• Horticultural Science & Technology
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• v.32 no.5
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• pp.694-701
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• 2014

Allium hookeri L. (Alliaceae family) is an important ethnomedicinal plant native to the Himalayan region of Asia. The aim of this research was to establish a high-frequency plant regeneration system for in vitro propagation of A. hookeri. Among the tissue types examined, receptacle explants derived from immature flower buds showed the highest regeneration rate of shoots ($93.33{\pm}4.63%$), roots ($76.67{\pm}7.85%$), and calli ($80.00{\pm}7.43%$) when cultured on Gamborg B5 (B5) medium containing $10{\mu}M$ 6-benzylaminopurine (BA) + $1{\mu}M$ naphthalene acetic acid (NAA), $0.5{\mu}M$ BA + $5{\mu}M$ NAA, and $1{\mu}M$ BA + $10{\mu}M$ NAA, respectively. Shoot multiplication was superior when cultured in liquid rather than on solid medium and relatively high concentrations of BA, ranging from 5 to $10{\mu}M$. Efficient bulblet formation following root induction from shoot clumps was achieved with culture in liquid B5 medium containing 7% (w/v) sucrose. Regenerated bulblets were successfully acclimatized to ex vitro conditions with a greater than 95% survival rate. By this method, a maximum of 62 plantlets per receptacle could be propagated within 9 weeks of initial culture. The in vitro propagation system established in this study will promote A. hookeri biotechnology, including large-scale production of healthy and aseptic clones, preserving parental genotypes with desirable traits, and genetic manipulation to enhance medicinal value.

• Journal of Plant Biotechnology
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• v.49 no.3
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• pp.207-212
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• 2022

The optimal culture conditions for root organogenesis from the callus of peonies (Paeonia lactiflora Pall.) were investigated. Root explants with vascular bundles were cultured in Murashige and Skoog (MS) medium combined with 0.5-4.0 mg/L auxins (indole acetic acid [IAA], naphthalene acetic acid [NAA], indolebutyric acid [IBA], and 2,4-dichlorophenoxyacetic acid [2,4-D]) and 0.0-2.0 mg/L cytokinins (kinetin, zeatin, and benzylaminopurine [BAP]) to induce callus formation. The callus was then cultured in MS medium combined with three concentrations (0.1, 0.5, and 1.0 mg/L) of IAA, NAA, IBA, kinetin, zeatin, and BAP in the dark for 6 weeks. Based on the results, the effects of dark and light conditions on the callus cultured in MS medium with combinations of 0.1-1.0 mg/L IBA and zeatin for 6 weeks were studied. Callus formation was most effective (>+++) in the medium with a combination of 1.0 mg/L NAA and 1.0 mg/L zeatin. A high number of long adventitious roots were observed in the mediums with 0.1 mg/L IBA (6.66 and 4.82 cm) and 0.5 mg/L zeatin (2.32 and 0.72 cm) among auxins and cytokinins, respectively. The highest number (14.06) of adventitious roots were formed from the callus cultured in light in the MS medium combined with 0.1 mg/L IBA and 0.5 mg/L zeatin. This same medium induced the formation of the longest adventitious root (5.45 cm) in the dark. Thus, optimization of in vitro culture conditions may be possible for the mass propagation of adventitious roots in peonies.

• Journal of Plant Biotechnology
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• v.5 no.2
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• pp.107-113
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• 2003

