• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.348-353
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• 1996

Mutation tachniques inducing more useful mutations and reducing somatic effects need to be improved for crop breeding. Seeds of barley varieties ; Dema, Grosso were treated with two types of mutagens ; 1) chemical treatment: single treatment or double treatment of two mutagens (N-nitroso-N-methylurea ; MNH, Sodium Azide; NaN$_3$) 2) gamma ray irradiation treatment. After treatment, half of seeds were used for germination test and half of seeds were sown to the field. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher rate of growth reduction rate was in M$_1$ seedling. In chemical treatment, germination rate of seeds, growth rate of coleoptile and root in double treatment of chemical mutagens were better than single treatments, especially in same dose. Growth inhibition rate of plant in double treatment of 1.0mM MNH(0.5mM MNH + 0.5mM MNH), for example, were less than one of plants of single treatment of 1.0mM MNH in pot and petri dish test. Growth reduction rate of culm and fertility rate in M$_1$ plants double treated in same dose of single treatment were also less than single one. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher frequency of chlorophyll mutants was in M$_2$ seedling. The rate of chlorophyll mutants in double treatment of chemical mutagens were higher than single treatment. Double treatment methods can be a improved method for induction of new good mutants, which were induced more useful mutations and reduced harmful somatic effects.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.1-8
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• 1991

Developmental micropropagation method and somatic embryogenesis for hybrid poplars, Populns ehrarnericana Eco28, P. nigra ${\times}$ P. moximowiczii 62-9, were established using nodule culture system. Calli of Eco28 and 62-9 clone were initiated from leaf explant on the medium with 0.5mg/l and 2.0mg/l 2, 4-D, respectively. Cell suspension culture was established from callus derived from leaf explant culture. When suspended on MS medium with optimal combination of BA and NAA fine nodules were obtained after 2 weeks of culture. For shoot regeneration, nodules were transferred into liquid and agar solidified medium. Numerous shoots were regenerated from nodules of 62-9 on liquid media. Organogenesis was effectively achieved on agar solidified regeneration media containing different concentrations of BA and adenine sulfate. Average numbers of 27 and 24 shoots per nodule were induced from 62-1 and Eco28 clones after 8 weeks of culture, respectively. In addition, somatic embryogenesis also occurred in the same regeneration medium. This procedure can be applied to vegetative propagation, utilization of somaclonal variation, production of secondary metabolite and materials of biotechnology research.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.633-637
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• 2010

This study was conducted to evaluate various effects of kinds of culture medium, concentrations of abscisic acid (ABA) or /kinds of osmotica on maturation of somatic embryos (SEs) with four (LL-L, LL-K, LL-P and LL-N) embryogenic tissue lines (ETLs) in Japanese larch (Larix leptolepis). In comparison of two culture medium, the LL-P produced the highest number of the cotyledon-staged SE (134.9/90 mg tissue) in 1/2LM medium. In contrast, no SEs were obtained except the LL-P (32.9) in medium of BLG. Effects of two concentrations of ABA in the medium with four ETL for SEs maturation were also compared. In the test of 60 or 100 ${\mu}M$ ABA, the highest result was obtained in 60 ${\mu}M$ ABA (142.9). However, the influence of ABA had little on SEs production except the LL-N regardless of concentrations of ABA. In comparison of different kinds/concentrations of osmotica, the best response was obtained from the treatment of 0.2 M maltose, the LL-K (540.5). In conclusion, the effects of production of SEs were greatly rely on the ETLs, rather than kinds of medium, concentrations of ABA or osmotica which were used in maturation of SEs.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.449-454
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• 2011

This experiment was conducted to evaluate growth rate among 15 embryogenic tissue lines (ETLs), comparison of maturation on somatic embryos (SEs) with 13 ETLs and efficiency with various concentrations of gelrite on SEs germination in Japanese red pine (Pinus densiflora). In comparison of ETLs growth rate (folds) with 15 lines, the 05-4 line (5.3 folds) showed the highest rate, on the other hand, the lowest one was recorded in the line of 05-37 (1.4 folds). The 13 ETLs were tested for the extent of SEs production. The best production was recorded in the line of 05-4 (39.8/90 mg F.W.). However, most of ETLs, except 5 lines (05-4, 12, 21, 29 and 37), did not produce SEs at all, therefore, big differences in the ability of SEs production existed among the ETLs tested. Effects of various gelrite concentrations for SEs germination with 3 ETLs were also compared. The highest result was obtained from 0.2% gelrite concentration with 05-4 line (47.3%), there was a inclination that the rate of germination was gradually declined over 0.2% gelrite concentration with the 05-4 and 29 lines. respectively. In contrast, in the line of 05-37, no SEs germination occurred on medium with 0.1 or 0.2% gelrite. In conclusion, the growth rate, SEs production and germination frequency were appeared to deeply depended on the ETLs.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.212-217
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• 2011

A photoautotrophic micropropagation methodology in liquid culture medium has a number of advantages for large-scale propagation of plants. This paper describes an improved system for the mass propagation via somatic embryogenesis of the medicinal plant Kalopanax septemlobus Nakai. Somatic embryo-derived young plantlets of K. septemlobus were cultured either under heterotrophic conditions with sucrose on half-strength MS medium with $30gL^{-1}$ sucrose, under heterotrophic conditions without sucrose, or under photoautotrophic conditions (MS liquid medium without sucrose under forced aeration) for four weeks before transferring the plantlets for acclimatization. Plantlets grown under photoautotrophic conditions had more leaves, higher chlorophyll content, a higher net photosynthetic rate (NPR), and a higher survival rate. The results indicate that the photoautotrophic conditions with a forced ventilation system are effective in enhancing the growth of plantlets and the rate of net photosynthesis. The plantlets grown under photoautotrophic conditions had a high survival rate (92%) upon ex vitro transplantation. Our study shows that autotrophically produced plantlets acclimatize better and sooner upon ex vitro transplantation than conventionally cultured plants.

