• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.77-85
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• 2004

Development of efficient plant regeneration and genetic transformation protocols (using the Particle Inflow micro-projectile Gun and the shoot-tips as target tissue) of Sorghum bicolor (L.) Moench in terms of expression of the reporter gene, $\beta$-glucuronidase(uidA) is reported here. Two Indian cultivars of sorghum were used in the study, viz. M-35-1 and CSV-15. Plant regeneration was achieved from one-week-old seedling shoot-tip explants via multiple-shoot-clumps and also somatic embryos. The multiple-shoot-clumps were produced on MS medium containing BA (0.5, 1.0 or 2.0 mg/$L^{-1}$), with biweekly subculture. Somatic embryos were directly produced on the enlarged dome shaped expansive structures that developed from shoot-tip explants (without any callus formation) when cultured on MS medium supplemented both with BA (0.5, 1.0 or 2.0 mg/$L^{-1}$) and 2,4-D (0.5 mg/$L^{-1}$). Whereas each multiple-shoot-clump was capable of regenerating more than 80 shoots via an intensive differentiation of both axillary and adventitious shoot buds, the somatic embryos were capable of 90% germination, plant conversion and regeneration. The regenerated shoots could be efficiently rooted on MS medium containing 1.0mg/$L^{-1}$ IBA and successfully transplanted to the glasshouse and grown to maturity with a survival rate of 92%. The plant regeneration efficiency of both the genotypes were similar. After the micro-projectile bombardment, expression of uidA gene was determined by scoring blue transformed cell sectors in the bombarded tissue by an in situ enzyme assay. The optimal conditions comprising a helium pressure of 2200 K Pa, the target distance of 11 cm with helium inlet fully opened and the use of osmoticum have been defined to aid our future strategies of genetic engineering in sorghum with genes for tolerance to biotic and abiotic stresses.

• Journal of Plant Biotechnology
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• v.30 no.1
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• pp.59-63
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• 2003

This experiment was conducted to propagate Zantedeschia spp. in vitro. The frequency of adventitious bud clusters (ABC) formation from shoot tips in Z. 'Best Gold' was high at more than 65% on media with 2.0∼5.0 mg/L BA or 0.1∼1.0 mg/L thidiazuron. The highest formation rate of ABC (75%) was obtained on medium containing 2.0 mg/L BA. Comparing to treatment of BA alone, combined one of BA and NAA did not stimulate the formation of ABC and the shoot regeneration from shoot tips. The proliferation of ABC from sections (0.7∼1.0 cm) of ABC occurred effective on medium with 2.0 mg/L BA. Shoots developed from the sections (0.7∼1.0 cm) of ABC grew and rooted favorably on media containing 1.0∼2,0 mg/L IBA. The shoots were multiplicated effectively on medium with 0.5 mg/L thidiazuron in Z. 'Childsiana', on medium with 3.0 mg/L BA in 2. 'Golden Affair', and on medium with 5.0∼10.0 mg/L BA in Z. 'Pacific Pink'.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.293-298
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• 2007

Robinia pseudoacacia var. umbraculifera, commonly called umbrella black locust were regenerated after co-cultivation of internode segments with Agrobacterium tumefaciens which included yeast cadmium factor 1 (YCF 1) gene. The tolerance to cadmium and lead for plants can be increased by the YCF1 gene expression. Moreover, the recent studies have shown that YCF1 gene transgenic plants increase the accumulation of cadmium and lead into plant vacuoles. The effect of plant growth regulator such as 2,4-dichlorophenoxyacetic acid (2,4-D), ${\alpha}$-naphthaleneacetic acid (NAA), 6-benzyladenine (BA), and thidiazuron (TDZ) were studied to evaluate the propagation of plants through internode explants. The efficient induction of multiple adventitious shoots and callus were observed on a medium supplemented with 0.1 mg/L TDZ + 0.2 mg/L BA. To induce shoot elongation and rooting, regenerated shoots were transferred into basal MS medium without any plant growth regulator. Successful Agrobacterium tumefaciens mediated transformation was obtained by 20 min vacuum-infiltration with $50{\mu}M$ acetosyringone on the optimal multiple shoot induction medium with 30 mg/L hygromycin and 300 mg/L cefotaxime. To confirm the integration and expression of transgene, Polymerase Chain Reaction (PCR) and Reverse Transcriptase PCR (RT-PCR) were performed with specific primers. The frequency of transformation was approximately 18.94%. This study can be used to genetic engineering of phytoremediator.

• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.394-402
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• 2009

Adventitious shoots were induced from pinnae, petiole and rhizome in Pteris cretica 'Wilsonii' in order to develop the efficient mass propagation method, using in vitro culture. Only homogenized rhizome segments could regenerate young sporophytes. Efficient regeneration of multiple shoots was obtained on the one-eighth strength MS medium containing 1% sucrose, and $50mg{\cdot}L^{-1}$ $NaH_2PO_4$. To achieve higher rate of regeneration from rhizome segments, rhizome segments were exposed to growth regulators for 2 months and then subcultured on hormone-free medium. The greatest shoot regeneration was obtained by $1{\mu}M$ kinetin with $5{\mu}M$ NAA. BA was effective in formation of GGB (kind of meristems), but they showed low shoot regeneration rate. Plants obtained from present experiments were transplanted to examine good environmental conditions for acclimation. Juvenile plants obtained by the one-eighth strength MS medium showed highest survival rate and vigorous growth at the seedling stage.

• Korean Journal of Plant Resources
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• v.28 no.6
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• pp.690-696
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• 2015

We micropropagated pear (Pyrus species) using shoot tips and nodal explants from three pear genotypes. The ability to establish shoot tip cultures, proliferate shoots, induce rooting, and acclimatize the resulting plantlets are all elements of in vitro micropropagation. Shoots were induced from shoot tips on Murashige and Skoog medium (MS) with five different plant growth regulator combinations. The highest shoot formation rates were achieved for the three genotypes using MS supplemented with 1.0 mg/L N⁶-benzyladenine (BA) and 0.1 mg/L gibberellic acid (GA₃). The maximum shoot number and shoot length for the three cultivars were recorded with 2.0 mg/L BA and 0.2 mg/L indole-3-butyric acid (IBA) in multiplication medium using nodal explants produced from microshoots. Nodal explants with one or two axillary buds cultured for three weeks initiated roots on medium supplemented with various concentrations of 1-naphthaleneacetic acid (NAA) or/and IBA in half-strength MS medium for adventitious rooting. The highest rooting response was with the combination of 0.2 mg/L NAA and 0.2 mg/L IBA. A combination of NAA and IBA resulted in a significant increase in the rooting ratio over NAA or IBA alone. In this medium, the root formation rate according to ranged from 68.9% for the BaeYun No. 3 genotype to 51.8% for the Hwanggeum genotype. We also investigated the influence of the concentration the polyamine phloroglucinol in rooting medium. For all three genotypes, the highest rooting ratio, longest root length, and greatest root number were observed in the treatments with 75-150 mg/L phloroglucinol. Most rooted plants were acclimatized successfully.

• Journal of Forest and Environmental Science
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• v.37 no.4
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• pp.304-308
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• 2021

Iris koreana (Iridaceae) is an endangered plant native to Korea. In order to develop an in vitro propagation method, we investigated the effect of 2,4-dichlorophenoxy acetic acid (2,4-D) and a-naphthalene acetic acid (NAA) on callus induction in different I. koreana tissues. In addition, we also investigated the effect of 2,4-D and Benzyl aminopurine (BA) treatments on adventitious shoot induction in viable calli and the effect of indole-3-butyric acid (IBA) on root formation in viable shoots. We found that callus production was highest with 1.0 mg/L NAA (94.4% cultured rhizome explants), and adding low concentrations of 2,4-D to BA containing media significantly increased the frequency of shoot primordial formation. The best rooting results were obtained with 1.0 mg/L IBA, on which 98% of regenerated shoots developed roots and produced an average of 7.4 roots within 45 days. This in vitro propagation protocol will be useful for conservation, as well as for mass propagation.

• Journal of Plant Biotechnology
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• v.29 no.3
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• pp.179-183
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• 2002

