• 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 Biology
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• v.39 no.3
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• pp.167-172
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• 1996

Efficient plant regeneration has been achieved via organogenesis in the red pepper plant (Capsicum annum L.). Shoots were induced from seed explants of cultivar 'Friendship' on Murashige and Skoog's (MS) basal medium supplemetned with; NAA or IAA, and BAP or zeatin. Seed explants on the medium supplemented with 0.1-0.3 mg/L IAA and 2-5 mg/L zeatin for 2 weeks vigorously formed normal shoots in more than 90% of the explants. When these were transferred to MS medium containing 0.5-1.0 mg/L GA, 90-100% of the shoots have elongated within 1-2 weeks. The elongated shoots rooted in media supplemented with 0.3 mg/L NAA. It was revealed that this method is very rapid and efficient regeneration system for red pepper and regenerated plants can be obtained after only 5-6 weeks of culture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.279-283
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• 2011

The immature embryos during seed development were examined to predict the suitable embryos for an efficient regeneration system. Five spring wheat genotypes and five winter wheat genotypes were tested using immature embryos as explants. Spring wheat genotypes showed much higher levels of plant regeneration than those of winter wheat genotypes. The highest frequencies of embryogenesis and regeneration were obtained when embryos at 13-14 days after anthesis (DAA) were used as explant and decreased using embryos at 21-22 DAA during seed development. Significant differences were also found for callus induction and regeneration as affected by immature embryo size. The regeneration efficiency was drastically decreased in spring and winter wheat genotypes when embryos larger than 2.0 mm of length were used. The optimum developmental stage and embryo length for regeneration efficiency were at 13-14 DAA and 1.0-1.5 mm, respectively. The selection of suitable embryos for the high frequencies of embryogenesis and regeneration leads us to efficient genetic improvement of wheat.

• Plant Biotechnology Reports
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• v.4 no.2
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• pp.139-148
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• 2010

Jatropha curcas L. (Physic nut) is a commercially important non-edible oil seed crop known for its use as an alternate source of biodiesel. In order to investigate the morphogenic potential of immature embryo, explants from four developmental stages were cultured on medium supplemented with combinations of auxins and cytokinins. It was found that the size of embryo is critical for the establishment of callus. Immature embryos (1.1-1.5 cm) obtained from the fruits 6 weeks after pollination showed a good response of morphogenic callus induction (85.7%) and subsequent plant regeneration (70%) with the maximum number of plantlets (4.7/explant) on Murashige and Skoog's (MS) medium supplemented with IBA (0.5 $mg\;l^{-1}$) and BA (1.0 $mg\;l^{-1}$). The above medium when supplemented with growth adjuvants such as 100 $mg\;l^{-1}$ casein hydrolysate + 200 $mg\;l^{-1}$ L-glutamine + 8.0 $mg\;l^{-1}$ $CuSO_4$ resulted in an even higher frequency of callus induction (100%). Plant regeneration (90%) with the maximum number of plantlets (10/explant) was achieved on MS medium supplemented with 500 $mg\;l^{-1}$ polyvinyl pyrrolidone + 30 $mg\;l^{-1}$ citric acid + 1 $mg\;l^{-1}$ BA + 0.5 $mg\;l^{-1}$ Kn + 0.25 $mg\;l^{-1}$ IBA. It was observed that plantlet regeneration could occur either through organogenesis of morphogenic callus or via multiplication of pre-existing meristem in immature embryos. The age of immature embryos and addition of a combination of growth adjuvants to the culture medium appear to be critical for obtaining high regeneration rates. Well-developed shoots rooted on half-halfstrength MS medium supplemented with 0.5 $mg\;l^{-1}$ IBA and 342 $mg\;l^{-1}$ trehalose. The rooted plants after acclimatization were successfully transferred to the field in different agro-climatic zones in India. This protocol has been successfully evaluated on five elite lines of J. curcas.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.107-113
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• 2015

