• Proceedings of the Botanical Society of Korea Conference
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• 2001.04a
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• pp.21-21
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• 2001

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.269.2-269
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• 1997

No Abstract, See Full Text

• Korean Journal of Plant Resources
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• v.23 no.6
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• pp.503-512
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• 2010

Anther derived double haploids (DHs) from sweet pepper genotypes ('Special', 'Derby', 'Bossanova', 'Fiesta', 'Debora' and 'Minipaprika') were used to study the agronomic variation in 2006. Ninety-nine successful DHs regenerants (32 from 'Special', 25 from 'Derby', 23 from 'Bossanova', 10 from 'Fiesta', 6 from 'Debora' and 3 from 'Minipaprika') were transplanted at plastic house and studied on their agronomic characters. Variation in agronomic characters was observed within the DHs of each genotype. DHs obtained from 'Derby' and 'Fiesta' exhibited wide variation in fruit yield $plant^{-1}$ whereas averaged fruit yield $plant^{-1}$ was highest in 'Derby' (1608 g) and less variation was observed in DHs of 'Bossanova'. Based on the agronomic characters expressed in DHs population at this environment, SP55, SP56, SP60, and SP116 from 'Special', SP8, SP10, SP14, SP16, and SP34 from 'Derby', SP115, SP119, SP142, SP143, SP196, and SP199 from 'Bossanova', SP41, SP45, and SP114 from 'Fiesta', SP21 from 'Debora' and SP91 from 'Minipaprika' identified as elite inbred lines and these DH lines could be used for commercial hybrids production in sweet pepper. Genetic relationship among the selected inbred lines using molecular markers and their response to diseases are further recommended to study.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.107-111
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• 2004

To establish an efficient acclimation system for regenerated plantlets of soybean, we used various media with hydroponic nutrient solutions before regenerants were transplanted into soil. The hydroponic nutrient solution was essential for the survival of the plantlets. The vermiculite with nutrient solution at pH 5.5 was found to be the best medium with 97-100% survival rate and better growth of regenerants plantlets. Regeneraed grew best in the following order of solutions: Yoshida solution, modified Yoshida solution, SoyI, Soy II, and MS medium. However, Soy I solution (EC 2.9 mS/cm), developed by the Honam Agricultural Research Institute proved to be the most effective for acclimation in terms of the time required for vigorous growth and economical use of chemicals.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.259-264
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• 2002

Induction of embryogenic callus from Allium wakegi Araki explants was promoted on medium containing 2,4-D, and production of abnormal embryos from the embryogenic callus increased as 2,4-D concentration was raised. Shoot tip was found to be the best explant source for embryogenic callus formation followed in the order by bulb scale and leaf section. Medium containing 0.09 M sucrose was effective for embryogenic callus production. The regenerants from embryogenic callus on medium containing 2,4-D and BA at different concentrations was consisted of diploids, tetraploids and a few mixaploids of 2n＋4n, and their chromosomal aberration rate ranged from 8.0 to 33.3%. Frequency of chromosomal aberrants was the highest (18.7%) in the regenerants obtained from bulb scale-derived embryogenic callus among others. Plant regeneration rate was high (33.5%) from the shoot tip-derived embryogenic callus and the frequency of chromosomal aberrants was very low (7.0%). The plantlets regenerated on medium containing 0.26 M sucrose resulted in high chromosomal aberrants. The regenerants on medium containing sucrose at 0.09∼0.20 M produced chromosomal aberrants at around 15.2∼16.6%.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.127-132
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• 1999

Protoplasts were isolated from the leaf mesophyll tissue of in vitro 4-weeks-old Arabidopsis thaliana and cultured in MS liquid medium supplemented with 2.0 mg/L NAA, 0.5 mg/L BAP and 9% mannitol in the dark at $25^{\circ}C$. When protoplast-derived microcolonies were dehydrated, the frequency of callus induction enhanced approximately 7-fold higher compared with non-dehydrated microcolonies in CP medium. Fifty callus lines were selected from dehydrated microcolonies. Shoots were efficiently initiated from the green spots of the selected shoot forming calli cultured on MS regeneration medium supplemented with 0.05 mg/L IAA, 7.0 mg/L 2-iP and 30 g/L sucrose under continous illumination for 4 weeks. Shoot regeneration frequencies (calli regenerating at least one shoot) were 3.5%~56%. Histological observations of shoot forming callus revealed that tracheary elements initiated from inner compact cells, and that meristemoids developed to shoot primordia and shoots. Roots were induced from these regenerating shoots on MS medium without phytohormones. These regenerants were successfully transplanted into potting soil. Morphological characterization of 50 protoplast-derived plants showed that the frequency of normal type was 78%.

