• Journal of Plant Biotechnology
• /
• v.6 no.2
• /
• pp.97-102
• /
• 2004

This study was carried out to establish The regeneration of healthy seedlings from the nodal segment culture of Chinese yam (Dioscorea opposita cv. Danma), cultivated in Korea. Different explants such as leaves, petioles, roots and nodal pieces, excised from the in vitro grown seedlings of Chinese yam, were cultured on MS medium supplemented with various combinations of growth regulators. All the growth regulators used induced plantlet regeneration from the nodal segments at a high frequency, while there was no induction of shoot or callus from leaf, petiole or root tissues. The medium supplemented with 0.01mg/L NAA, 0.5mg/L BA, 0.5-1.0mg/L kinetin and without plant growth regulator was effective for shoot development of buds from the nodal segment culture. The concentration of BA and NAA was an important factor in the bud induction of buds from the nodal segments of Chinese yam. Nodal segments cultured on the medium containing 1.0mg/L NAA and 0.5-1.0mg/L BA gave the best response to bud formation. The addition of GA$_3$ to the culture medium suppressed shoot induction and growth, while it increased microtuber formation. The shoot growth and microtuber formation were also affected by medium strength and solidity. The MS basal medium containing 1 g/L gelrite was suitable for microtuber formation from the nodal segment of Chinese yam.

• Korean Journal of Plant Resources
• /
• v.18 no.3
• /
• pp.403-409
• /
• 2005

Mature nodal segments of 2-year-old greenhouse stock plant were cultured on Murashige and Skoog basal medium supplemented with the different kinds and various concentrations of cytokinins to produce multiple shoots in in vitro condition. The most adventitious shoots were produced from excised ends of nodal segments. The highest average number $(24.6\;{\pm}\;4.6)$ of shoots was produced with the combination of BA 1.0mg/L and TDZ 0.1mg/L in MS medium. In addition, several shoots were formed from lenticels of bark cambium with the same treatment. These concentrations promoted high shooting capability upto $94.6\%$ and NAA was the best cytokinin among five different PGR sources.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.10a
• /
• pp.16-16
• /
• 2019

The Cassava (Manihot esculenta Crantz) is a perennial woody shrub cultivated mainly in the tropics for its starchy tuberous roots. It belongs to the family Euphorbiaceae which also includes rubber (Hevea brasiliensis) and castor bean (Ricinus communis). Among tropical crops, rice, sugarcane, maize and cassava are the most important sources of calories for human consumption. Problems in the propagation of cassava are virus diseases and low rates of seed germination. Thus, a study was undertaken to develop an efficient in vitro mass propagation protocol of Manihot esculenta Crantz. Young and actively growing stem segments were excised from adult plants of cassava. Samples were cut into a 3~4 cm nodal segments with single node after sterilization, and cultivated in the different medium supplemented with various plant growth regulators for 4 weeks. For shoot multiplication, single-node stem segments, approximately 1 cm in length, were taken from in vitro derived shoots and subcultured. After 4~6 weeks, the shoot generation rate was 55.6%, the shoot number and its length were 1.0/explant and 2.3 cm in the most favorable medium composition. Our experiments confirmed that in vitro growth and multiplication of plantlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

• Plant Biotechnology Reports
• /
• v.3 no.3
• /
• pp.175-182
• /
• 2009

Simple, reproducible, high frequency, improved plant regeneration protocol in Eastern Cottonwood (Populus deltoides) clones, WIMCO199 and L34, has been reported. Initially, aseptic cultures established from axillary buds of nodal segments from mature plus trees on MS liquid medium supplemented with $0.25mg\;1^{-1}$ KIN and $0.25mg\;1^{-1}$ IAA. Nodal and internodal segments were found to be extra-prolific over shoot apices during course of aseptic culture establishment, while $0.25mg\;1^{-1}$ KIN concentration played a stimulatory role in high frequency plant regeneration. Diverse explants, such as various leaf segments, internodes, and roots from in vitro raised cultures, were employed. Direct plant regeneration was at high frequency of 92% in internodes, 88% in leaf segments, and 43% in root segments. This led to the formation of multiple shoot clusters on established culture media with rapid proliferation rates. Many-fold enhanced shoot elongation and growth of the clusters could be achieved on liquid MS medium supplemented with borosilicate glass beads, which offer physical support for proliferating shoots leading to faster growth in comparison to semi-solid agar or direct liquid medium. SEM examination of initial cultures confirmed direct plant regeneration events without intervening calli. In vitro regenerated plants induced roots on half-strength MS medium with $0.15mg\;1^{-1}$ IAA. Rooted 5- to 6-week-old in vitro regenerated plants were transferred into a transgenic greenhouse in pots containing 1:1 mixture of vermicompost and soil at $27{\pm}2^{\circ}C$ for hardening and acclimatization. 14- to 15-week-old well-established hardened plants were transplanted to the field and grown to maturity. The mature in vitro raised poplar trees exhibited a high survival rate of 85%; 4-year-old healthy trees attained an average height of 8 m and an average trunk diameter of 25 cm and have performed well under field conditions. The regeneration protocol presented here will be very useful for undertaking genetic manipulation, providing a value addition to Eastern Cottonwood propagation in future.

