• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.347-351
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• 1998

Plant regeneration via organogenesis from leaf and stipule explants of micropropagated shoots of strawberry (Fragaria $\times$ ananassa cv. Suhong) was achieved. Leaf and stipule explants were detached from shoot-tip cultured shoots and cultured on MS medium with various combinations of BA and NAA under light or dark condition. Shoot regeneration from leaf explant was observed after 3 weeks in culture and was good at the high ratio of BA and NAA among various combination treatments. The highest shoot regeneration frequency from leaf explants was obtained with 1.0 mg/L BA and 0.1 mg/L NAA, in which 31.1% shoot regeneration frequency(1.7 shoots per leaf explant) was yielded. In case of stipule explants, shoot regeneration was largely affected by plant growth regulators during incubation under dark condition for initial 4 weeks but not under continuous light condition. The combination treatment with 2.0 mg/L BA and 0.1 mg/L NAA showed the most excellent shoot regeneration from stipule explants, where 44.4% regeneration frequency(4.0 shoots per explants) obtained. Regenerated shoots were rooted on MS medium with 0.1 mg/L NAA after shoot elongation, and the plantlets regenerated were transferred to soil mixtures with vermiculite and perlite for acclimation.

• Journal of Plant Biotechnology
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• v.49 no.2
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• pp.131-138
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• 2022

An efficient genetic transformation protocol is a fundamental requirement for high regeneration capacity from cultivated durum wheat (Triticum durum) varieties. In this study, wereportedtheeffectsoftwoauxins,2,4-dichlorophenoxyaceticacid(2,4-D)and4-amino-3,5,6-trichloropicoli nicacid(picloram), at a concentration of 2 mg/Laloneandincombination on the embryogenic callus and plantlet regeneration of four durum wheat varieties (Amria, Chaoui, Marouane, and Tomouh) using mature embryos (MEs) and immature embryos (ImEs). Significanteffectsofvariety,culturemedium(theauxinused),andvariety-mediuminteraction were observed on the callus weight and plantlet regeneration of both MR and ImE explants. The medium used for callus induction significantly affected plantlet regeneration (p < 0.001). Comparedto2,4-D, picloram led to a higher plantlet regeneration rate in both ME and ImE explants (19.8% and 40.86%, respectively). Plantlet regeneration also varied significantly depending on the variety and medium used. PicloramledtohighplantletregenerationofbothME and ImE explants in all varieties except Tomouh, which showed high plantlet regeneration of ME explants in 2,4-D. A comparison of ME and ImE responses indicated that ImEs are the best explants for high plantlet regeneration in durum wheat. Ourfindingssuggestthatpicloramisthebestauxin and should be used instead of 2,4-D due to its positive effect on increasing plant regeneration of durum wheat ME and ImE explants.

• 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.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.17-21
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• 2001

To develop a selection system for regenerating plants from transformed tissues, effects of four antibiotics (kanamycin, hygromycin, carbenicillin, cefotaxime) and herbicide (phosphinotricin) on shoot regeneration from cotyledon and hypocotyl explants of Chinese cabbage (Brassica campestris L. ssp. pekinensis) were studied. For cotyledon, shoot induction was not significantly affected by kanamycin at $1mg{\cdot}L^{-1}$, but the number of shoots formed was significantly reduced at $2mg{\cdot}L^{-1}$, and no shoots were regenerated from any explants at $6mg{\cdot}L^{-1}$ or higher. Hypocotyl explants showed similar result as cotyledon. Kanamycin at $7mg{\cdot}L^{-1}$ may be adequate for selecting Chinese cabbage transformants. Hygromycin at $4mg{\cdot}L^{-1}$ or higher completely inhibited the growth and shoot regeneration of Chinese cabbage explants. Therefore, resistance gene to hygromycin may also be used as a selective marker for Chinese cabbage transformation. Carbenicillin and cefotaxime, the cephalosporin type of antibiotics, had little effect on shoot regeneration of Chinese cabbage explants. Since carbenicillin and cefotaxime have low toxicity to Chinese cabbage, they are suitable for use in tissue culture to eliminate Agrobacterium in transformation experiments after co-cultivation. Shoot regeneration from cotyledon and hypocotyl explants was significantly reduced in presence of $1mg{\cdot}L^{-1}$ phosphinotricin (PPT) and completely inhibited by $2mg{\cdot}L^{-1}$ or higher. PPT, same as antibiotics, may also be used to select transformed cells. Since Chinese cabbage is known to be recalcitrant to in vitro shoot regeneration compared to other Brassica species, even though lower levels of selectable markers result in more transformants but simultaneously allow more untransformed escapes to develop, lower levels of antibiotics and herbicides could be successfully used as a selectable marker to reduce selection pressure.

