• Korean Journal of Plant Tissue Culture
• /
• v.25 no.3
• /
• pp.207-217
• /
• 1998

Total of 78 strains were characterized based on the morphological characteristics of colonies isolated on Schroth, and New & Kerr's media for selection of hypervirulent wild-type Agrobacterium spp from galls, hairy root-like process and soil of Populus, Malus, Salix and Diopyros in Korea. Among them, 48 strains were able to induce tumors in carrot disc. Hypervirulent A. tumefaciens SP101 and SM042 were identified as biotype 1 and biotype 2, respectively, These strains formed fast growing, larger tumors as compared to those induced by other strains. The binary vector pGA643 with kanamycin resistant gene was mobilized from E. coli MC100 into A. tumefaciens strain SM042 isolated from soil, and/or disarmed vector PC2760 using a triparental mating method with E. coli HB101/pRK2013, and transconjugants, A. tumefaciens SM643 and PC643 were obtained in minimal media containing kanamycin and tetracycline. Tobacco tissues were cocultivated with conjugant Agrobacterium and then transferred to selective medium with 2,4-D and kanamycin to induce the transformants. Calli were formed more efficiently in cocultivation with A. tumefaciens SM643 than that with A. tumefaciens PC643. Most of calli transformed with A. tumefaciens PC643 were friable and regenerated into normal plantlets, while the calli transformed with A. tumefaciens SM643 were compact, hard, and mixed with friable calli. The friable calli formed normal shoots, while compact calli did not form shoots but only grew to typical compact tumor calli. When the shoots formed directly from tobacco stems without callus induction after transformation by A. tumefaciens SM643 with wild-type Ti-plasmid, normal transformed plants can be induced without using disarmed Ti-plasmid.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.3
• /
• pp.232-236
• /
• 2004

In order to optimize tissue culture conditions for genetic transformation of orchardgrass (Dactylis glomerata L.), the effects of culture medium supplements on tissue culture responses were investigated with mature seeds of a cultivar, 'Roughrider', as explant tissues. The optimal concentration of 2,4-D for the induction of embryogenic callus from mature seeds was 3 mg/L. Plant regeneration frequency was 36.3% when embryogenic calli were cultured on the regeneration medium supplemented with 1mg/L 2,4-D and 3mg/L BA. Addition of 1 g/L casein hydrolysate and 300 mg/L L-proline improved frequencies of embryogenic callus induction and plant regeneration up to 57.3 and 60.7%, respectively. Supplementation of the media with 10 mga $\textrm{AgNO}_3$ and 40 mg/L cysteine enhanced frequencies of callus induction and plant regeneration. Efficient regeneration system established in this study will be useful for molecular breeding of orchardgrass through genetic transformation.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.26 no.4
• /
• pp.187-192
• /
• 2006

In order to investigate the effects of genetic variations of orchardgrass in tissue culture response, calli were induced from mature seeds of eight varieties, 'Hapsung 2', '93E', 'Amba', 'Ambassdor', 'Frode', 'Frontier', 'Potomac' and 'Roughrider', and plant regeneration frequency was compared. Significant differences were observed among the varieties in both callus induction and plant regeneration. Callus induction rate of viable seeds varied from 24.3% to 71.7%. Plant regeneration frequency ranged from 76.6% to 29.7%. 'Roughrider' varieties showed higher regenerability with the frequency of 76.6%. These results can be used not only to provide additional improvements in the plant regeneration frequency from transgenic callus, but also useful for molecular breeding of orchardgrass through genetic transformation.

• Korean Journal of Medicinal Crop Science
• /
• v.4 no.2
• /
• pp.126-131
• /
• 1996

Plant regeneration from the stem tissue of Houttuynia cordata Thunberg was investigated. The medium supplemented with the combination of 2, 4-D 1 mg/L and kinetin 0. 5 mg/L was the most effective for the embryogenic callus formation. The internode segment produced more callus formation than the leaf segment. ${\frac{1}{2}}\;MS$ medium was the most effective for the embryogenic callus formation. The medium supplemented with the 1% activated charcoal produced the whole plant directly without the callus formation from the nodes. The medium supplemented with the combination of NAA 0. 2 mg/L and BA 1 mg/L was the most effective for the plant regeneration from the embryogenic callus.

