• Journal of Sericultural and Entomological Science
• /
• v.44 no.1
• /
• pp.13-18
• /
• 2002

The morphorogical characteristics of the Morus tiliaefolia growing wild in the Korean peninsula are as follows. The chromosome number of somatic cell is 2n=84,that is hexaploid. The shape of male inflorescence is a long cylinder shape of 3.6∼6.0 cm. The length of female inflorescence is 1.8 cm, red violet or violet and the weight of mulberry fruits is 1.39∼1.65 g. The winter bud is very big in comparison with the branch and the accessory bud does not exist. The leaf is big and lobed leaf or entire leaf, the density of lenticell is 9.42$\pm$1.29 ㎠. The length of leaf trichome is 236∼438 ㎛ and the distribution density is 16∼37/25 ㎟ and heigh density of leaf back. The trichome shape of the leaf surface is cylinder shaped, in the leaf back it is thin and long corn shaped.

• The Korean Journal of Zoology
• /
• v.18 no.2
• /
• pp.71-86
• /
• 1975

The G-banding patterns of normal and of delayed spiralized chromosomes by BUdR were investigated in three established cell lines of dwarf hamsters. The results obtained were as follows: 1. The number of G-bands appeared in Chinese hamster T-233 cell line was 65. The centromeric dark band was found in No.1 chromosome and weakly stained bands were also observed in part of the centromeric regions of Nos. 2, 3, 8 and $X_2$ chromosomes. Two homologous X chromosomes were found in different banding patterns. Terminal dark bands were shown in No. 1 chromosome. No conspicuous bands appeared in No. 10 chromosome. 2. Eighty four bands appeared in Armenian hamster Y-1249 cell line. Centromeric dark bands were observed in Nos. 5 and 10 chromosomes and moderatly stained bands were also found in near the centromeric region of the long arms of Nos. 7 and 9 chromosomes. Two isomorphic X chromosomes were also distinguished by their banding patterns. 3. In Y-1313 Armenian hamster cell line, the bands were 69. No centromeric dark bands were observed in this cell line, but moderatly stained bands appeared in the centromeric area in the long arm of No. 9 chromosome. The banding patterns of these two cell lines of Armenian hamster were quite different and readily distinguished. Only No. 8 chromosome showed similar G-banding patterns. Although Nos. 5, 7 abd 8 chromosomes revealed the same number of bands in these two cell lines, the location and staining intensity were quite different. 4. Chromosomes of Nos. 1, 2, 6, $X_1$ and $X_2$ in T-233 cell line and of 1, 4, 7, 8, 9, $X_1$ and $X_2$ in both cell lines of Armenian hamster were found to be elongated due to the inhibition of mitotic spiralization by BUdR. G-banding patterns of these chromosomes were found to be identical to those of normal chromosomes in these cell lines.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.3
• /
• pp.201-207
• /
• 1993

This study was carried out to ascertain the flowering and boiling habits in conditions of vinyl mulched cultivation. The effects of vinyl mulching cultivation in cotton was early flowering. The flowering period was no more than 26 days and shedding of flower bud was lower. The total boll setting rate to flower number was about 38%. The number of flowering plants was rapidly increased until Aug. 8, then later was decreased, the period of the highest flowering occured was for 5 days from Aug. 6 to Aug. 10. Boll setting was increased that the flowers opened before July 30, then the later flowers was tended to decrease belling in spite of the increased flowering. However flower bud shedding had a tendency to decrease after the highest boiling period. The effect of weather, max. temperature and hours of sunshine on flowering days were highly positive significant correlation. Minimum temperatures, high air humidity and amount of rainfall had a negative significant correlation. The demanded days to flowering on the same internode in each fruiting branches was taken average 1.2 days, these days among the fruiting branches of the same internode was 3.6 days.

• Journal of Plant Biotechnology
• /
• v.35 no.3
• /
• pp.229-234
• /
• 2008

An efficient micropropagation was established by using axillary bud explants from two-year-old tree(Echinosphorea koreensis Nakai), which has been known as a rare and endangered species. Among various basal media tested, DKW medium was shown to be the best for axillary shoot elongation. The addition of both BA and TDZ to the medium induced 6 to 10 shoots per explant during eight weeks of culture, without showing any abnormal morphology at the shoot proliferation stage. However, high concentration of TDZ(>0.05 mg/L) appeared to cause hyperhydration on either leaf or shoot at the later developmental stage. Approximately 20% of shoots produced roots by the addition of 1.0 mg/L NAA but not by IBA($0.2{\sim}1.0$ mg/L). Ex vitro micro-cuttings were better source for root induction; up to 58.6% of the micro-cuttings rooted when 100 mg/L IBA was applied to the soil(vermiculite). More than 90% of plantlets with roots were successfully acclimatized and grew normally in the field. Therefore, we suggest that this endangered tree species can be effectively micropropagated by axillary bud culture system developed in this study.

