• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.217-222
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• 2011

Success in molecular breeding for better adapted varieties to environmental stresses depend upon the concerted efforts by various research including tissue culture, transformation, genetics and breeding. In order to optimize tissue culture conditions of Siberian wildrye grass, the effects of plant growth regulators on callus induction and plant regeneration were investigated with mature seeds. The highest callus induction frequency was observed when the mature seeds were cultured on MS medium supplemented with 5 mg/L 2,4-D. The highest plant regeneration frequency was observed when callus was transferred to N6 medium supplemented with 1 mg/L 2,4-D and 3 mg/L BA. Regenerated plants were grown normally when shoots were transplanted to the soil. A short tissue culture period and regeneration system would be beneficial for molecular breeding of Siberian wildrye grass by the production of transgenic plant.

• Korean Journal of Agricultural Science
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• v.7 no.2
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• pp.59-64
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• 1980

These experiments were carried out to define the effects of 2.4-D, NAA and Benzyladenine on the differentiation and growth of the organs and the induction of callus from the potato meristem. The results were summarized as follows ; 1. The differentiation and growth of the shoots from the potato meristem was promoted in increased concentration of Benzyladenine but the callus was not induced on the M.S. medium containing Benzyladenine. 2. On the M.S. medium containing NAA 0.5 mg/l or higher concentration of NAA, the shoots were not initiated but the callus were induced from potato meristem. The growth of callus was promoted in increased concentration of NAA. 3. The roots were initiated from 50% of potato meristems planted on the M.S. medium containing more than 0.1 mg/l of NAA but the roots were pot initiated on the medium containing 2.4-D. 4. The shoot growth was significantly increased by increasing of 2.4-D concentration up to 0.1 mg/l, but the shoots were not initiated on the medium containing 2.4-D more than 1.0 mg/l. 5. For the induction and growth of the callus from potato meristem, NAA was more effective than 2.4-D and the most effective medium was M.S. medium supplemented with 2.0 mg/l of NAA. 6. The M.S. mediums supplemented with BA 2.0 mg/l and NAA 0.1 mg/l or BA 1.0 mg/l and 2.4-D 0.1 mg/l showed good results for entire plant regeneration from potato meristem.

• The Plant Pathology Journal
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• v.15 no.1
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• pp.38-43
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• 1999

Mutants of the monopartite geminivirus beet curly top virus (BCTV) have been screened for infectivity, systemic movement, replication and symptom development in Arabidopsis thaliana. As known by coding for coat protein, R1 mutant was not infectious and did not move systemically. R2, R3 and L2/L3 mutants produced milder symptoms compared to wild type BCTV but the infectivity was reduced by 40% to 60%. R2 ORF is thought to be involved in the regulation of ssDNA and dsDNA accumulation because only dsDNA was accumulated on R2-infected organs. Disruption of ORF L4 resulted in reduced infections, but the viral DNA was accumulated in infected organs from roots to shoot tips as much as wild type BCTV on Sei-O. In addition, 4 mutants did not produce callus-like tissues on infected organs, suggesting that L4 ORF may play a role in the induction of host cell divisions by virus infection. This result was supported by the patterns of mRNA expression and promoter analysis of the cell cycle marker gene, cycl, on Arabidopsis. cycl mRNA was accumulated on symptomatic organs by wild type BCTV infections but not by L4 mutant. We conclude that the BCTV L4 ORF is essential for symptom developments, specially callus-like formation on infected organs.

• Journal of Plant Biotechnology
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• v.8 no.1
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• pp.27-35
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• 2006

Plantlet regeneration in Asteracantha longifolia(L.) Nees (Acanthaceae), a medicinal herb has been achieved from seedling explants on basal MS medium. Three different seedling explants including node, internode and leaf segments on used. Of these three explant, leaf explants gave better response for both callus mediated organogenesis and direct multiple shoot induction. Number of explants showing differentiation of shout buds was higher on MS media supplemented with BA compared to kinetin. MS medium fortified with BA ($2.0mgl^{-1}$) and NAA ($0.5mgl^{-1}$) was found to be most suitable for both callus mediated organogenesis and elongation of shouts. The elongated shoots were successfully routed on MS medium fortified with NAA or IBA. Among them $0.1mgl^{-1}$ NAA or $0.2mgl^{-1}$ IBA provides better response for rhizogenesis. Regenerated plantlets were successfully established in soil where 85.4% or them developed into morphologically normal and fertile plants. RAPD profiling using four decamer primers confirmed the genetic uniformity of the regenerated plantlets and substantiated the efficacy and suitability of this protocol for in vitro propagation of A. longifolia.