• KSBB Journal
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• v.16 no.5
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• pp.480-485
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• 2001

Genetic transformation in dandelion(Taraxacum mongolicum Hand). was studied. We used for transformation by Agrobacterium tumefaciens strian LBA4404 harboring a binary vector pBI121 carrying the CaMV 35S promoter-GUS gene fusion used as a reporter gene and NOS promoter-NPTII gene as a positive selection marker. To obtain transformed plants, leaf explants of dandelion were cocultured with Agrobacterium tumefaciens LBA4404 for 10 mins, then transferred to MS medium containing 1 $\mu$M IAA, 1$\mu$M BA, 100$\mu$g/ML carbenicillin and 50 $\mu$g/ML kanarmycin sulfate. After two weeks of subculture of the explants, Kanamycin-resistant shoots were formed on explants survived. When subjected to GUS histochemical assay, all of the regenerants showed the GUS-positive responses. Plantlets were be be transformed to soil for further growth.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.170-173
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• 2009

Leaf and petiole explants of Pulsatilla koreana NAKAI were cultured on MS medium supplemented with various concentrations of zeatin, kinetin or BAP combined with 0.05 mg/L IAA. After 6 weeks of culture, effects of cytokinin on adventitious shoot formation from explants were investigated. The highest frequency of shoot formation was obtained when petiole explants were cultured on medium with 0.5 mg/L zeatin and 0.05 mg/L IAA. Regenerated shoot were transferred on to root induction medium. The best root formation was observed at 1/2 MS medium with 1.5 mg/L NAA. Rooted plantlets were transplanted to a mixture of perlit and soil (1:3), where they were successfully acclimatized.

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.137-142
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• 2000

Calli were induced from the explants of infloresence, petiole and leaf blade of Cnidium officinale on MS medium with 2.4-D, while embryogenic callus was induced only from inflorescence explants. Somatic embryos of 78 per explant were formed during subculture of the explants on medium without 2.4-D after culture on medium with 2 mg/L 2.4-D. Cotyledonary variation, cup-shaped cotyledon of 49% and other abnormal cotyledons of 13.5 % was observed on the somatic embryos. However this variation could be overcomed by the addition of activated charcoal onto culture medium. Somatic embryos at cotyledonary stage germinated on MS basal medium but the germination rate was very poor, blow 50 %. Somatic embryos on the medium with activated charcoal showed improved germinaton.

• Plant Biotechnology Reports
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• v.3 no.4
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• pp.341-345
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• 2009

This study describes culture conditions for a plant regeneration system via a combined pathway of somatic embryogenesis and organogenesis in root explant cultures of the commercial rose cultivar 'Charming'. Root explants formed white calluses at a frequency of 30% after 6 weeks of culture on Schenk and Hildebrandt (SH) medium supplemented with $11mg\;1^{-1}$ 2,4-dichlorophenoxyacetic acid. After 6 weeks of transfer to SH medium without growth regulators, initial white calluses gave rise to globular somatic embryos at a frequency of 2.8%, which were subsequently dedifferentiated to embryonic tissues. Somatic embryos or embryonic tissues initially derived from root explants did not undergo development beyond cotyledonary stage. To produce adventitious shoots, embryonic tissues were sliced and cultured on SH medium with $0.5mg\;1^{-1}$ 6-benzyladenine. After 4 weeks of culture, 28% of embryonic tissue explants formed adventitious shoots. Regenerated shoots were rooted on half strength SH medium with $0.1mg\;1^{-1}$ ${\alpha}-naphthalaneacetic$ acid and subsequently grown to maturity. Root-derived embryonic tissues were proliferated by subculture, while retaining the capacity for shoot production for a few years.

• Korean Journal of Plant Resources
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• v.11
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• pp.40-47
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• 1998

When the leaves, roots and stem segments of seedling of Polygonatum odoratum were cultured on Murashige and Skoog medium with 2.0mg/l BAP, stem segments were the most efficient explants for adventitious shoot inductino. To observe the efficient combination of growth regulators on the adventitious shoot formation , stem segments were cultured on MS medium with various kinds of cytokinins (BAP, kinetin, zeatin). From this experiment, cytokinin treatement was prerequisite for theadventitious shoot formatino,especially BAP was the most effective. Auxin (NAA or IBA) in combination with cyotokinin highly enhanced the adventitious shoot formation. Twenty five percents of explants produced the adventitious shoots on medium with 2.0mg/l BAP solely, while 83% of explants produced the adventitious shoots on medium with 2.0mg/l BAP and 0.1mg/l IBA. Root formationform adventitious shoot was promoted after transfer to 1/2 MS medium supplemented with 0.1mg/l IBA and 0.5mg/l zeatin, thereafter the plantlets with shoots and roots were cultured on 1/2MS medium lacking growth regulators. When the stem segments were cultured to MS medium with 1.0mg/l 2,4 NAA and IBA , yellow and nodulous cali were formed from the stem segments which were developed into adventitious roots. These roots were actively grew after transferred to MS liquid medium lacking growth regulators.

• Korean Journal of Plant Resources
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• v.20 no.3
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• pp.251-254
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• 2007

This study was conducted to investigate the optimal plant growth regulator level for the shoot formation of Lycium chinense Mill. In vitro plant propagation was developed for leaf explants of boxthorn. Leaf explants were cultured on MS medium supplemented with cytokinins (BA and 2-iP) alone. Plants were successfully regenerated through in vitro culture by using leaf explants of boxthorn grown in the field. After 4 weeks of culture, 58% of shoot formation had developed from the leaf explants. The shoot formation rate of 'Jangmyeong' was highest followed by 'Myeongan', ;Cheondae', and 'Bullo'. The use of 0.2mg/L BA was critical for enhanced production of shoot formation and resulted in 58% of the culture producing shoot formations. Regenerated plantlets transplanted to pots were developed and successfully acclimatized to greenhouse.