• The Plant Pathology Journal
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• v.19 no.3
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• pp.162-165
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• 2003

Transformation of Fuji apple (Malus domestica 'Fuji') was performed using Agrobacterium tumefaciens harboring a coat protein (CP) gene of Cucumber mosaic virus (CMV). A plasmid DNA containing the virus CP and NPT II genes was introduced into the loaves of apple by th e Agrobacterium - mediated transformation procedure. Regenerated transformants of the apple were obtained by kanamycin resistance conferred by the introduced NPT II gene. PCR analysis showed that 3 out of 20 putatively selected R0 plant lines contain the CMV-CP gene. Nine putative transgenic lines out of 20 lines were investigated with the PCR analysis; 5 regenerants produced a 450 bp DNA band and 3 regenerants showed a 671 bp DNA band for the NPT II and CMV-CP genes, respectively. Southern hybyidization results demonstrate the successful integration of the CMV-CP gene into the genome of the apple. This is the first report on the generation of useful vius resistance source of transgenic apple for molecular breeding program.

• Korean Journal of Plant Resources
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• v.28 no.6
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• pp.697-703
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• 2015

Twenty apple germplasm accessions from the Korean Genebank were successfully cryopreserved using two-step freezing to back up genetic resources maintained by field collections. This study examined the morphological and genetic stability of cryopreserved dormant apple buds that were stored in liquid nitrogen, and then rewarmed and regrown. Whole plants were regenerated directly from dormant buds through budding without an intermediary callus phase. The cryopreserved buds produced high levels of shoot formation (76.2-100%), similar to those of noncryopreserved buds (91.3-100%), with no observed differences between cryopreserved and noncryopreserved materials. Three of the twenty cryopreserved apple germplasm accessions were used to assess morphological and genetic stability. No differences in morphological characteristics including shoot length, leaf shape, leaf width/length ratio, and root length were observed between controls (fresh control and noncryopreserved) and cryopreserved plantlets. The genetic stability of regenerants (before and after cryopreservation) was investigated using inter simple sequence repeat (ISSR) markers. The ISSR markers produced 253 bands using four primers, ISSR 810, SSR 835, ISSR 864, and ISSR 899. These markers showed monomorphic banding patterns and revealed no polymorphism between the mother plant and regenerants before and after cryopreservation, suggesting that cryopreservation using two-step freezing does not affect the genetic stability of apple germplasm. These results show that two-step freezing cryopreservation is a practical method for long-term storage of apple germplasms.

• Korean Journal of Microbiology
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• v.24 no.1
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• pp.24-31
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• 1986

The optimal conditions for the formation and the regeneration of Pseudomonas spheroplast were measured. Pseudomonas spp. cells were transformed to spheroplasts from 99.0% to 99.9% by treatment of $100{\mu}g/ml$ lysozyme and 10mM EDTA at room temperature. The optimal pH for the spheroplast formation was pH 8.0. Magnecium chloride, calcium chloride and streptomycin were effective on the stabilization of Pseudomonas spheroplast, while $Mg^+\;and\;Na^+$ ions were effective on the formation of Pseudonomas spheroplast. Rich Regeneration Medium was used for the regeneration of Pseudonomas spheroplast. To improve regeneration frequency, Bovin Serum Albumine and cationic ions were added to the spheroplast dilution beffer and regeneration environment respectively. Treatment of 20mM calcium chloride in ehr Rich Regeneration Medium could improve the yield of regenerants as much as 28-fold. Treatment of 1% Bovin Serum Albumine in the spgeroplast formation and dilution buffer increased the yield of regenerants to 10-fold. Also, the regeneration frequency was improved to 14-fold shen Rich Regeneration Meidum containing 0.5% Gelatin was used for regeneration as well as 1% Bovin Serum Albumine.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.315-318
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• 1994

To obtain transformed plants, we cocultured cotyledonary explants of Codonopsis lanceolata with Agrobacterium tumefaciens LBA4404, a disamed strain harboring a binary vector pBI121 carrying the CaMV35S promoter-$\beta$-glucuronidase (GUS) gene fusion used as a reporter gene and NOS promoter-neomycin phosphotransferase gene as a positive selection marker in MS liquid medium with 1mg/L BA. After 48 h of culture, explants were transferred onto MS solid medium with Img/L BA, 250mg/L carbenicillin, and 100mg/L kanamycin sulfate and cultured in the dark. Numerous adventitious buds formed on the cut edges of the explants after 2 weeks of culture. When subjected to GUS histochemical assay buds showed a positive response at a frequency of 15%. Explants formed adventitious shoot at a frequency of 56.7%, after 6 weeks of culture. Upon transfer onto the basal medium, most of the shoots were rooted and subsequently the regenerants were transplanted to potting soil. Southern blot analysis confirmed that the GUS gene was incorporated into the genomic DNA of the GUS-positive regenerants.