• Journal of agriculture & life science
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• v.43 no.6
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• pp.59-65
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• 2009

Combinations of plant growth regulators, darkness treatments, and the order of expanding leaves for explants were evaluated for optimizing in vitro shoot regeneration rate of 'Whangkeumbae' pear. In a MS medium, supplemented with $8.88{\mu}M$ 6-benzylaminopurine (BA) and $0.49{\mu}M$ indole-3-butyric acid (IBA), green foci were observed on the surface of the callus 8 days after culture initiation. Some adventitious buds were later induced from those green foci, resulting in the appearance of normal shoots. In a medium containing $22.20{\mu}M\;BA$, the surface of the callus became compact and greenish, and many adventitious buds were formed over the entire area of the callus surface. When comparing BA concentration via histological observation, the section which had been treated with $22.20{\mu}M\;BA$ exhibited closer cell aggregation than those with $8.88{\mu}M\;BA$. The darkness treatment enhanced the formation of adventitious shoots for up to 3 weeks. The youngest two expanding leaves, proximal to the shoot apex, were proved to be the most regenerative, and yielded the highest shoot number per regenerating leaf. A fourth strength MS medium, which was supplemented with $0.54{\mu}M\;NAA$, yielded good quality plantlets, with regard to root number and root length.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.326-335
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• 2011

When bougainvilleas are subjected to indoor low-light conditions, flower bracts regularly abscise. This study elucidates the effects of plant growth regulators on bract longevity of potted bougainvillea. Potted 'Taipei Red' bougainvillea in four different bract development stages were treated with 1-MCP (1-methylcyclopropene), NAA (1-naphthaleneacetic acid), SNA (sodium salt of naphthaleneacetic acid), IBA (indolebutyric acid), BA (6-benzylaminopurine), $KH_2PO_4$ (potassium dihydrogen phosphate), Put (diamine putrescine), SA (salicylic acid), or STS (silver thiosulfate) and were moved to indoor low-light conditions after treatments. Experimental results indicate that 1-MCP, NAA, SNA, BA, Put, and SA prolonged bract longevity, and this effect increased as bract stage increased. The effect of STS was significant in early bract stages and decreased as bract stages increased. Additionally, 1-MCP, NAA, SNA, BA, Put, SA, and STS treatment significantly reduced endogenous ACC (1-aminocyclopropene-1-carboxylate) content and ACC oxidase activity, suggesting that the inhibition of ethylene production was achieved via physiological metabolism. However, treatment with IBA or $KH_2PO_4$ had no effect on the bract longevity at any stage. In the combined chemical treatments, NAA + STS or NAA + SA were effectively for prolonging bract longevity and contained less protein or chlorophyll degradation, decrease ACC oxidase or ethylene production than the control. In conclusion, we propose that combined chemical treatment significantly prolonged the bract longevity and more effectively than single chemical treatment at any stage.

• Journal of Plant Biotechnology
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• v.43 no.4
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• pp.438-443
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• 2016

The in vitro propagation of the commercially important Phalaeonopsis hybrid 'Little gem' was achieved by culturing the apical part and axillary buds excised from flower stalks. The explants were cultured on 5 different basal media: $3.0{\cdot}L^{-1}$ Hyponex and $4.0{\cdot}L^{-1}$ peptone ($H_3P_4$) and Murashige & Skoog (MS) media were shown to be suitable for shoot regeneration. The MS medium supplemented with $5.0mg{\cdot}L^{-1}$ 6-benzylaminopurine (BA) was found to be more efficient for shoot regeneration. However, the number of shoots induced by axillary buds was higher than that induced by the apical part. Incubation of the apical part under darkness for one week, as well as of the explants in the same medium with activated charcoal (AC) $0.5g{\cdot}L^{-1}$ promoted shoot regeneration and shoot growth; similar growth was not observed with axillary buds.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.52-52
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• 2018

