• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.77-85
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• 2004

Development of efficient plant regeneration and genetic transformation protocols (using the Particle Inflow micro-projectile Gun and the shoot-tips as target tissue) of Sorghum bicolor (L.) Moench in terms of expression of the reporter gene, $\beta$-glucuronidase(uidA) is reported here. Two Indian cultivars of sorghum were used in the study, viz. M-35-1 and CSV-15. Plant regeneration was achieved from one-week-old seedling shoot-tip explants via multiple-shoot-clumps and also somatic embryos. The multiple-shoot-clumps were produced on MS medium containing BA (0.5, 1.0 or 2.0 mg/$L^{-1}$), with biweekly subculture. Somatic embryos were directly produced on the enlarged dome shaped expansive structures that developed from shoot-tip explants (without any callus formation) when cultured on MS medium supplemented both with BA (0.5, 1.0 or 2.0 mg/$L^{-1}$) and 2,4-D (0.5 mg/$L^{-1}$). Whereas each multiple-shoot-clump was capable of regenerating more than 80 shoots via an intensive differentiation of both axillary and adventitious shoot buds, the somatic embryos were capable of 90% germination, plant conversion and regeneration. The regenerated shoots could be efficiently rooted on MS medium containing 1.0mg/$L^{-1}$ IBA and successfully transplanted to the glasshouse and grown to maturity with a survival rate of 92%. The plant regeneration efficiency of both the genotypes were similar. After the micro-projectile bombardment, expression of uidA gene was determined by scoring blue transformed cell sectors in the bombarded tissue by an in situ enzyme assay. The optimal conditions comprising a helium pressure of 2200 K Pa, the target distance of 11 cm with helium inlet fully opened and the use of osmoticum have been defined to aid our future strategies of genetic engineering in sorghum with genes for tolerance to biotic and abiotic stresses.

• Journal of Plant Biotechnology
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• v.6 no.4
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• pp.235-239
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• 2004

We studied the effect of genotype, explant, age of explant, medium (plant growth regulators and gelling agents), and standardized an efficient regeneration protocol for inbred lines of Chinese cabbage (Brassica rapa ssp. pekinensis). Of the different concentrations of NAA and BA tested, the combination of $5\;\cal{mg/L}\;BA\;and\;0.5\;\cal{mg/L}$ NAA gave the highest frequency of shoot regeneration. The cotyledonary explants had more shoot regeneration frequency ($\ge40\%$) than the hypocotyl ex-plants. Besides, the cotyledonary explants, excised from the 4-day old seedlings, showed higher shoot regene-ration ($56.7\%$). Of the three gelling agents and their concentrations used, 16 g/L agar was found to be the best for shoot regeneration. Shoot regeneration frequency in-creased significantly by supplementing the medium with $4\;\cal{mg/L}\;of\;AgNO_3$ MS medium devoid of NAA showed higher frequency of rooting in the regenerated shoots than the ones supplemented with NAA. Our improved regeneration protocol will be especially useful for the genetic transformation of Chinese cabbage inbred lines to develop transgenic hybrids.

• Journal of Plant Biotechnology
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• v.44 no.2
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• pp.164-170
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• 2017

A rapid and efficient in vitro regeneration system was established for Hibiscus syriacus L. The successful regeneration protocol employs induction of shoot organogenesis on leaf, petiole, and root explants. Among the various plant growth regulators evaluated, thidiazuron (TDZ) was the most effective for inducing rapid shoot formation. Most efficient shoot regeneration frequency was obtained from Murashige and Skoog (MS) media containing 0.01 mg/L TDZ. Regeneration efficiency was highest in the roots, and lowest in the leaves. A combination of 0.01 mg/L TDZ with benzyladenine (BAP) markedly improved the frequency of shoot differentiation from the root (up to 98%) and petiole (up to 88%) explants. Furthermore, leaf and petiole explants showed the highest frequency of shoot induction in half-strength MS media containing 0.01 mg/L TDZ and 1.0 mg/L BAP, while root explants formed the greatest number of shoots when 0.01 mg/L TDZ and 0.1 mg/L BAP were added to half-strength MS media. Although the frequency of shoot differentiation from leaf explants was only 50%, the leaf is considered the most efficient plant organ for use in tissue culture because leaves are easier to obtain than roots and petioles. Our findings show that various organs of H. syriacus can be used for plant regeneration, and the protocol developed in this study may be applicable in the horticulture industry.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.307-313
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• 2009

Mature dry seeds of Korean cultivars, Daepungkong, Muhankong, Myeongjunamulkong, Somyeongkong, Sowonkong, Jinpumkong, and Pungsannamulkong were used. The influence of antibiotics on elimination of Agrobacterium growth and shoot regeneration was estimated with cotyledonary node. Cefotaxime and timentin at the concentration of 250 and 500 mg/l suppressed Agrobacterium, especially cefotaxime was an efficient antibiotic to suppress Agrobacterium in all cultivars. While carbenicillin and timentin at the concentration of 50 and 100 mg/l were not sufficient to control the development of Agrobacterium, respectively. Cefotaxime and timentin represented high shoot formation rates compared with carbenicillin. Carbenicillin at low concentrations did not effectively suppress Agrobacterium and also had no effect on shoot development. Cefotaxime at the concentration of 250 mg/l showed maximum frequency of shoot regeneration in cvs. Somyeongkong and Sowonkong. Furthermore, on medium containing cefotaxime, shoot was more quickly formed than the other antibiotics. The use of cefotaxime was very useful for elimination of Agrobacterium growth with cotyledonary node of Korean soybean cultivars.

