• Korean Journal of Plant Tissue Culture
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• v.25 no.1
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• pp.57-61
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• 1998

Soybean and tobacco tissue cultured with modified MS media containing 4 different ratio(as N) of nitrate to ammonium combination which were 3:0, 2:1, 1:2 and 0:3. The highest callus growth in soybean were observed in the 2:1 medium. The medium containing nitrate only was detrimental to soybean callus growth. Tobacco callus grown with nitrate-only grew as well as those in the 2:1 and very slowly with ammonium-only. In tobacco callus, the total nitrogen in the callus increased with the increase of nitrogen concentration in the medium, but in soybean callus, the opposite result was noted. Nitrate reductase activity in tobacco callus was high when grown with nitrate-only but low with ammonium-only. In case of soybean callus, nitrate reductase activity was high in the 2:1 and remarkably low in nitrate-only medium. Both in soybean and tobacco callus, the activity of glutamine synthetase was high with nitrate-only, but low with ammonium.

• Journal of Korean Society of Forest Science
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• v.13 no.1
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• pp.25-39
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• 1971

Recently successful induction of haploid plant by means of anther culture method has become a big topic among geneticists and plant breeders. The haploid plant can be used as a precious material for such basic researches as mutation or genetics. Once the haploid is obtained, production of homozygous plant is not a difficult problem. The method of producing homozygous plant can, also, be applied to the practical breeding works. When applied to the hybridization of self-fertilizing breeding period would be greatly shortened and in cross-fertilizing vegetables production of uniform hybrid seed would be very easily obtained. Last few years many scientists attempted anther cultures using various plant species, but it was successful only in several species. Unlike the other tissue cultures which use somatic organs or tissues as explants, anther culture seems to be very difficult because the plants or calli have to be induced from the haploid microspores or pollen grains. In the present experiment anther culture of fruit trees and ornamental shrubs of four genera and seven species was attemped. Anthers of Various stages ranging from tetrad and late microspore were cultured on the modified Murashige and Skoog's medium supplemented with various concentrations of auxins and kinetin as growth regulators. Handling of materials, sterilization, and other operations of culture were done by routine methods. The results were summarized as follows: 1. Calli were induced in the anthers of Forsythia Koreana Nak., Rhododendron mucronuratum Turcz., R. yedoense Max. var. Poukhanense Nak., and Prunus armeniaca L. var. ansu Max. No signs of callus were observed in Prunus persica Sieb. et Zucc. var. vurgaris Max., Pyrus ussuriensis var. macrostipes (Nak.), and Prunus salcina Lindley. 2. Calli were easily formed in any of the media with differing concentrations of auxins and kinetin. 3. In F. Koreana calli developed from anther surface and connective. Callus emerging out of anther locule was not observed. 4. Somatic calli arose from filament, connective, and inside of anther wall in R. mucronulatum. Many of the microspores accumulated starch grains. 5. The anther lobes located opposite the filament of R. yedoense turned easily to calli. This phenomenon was not observed in R. mucronulatum. Microspore embedded for a period in the medium became starch pollen. No callus was observed arising from microspore. 6. In P. armeniaca calli were not induced from somatic anther tissues. Instead, callus emerged out of anther locule rupturing the anther slit. Starch was not formed in the microspore. 7. In P. persica, Pyrus ussuriensis, and P. salcina, calli were not observed in the anthers examined more than 60 days after culture. Microspores of these species, however, were free of starch grains even after long period of subculture. 8. It was learned that somatic calli of the species examined arose usually from endothelium of anther wall, septum of two neighboring anther locules, parenchyma tissues of connectives, or anther lobes. 9. In the anther locule of P. armeniaca cultured long in medium, swollen microspores, polynucleate microspores, multicellular pollen grains, or callus mass were frequently observed, this indicating that the callus of this species was microspore-origin. 10. It was clarified that in P. armeniaca production of haploid plant by anther culture might be possible.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.103-107
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• 1999

The effects of MS salt strength, sucrose, and cultural conditions on bulblet formation and growth were investigated to optimize the conditions for micropropagating bulblets from in vitro bulb scales of Lilium Oriental Hybrid 'Casa Blanca'. There was no difference on bulblet formation in the range of 1/2~2 $\times$ strength of MS salt, but it was inhibited remarkably in 3 $\times$ strength of MS salt. The growth of regenerated bulblets was most stimulated on MS basal medium. Favorable bulblet formation and its growth from bulb scales were achieved when grown on the media with 1 : 2 or 1 : 3 in the ratio of NH$_4$^+ : NO$_3$^- , as well as on MS basal medium (NH$_4$^+ : NO$_3$^- = about l : 2). Therefore, MS basal medium was very suitable for bulblet formation and growth from bulb scales. Bulblet formation was inhibited but its growth was stimulated with increase sucrose concentration in the medium. The growth of regenerated bulblets was very effective on the media with 9~12% sucrose. Addition of activated charcoal (AC) to the medium inhibited bulblet formation from bulb scales, but enhanced the growth of regenerated bulblets. Especially, the medium containing 1 g/L AC was most effective on the growth of bulblets. No difference was found on bulblet formation and growth from bulb scales under light and dark conditions. In vitro micropropagation of L. Oriental Hybrid 'Casa Blanca' was supposed very reasonable to enhance the growth of the bulblets after forming of bulblets from in vitro bulb scales, and then, subculture the bulb scales from the grown bulblets on MS medium with 9% sucrose and 1 g/L AC.