• Journal of Forest and Environmental Science
• /
• v.25 no.2
• /
• pp.111-118
• /
• 2009

Multiple shoot induction and plant regeneration using apical bud and nodal explants of 100 year old tree of Anthocephalus cadamba, an important sacred and medicinal tree in India was achieved for the first time. Aseptic explants cultured in Murashige and Skoog (MS) medium augmented with different concentrations of BAP (0.1, 0.5, 1.0, 2.5, 5.0 and 10 mg/l), when maintained for 60 days, healthy shoots were induced in presence of BAP (1 mg/l). Lower concentrations of BAP (0.1 - 0.5 mg/l) induced only one shoot per explant. Increase in number of shoots per explant was observed in presence of higher concentrations of BAP (2.5, 5.0 and 10 mg/l). However, elongation of shoots was completely inhibited. Bud break and shoot regeneration was largely associated with seasonal factors. Apical buds cultured during June to August exhibited early bud break within two weeks of initial culture. In rest of the months, bud break and shoot regeneration was very slow irrespective of the various concentrations of BAP used in the medium. Explants sourced from three different maturity levels of shoots indicated that actively growing shoots from the mother plant with 1 - 2 nodal segments was more suitable for culture initiation than the explants collected from mature shoots at dormant stage. Regenerated shoots with 2 - 3 pairs of leaves when transferred to half strength MS medium fortified with IBA (1 mg/l), 60% of the shoots induced healthy roots, indicating the possibility of large scale micropropagation.

• Korean Journal of Plant Tissue Culture
• /
• v.28 no.1
• /
• pp.1-6
• /
• 2001

The timing for the determination in root formation from nodal and internodal explants of cassava (Manihot esculenta Crantz, cv. MCol 22) was investigated. Nodal explants about 10 mm with an axillary bud formed adventitious roots directly on MS basal medium for 8 days of cultures. But internodal segments without an axillary bud did not develop the adventitious roots on the same medium, and most internodal segments excised from nodal explants after cultures of 5 days on MS basal medium developed adventitious roots. On the other hand, the internodal segments rooted at 90% after cultures on medium with 0.5 mg/L IBA for 5 days, with 1 mg/L IBA for 2.5 days, and with 2 mg/L IBA for 1.5 days respectively. Thus the period of culture on medium with IBA and its IBA concentration affected the rooting rate. Therefore, it is suggested that the determination for root formation occurred before the differentiation of root primordia on medium with IBA, and root inducing factors in medium were absorbed and accumulated during the period of determination for root primordium differentiation in internodal segment of cassava.

• Structural Engineering and Mechanics
• /
• v.5 no.1
• /
• pp.33-49
• /
• 1997

A method of analysis is proposed for curved multicell box girder grillages. The method can be used to analyze box girder grillages comprising straight and/or curved segments. Each segment can be modelled by a number of beam elements. Each element has three nodes and the nodal degrees of freedom (DOF) consist of the six DOF for a conventional beam plus DOF to account for torsional warping, distortion, distortional warping, and shear lag. This element is an extension of a straight element that was developed earlier. For a more realistic analysis of the intersection regions of non-colinear box girder segments, the concept of a rigid connector is introduced, and the compatibility requirements between adjoining elements in those regions are discussed. The results of the analysis showed good agreement with the shell finite element results, but the proposed method of analysis needs a fraction of the time and effort compared to the shell finite element analysis.

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

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.10b
• /
• pp.2-3
• /
• 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 initiation from nodal segments was very rare. Mature apices produced callus. Although removal 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 Bio-Environment Control
• /
• v.14 no.4
• /
• pp.298-301
• /
• 2005

Potato (Solamum tuberosum 'Dejima') plantlets were investigated on culture type and initial quantity of inoculation in bioreactor and survival rate by hydroponics for mass production. rode stems (1 to 1.5cm in length) of potato plantlets multiplied in vitro were grown for 3 weeks in liquid Murashige and Skoog (MS) medium with sucrose $30 g\; L^{-1}$. When plantlets (80-node inoculation) were raised in 10L balloon type bubble (BB) bioreactor, the healthiest growth of plantlets was obtained from explants cultured in ebb & flow culture with medium supplied periodically 12 times per day. The suitable inoculation quantity of 20L BB bioreactor was 120 pieces of stem segments (mean 2.2g fresh weight) in ebb & flow culture. Number of nodal shoot was eight on the average. In controlled culture room, survival rate of plantlets at 7 days after stem cutting was above $70\%$ when they were acclimatized by hydroponics grown in deep flow and solid medium culture. The highest survival rate of the stem cutting plantlets was in nutrient solution adjusted to EC $1.4dS{\cdot}m^{-1}$. Stem cutting plantlets through one culture could be obtained $670\~900$, when plantlets were grown in ebb & flow culture during 3 weeks using a 20L bioreactor with initial 120 pieces of nodal segments. 11 is possible In do mass production of seedlings cultured in bioreactor and hydroponics.