• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 심포지엄
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• pp.9-18
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• 2003

A method for rapid propagation of mature Jack fruit was developed. Four types of explants (mature embryos, apical meristems of young seedlings, apices from mature plants and nodal segments) were used. It has been found 88% of young apical meristems produced shoots in Campbell and Durzan (CD) medium compared to 60% in Murashige and Skoog (MS) medium. Only 1/3 of them produced multiple shoots. Shoot idtiation from nodal segments was very rare. Mature apices produced callus. Although removed of the sheathing cover around mature buds enhanced the shoot initiation but success rate was low in growth regulator free medium. Embryos respond to the CD medium but not to the MS medium. Embryos from seeds soaked in water for 24 hours produced shoots after 8 weeks of incubation and the success rate was 70% while embryos from dry seeds only produced roots. There was no significant effect of cold storage (refrigeration) for 7 days on shoot initiation from mature embryos (65%) but the ability for shoot induction declines with storage time (55% after 21 days of cold storage). Mature axillary buds were established in Modified Campbell and Durzan (CD) medium supplemented with 0.5mg/1 and IBA. There was a significant difference in the growth performance of shoots according to the period of the year in which explants were collected. Highest (60%) was observed in November-January period. It was only 30% when the explants were collected in February-April or May-July and decreased to 20% in August-October. The shoots produced in November-January showed a higher vigor than those produced in other months. Since Jak fruit show seasonal changes in fruit bearing and shedding of leaves, it can be suggested that the difference in growth performances of tissues cultured in artificial culture media would have been affected by endogenous rhythms.

• Journal of Plant Biotechnology
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• 제48권4호
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• pp.255-263
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• 2021

Paederia foetida L. is an important medicinal plant that has been used for the treatment of various gastrointestinal related ailments by different tribal communities in India. This plant is also known for its use as a food. Due to overexploitation, P. foetida has been classified as a vulnerable plant in some states of India. The propagation of P. foetida by conventional methods is easy but very slow. Synthetic seed technology offers incredible potential for in vitro propagation of threatened and commercially valuable plants, and can also facilitate the storage and exchange of axenic plant material between laboratories. However, synthetic seed production for P. foetida has not yet been reported. Thus, to the best of our knowledge, the present study is the first attempt to produce synthetic seeds of P. foetida by calcium alginate encapsulation of in vitro regenerated axenic nodal segments. Sodium alginate (3%) and CaCl₂ (100 mM) were found to be the optimal materials for the preparation of ideal synthetic seeds, both in terms of morphology and germination ability. The synthetic seeds showed the best germination (formation of both shoot as well as root; 83.3%) on ½ MS medium augmented with 0.5 mg/L indole-3-acetic acid. The plantlets obtained from these synthetic seeds could be successfully acclimatized under field conditions. We also studied the storage of these synthetic seeds at low temperature and their subsequent sprouting/germination. The seeds showed a germination rate of 63.3% even after 21 days of storage at 4 ℃; thus, they could be useful for transfer and exchange of P. foetida germplasm.

• Journal of Plant Biotechnology
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• 제5권4호
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• pp.239-244
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• 2003

A protocol has been developed for rapid large scale clonal propagation of an aromatic endangered medicinal plant, Hemidesmus indicus R. Br. with the elimination of the problems such as premature leaf fall and callus formation during caulogenesis and rhizogenesis. Multiple shoots were induced from shoot tip and nodal explants on Murashige and Skoog (MS) medium supplemented with 1 mg/L Benzylaminopurine (BAP) and 0.5 mg/L Napthaleneaceticacid (NAA). Addition of 15 mg/L adenine sulphate to the above medium checked leaf abscission completely, reduced the time required for caulogenesis and restored morphogenetic potential after several subcultures. The in vitro grown propagules were rooted in 1/2 MS medium supplemented with 2 mg/L Indolebutyric acid (IBA) +1 mg/L NAA and sucrose 0.7% (w/v). Addition of charcoal at 100 mg/L to the rooting medium quickened root initiation with a complete check on callus formation. The effect of sucrose concentration on both caulogenesis and rhizogenesis was also studied. The resultant plantlets were acclimatized and grown in fields where ninety eight percent of the rooted shoots survived and grew normally. The estimation of the secondary metabolite content in the shoots of the regenerated plant and the mother plant indicated that the concentration of the three secondary metabolites lupeol, vanillin and rutin was similar.