Development of herbicide resistant transgenic legume plants through Agrobacterium-mediated transformation has been worked in many previous studied. Plant regeneration after infection is the important step to obtain successful transgenic plants. Many attempts try to find the optimum media condition for plant regeneration after infection. However, the transformation efficiency of legume plants is still low. In this study, regeneration of some Korean legume species including two soybean cultivars (Dawon and Pungsan) and pea have been done with organogenesis which is used various kind of explants such as cotyledonary-nodes in soybean and bud-containing tissue in pea. We developed the optimum media condition for plant regeneration regulators under Agrobacterium-mediated transformation using different kind and various concentration of plant growth. As the results, B5 medium containing 2 mg/L of 6-benzylaminopurine was selected in this study for the optimum plant regeneration media. The segments were inoculated with Agrobacterium suspension harbored an IG2 vector containing bar gene which confers resistance to phosphinotricin (PPT) in 3, 5 and 7 days. The transformation efficiency was achieved in Dawon 3.03 % and pea 1.46 % with co-cultivation period of 7 days which is showed a high number of GUS positive expression period.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.81-86
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• 2009

An efficient and reproducible plant regeneration system was established using transverse thin cell layers (tTCLs) in five cultivars of Brassjca juncea L. The effects of medium conditions, explant types (tTCLs of hypcotyl and cotyledonary petiole) on shoot regeneration were examined in this study. The maximum shoot regeneration frequency was obtained in Murashige and Skoog (MS) medium supplemented with 4 mg/L 6-benzylaminopurine (BA) and 0.2 mg/L 1-naphthaleneacetic acid (NAA). The hypocotyls derived tTCL explants had more shoot regeneration frequency (52%) than the cotyledonary petiole derived tTCL explants. Shoot induction was further improved by the addition of silver nitrate ($AgNO_3$) in the regeneration medium. A significant genotypic effect was also observed between the five cultivars; Rai-5 displayed higher capacities to produce shoots than other cultivars. Regenerated shoots were rooted on MS basal medium without PGRs which induced 90% of roots. The plantlets established in greenhouse conditions with 99% survival, flowered normally and set seeds. The regenerated plants were fertile and identical to source plants.

• Journal of Forest and Environmental Science
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• v.29 no.4
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• pp.275-281
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• 2013

To establish in vitro nodal culture conditions of Echinosophora koreensis Nakai, one of rare and endangered species famous for beautiful flowers in the Korean Peninsula, the influence of plant growth regulators (PGRs) on shooting and rooting from in vitro shoots was investigated. In shoot multiplication, addition of 6-benzylaminopurine (BA) to the half-strength Driver and Kuniyuki's media in the range of 2.22 to 8.88 ${\mu}M $induced 2.5 to 2.7 shoots per axillary bud; and addition of 2.27 ${\mu}M $ thidiazuron (TDZ) produced 3.2 shoots, during 4 weeks of culture, while zeatin and isopentenyl adenine (2ip) were not effective on shoot multiplication as observed from several combination treatments of BA with other PGRs. Shoots established were smaller than 2 cm in length, in most of the treatments. while in BA 8.88 ${\mu}M $ treatment more than 30% of shoots were longer than 2 cm and shorter than 4 cm. In rooting, naphthalene acetic acid (NAA) from 5.37 to 21.48 ${\mu}M $ showed the rooting rate from 40.0 to 62.5%. Indole butyric acid (IBA) addition had little effect on rooting (<10%), although some roots in IBA-containing media were longer than those in NAA. Micropropagation from axillary buds of nodular explants was applicable and promising to multiplication and conservation of Echinosophora koreensis Nakai.

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.263-270
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• 2006

Pongamia pinnata Pierre is a tree legume, having potential in production of raw material for biodiesel. A protocol for in wk propagation of this plant was standardized using seedling explants. Growth regulators (GR) including gibberellic acid $(GA_3),\;N^6-benzylaminopurine(BA)$, thidiazuron (TDZ), and Adenine sulphate (Ads) were tested for optimum germination of seeds. Removal of seed coat prior to germination, controlled fungal growth partially but enhanced bacterial growth. Antibiotic cefotaxime was ineffective in controlling bacterial contamination. Seedling derived nodal explants and cotyledon nodes with attached cotyledons were excised and cultured for induction of shoots. Optimum sprouting and multiplication of shoot buds were obtained in MS medium supplemented with $8.88{\mu}M$ BA. These buds differentiated and rooted on medium devoid of GR. Optimum growth of Pongamia seedling was obtained in cotton plugged culture vessels. Reculturing of the cotyledon node explants produced more shoots from the same site. This process of removing shoots and reculturing of cotyledon node was followed for eight passages yielding 4 to 8 shoots in each cycle. The shoots (75%) rooted on half strength MS basal medium supplemented with 0.22% charcoal. All plants survived on transfer to soil. This is the first report on in vitro regeneration of Pongamia pinnata. This report demonstrates the possibility of coupling more than one parameter in single experiment to hasten the process of standardization. The process of cycling the nodal explant repeatedly for production of large number of shoots from single meristem may find application in genetic transformation experiments wherein meristems are used for transformation.