• Journal of Plant Biotechnology
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• v.42 no.2
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• pp.88-92
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• 2015

Cassava (Manihot esculenta Crantz) is a useful root crop for food, animal feed and various industrial materials including biofuel. Despite of its importance as an industrial crop, the genetic engineering approaches to manipulate transgenic plant development in cassava are limited. In this study, to develop new cultivar with high level of carotenoids and enhanced tolerance to environmental stresses, sweetpotato IbOr gene involved in accumulation of carotenoids was introduced into an Indonesian IDB high-yielding cassava cultivar under the control of oxidative stress-inducible SWPA2 promoter through Agrobacterium-mediated transformation of friable embryogenic calli. The 19 transgenic lines were successfully generated on the basis of gDNA-PCR and IbOr transcript levels for further characterization in terms of carotenoid contents and environmental stresses. Therefore, IbOr transgenic cassava plants may be developed for enhanced biomass production with high levels of carotenoids on marginal lands.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.119-124
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• 1997

Plantlets were regenerated from various explants (shoot tip, leaf blade, petiole and root segments) via organogenesis and/or somatic embryogenesis from Armoracia rusticana(Lam) Gaerth., Mey, et Scherb.. Shoot regeneration rate from callus was highest on the MS mediums supplemented with 0.5 ㎎/L IAA, 5.0㎎/L BA and 10.0㎎/L spermine. A Low frequency of regeneration occurred on hormone-free MS medium. Multiple shooks were regenerated at a pH of 4.0 to 8.0 on MS medium supplemented with 1.0 ㎎/L BA and 0.1 ㎎/L NAA. Polyamines promoted shoot- and root-formation by 2 to 4 times normal, Specific proteins associated with organogenesis were identified. Somatic embryogenesis occurred directly from the leaf blade, petiole and root segments cultured on MS medium with 2.0 ㎎/L BA and 2.0 ㎎/L BA and 2.0 ㎎/L NAA. Three types of regeneration in A, rusticana were clearly established, which could be applied to the study of morphogenesis and genetics at cell, tissue and organ levels.

• 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.

• Korean Journal of Plant Taxonomy
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• v.35 no.2
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• pp.129-142
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• 2005

Somatic chromosome numbers of 19 taxa of Korean Rubus was investigated. Subg. Anoplobatus (2 species), subg. Cylactis (1 species), subg. Idaeobatus (15 taxa) and subg. Malachobatus (1 species) are found in Korea. All taxa belonging to subg. Idaeobatus except for R. parvifolius which shows tetrapolid and hexaploid are diploid. The basic chromosome number of the genus was x=7. New chromosome numbers for 5 taxa were reported here: R. hongnoensis of Jeju-island endemic species, 2n=14; R. longisepalus, 2n=14; R. longisepalus var. tozawai, 2n=14; R. parvifolius, 2n=28; R. parvifolius var. taquetii, 2n=28. The rest 12 taxa except for R. coreanus Miq was well counted as 2n=14 and well consistent with previous reports from China and Japan. Our new chromosome level for R. parvifolius as 6x may indicate that speciation by polyploidization has occurred within Korean population. Unlikely to Japanese population (2n=42), Korean population of R. buergeri has same ploidy level with Taiwanese population as 2n=56.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.121-126
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• 1999

Calli were induced from the petiole explants of Pimpinella brachycarpa on MS medium supplemented with 0.5 mg/L 2,4-D and 0.1 mg/L BA after four weeks of culture. Compact clusters of small and dense cells among these calli were selected and suspension-cultured as the source of embryogenic calli. When transferred to MS medium with 0.1 mg/L NAA, the suspension-cultured cells grew to embryogenic callus. Somatic embryos derived from these embryogenic calli developed into plantlets. The cDNA library was constructed in the embryogenic callus and in order to screen the cDNA library, these cDNAs were plated at a density 1.5 $\times$ 10^5 plaques per 15 cm petridish. Among 19 clones showing preferential hybridization with petiole HD-Zip gene, five clones were obtained after second screening. Four clones among them, were highly homologous to P. brachycarpa shoot-tip Phz4 gene, but one clone, Phc5 was about 1.5 kb which has an extra 163 bp to 5' upstream of Phz4. The Phc5 was 1,531 bp containing poly A tails of 18 bases. ATG start codon for Phc5, was located at position 284 with an open reading frame of 906 by which encodes a polypeptide of 302 amino acids. The Phc5 protein revealed that the polypeptides between 135 and 195 contain a homeodomain as the `leucine zipper' motif.