• 식물조직배양학회지
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• 제28권4호
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• pp.189-195
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• 2001

화경절 액아 유래 신초의 잎을 이용한 팔레높시스 대량번식에서 배양재료로 이용되는 신초의 발생수를 증가시키기 위해 화경배양을 위한 배지, 배양온도 화경 전처리 등 기내 배양조건과 계통 간 화경의 발육형태에 대해 조사하였다. 화경절 액아의 신초발생률은 MS배지에서 90.9%, Hyponex 배지에서 54.4%이었다. 5 mg/L의 BA가 첨가된 MS배지에서 신초가 많이 형성되었으며 발육상태도 양호하였다. 화경 액아의 위치별 발육형태는 기저부 쪽일수록 신초발생이, 상부 쪽일수록 2차화경이 많이 발생되었으며 25~28$^{\circ}C$의 배양온도는 액아로부터 신초를 얻는 데 적절하였으며, 황화처리는 오염률을 낮추는 데 효과가 있었으나 페놀물질 유출량의 감소효과는 없었다. 수집한 30계통 중 27계통의 화경에서 신초를 얻었으며 화경편 당 평균 신초수는 3.17개이었으나 Phal. 3020, 3039 등은 신초가 많이 발생되어 다른 계통과 차이가 있었다. 교잡 F$_1$계통의 화경발육 양상은 모본(수집계통)과 비슷하였다.

• 한국약용작물학회지
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• 제7권3호
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• pp.155-161
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• 1999

본 연구는 조직배양을 이용하여 도입된 다수확 우량마 (Dioscorea alata L. ) 의 대량증식을 위한 배양체계 를 확립 하였다. 식물생장조절제 (NAA) 및 sucrose를 첨가한 MS배지에서 마의 무균경단편을 배양하면 경단편에 괴경이 형성되었다. 이 괴경 형성에 미치는 식물생장조절제의 종류와 농도, Sucrose의 농도 및 광조건에 대한 영향을 조사한 결과, 마의 괴경 형성은 식물 생장조절제의 첨가에 의해 촉진되어서 괴경형성율은 NAA 1mg/l을 첨가한 배지에서 최고율이었다. Sucrose 농도를 높일수록 형성률이 상승되어 6%처리구에서 최고에 달했다. 괴경 형성에 가장 큰 영향을 미치는 것은 광조건으로 암흑조건의 형성율은 명조건 보다 크게 상회하였다. 그리고 암조건에서는 액아부위가 맹아하지 않고 무균 경단편에 괴경만이 형성 되었다. 이상의 결과에서 마의 괴경 형성에 최적의 배양조건은 NAA 1mg/l, surcrose 6%를 침 가한 1/2MS 배지에 무균경단편을 치상하여 $25^{\circ}C$ 암흑조건하에 배양한 것이었다.

• 대한기계학회논문집A
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• 제24권11호
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• pp.2705-2712
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• 2000

In meshless methods some techniques to impose essential boundary conditions have been developed since the approximations do not satisfy Kronecker delta properties at nodal points. In this study, new scheme for imposing essential boundary conditions is developed. Weight functions are modified by multiplying with auxiliary weight functions and the resulting shape functions satisfy Kronecker delta property on the bound ary nodes. In addition, the resulting shape functions possess and interpolation features on the boundary segments where essential boundary conditions are prescribed. Therefore the essential boundary conditions can be exactly satisfied with the new method. More importantly, the impositions of essential boundary conditions using the present method is relatively easy as in finite element method. Numerical examples show that the method also retains high convergence rate comparable to Lagrange multiplier method.