• Korean Journal of Plant Tissue Culture
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• v.24 no.1
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• pp.49-52
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• 1997

The effects of several additives on plant regeneration were investigated from leaf disc culture of S. tuberosum cv. Atlantic which is known as poor in regeneration ability. The presence of 2 g/L casein hydrolysate significantly enhanced shoot regeneration. Addition of 10~20 $\mu$M $AgNO_3$, not only increased the frequency of shoot regeneration but also maintained the leaf disc green presumably by the inhibitory action of ethylene accumulation in vitro. Decrease of sucrose levels to below 3% significantly increased the degree of regeneration. The addition of CuSO$_4$had no effect on shoot regeneration.

• Korean Journal of Medicinal Crop Science
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• v.14 no.5
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• pp.293-298
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• 2006

Optimum culture conditions for high frequency plant regeneration from leaf explants of Kalanchoe daigremontiana Hamet &Perrier were established. Shoot regeneration was achieved from leaf explant cultures using MS medium supplemented with indole-3-acetic acid (IAA) and thidiazuron (TDZ) or benzyladenine (BA). Percent regeneration was influenced by plant growth regulators and source of explants. MS medium supplemented with TDZ (1.0 mg/l) and IAA (0.4 mg/l) was the most effective, providing shoot regeneration for 76.7 % of ex vitro leaf explants associated with a high number of shoots per explant (9.5 mean shoots per explant), whereas 100% shoot regeneration associated with 12.4 shoots per explant occurred from in vitro leaf explants on the same medium. Clusters of shoots were multiplied and elongated on MS medium containing several concentrations of BA. MS medium supplemented with 0.25 mg/l BA was proved as the most effective shoot elongation medium. Elongated shoots (2-3 cm) were rooted at 100% on half-strength MS medium. Rooted plantlets were then transferred to potting soil. Regenerated plants were established in the soil with 90% success.

• Current Research on Agriculture and Life Sciences
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• v.31 no.2
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• pp.94-100
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• 2013

An efficient plant regeneration protocol is developed for a standard-type chrysanthemum. When petal segments derived from flower buds (4 or 8cm in diameter) were used as the culture material, the highest shoot regeneration frequency (96%) was obtained on a Murashige and Skoog (MS) medium supplemented with 0.5 mg/L IAA, 2 mg/L BA, 3% sucrose, and a 0.8% agar. Pre-culturing the explants under dark conditions for 14 days produced better results for the shoot regeneration frequency than the explants cultured under a continuous 16 h photoperiod ($40{\mu}molm^{-2}s^{-1}$). The shoot regeneration frequency ranged from 19.0% for the Shinmato cultivar to 89.1% for the Baeksun cultivar. Activated charcoal (0.2%) enhanced the root formation of the regenerated shoots in a hormone-free MS medium. The rooted plantlets were acclimatized and successfully established in a greenhouse.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.81-86
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• 2009

An efficient and reproducible plant regeneration system was established using transverse thin cell layers (tTCLs) in five cultivars of Brassjca juncea L. The effects of medium conditions, explant types (tTCLs of hypcotyl and cotyledonary petiole) on shoot regeneration were examined in this study. The maximum shoot regeneration frequency was obtained in Murashige and Skoog (MS) medium supplemented with 4 mg/L 6-benzylaminopurine (BA) and 0.2 mg/L 1-naphthaleneacetic acid (NAA). The hypocotyls derived tTCL explants had more shoot regeneration frequency (52%) than the cotyledonary petiole derived tTCL explants. Shoot induction was further improved by the addition of silver nitrate ($AgNO_3$) in the regeneration medium. A significant genotypic effect was also observed between the five cultivars; Rai-5 displayed higher capacities to produce shoots than other cultivars. Regenerated shoots were rooted on MS basal medium without PGRs which induced 90% of roots. The plantlets established in greenhouse conditions with 99% survival, flowered normally and set seeds. The regenerated plants were fertile and identical to source plants.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.49.2-49.2
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• 2007

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• Journal of Plant Biotechnology
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• v.40 no.4
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• pp.203-209
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• 2013

Genetic manipulation of pear (Pyrus pyrifolia Nakai) breeding is still difficult due to lack of reliable regeneration system. The aim of this research is to establish shoot regeneration system from leaf explants for pear (P. pyrifolia cv. Niitaka) using various concentrations of plant growth regulators and carbon source supplemented to medium. The highest regeneration rate of about 20% was found on a medium containing 4.4 g/L of Murashige and Skoog (MS) without vitamins, Linsmaier and Skoog (LS) vitamins were added separately. Leaf explants of pear were cultured on MS medium containing 7 g/L of Daishin agar supplemented with various concentrations of NAA (0.01, 0.05, 0.1, 0.5 mg/L) in combination with BA(3, 5, 10 mg/L) for shoot regeneration. In medium with 5 mg/L of BA and 0.01 mg/L of NAA, adventitious shoot regeneration rate was higher than others treated. The optimal results were observed using MS medium supplemented with 30 g/L sorbitol as carbon source on regeneration system. Sorbitol is considered better carbon source than sucrose for shoot regeneration of pear (P. pyrifolia cv. Niitaka). In order to increase of shoot regeneration in pear (P. pyrifolia cv. Niitaka), plant agar and Daishin agar used as gelling agents, Daishin agar is more efficient in shoot regeneration.