• Korean Journal of Plant Resources
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• v.24 no.3
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• pp.280-285
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• 2011

In this study, we established a novel somatic embryogenesis and plant regeneration system through cell suspension culture of white dandelion (Taraxacum coreanum NAKAI.). Embryogenic calli could be initiated from leaf and root explants of sterile seedlings on solid Murashige and Skoog (MS) medium supplemented with 1.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) after 3-week cultures. To proliferate embryogenic calli rapidly, cell suspension culture was performed with transferred to liquid MS medium with various combinations of plant growth regulators (PGRs) including 2,4-D, ${\alpha}$-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA), $N^6$-benzylamino purine (BAP), thidiazuron (TDZ), and kinetin. During suspension cultures, embryogenic calli not only greatly proliferated, but shoot organogenesis also simultaneously occurred from the surface of somatic embryos. Among them, TDZ at lower concentration, 0.1 mg/L produced the highest efficiency of somatic embryo formation and shoot organogenesis. Rooting of embryogenic calli with adventitious shoots was done on solid MS medium containing 0.1 mg/L NAA and 0.3% activated carbon. Nearly 80% of embryogenic calli with shoot organogenesis could be rooted normal. Well-rooted plantlets were transferred into pots under a greenhouse condition, and plants derived from this system appeared phenotypically normal.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.25-29
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• 2002

The study was carried out to establish an efficient protocol for shoot organogenesis and plant regeneration from stem explant cultures of Lycopersicon esculentum cv. Micro-Tom. The regenerated shoots obtained from stem explant cultures on solid MS medium containing the different concentrations of BAP. The highest number of shoots (5.3) per explant and shoot growth (0.7 cm) was obtained on MS medium containing 4.0 mg/L BA. The additions of AgNO$_3$ and putrescine substantially improved the shoot regeneration frequency, at the optimal concentration of 7 mg/L and 50 mg/L respectively. The regenerated shoots (about 1 cm) were normal and could be easily rooted with 0.1 mg/L IBA treatment. The rooted plants were hardened and transferred to vermiculite with a 92% survival rate where they grew normally.

• Journal of Plant Biotechnology
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• v.3 no.2
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• pp.95-100
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• 2001

To select the section with shoot formation ability, the calli and shoot formation from three sections (first leaf including cotyledonary node, hypocotyl and cotyledon explants) of 5-days-seedlings of soybean were induced on MS medium supplemented with 1.0 mg/L BAP, 3% sucrose, and 0.3% gelrite for one month. The first leaf section exhibited the highest shoot formation rate (51%), followed the hypocotyl section (10%) and the cotyledon section (0%). The shoot formation rates and shoot number of the four excised sections (whole first leaf, a half of the first leaf, a third of the first leaf and only node) of the first leaf were also investigated on the same medium. A half of the first leaf explant and the third of the first leaf explant had higher shoot formation rates (76-80%) and numbers (3-4 / explants) than those in other two explants. Effects of six cytokinins (kinetin, zeatin, BAP, 2iP, PBA, and TDZ) on shoot formation were determined, using the half of the first leaf explants. Zeatin (1.0 mg/L) exhibited the highest in shoot formation rate (94%) and numbers (8 / explant). In addition, the combined effects of three cytokinins (zeatin, BAP, and TDZ; 0.5, 1.0, 2.0 mg/L, respectively) and an auxin (IAA; 0.0, 0.5, 1.0, 2.0 mg/L) were determined. The combination (1:1, v/v) of zeatin (1.0 mg/L) and IAA (1.0 mg/L) exhibited the highest in shoot formation rate (96%) and numbers (16 / explant), twice more than zeatin (1.0 mg/L) alone. The shoot cuttings were transferred and cultivated on the rooting media supplemented with only auxin, IBA at various concentrations. The highest root formation (8 / shoot) was achieved on the medium supplemented with 1.5 mg/L. After 4 weeks of cultivation, the plantlets with an extensive root system were transplanted in pots with a soil mixture of vermiculite and fine sand. Transferred to field, about 75% of the plantlets survived.