• Journal of Plant Biotechnology
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• v.37 no.1
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• pp.96-101
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• 2010

Leaf explants of the Solanum hainanense plant, grown in vitro, were cultured in basal Murashige and Skoog (MS) media supplemented with 0.5 mg/L kinetin and 1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) for callus initiation. For maintenance and proliferation, the callus was cultured on MS medium supplemented with 1 mg/L 6-benzylaminopurine (BAP) and 0.5 mg/L 2,4-D. The glycoalkaloid content in the callus was at its maximum after ten weeks of culture (188.65 mg/g), whereas that of the one-year-old control was 22.22 mg/g in the root and 5.99 mg/g in the stem. The glycoalkaloid extracted from the callus inhibited the activity of collagenase on collagen gel. High performance liquid chromatography (HPLC) analysis showed that biotransformation occurred when a callus was grown on medium supplemented with various carbon sources. These results suggest that callus of S. hainanense is a good material for production of glycoalkaloid.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.36-36
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• 2018

Soybean is the important crop in Asian countries as protein source, oil production and animal feed. Improving soybean using genetic transformation is the principal tool in nowadays. Developing herbicide resistant transgenic soybean plants through Agrobacterium-mediated transformation has been worked in many previous studied. However, the transformation efficiency is still low. Many attempts try to find the optimum media condition for plant regeneration after infection. After transformation, the plant regeneration is very important condition to promote growth of transgenic plant. In this study, we optimized a regeneration condition for two Korean soybean cultivar, Dawonkong and Pungsannamulkong using cotyledon, cotyledonary nodes and hypocotyl as explant. The results showed that shoot regeneration of cotyledonary nodes on B5 medium containing 2 mg/L 6-benzylaminopurine showed the highest percentage of regeneration in Dawonkong (75.8%) while Pungsannamulkong presented high number of shoots 2.12 shoots per explant. For transformation condition, co-cultivation in 7 days showed a high number of GUS positive expression. Most of explants can survived under media including 5 mg/L of glufocinate which refers phosphinotricin for 2-week selection. Washing with 400 mg/L of cefotaxime in several times and selection in plant regeneration media with 400 mg/L of cefotaxime can prevent bacteria growth, effectively.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.60-60
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• 2020

To establish in vitro axillary bud culture conditions of Echinosophora koreensis Nakai, one of Korean endemic endangered species famous for beautiful flowers, we tested the influence of plant growth regulators (PGRs) in shooting and rooting stage from in vitro plants. In shoot multiplication, addition of 6-benzylaminopurine (BA) to the media induced 2.5 to 3 shoots per bud during 4 weeks of culture. And media including 0.5 mg L^-1 thidiazuron (TDZ) produced 3 to 4 shoots per bud. However, zeatin and isopentenyl adenine (2-ip) were not successful to increase shoot number, and the combination treatments of BA with other PGRs were also not effective. Shoots were smaller than 2 cm in length, in most of the treatments. In rooting, naphthalene acetic acid (NAA) treatments in the range of 0.5 to 4.0 mg L^-1 appeared to increase rooting rate by 10% to 60% approximately when compared with the control but roots developed with callus clusters. Indole butyric acid (IBA) addition had little effect on rooting (below 10%), while some roots were longer than in NAA treatments and some shoots were longer on high IBA concentrations (4.0 to 8.0 mg L^-1). It is suggested that micropropagation is a highly applicable and promising to multiplication and conservation of rare and endangered endemic species.