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.207-217
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• 1998

Total of 78 strains were characterized based on the morphological characteristics of colonies isolated on Schroth, and New & Kerr's media for selection of hypervirulent wild-type Agrobacterium spp from galls, hairy root-like process and soil of Populus, Malus, Salix and Diopyros in Korea. Among them, 48 strains were able to induce tumors in carrot disc. Hypervirulent A. tumefaciens SP101 and SM042 were identified as biotype 1 and biotype 2, respectively, These strains formed fast growing, larger tumors as compared to those induced by other strains. The binary vector pGA643 with kanamycin resistant gene was mobilized from E. coli MC100 into A. tumefaciens strain SM042 isolated from soil, and/or disarmed vector PC2760 using a triparental mating method with E. coli HB101/pRK2013, and transconjugants, A. tumefaciens SM643 and PC643 were obtained in minimal media containing kanamycin and tetracycline. Tobacco tissues were cocultivated with conjugant Agrobacterium and then transferred to selective medium with 2,4-D and kanamycin to induce the transformants. Calli were formed more efficiently in cocultivation with A. tumefaciens SM643 than that with A. tumefaciens PC643. Most of calli transformed with A. tumefaciens PC643 were friable and regenerated into normal plantlets, while the calli transformed with A. tumefaciens SM643 were compact, hard, and mixed with friable calli. The friable calli formed normal shoots, while compact calli did not form shoots but only grew to typical compact tumor calli. When the shoots formed directly from tobacco stems without callus induction after transformation by A. tumefaciens SM643 with wild-type Ti-plasmid, normal transformed plants can be induced without using disarmed Ti-plasmid.

• Korean Journal of Medicinal Crop Science
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• v.27 no.6
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• pp.397-403
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• 2019

Background: Oplopanax elatus is widely distributed at high altitudes (about 1,100 m) in China, Russia and Korea. It is hard to propagate, breed, and difficult to grow. Hence, it has been designated as a rare and endangered medicinal plant. A study was conducted to establish a system for large scale seedling production of Oplopanax elatus in vitro and to find the ideal environment for its seedling growth. Methods and Results: In this study, the explants produced under in vitro conditions during our previous study were grouped into three categories (under 10 mm, 10 mm - 30 mm and above 30 mm) based on plant height and were transferred to the growth-chamber and greenhouse for two weeks in each setting for acclimatization. The plantlet category of above 30 mm showed good performance, and was further evaluated under three acclimatization methods as follows: three different growth media (commercial soil, commercial soil + perlite, commercial soil + sand), four shading levels (0%, 50%, 70%, 90%) and four altitude levels (157 m, 218 m, 601 m, 870 m) in Gangwon province of South Korea. As results, O. elatus seedlings showed better growth characteristics at 870 m of altitude, 70% shading level and in the commercial soil compared to other treatments. Conclusions: The regenerated seedlings of Oplopanax elatus obtained through plant tissue culture would be advantageous for use in large scale seedling production systems paired with a good acclimation method. For obtaining optimal results, it is recommended that seedling be acclimatized in a high altitude environment.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.215-220
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• 1994

Pollen-derived embryos cultured on the hormone-free medium showed a low germination frequency (12.5%) and poor growth response after germination. The greatest frequency of germination (81.3%) was obtained from the embryos cultured on medium with 0.3mg/L GA$_3$.The greatest frequency of generation (81.3) was obtained from embryos cultured on medium with 0.3mg/L GA$_3$. The embryos precultured for 20 days on medium with 0.3mg/L GA$_3$were transferred to the medium with various combination of hormones such as IAA, kinetin, zeatin, 6-benzylaminopurin (BA) and Gh$_3$. The germination frequency of cotyledonary stage embryos showed above 72% on media with all of the hormonal combinations, but the embryos germinated on medium with 2mg/L BA or 0.1mg/L kinetin and 0.3mg/L GA$_3$ developed more vigorously into plantlets than those of other hormonal combinations. Torpedo-stage embryos cultured on medium with 0.3 mg/L Gh$_3$ were pretreated for 8 weeks at 2-week intervals at 4$^{\circ}C$, The germination frequency of the cold-preheated embryos increased with the increment of pretreatment period from 2 to 8 weeks. The greatest frequency of germination (73.3%) was obtained from the embryos pretreated for 8 weeks at 4$^{\circ}C$. The chromosomes of the root-tip cells of W plane grown for 40 days after germination were observed. Most of the regenerated plants were haploid (55.8%) or diploid (315%), but triploid (1.3%), tetraploid (5.2%), or aneuploid (6.5%) were also detected among them.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.259-264
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• 1999