This study was conducted to find out the effective induction method of tetraploid plants to obtain potential data for cultivating superior varieties by colchicine treatment. The seed germination were decreased by the higher concentration of colchicine treatment and longer soaking time. A total of 907 individuals were germinated in 16 treated plots except control (untreated plot) and 28 tetraploids were induced which was about 3.1% of the number of seed germinated. The plant regeneration rate by colchicine treatment on explant of Prunella vulgaris for. albiflora Nakai under in vitro culture was decreased with the higher concentration of colchicine. While a total of 312 individuals were regenerated in all treatments, the explant was soaked in more than 0.05% for over 1 hour, tetraploid could be obtained. In particular, for the soaking treatment in 0.05% for 6 hours and 12 hours, 37 tetraploids were induced, which was about 57.8% of the number of plant regenerated. In accordance with the observation on doubling of DNA contents in leaf in order to identify polyploid, the peak DNA content of G1 phase was 101.3 for diploid and 197.2 for tetraploid. The result confirmed the doubling of DNA content. Furthermore, the number of chloroplasts per guard cell depending on polyploid was around 10 in diploid and 19.3 in tetraploid, which was around 1.9 times as much as diploid.

• Plant Biotechnology Reports
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• v.3 no.4
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• pp.333-340
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• 2009

Developmental anomalies in the plumule meristem of peanut (Arachis hypogaea L.) somatic embryos resulted in poor shoot differentiation and reduced plant recovery. Existing meristems with caulogenic potential have never been tested for embryogenesis in peanut. The present experiment was designed to test the mature zygotic embryo axis derived plumule with three meristems for somatic embryogenesis. Embryogenic masses and embryos developed from the caulogenic meristems in the axils. Exposure of 2 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation temporarily which then regained the ability to form the shoot on withdrawal of 2,4-D. Exposure of 4 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation irreversibly. No shoot formation was noted from the tips in any of the cultures which were in secondary medium with $13.6{\mu}M$ 2,4-D. Development of somatic embryos directly from axillary meristems was confirmed histologically. Conversion frequency of these embryos was 11%. Thus, in this report, we describe a method to obtain somatic embryos from the determined organogenic buds of the axillary meristem, by culturing the nodal explant vertically on embryo induction medium. It also displays the possibility of obtaining both embryogenic and organogenic potential in two parts of the same explant simultaneously. The possibility of extending this approach for genetic transformation in in vivo system through direct DNA delivery or Agrobacterium injection in meristems can also be explored. Using Agrobacterium rhizogenes, we have demonstrated the possibility of gene transfer in the axillary meristems of seed-derived plumule explant.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.505-510
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• 2010

This study was conducted to refine a micropropagation method of water hyacinth (Eichhornia crassipes) in vitro. When young shoots were cultured on media with various concentrations of BA or TDZ alone, LS medium containing $5.0\;mgl^{-1}$ BA was found favorable for shoot proliferation from young shoots with a mean of 4.2 shoots. Using BA together with IAA, more shoots were obtained on LS medium containing $5.0\;mgl^{-1}$ BA and $1.0\;mgl^{-1}$ IAA with a mean of 5.7 shoots. In liquid medium, number of shoots and fresh weight per explant increased significantly. The best shoot proliferation and increasing of fresh weight were achieved on LS liquid medium containing $5.0\;mgl^{-1}$ BA and $1.0\;mgl^{-1}$ IAA with 6.9 shoots and more than 4,000 mg fresh weight. Of the different concentrations of LS salt, double strength of LS medium provided the highest shoot proliferation with 7.3 shoots, and fresh weight with 5,539 mg per explant. Shoot proliferation on LS medium containing $50\;gl^{-1}$ sucrose had better results with 8.7 shoots and 5,979 mg per explant in fresh weight than other conditions. In conclusion, the optimal level for shoot proliferation and biomass increase of water hyacinth was attained with the application of the double strength of LS medium containing $5.0\;mgl^{-1}$ BA, $1.0\;mgl^{-1}$ IAA and $50\;gl^{-1}$ sucrose.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.50-58
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• 1999