• Journal of Forest and Environmental Science
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• v.30 no.4
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• pp.405-411
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• 2014

Wild Korean ginseng has been recognized as highly precious medicine since ancient times. Nowadays, the population of wild ginseng in the forest of Korean peninsula is very rare due to indiscreet harvest. In this work, we investigated the plant regeneration via somatic embryogenesis from embryogenic callus of old wild ginseng (more than 50 years-old) and compared the features of plants regenerated from 5-years old and 50 years-old ginseng. Induction of embryogenic callus from adventitious roots of 50 year-old wild ginseng required 83 weeks of culture, but only 10 weeks were sufficient for 5 year-old ginseng. Height and width of plants derived from the old wild ginseng was smaller and slender compared to the plantlets derived from 5 year-old ginseng. Total chlorophyll contents was 2-6 time lower in plantlets regenerated from 50 year-old wild ginseng than those from 5 year-old ginseng, but anthocyanin content was higher in 50 year-old ginseng. Our results revealed that plants regenerated from old wild ginseng have different morphological and physiological characters probably due to age-dependent phenomenon.

• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.31-38
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• 1999

An artificial symbiosis was established between diazotropic Azomonas insignis and strawberry (Fragaria x ananassa). The partnership was created by in vitro techniques through callus induction and organogenesis. The basis of this partnerships is the bacterial dependence on the plants metabolic activity, using maltose in the medium as a carbon and energy source which can be utilized by the plant cells only. The presence of bacteria in the intercellular spaces of the callus tissues and regenerated plants was proven by microscopic techniques. Nitrogenase activity could also be detected in the plant tissues. For successful and high frequency introduction of bacteria to the plant tissues, biolistic gun method was used. On the basis of the DNA transfer method, Azotobacter vinelandii bacteria were delivered directly into strawberry tissues by the particle bombardment. This was the first use of living bacteria as microprojectils for bombardment of plant tissues. The treatment was successful, the presence of bacteria in the developing callus tissue and regenerated plants were detected by light and electron microscopy.

• Korean Journal of Plant Tissue Culture
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• v.28 no.6
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• pp.323-328
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• 2001

In order to optimize the conditions of callus induction and plant regeneration in seed culture of Italian ryegrass, the effects of basic medium and carbon sources on seed culturability and genotypic difference of plant regenerability were investigated. MS medium was better than N6 and B5 medium in enhancing callus growth and plant regeneration. Sucrose was superior to maltose in plant regeneration as carbon source in the medium. The genotypic difference in plant regenerability was obvious among four cultivars of Italian ryegrass tested. 'Rio' and 'Jeanne' showed to have higher regenerability with the frequency of 38% and 56%, respectively.

• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.245-249
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• 2003

This study was carried out to establish a regeneration system from leaf explant of purple sweetpotato(Ipomoea batatas L.) The optimal concentrations of plant growth regulators for callus induction and shoot formation were determined. The optimal combination for callus formation was 1$\mu$M 2,4-D 5$\mu$M BM, and highest yield of embryogenic calli were observed on Murashige and Skoog basal medium containing 0.5$\mu$M 2,4-D under light condition after 4weeks of culture. Embryogenec callus was subcultured on medium supplemented with 5$\mu$M ABA for 4 days. Subsequently, regeneration of adventitious shoots occurred when these embryogenic calli were transferred onto medium with 3∼6$\mu$M gibberellic acid. Regenerated shoots were developed into normal plantlets.

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.237-242
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• 2006

Commercial cultivars and elite germplasms of barely (Hordeum vulgare L) are still recalcitrant to genetic transformation because of the lack of an efficient regeneration system. In this study, we established an efficient plant regeneration procedure from embryogenic calli derived from mature embryos. Callus induction from germinated mature embryos was best as over 95% in CIM medium (CI medium containing $2.5mg/{\ell}$ dicamba) under dark incubation. Development of embryogenic callus was highest as over 50% in CI3D medium (EC medium supplemented with $3mg/{\ell}$ 2,4-D). The highest regeneration of plants from embryogenic callus (40%) was obtained with CIS medium ($SI+1mg/{\ell}IAA\;and\;2mg/{\ell}\;BA$). These plant regeneration conditions could be useful in improving barley transformation efficiency.

• Korean Journal of Plant Tissue Culture
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• v.24 no.6
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• pp.341-344
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• 1997

Calli were induced from the cotyledon and the hypocotyl of alfalfa and the callus lines were tested for the resistance to glyphosate in the liquid medium containing 0.01-3.00 mM glyphosate. Some resistant cell lines were selected from the gradual increase of glyphosate concentration and the lines resistant to 10 mM glyphosate were analyzed with EPSPS activity. Vigorous callus proliferation from the cotyledon and the hypocotyl was observed from the MS medium containing 1 mg/L 2,4-D and 0.5 mg/L kinetin. The hypocotyl was thought to be better explant source for callus induction than the cotyledon. $ID_{50}$ (Inhibition Dosage of 50%) to glyphosate was between 0.1 mM and 0.2 mM level. A49-10G and A58-10G cell lines selected as resistant to 10 mM glyphosate had 8.0 and 9.1 fold increased EPSPS activity to those of the control lines, respectively.