This study was carried out to investigate the influence of medium composition for in vitro mass propagation of Lycoris squamigera Max. After the disks of short stems, segments of leaf within bulb and scale were cultured on MS basal medium supplemented with various plant growth regulators, they were examined for the extent of callus formation, shoot and root regeneration. In the culture of stem disks, adventitious shoots were regenerated from the basal tissue of bulb scales, and combined medium of 1.0 mg/L 2,4-D or NAA＋2.0 mg/L BA or kinetin showed the the best response and 4∼6 shoots per explant formed. In the culture of leaf segments within bulbs, both MS medium supplemented with 1.0 mg/L NAA＋2.0 mg/L TDZ and with 1.0 mg/L 2,4-D＋1.0∼2.0 mg/L BA were produced callus profusely on the base of leaf tissue and 3∼6 shoots were regenerated per explant. In the scale segments culture, calli were produced on the basal tissue on medium with 1.0 mg/L 2,4-D＋1.0∼2.0 mg/L BA. The best result were shown on MS medium with 1.0 mg/L NAA＋2.0 mg/L TDZ, and 1.0 mg/L 2,4-D＋1.0∼2.0 mg/L BA. Maximum number of regenerated shoots was up to 10∼12. Adventitious root formation from explants were formed profusely on MS medium with 1.0 mg/L NAA＋2.0 mg/L kinetin. The most desirable method for mass propagation of plantlets was the shoot regeneration from scale segments then subsequently subcultured on medium for rooting.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.303-309
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• 2013

This study was performed to clarify the effect of medium compositions and plant growth regulators on the shoot, root formation and growth of 'Jarang' grape for mass propagation of virus-free plant. The formation and growth of shoot were considerably favorable in half-concentration of MS medium. However, the formation of adventitious root per explants (avg. 2.1) was effective in higher concentration (two times) of MS medium. For sucrose concentration, 1% for the shoot formation, 3% for the adventitious root formation and 1% for the growth were observed as yield significant results. With the addition of 0.05% of activated carbon, the shoot growth was improved, and it was effective for the adventitious root formation and growth as well. A pH of 6.8 in the medium was the most suitable for mass propagation; the results showed significant enhancement in the number of nodes and the length of the shoot, 3.9 and 1.3 cm, respectively. The shoot growth was the most vigorous in BA 1.0 mg/L due to the impact of the growth regulator on the mass propagation in it. Consequently, 16.9 shoots per explant were formed in NAA 1.0 mg/L so good results were obtained.

• Journal of Plant Biotechnology
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• v.6 no.1
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• pp.25-37
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• 2004

Successful genetic transformation of plants requires non-chimeric selection of transformed tissues and their subsequent regeneration. With rare exceptions, most transformation protocols still rely heavily on antibiotics for selecting transgenic cells that contain an antibiotic-degrading selectable marker gene. Here, the morphogenic capacity of in-vitro explants of chrysanthemnum and tobacco stems and leaves (control and transgenic) changed with the addition of aminoglycoside antibiotics (AAs), In a test of 6 AAs, phytotoxicity occurred at concentrations of 10 to 25 and 50 to 100$\mu\textrm{g}$ $mL^{-1}$ in chrysanthemum and tobacco explants, respectively. Light conditions as well as explant source and size also had significant effects. The use of transverse thin cell layers (tTCLs), in conjunction with high initial AA selection levels, supported the greatest regeneration of transgenic material (adventitious shoots or callus) and the lowest number of escapes. Flow-cytometric analyses revealed no endodu-plication in chrysanthemum, even at high AA levels. However, this phenomenon was observed in tobacco calli(8C or more), even at low AA concentrations (i.e., 5 to 10 $\mu\textrm{g}$ mL$^{-1}$ ).

• Korean Journal of Plant Resources
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• v.24 no.3
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• pp.280-285
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• 2011

In this study, we established a novel somatic embryogenesis and plant regeneration system through cell suspension culture of white dandelion (Taraxacum coreanum NAKAI.). Embryogenic calli could be initiated from leaf and root explants of sterile seedlings on solid Murashige and Skoog (MS) medium supplemented with 1.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) after 3-week cultures. To proliferate embryogenic calli rapidly, cell suspension culture was performed with transferred to liquid MS medium with various combinations of plant growth regulators (PGRs) including 2,4-D, ${\alpha}$-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA), $N^6$-benzylamino purine (BAP), thidiazuron (TDZ), and kinetin. During suspension cultures, embryogenic calli not only greatly proliferated, but shoot organogenesis also simultaneously occurred from the surface of somatic embryos. Among them, TDZ at lower concentration, 0.1 mg/L produced the highest efficiency of somatic embryo formation and shoot organogenesis. Rooting of embryogenic calli with adventitious shoots was done on solid MS medium containing 0.1 mg/L NAA and 0.3% activated carbon. Nearly 80% of embryogenic calli with shoot organogenesis could be rooted normal. Well-rooted plantlets were transferred into pots under a greenhouse condition, and plants derived from this system appeared phenotypically normal.