The effect of sodium sulphate on shoot induction and multiple shoot formation from nodal explants of Vitex negundo L. was tested on Murashige and Skoog's (MS) medium fortified with different auxins, cytokinins and sucrose. Highest percentage $(97.78\%)$ of explants for shoot induction and multiple shoot (20.68/explant) production were observed in the combination treatment of $N^6-Benzyl$ adenine (BA) $(17.80\;{\mu}M/L)$, ${\alpha}-Naphthalene$ acetic acid (NAA) $(2.15\;{\mu}M/L)$ and $5\%$ sucrose supplemented with 100 mg/L sodium sulphate. In vitro raised shoots were rooted on the half-strength MS medium fortified with different concentrations of NAA, Indole-3-acetic acid (IAA), and Indole-3-butyric acid (IBA) alone and in combinations. Among the treatments, $4.90\;{\mu}M/L$ of IBA was found most effective $(95.56\%)$ in inducing roots. The rooted plantlets were shifted to glasshouse for acclimatization and later transferred to the field with cent percent survival. Furthermore, in vitro flowering was observed in the shoots cultured on MS medium supplemented with BA $(8.90\;{mu}M/L)$ and NAA $(1.61\;{\mu}M/L)$.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.87-96
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• 2018

BACKGROUND: The vigorous shoot growth in upper part of apple tree canopy leads to poor fruit quality and flower bud formation in lower part of canopy. So, this study was conducted to develop the proper control method about the shoot growth in upper part of apple tree canopy. METHODS AND RESULTS: Trunks of 'Fuji'/M9 apple trees were cut (back pruned) to 2.5 m in tree height on 11 February (dormant) or 12 April (full bloom). Naphthalene acetic acid (NAA) was applied at 2.0% to cut surface when trunk was pruned. Prohexadione-calcium (Pro-Ca) was sprayed at 250 mg/L above 2.0 m in tree height at 23 April (petal fall). The NAA or Pro-Ca application after trunk was pruned at dormant (TR-2 and TR-3) significantly reduced shoot growth in upper part of canopy compared with the control (tree was only pruned at dormant, TR-1), but the percent of shoots showing the secondary growth of TR-3 was higher over 2 times than that of TR-2. The reduction of shoot growth in upper part of canopy by TR-2 and TR-3 increased the fruit red color from the lower part in the treating year and blooming of the lower part in the following year. CONCLUSION: Applying 2.0% NAA to cut surface of pruned apple trunk at dormant was the most effective way for stabilization of the tree vigor in upper part of the canopy in a high density apple orchard.

• 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.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.315-319
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• 2001

The study was carried out to develop a simple and efficient system to regenerate plants from cotyledon and hypocotyl tissues of Chinese cabbage (Brassica campestris L. ssp. pekinensis cv Seoul). Among the various combinations of naphthalene acetic acid (NAA) and 6-benzyladenine (BA) tested, the best shoot induction medium for cotyledon, with 2.67 shoots per explants, contained $2.0mg{\cdot}L^{-1}$ NAA, $1.0mg{\cdot}L^{-1}$ BA and $16.7mg{\cdot}L^{-1}$ $AgNO_3$. The shoot induction medium with $1.0mg{\cdot}L^{-1}$ NAA, $5.0mg{\cdot}L^{-1}$ BA and $16.7mg{\cdot}L^{-1}$ $AgNO_3$, was best for shoot induction from hypocotyl explants, with 1.87 shoots per explants. After shoot induction, regenerated shoots were excised and rooted on rooting medium. Rooted plantlets were then hardened in the high humidity growth chamber and transplanted to pots, and then grown in the greenhouse. Regenerated plants appeared phenotypically normal and there were no changes in chromosome number.

• Journal of Plant Biotechnology
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• v.6 no.3
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• pp.189-192
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• 2004

Adventitious multiple shoots were developed from leaf, petiole and internode explants of Geophila reniformis D. Don. on MS medium supplemented with various concentrations of $N^6$-benzylaminopurine (BAP) or Kinetin (KIN) alone or in combination with indole-3-acetic acid (IAA). Leaf showed maximum organogenetic potential, followed by petiole and internode. Murashige and Skoog (MS) medium supplemented with 22.22 $\mu{M}$ BAP and 4.57 $\mu{M}$ IAA induced maximum shoot buds from leaf explants. Internodal segments showed low potential of direct organogenesis. The regenerated shoots rooted the best in presence of 10.75 - 13.44 $\mu{M}$ $\alpha$-naphthalene acetic acid (NAA) along with 2.22 $\mu{M}$ BAP, and were successfully established in the field with a survival rate of 89.11%.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.488-493
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• 2011

