• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.3
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• pp.171-176
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• 2008

Efficient plant regeneration system of birdsfoot trefoil (Lotus corniculatus L.) was development. The factors affecting the somatic embryo formation, its proliferation and regeneration capacity of leaf and stem explants of Empire cultivar was investigated. The highest number of somatic embryos was obtained on B5 medium supplemented with 1 mg/L NAA and 1 mg/L BA. Depending on different explants, highest frequency of embryogenic callus and regeneration were observed in Empire with leaf explants. The response from stem explants was slower and callus induction was less than that from leaf explants. Regenerated shoots formed complete plantlets in on 1/2 MS medium supplemented with 1 mg/L IBA. Regenerated plants were morphologically uniform with normal shape and growth pattern.

• Journal of Plant Biology
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• v.39 no.1
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• pp.71-77
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• 1996

Embryogenic callus was selected from callus induced from hypocotyl segment cultures of Daucus carota seedlings on MS basal medium supplemented with 1.0 mg/L 2,4-D. Cell clumps prepared from the embryogenic callus were transferred to MS medium without 2,4-D for somatic embryo development. Cotyledonary abnormalities were frequently observed on somatic embryos developed after the incubation of cell clumps in MS basal medium with 1.0 mg/L 2,4-D for one week and then subculture in the same medium but without 2.4-D for two weeks. The percentage of abnormalities was as follows: 5% one cotyledon, 21% three cotyledons, 6% four cotyledons, 5% five cotyledons, 0.2% six cotyledons and 1% trumpet-like cotyledons. On the other hand, the normal somatic embryo with two cotyledons appeared at 63%. The germination rate of somatic embryos was higher in two cotyledon somatic embryos than in multicotyledonary embryos. Trumpet-like somatic embryos did not germinate normally showing limited elongation and enlargement of roots and cotyledons without shoot development. From anatomical examination circular procambium in the root of somatic embryo began to branch around the middle regions of the hypocotyl which extended into the cotyledons through the cotyledonary nodes and the number of branched procambial strands in hypocotyl was equal to the number of cotyledons. Monocotyledonous somatic embryo always had larger cotyledon than that of somatic embryos with multicotyledons and had horseshoe-like cotyledons where the procambium was of the same structure.ucture.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.235-242
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• 2011

In order to improve forage characteristics of Italian ryegrass by genetic transformation, an efficient callus induction from mature seed and optimal plant regeneration system were established using a domestic cultivar 'Kospeed'. Addition of 5 mg/L of 2,4-D showed highest frequency of embryogenic callus induction from mature seeds. N6 medium showed higher frequency of both callus induction and plant regeneration as compared with MS and SH medium. The highest plant regeneration frequency 67% was obtained when embryogenic calli were transferred to N6 medium containing 1 mg/L 2,4-D and 5 mg/L BA. Supplementation of regeneration medium with sucrose at 30 g/L level maximized regeneration frequency as compared to the other concentrations. These data would be very helpful for molecular breeding of domestic Italian ryegrass cultivar through genetic transformation.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.511-516
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• 2010

The process to acquire intron-GUS gene-expressed transformants from somatic embryos (including embryogenic calli) of Rosa hybrida cv. 'Sweet Yellow' using Agrobacterium-meditated transformation method was reported in this study. Somatic embryos including embryogenic calluses were infected with Agrobacterium tumefaciens AGL1 strain (O.D = 0.7~1.6) including intron-GUS gene for 30 min, and were co-cultured for 3 days. After co-cultivation, they were cultured on embryo germination medium (EGM) supplemented with $250\;mg{\cdot}L^{-1}$ cefotaxim at $4^{\circ}C$ for 7 days. Then, transient GUS gene expression was observed. Shoots were regenerated from the shoot primodia induced from the intron-GUS gene-transferred either somatic embryos or embryogenic calli cultured on EGM supplemented with both cefotaxim $250\;mg{\cdot}L^{-1}$ and ppt $2\;mg{\cdot}L^{-1}$. Before induction of rooting from shoots cultured on shoot growing medium supplemented with both cefotaxim $250\;mg{\cdot}L^{-1}$ and ppt $2\;mg{\cdot}L^{-1}$, the shoots were cultured on multi-shoot induction medium supplemented with both cefotaxim $250\;mg{\cdot}L^{-1}$ and ppt $2\;mg{\cdot}L^{-1}$ to induce multi-shoots. When expression of the gene from a part of the multi-shoots was identified by GUS transient assay, the putative transgenic multishoots were transferred to rooting medium supplemented with cefotaxim $250\;mg{\cdot}L^{-1}$. After the formation of healthy roots, transgenic plantlets were transferred to the greenhouse after acclimatization. The expression rate of the intron-GUS gene in the multi-shoots was 100%.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.113-118
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• 2004

Somatic embryos were formed from calli obtained from axillary shoots (raised from nodal segments of glasshouse-grown plants under aseptic conditions), internodal segments (from in vitro-raised plants), and root and coty-ledonary leaf segments (from in vitro-raised seedlings) after 8 weeks of initial culture. Embryo formation was the highest (97.33%) from cotyledonary leaf callus on Mura-shige and Skoog's (MS) medium containing kinetin (KN) (3 mg/L). Somatic embryo induction was lesser with different combinations of auxins while it increased to 100% in internodal segment and cotyledonary leaf calli with 6-benzyladenine (BA) (2mg/L) along with 2,3,5-triiodobenzoic acid (TIBA) (2mg/L). The shoots were induced from somatic embryos raised from root, coty-ledonary leaf and internodal segment calli grown on MS medium containing BA in combination with indole-3-acetic acid (IAA). Maximum of 66.67% cultures formed shoots on MS medium containing BA (1mg/L) in combination with IAA (2mg/L). The shoots raised from somatic embryos were rooted on MS medium supplemented with indole-3-butyric acid (IBA) (2mg/L). The plantlets transferred to the field showed 70% survival rate after one year.