In order to study the role of ethylene on the formation of adventitious roots, trichomes and calli, the effects of 1-aminocyclopropane-l-carboxylic acid (ACC), ethephon, $CoCl_2$ and $AgNO_3$ were investigated in the leaf segments from ecotype Columbia of Arabidopsis thaliana. When the leaf segments were cultured on the media for forming adventitious roots (0.1 mg/L NAA), trichomes (2.0 mg/L NAA) and calli (10.0 mg/L NAA), and then each cultures was treated with 1-100 mg/L of ACC and ethephon, respectively. On the adventitious root-forming medium adventitious root formation was decreased, and trichomes were induced. And on the trichome-forming medium trichome formation was decreased, and calli were induced. In order hand each culture was treated with 1-100 mg/L of $CoCl_2$ and $AgNO_3$, respectively. On the adventitious root-forming medium adventitious roots was increased without trichome formation, and on the trichome-forming medium trichome formation was decreased, and adventitious roots were induced. However on the callus-forming medium treated with ACC, ethephon, $CoCl_2$ and $AgNO_3$, respectively, callus formation was inhibited and trichomes were induced in all cultures.

• Korean Journal of Plant Resources
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• v.12 no.1
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• pp.1-9
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• 1999

The experiments were carried out to determine the optimum conditions for the induction of hairy roots in ginseng(Panax ginseng C.A. Meyer) by Agrobacterium spp. We were examined the antibiotics resistance of Agrobacterium spp and various ginseng parts, and the media for induction of hairy roots. The optimum concentration of NaOCl for sterilization of ginseng root segments without tissue damage with reduce of contamination was 7% NaOCl for 15-20 min and 9% NaOCl for 5 min, respectively. The more ginseng ages, the more contamination of ginseng root segment by sterilized in 7% NaOCl for 20 min, and especially in ginseng root segments with epidermis in six-year old roots. The growth of Agrobacterium spp were inhibited, but ginseng root segments was death in 30mg/L tetracycline. In 500mg/L cefotaxime or 500mg/L carbenicillin, the growth of Agrobacterium sup were inhibited, and root segments was grown normally. The optimum conditions for induction of hairy roots were using the root segments of three-year old ginseng cultured in 1/2MS medium supplemented with 500mg/L cefotaxime, and inoculation of Agrobacterium to root segments were better co-culture than smear method. After 2 weeks co-culture, the callus induced in cambium of root segments cultured in 1/2MS solid medium with 500mg/L cefotaxime. And then after 2 weeks, ginseng hairy roots were induced in callus of root segments. PCR analysis of rot C gene fragment confirmed that hairy roots were transgenic tissues.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.455-461
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• 1987

The ovaries or the ovules of grasses were pollinated and cultured in vitro to raise the interspecific or the intergeneric hybrids between tall fescue, meadow fescue, and Italian ryegrass. The isolated and suface-sterili-zed pistils were dusted with compatible pollens on stigma, on stump after removing stigma, or on excised ovule. Furthermore, the fertilized ovaries and ovules were cultured on MS, M6, or White's media and treated with plant growth regulators: IAA, kinetin, BA to promote embryo development and seed maturity. The in vitro fertilization in grass species ranged from 44 to 92% depending on ovary and pollen parents. The stigmatic pollination was resulted in 67.8% fertilization, the stump pollination 89.0%, and the excised ovule pollination 61.0%, repectively. White's medium was the most effective to provide embryo development and seed maturity in grass species. And the combined treatment of IAA 10mg/$\ell$, kinetin 0.2mg/$\ell$, was better than the non-treatment. Only two seedlings, one complete and one abnormal with root formation were obtained from 127 ovaryies cultured. The anatomy of ovules in vitro cultured was revealed the differentiation of vascular system and meristematic tissue, and the formation of sclerenchyma cells inside ovule.

• Journal of Mushroom
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• v.3 no.2
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• pp.71-74
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• 2005

The sterile form of Inonotus obliquus is used for preparation of the medicine befungin that is effective in the treatment of gastritis, gastric ulcers, and several tumors. The fungus is known to be produced mainly on the stems of Betula platyphylla var. japonica that grows at high altitudinal (above 1,100 m) region in Korea. But, we found the mushroom on the stem of Betula costata at Mt. Jumbong in Korea. We isolated a pure culture of the fungus from the stem of B. costata by use of potato dextrose agar (PDA) medium with streptomycin. We could isolate the fungus from plant's tissue filled with hyphae, but not from other parts. The spore collected from the sclerotia showed $6.0{\sim}10.0{\times}4.5{\sim}6.0{\mu}m$ in diameter, and the hypha was $2.5{\sim}5.0{\mu}m$ in thickness. The colony showed irregular features and scattered yellow color at the center as the culture ages. We could find brownish setae at the yellow region of colony at 20 days of culture, and the size ranged $4{\sim}6{\times}100{\sim}420{\mu}m$. The oatmeal agar (OA) provided best growth for I. obliquus among five media (CDA, CMA, MA, OA and PDA). Optimum temperature ranged $25{\sim}30^{\circ}C$, and optimum pH was relatively alkaline with the range of pH 8.0~9.5.