Callus culture initiation of strawberry (Fragaria${\times}$ananassa Duch.) was investigated at different Murashige and Skoog (MS) medium strengths, types and concentrations of plant growth regulators, and incorporating a cold pretreatment period to determine the optimal nutritional and environmental conditions. No high quality callus was induced on MS media without auxin regardless of medium strength. When 6-benzylaminopurine (BA) was combined with indole acetic acid (IAA), naphthalene acetic acid (NAA), and 2,4-dichlorophenoxyacetic acid (2,4-D), high quality callus were highly induced compared to medium supplemented with auxin alone. When $0.5mg{\cdot}L^{-1}$ BA was combined with IAA, NAA, and 2,4-D, high quality callus induction was more effective than the medium supplemented with the other BA concentrations. The best combination of auxin and cytokinin for high quality callus induction was $1.0mg{\cdot}L^{-1}$ NAA and $0.5mg{\cdot}L^{-1}$ BA. Although the differences in callus induction were not significant, high quality callus induction at half strength MS medium was more effective than at full strength medium. When $30g{\cdot}L^{-1}$ sucrose was added to the half strength MS medium, the rate of high quality callus induction increased. The optimum cold pretreatment temperature and period for high quality callus induction were $4^{\circ}C$ and 72 h, respectively. Regeneration rate of high quality callus increased in MS medium supplemented with thidiazuron.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.343-348
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• 2017

Cymbidium aloifolium (L). Sw. is an exquisite epiphytic orchid of the Kolli Hills (Eastern Ghats) of Tamil Nadu in Southern India. It is fast disappearing from its natural habitats due to deforestation and low germination rate in natural habitat. In the present study, an attempt was made to germinate the seeds from un-dehisced capsule of Cymbidium aloifolium (L). Sw under in vitro condition. The seed germination and protocorm development were recorded in three different well known media namely Knudson C (KC), Half strength Murashige & Skoog (1/2 MS) and Vacin & Went (VW) media. The highest seed germination of 90% was observed KC basal media after $30^{th}$ days whereas germination percentages were 40% and 30% on 1/2 MS and VW media respectively. The well-developed protocorm were transferred to KC media supplemented with 6-Benzyl Amino Purine (BAP) and Naphthalene acetic acid (NAA) where BAP (1.0 mg/l) and NAA (1.0 mg/l) together were found to be optimum for the highest shoot formation. About 90% of the shoots found to be well rooted after transfer to the KC medium differently supplemented with 1.5 mg/l Indole-3-acetic acid (IAA) and 1.0 mg/l Indole-3-butyric acid (IBA). Though rooting also took place in the two basic media but the duration was longer when compared with the hormone-supplemented media. The rooted plantlets were hardened and kept under greenhouse conditions which can be relocated in natural habitats.

• Journal of Plant Biotechnology
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• v.2 no.1
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• pp.51-54
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• 2000

Leaf explants of the cucumber (Cucumis sativus L.) were cultured on Murashige and Skoog's (MS) medium supplemented with various concentrations of $\alpha$-naphthalene acetic acid (NAA) and 6-benzylaminopurine (BAP). Direct shoot orgnogenesis as well as callus formation with somatic embryos and multiple shoots was observed from leaf explants of cvs. Shinhukjinju and Chungjang. The highest frequency of shoot formation 80% was observed on MS medium supplemented with NAA/BAP (5.0 ${\mu}{\textrm}{m}$/2.5 ${\mu}{\textrm}{m}$), with explants forming 3-7 shoots. Shoots formation occured within 3 to 4 weeks. Only one subculture of calli was required for plant regeneration on normal growth regulator-free medium. Plantlets transferred to soil developed into plants of normal appearance, which flowered and set fruits.