propagation methods and the effective components in the root of Paeonia albiflora pallas, Paeonia moutan Sims and Paeonia albiflora pallas root grafted with Paeonia mouton sims The optimum seeding time of August 20 to september 10 for increasing germination ratio. The growing and developing of Paeonia albiflora Pall. for root dividing methods was advantageous to practice at Autum than at spring season. The shoot cutting method during the flowering time was proper to increase the rooting ratio with the aid of Ruton, the plant growth regulator but not emerged of apical bud. The grafting stages between the Paeonia albiflora pall. and Paeonia moutan Sims was available to practice during the September for increasing the thickness growth of root. Among the effective components of the paeony the paeoniflorin was shown high, while paeonol in paeony moutan. The paeoniflorin of herbaceous paeony / paeony moutan was increased about 75.9% than herbaceous paeony alone, and the other compoents are similar to those of herbaceous paeony root.