• Korean Journal of Agricultural Science
• /
• v.14 no.2
• /
• pp.205-212
• /
• 1987

To examine the morphogenetic response, stem segments of 8 Populus spp. and 3 different explants of P. nigra var. italica were cultured on MS (Murashige and Skoog 1962) and WPM (Woody Plant Medium) medium containing various phytohormones. The results obtained were as follows: 1. Shoot regeneration and development from stem segment of 8 Populus spp. showed a quite difference according to the section and the species. All of the species of Leuce and Tacamahaca section did not form adventitious buds, while most of explants showed axillary or dormant bud elongation after 4 weeks. But P. nigra var. italica of Aigeiros section showed a successful adventitious bud formation (mean 5.4 buds per explant). 2. Leaf, petiole, and internode segment of P. nigra var. italica showed a quite differences according to media and ex plants upon the morphogenetic response. Adventitious bud formation from leaf was more abundant and readily initiated on the abaxial side than on the adaxial side. Mean number of 103 adventitious buds per explant was obtained from abaxial side of leaf segment cultured on WPM medium containing $0.2mg/{\ell}$ BAP for 5 weeks. 3. 2,4-D (2,4-dichlorophenoxy acetic acid) supplemented to media appeared to be negative upon the adventitious bud formation of P. nigra var. italica, while it promoted callus formation from all explants. Especially, NAA (${\alpha}$-naphtalene acetic acid) or NAA combination with BAP (6-benzylaminopurine) promoted root regeneration from the all explant of P. nigra var. italica in this study.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.2
• /
• pp.383-399
• /
• 1998

Tooth development is usually described in four stages such as bud stage, cap stage, bell stage and crown stage. Exact time of appearance of tooth primordia is different among reports, and up to now there is no timetable regarding initial tooth development. To understand the congenital malformations and other disorders of the orofacial region, there is a need to establish a standard timetable on early tooth development. Till now, studies on the tooth development were mainly on later fetuses, and only few reports on early stage. Also, there were no reports on the time when bud stage turns to cap stage, and cap stage to bell stage. In this study, external morphology of face and the early development of the tooth, and transition of bud stage to cap stage, cap stage to bell stage were studied using 27 staged human embryos and 9 serially sectioned human fetuses. The results are as follows: 1. Mandibular region was formed by union of both mandibular arch at stage 15, and maxillary region by union of maxillary arch, medial nasal prominence, and intermaxillary segment at stage 19. 2. Ectodermal thickening which represents the primordia of tooth appeared in mandibular region at stage 13, and maxillary region at stage 15. 3. Bud stage began from mandibular primary central incisor at stage 17, and maxillary primary central incisor at stage 18. And the sequence of appearance was in the mandibular primary lateral incisor at stage 19, maxillary primary lateral incisor at stage 20, mandibular primary canine at stage 22, maxillary primary canine and primary first molar at stage 23, madibular primary first molar and maxillary primary second molar at 9th week, and mandibular primary second molar at 10th week of development. 4. Cap stage began from the primary anterior teeth at 9th week, and primary second molar still had the characteristics of cap stage at 12th week of development. 5. Transition to bell stage started from the primary anterior teeth at 12th week, and primary second molar started at 16th week of development. 6. Trnasition to crown stage started from primary anterior teeth at 16th week, and primary second molar at 26th week of development.

• Korean Journal of Medicinal Crop Science
• /
• v.5 no.4
• /
• pp.294-301
• /
• 1997

Fatty acid, amino acid and organic acid contents were analyzed by gas chromatography, amino acid analyzer and high pressure liquid chromatography, respectively, in order to compare the chemical constituents of upland wasabi plant propagated by seed and auxiliary bud. Total fatty acid content and fatty acid composition of upland wasabi were not affected by the propagation methods. Generally, fatty acid content of leaf was higher than that of other parts such as enlarged stem, petiole, peduncle and root. In fatty acid composition, leaf had highest content of linolenic acid, 60-63%, in plant propagated by both seed and auxiliary bud, followed by palmitic acid, oleic acid and linoleic acid in the order. Similarly, total amino acid content was not influenced by propagation methods but plant propagated by seed had higher amount of amino acid content in enlarged stem, petiole and root than that by auxiliary bud -propagated plant. A total of 17 amino acids including 7 essential amino acids were identified in both seed and auxiliary bud propagations. Like total fatty acid content and fatty acid composition, leaf contained high amount of amino acids, especially glutamic acid, asparatic acid and leucine. Organic acid contents were similar in both propagation methods. The major organic acid in upland wasabi was acetic acid (60.0-78.2%), followed by succinic acid (9.9-29.7%) and malic acid (2.9-7.9%). Maleic acid content was least (0.5-2.6%). The result indicates that content and composition of fatty acid, amino acid, and organic acid in upland wasabi were not influenced by propagation methods.