• Steel and Composite Structures
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• 제35권5호
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• pp.641-657
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• 2020

A unique lightweight string truss deployable bridge assembled by thin-walled fiber reinforced polymer (FRP) and metal profiles was designed for emergency applications. As a new structure, investigations into the static structural performance under the serviceability limit state are desired for examining the structural integrity of the developed bridge when subjected to unsymmetrical loadings characterized by combined torsion and bending. In this study, a full-scale experimental inspection was conducted on a fabricated bridge, and the combined flexural-torsional behavior was examined in terms of displacement and strains. The experimental structure showed favorable strength and rigidity performances to function as deployable bridge under unsymmetrical loading conditions and should be designed in accordance with the stiffness criterion, the same as that under symmetrical loads. In addition, a finite element model (FEM) with a simple modeling process, which considered the multi segments of the FRP members and realistic nodal stiffness of the complex unique hybrid nodal joints, was constructed and compared against experiments, demonstrating good agreement. A FEM-based numerical analysis was thereafter performed to explore the effect of the change in elastic modulus of different FRP elements on the static deformation of the bridge. The results confirmed that the change in elastic modulus of different types of FRP element members caused remarkable differences on the bending and torsional stiffness of the hybrid bridge. The global stiffness of such a unique bridge can be significantly enhanced by redesigning the critical lower string pull bars using designable FRP profiles with high elastic modulus.

• 한국약용작물학회지
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• 제14권5호
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• pp.278-281
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• 2006

The effect of plant growth regulators was investigated on in vitro shoot proliferation from axillary bud explants of Hypericum erectum. To determine the optimal cytokinin for proliferation of axillay buds, we carried out screening four cytokinins (BA, kinetin, 2iP, TDZ). When nodal segments were cultured on MS medium supplemented with $4.5\;{\mu}M$ TDZ (thidiazuron), a number of shoots were induced. Our results indicated that the addition of TDZ to culture medium resulted in the induction of significantly more axillary buds than in the addition of other cytokinins. The optimal concentration of TDZ for proliferation of axillary buds was $10\;{\mu}M$. 92% of shoots spontaneously rooted without any plant growth regulator (PGR) and formed whole plantlets within one month. More than 95% of these regenerants survived and they did not show any detectable variation in morphology or growth characteristics compared to their donor plants.

• Advances in Traditional Medicine
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• 제7권2호
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• pp.197-204
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• 2007

The present study focused on the establishment of micropropagation protocol for the high value Pluchea (P.) indica (L.) Less., genotype, an important medicinal plant and evaluation of the diuretic activity of the leaf extract of the tissue cultured plant. Leaf explants, nodal segments and shoot tips were cultured in MS medium supplemented with auxin and cytokinin and their combinations. With the objective of inducing callus giving rise to new adult plants, naphthalene acetic acid was found to be most effective for (80%) for callus induction. The methanolic extract of leaves of the micropropagated P. indica was investigated for its diuretic activity in Wistar albino rats. Urinary excretion parameters were studied for evaluation of diuretic activity using Frusemide (20 mg/kg, p.o.) as standard. The extract showed significant diuretic activity at the doses of 100, 200 and 300 mg/kg. p.o. An oral acute toxicity study for the extract was carried out and the $LD_{50}$ value was found to be 2,825 mg/kg body weight.

• Plant Biotechnology Reports
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• 제5권1호
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• pp.35-43
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• 2011

This communication describes for the first time an efficient and reproducible protocol for large-scale multiplication of Bambusa nutans. Nodal segments collected from field-grown clumps and cultured on Murashige and Skoog (MS) medium supplemented with $4.4{\mu}M$ benzylaminopurine (BA) and $2.32{\mu}M$ kinetin (Kin) gelled with 0.2% gelrite yielded 80% aseptic cultures with 100% bud-break. The in vitro-formed shoots obtained after bud-break were successfully multiplied in MS liquid medium supplemented with $13.2{\mu}M$ BA, $2.32{\mu}M$ Kin, and $0.98{\mu}M$ indole-3-butyric acid (IBA). Sub-culturing of shoots every 3 weeks on fresh multiplication medium yielded a consistent proliferation rate of 3.5-fold. Shoot clusters containing three to five shoots were successfully rooted with 100% success on half-strength MS liquid medium supplemented with $9.8{\mu}M$ IBA, $2.85{\mu}M$ indole-3-acetic acid (IAA), $2.68{\mu}M$ naphthaleneacetic acid (NAA), and 3% sucrose. Plantlets grown in vitro were acclimatized and subsequently transferred to the field. Inter-simple sequence repeat analysis has confirmed the genetic uniformity of the tissue-cultured plants up to 27 passages.