• Korean Journal of Medicinal Crop Science
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• v.15 no.1
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• pp.62-66
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• 2007

Plant Regeneration via organogenesis from leaf disk of Korean dandelion was investigated. Leaf disk cultured on MS medium with various combinations of BA (0-4 mg/L) and 2,4-D (0-1 mg/L). Shoot regeneration from leaf explant was observed after 3 weeks of culture. The highest shoot regeneration frequency from leaf disk was obtained with 2 mg/L BA. To analyze the effect of leaf age along shoot formation, we measured number of shoots per explant, shooting rate, fresh and dry weight of leaf explant. The highest number of shoots (11.5) per explant were obtained leaf from 7 weeks old plantlets after seed germination. The regenerated shoots were transferred in 1/2 MS medium with 0.5 mg/L NAA for root formation. Regeneratied plantlets thought organogenesis were growing to whole plants in the pots with acclimation.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.396-400
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• 2015

To investigate the optimal conditions for shoot organogenesis in Astragalus sinicus L., hypocotyl explants were cultured in Murashige & Skoog's (MS) medium supplemented with 0.1, 1.0, 2.0, or 4.0 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) for 6 weeks. 2,4-D concentration significantly effected morphogenesis: some produced calli with adventitious shoots and roots, some produced calli with adventitious roots, some produced only calli, and some produced deep-brownish calli with roots. The formation of calli with shoots and/or roots was observed at lower levels of 2,4-D, whereas calli without shoots or with deep-brownish roots were formed after treatment with higher levels of 2,4-D. Also, a shoot organogenesis ability of callus clones was observed after treatment with medium with 0.1 or 1.0 mg/L 2,4-D grown in MS medium with combinations of benzyl adenine (BA) and 2,4-D for 4 weeks. Medium with a combination of BA and 2,4-D was effective for shoot formation, whereas root organogenesis from calli decreased. The greatest amount of shoot formation was obtained when calli were cultured in MS medium containing 1.0 mg/L 2,4-D and 0.5 mg/L BA. Upon shoot transfer into 1/2 MS basal medium, plantlets developed, and the plantlets grew well in soil in a greenhouse.

• Journal of Plant Biotechnology
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• v.7 no.1
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• pp.57-65
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• 2005

The $F_1$ hybrid Red Coat is one of the most highly sought after cultivars of tomato in Australia and yields up to 7.5 $\cal{kg/plant}$. An experiment was conducted to de-termine the optimal strength and type of growth medium and sucrose concentration for shoot organogenesis of the Red Coat cultivar using cotyledonary explants. Two basal growth media, viz. MS and Gamborg' s $B_5$ at 0, 1/4, 1/2, full or double strength along with sucrose concentrations of 0, 0.5, 1.5, 3 or $5\%$, were evaluated using 25 replications. The main effects of treatment and their mutual interactions were evaluated for the proportion of explants that produced callus and/or shoots, number of shoots produced per explant, callus diameter and shoot height. The explants failed to produce shoots in the absence of mineral nutrient. Only a small proportion of the explants ($6\%$ with $B_5\;and\;3\%$ with MS) regenerated shoots in the absence of sucrose. Lower sucrose concentrations ($0.5-1.5\%$) along with full strength media were optimal for most of the traits studied. The $B_5$ medium outperformed MS medium for shoot organogenesis. For all the traits examined, significant differences in main effects (P < 0.05) and two-way interactions were detected, but no three-way interactions (medium type $\times$ medium concentration $\times$ sucrose concentration) were observed. Sucrose was found essential for the development of chlorophyll. Chlorophyll content increased with an increase in sucrose concentration up to $3\%$ and decreased at $5\%$ sucrose.

• Journal of Plant Biotechnology
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• v.6 no.1
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• pp.39-43
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• 2004

A successful, efficient system for multiple shoot induction and plant regeneration of soybean (Glycine max) was established. Four soybean genotypes were compared for organogenic responses on various media cultured under light conditions. The adventitious shoots (98%, 2.6 shoots/cotyledon) directly from one-day-old cotyledon after germination induced by the hormone treatment and its efficiency was higher than any other conditions. The optimal medium for the induction of multiple shoots from cotyledon in Pungsannamulkong(shoot formation rate, 98%), Lx 16 (83%) and IIpumgeomjeongkong(63%) was MS medium supplemented with 2 mg/L BAP, but for Alchankong(75%), MS medium supplemented with 1mg/L zeatin and 1mg/L IAA, 3% sucrose, 4% Phytagel. Higher root induction (88%) was observed from the shoots placed on rooting medium (hormone-free MS basal). Plantlets were transferred onto the same medium supplemented with 1% activated charcoal for further development. With this treatment, regenerated plantlets were obtained within 7-8 weeks (shoot induction for 4 weeks, rooting and shoot elongation for 3-4 weeks).