• Journal of Plant Biotechnology
• /
• v.30 no.3
• /
• pp.269-273
• /
• 2003

In order to develop an efficient micropropagation protocal for Eucalyptus pellita, on in vitro culture system has been was established by inducing axillary buds from greenhouse stock materials. Among 6different media tested, DKW medium was the best ot induce bast induce both shoot proliferation and growth. Average number of proliferated shoots of 403per explant was obtained at the concentration of 0.1mg/LBA. Most of the stem materials excreted phenolic compounds at the proximal part of the explant and caused darking of the media. Therefore, it was necessary to transfer frequently to a fresh medium and/or to add activated charcoal at the concentration of 0.02％(w/v). Generally on vitro roots were formed easily on 1/2DKW medium with NAA treatment. All the explants rooted at the medium containing 0.2mg/L NAA and displayed vigorous root growth in vitro culture conditions. After transferred to an artificial soil mixture (peatmoss: vermiculrite: perlite, 1:1:1, v/v/v) in the greenhouse, most rooted plantlets survived well without any morphological abnormalities. The results show that the species can be micropropagated effectively by the application of axillary bud culture system.

• Journal of Forest and Environmental Science
• /
• v.29 no.4
• /
• pp.275-281
• /
• 2013

To establish in vitro nodal culture conditions of Echinosophora koreensis Nakai, one of rare and endangered species famous for beautiful flowers in the Korean Peninsula, the influence of plant growth regulators (PGRs) on shooting and rooting from in vitro shoots was investigated. In shoot multiplication, addition of 6-benzylaminopurine (BA) to the half-strength Driver and Kuniyuki's media in the range of 2.22 to 8.88 ${\mu}M $induced 2.5 to 2.7 shoots per axillary bud; and addition of 2.27 ${\mu}M $ thidiazuron (TDZ) produced 3.2 shoots, during 4 weeks of culture, while zeatin and isopentenyl adenine (2ip) were not effective on shoot multiplication as observed from several combination treatments of BA with other PGRs. Shoots established were smaller than 2 cm in length, in most of the treatments. while in BA 8.88 ${\mu}M $ treatment more than 30% of shoots were longer than 2 cm and shorter than 4 cm. In rooting, naphthalene acetic acid (NAA) from 5.37 to 21.48 ${\mu}M $ showed the rooting rate from 40.0 to 62.5%. Indole butyric acid (IBA) addition had little effect on rooting (<10%), although some roots in IBA-containing media were longer than those in NAA. Micropropagation from axillary buds of nodular explants was applicable and promising to multiplication and conservation of Echinosophora koreensis Nakai.

• The Korean Journal of Zoology
• /
• v.34 no.4
• /
• pp.460-468
• /
• 1991

계배 limb bud간충직 연골원성 세포로부터 연골원세포로의 분화과정에서 Ca2+의 역할을 추구해 보기 위하여 Hamburger-Hamilton stage 23/24의 계배 limb bud간충직세포들을 미세배양법으로 배양하면서, Ca2+, calcium ionophore인 A23187, calcium channel blocker인 D600을 각각 농도 및 처리기간을 변화시켜 처리하면서 연골화의 정도를 검정하여, 연골세포 분화에 미치는 Ca2+의 작용양상을 분석하였다. 그 결과 Ca2+은 3 mM의 농도로 배양초기에 처리하였을 때 가장 효과적으로 연골화를 촉진하였으며, A23187(0.05 $\mu$ M) 처리는 세포내로 Ca2+유입을 증가시켜 연골화를 촉진시킨 반면, D6OO(30 $\mu$ M이하) 처리는 세포내로 Ca2+ 유입을 차단시킴으로서 연골화를 억제하는 것으로 나타났다. 이러한 결과에 따른 세포내로의 칼슘 유입 변화는 45Ca로 확인하였다. 그러므로 Ca2+에 의한 간충직세포의 연골세포로의 분화촉진 작용은 Ca2+이 연골화의 응집시기에 세포간의 접촉을 유도할 뿐만 아니라 배양 초기에 Ca2+이 세포 내로 들어감으로써 수반되는 일련의 기작에 의한 것임을 알았다.