This study was carried out to investigate the growth characteristics and propagation methods of L. obtusiloba as a woody landscape plant. The results are obtained as follows: L. obtusiloba was dioecious shrub and shaped with bush type. Leaves were ovate, obtuse, cordate, 7.05 cm long, 7.20 cm wide, and petiole 2.0 cm long. Flowers of L. obtusiloba were diclinous. Soil acidity ranged from pH 4.06 to 5.53 with the lowest at the Mt. Soo-Ri. Mt. Soo-Ri located near factory district, which was considered to damaged by environmental deteoration. While soil organic matter was highest at Mt. Soo-Ri, inorganic nutrients were low. L. obtusiloba grows in the area with low soil acidity and low content of inorganic. Therefore it seemed to be tolerant to air pollution. L. Obtusiloba was high seed germination rate in the plug box and its shoots were longer than seeding box and softwood cutting of L. obtusiloba showed the rooting rate of 50% at 5,000ppm on June 23. To develop a mass propagation method of Korean native L. obtusiloba through an axillary bud culture as a woody landscape plant, about 2∼3 cm shoots induced from explant were subcultured to new media contained different growth regulators. Shoots multiplied most effectively on a WPM containing 1.0 mg/l BA, producing 5.5 shoots with a shoot length of 2.5 cm per shoot explant.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.3
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• pp.198-204
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• 2005

Seeds of neem were collected from different parts of India and analyzed for their azadirachtin content by High Performance Liquid Chromatography (HPLC). In order to assess the effects of genotypic and geographical variation on azadirachtin content in cell cultures, callus development was attempted in the seeds containing high and low concentration of azadirachtin. The concentration of azadirachtin in callus cultures was significantly affected by the explant source. Seed kernels with higher azadirachtin content produced higher azadirachtin content in callus cultures and lower azadirachtin content was seen in callus cultures produced from seed kernels with low azadirachtin content. The protocol for development of elite stock culture of Azadirachta indica was established with the objective of selecting a high azadirachtin-producing cell line. The highest azadirachtin-producing cell line was selected and the effects of different media and illumination conditions on growth and azadirachtin production were studied in shake flask suspension culture. Detailed batch growth kinetics was also established. These studies provided elite starter culture and associated protocols for cultivation of A. indica plant cell culture in the bioreactor.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.284-288
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• 2013

This study aimed to get the basic data on the breeding of good varieties in Hypericum patulum Thunberg. The optimum materials, concentration and soaking time were examined to identify the effective approach to induce tetraploid plant by colchicine treatment to cultivate the varieties. For the seed germination rate of seed by colchicine treatment, the higher colchicine concentration was and the longer soaking time was, the more the germination rate decreased. While individuals were germinated in 16 test groups except control group (no treatment group), all the plants were diploid and no tetraploid was induced. For the plant regeneration rate by colchicine treatment on the explant of Hypericum patulum Thunberg that was under in vitro culture, the higher the colchicine concentration increased, the ress the regeneration rate. While total 147 individuals were regenerated in all treatment, when the explant was soaking treatment in more than 0.05% for over 6 hours, tetraploid could be obtained. In the soaking treatment of 0.05% for over 6 hours, tetraploid could be obtained. In particular, for the soaking treatment in 0.05% for 12 hours, 8 tetraploids were induced, which was about 47.1% of the number of plant regenerated. In accordance with the observation on doubling of DNA contents in leaf in order to identify polyploidy, the peak DNA content of G1 phase was 94.5 for diploid and 192.5 for tetraploid. It confirmed doubling of DNA content. Furthermore, the number of chloroplasts per guard cell depending on polyploid was around 10 in diploid and 17 to 19 in tetraploid, which were around 1.7 to 1.9 times as much as diploid.