• Journal of Plant Biotechnology
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• v.50
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• pp.169-175
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• 2023

A plant regeneration system was developed through shoot organogenesis from in vitro leaf explants of Chrysanthemum morifolium 'Ohblang'. The effects of different concentrations of plant growth regulators and AgNO₃ on efficient shoot regeneration and inhibition of browning were evaluated in chrysanthemum. The explants were cultured on MS shoot induction medium supplemented with 12 combination treatments of 6-benzyladenine (BA) 0.5, 1.0 and 2.0 mg/L, and α-naphthaleneacetic acid (NAA) 0.2, 0.5, 1.0 and 2.0 mg/L in darkness for 6 weeks and cultured under a 16/8 h photoperiod for 6 weeks. The highest shoot regeneration was obtained from the explants cultured on the medium with 1.0 mg/L BA and 1.0 mg/L NAA. Based on this result, AgNO₃ was added to a shoot induction medium containing MS salts, vitamins, 1.0 mg/L BA, 1.0 mg/L NAA, 30 g/L sucrose, and 6 g/L agar to reduce browning of chrysanthemum leaf explants. In the control treatment without AgNO₃, leaf explants turned brown at the cut edge; however, browning was not observed in AgNO₃ treatments. Shoot organogenesis was higher at low concentrations of AgNO₃ and decreased with an increase in AgNO₃ concentration. The explants cultured on shoot induction medium (MS salts, vitamins, 1.0 mg/L BA, 1.0 mg/L NAA) with 1 mg/L of AgNO₃ produced the highest shoot regeneration with 2.6 shoots per explants and a browning index of 0.7. When the regenerated shoots were detached from the explants and cultured on MS medium, the shoots were elongated and rooted successfully.

• Journal of Plant Biotechnology
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• v.50
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• pp.176-182
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• 2023

Plant regeneration protocols for adventitious shoot organogenesis from apple (Malus domestica 'Fuji') leaf explants were developed in the present study. The effects of dark incubation periods in the early stages of culture, pre-treatment methods, the number of explants per culture container, the type of culture containers, and the orientation of the explants on culture media were evaluated to determine the optimal shoot regeneration conditions for 'Fuji' apple leaf explants. Light incubation of explants produced minimal response. However, dark incubation of explants for 4 weeks during the initial culture period enhanced shoot regeneration frequency. Comparing the number of explants per container, a higher percentage of shoot regeneration was obtained with nine explants per container compared with four explants per container. Pre-treatment, before culture, by dipping explants in a liquid regeneration medium containing 40 g/L of sorbitol for 2 hours produced the highest shoot formation rate, and the time of shoot formation was accelerated. The percentage of shoot regeneration and number of shoots per regenerating explant reached a maximum of 87.5% and 4.7, respectively. The regenerated shoots were elongated and rooted on a rooting medium of 1/4 MS with 0.2 mg/L IBA. The plantlets were successfully acclimatized, and the regenerated plants produced normal phenotypes.

• Korean Journal of Medicinal Crop Science
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• v.14 no.2
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• pp.87-91
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• 2006

An efficient plant regeneration of C. asiatica was achieved from organogenesis using petiole explants of in vitro plantlet on MS basal medium controled with different plant growth regulators (NAA,2,4-D, IAA kinetin, and BA). Best results that 50%, efficiency of regeneration per explant for regeneration were obtained with IAA $17.13\;{\mu}M$ and BA $8.9\;{\mu}M$. Formation of adventitious shoots via organogenesis from the petiole explant was verified by histological sectioning of plantlets. Regenerated plants were transplanted into soil.