• Korean Journal of Plant Tissue Culture
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• v.22 no.4
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• pp.207-211
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• 1995

Immature zygotic embryos from immature seeds of Wasabia japonica (cv Dalma) were isolated and cultured on modified MS medium supplemented with 2,4-D, IAA, and BA. Immature zygotic embryos were classified into torpedo shape and cotyledon stage. The highest rates of callus formation were obtained of 1.0mg/L IAA(torpedo stage, 90.0%)and 1.0mg/L 2,4D plus 0.1mg/L BA(cotyledany stage,84.3%). Somatic embryos after 60 days of culture. These numerous somatic embryo could be seperated and subcultured on the same media for further propagation. After 90 days of culture, most somatic embryos were developed well organized embryos which were able to produce into whole plants.

• Korean Journal of Plant Resources
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• v.24 no.5
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• pp.628-635
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• 2011

This study was conducted to establish the tissue culture system for Korean domestic Miscanthus sinensis, which is used in various purposes such as forage, and bio-energy resources. With the mature seed of Miscanthus, optimum concentrations of plant growth regulators were identified for an efficient callus induction and regeneration. Among the treatments of 1~10 $mg{\cdot}L^{-1}$ 2,4-D, IBA, or NAA, callus induction rate was highest (85.3%) on MS medium containing 5 $mg{\cdot}L^{-1}$ 2,4-D. Under the condition, the callus were efficiently induced and proliferated with comparably lower frequencies of callus browning. In shoot regeneration, the treatment of NAA combined with BAP seemed to contribute more efficient conditions to shoot regeneration than those of NAA with Kinetin or 2-iP. Especially, regeneration efficiency and number of regenerated plants were 83.7% and 5.5 in 3 $mg{\cdot}L^{-1}$ NAA with 5 $mg{\cdot}L^{-1}$ BAP, respectively, which were higher frequencies than those in NAA with Kinetin or 2-iP. In results, 5 $mg{\cdot}L^{-1}$ 2,4-D and 3 $mg{\cdot}L^{-1}$ NAA combined with 5 $mg{\cdot}L^{-1}$ BAP were efficient for embryogenic callus induction and regeneration of Miscanthus. This system would be useful for mass-propagation and developing new cultivars via tissue culture of Miscanthus sinensis.

• Korean Journal of Plant Tissue Culture
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• v.22 no.1
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• pp.35-39
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• 1995

In order to investigate the effects of gelling agent on rice anther culture, anthers of rice (Japonica cv Daecheongbyeo) were cultured on N$_{6}$ media supplemented with 0.8, 1.2 or 1.6% Junsei agar and 05, 0.4, 0.6, 0.8 or 1.0% Gelrite (Phytagel, Sigma). On Junsei agar media, the frequency of callus induction was decreased in proportion to agar concentration. The frequency of callus induction was more increased as 67.6% and 54.8% in media containing 0.4 and 0.6% Gelrite than in agar media. The frequency of plant regeneration and spontaneous doubled-diploid was directly proportional to Junsei agar and Gelrite concentration. The number of green and spontaneous doubled diploid plant was highest on 0.6% Gelrite medium. In order to optimize the concentration of growth regulators for the callus induction medium containing 0.6% Gelrite, anthers were cultured on N$_{6}$ media supplemented with 2mg/L NAA, 2 mg/L 2,4-D, 1mg/L NAA and 1mg/L 2, 4-D, or 1mg/L NAA, 1mg/L 2,4-D and 0.5mg/L kinetin. The maximum frequency of callus induction and plant regeneration was obtained from the medium supplemented with 2 mg/L NAA and 0.6% Gelrite. In conclusion the induction of embryogenic callus, the frequency of plant regeneration and in vivo chromosome doubling was more effective in Gelrite media than in Junsei agar media.dia.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.2
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• pp.77-82
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• 2006

An efficient transformation system for the production of transgenic plants has been developed for tall fescue (Festuca arundinacea Schreb.) via Agrobacterium-mediated transformation of seed-derived callus. From the point of morphogenetic capacity, three types of callus were selected. High frequency of plant regeneration was obtained by selection of type II callus, and the plant regeneration frequency was 52.6% when embryogenic callus were cultured on the regeneration medium. Supplementation of the media with 10 mg/L $AgNO_3$ and 40 mg/L cysteine enhanced frequencies of plant regeneration up to 65.3%. The highest transformation efficiency was also obtained when type II callus were inoculated with Agrobacterium. Southern blot analysis of PCR products of transgenic plants demonstrated that transgenes were successfully integrated into the genome of tall fescue. Efficient regeneration system and transformation established in this study will be useful for molecular breeding of tall fescue through genetic transformation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.3
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• pp.165-170
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• 2008

Timothy (Phleum pratense L.) is an important grass species as forage. In order to optimize tissue culture conditions of timothy, the effects of plant growth regulators on callus induction and plant regeneration was investigated with mature seeds of colt cultivar. The optimal concentration of 2,4-D for the induction of primary callus from mature seeds was 3 mg/L. The highest embryogenic callus frequenc (25%) was observed when the mature seed were cultured on MS medium supplemented with 3 mg/L 2,4-D and 0.1 mg/L BA. The highest plant regeneration frequency was observed when type B 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 timothy by the production of transgenic plant.