• Korean Journal of Plant Tissue Culture
• /
• v.21 no.4
• /
• pp.247-252
• /
• 1994

The effects of explant sources, plant growth regulators on callus induction and plantlet differentiation from leaf blade, petiole, and meristem tissue of Pelalgonium citrosa were investigated under illumination or in dark condition Leaf blade explants cultured on Murashige and Skoog's medium containing 2,4-D and kinetin did not form callus or organ. But those cultured on medium with NAA and BA produced callcus and shoots. Dark condition was more effective than light condition to callus induction and showed that some of shoot were differentiated directly from leaf blade explane. Callus proliferated vigorously on meristem tissue after 7 days of culture, and multiple shoots were obtained Sum callus on medium with 0.5 mg/L NAA and BA. Roots formed readily from about 80% of the shoots cultured on medium with 1.0 mg/L NAA. Regenerated plantlets regenerated had phenotypically normal leaves and roots.

• Journal of Plant Biotechnology
• /
• v.31 no.1
• /
• pp.25-29
• /
• 2004

To establish the system of in uitro plant regeneration, the leaf segments of Sedum sarmentosum were cultured on MS media supplemented with different levels of 2,4-D, NAA and BA. The callus induction and growth showed a good response on MS medium supplemented with 3.0mg/L 2,4-D and 1.0mg/L BA, but a few callus induced on medium containing NAA and BA. In plant regeneration, combination of BA and NAA promoted shoot organogenesis from callus, and the highest frequency was obtained on MS medium supplemented with 0.2mg/L NAA and 3.0mg/L BA. When calli were transferred to the plant regeneration medium containing 0.2mg/L NAA and 3.0mg/L BA, healthy shoots without hyperhydricity were continuously induced (17.2 plantlets per callus) after 50 days of culture. When regenerated plantlets were transferred onto hormone-free MS medium, rooting was easily achieved from all of them.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.19 no.4
• /
• pp.303-308
• /
• 1999

The conditions for callus formation and plant regeneration were confirmed in birdsfoot trefoil (Lotus corniculatus L.). Among SH (Schenk and Hildebrandt), MS (Murashige and Skoog) and N6 medium (Chu), SH medium was highest degree of efficiencies respectively in callus formation and plant regeneration. In this study, we determined volume of hormones and other compounds appended in media. For callus formation, only $3mg/{\ell}$ of 2,4-D (2,4-dichlorophenoxy acetic acid) was appended in their media. For plant regeneration, we used BOi2Y medium (Bingham et al.). We obtained birdsfoot trefoil plants from callus by regeneration, about sixty days later transfer calli to regeneration media.

• Korean Journal of Plant Tissue Culture
• /
• v.21 no.2
• /
• pp.69-76
• /
• 1994

Callus growth and shoot regeneration of Solanum and Lycopersicon depended on genotype, growth regulators, and thiamine concentration. L. peruvianum LA 1277 and L. peruvianum LA 1373 and PI 251301 had the greatest callus growth while L hirsutum LA 1777, L.esculentum 'Diego'and 'Red Plum' had the least callus growth. Lycopersicon penvianum genotypes were superior to L. esculentur genotypes in regenerating plants. MG medium was more effective in regenerating shoots than MS medium. A low level of IAA (0.2mg/L) and high level of BA (2 mg/L) resulted in the greatest shoot regeneration. Shoot growth varied depending on thiamine concentration and genotype. Shoot proliferation of Solanum ptycathum, Solanum nigrum, and L. peruvianum PI 199380 was best on medium with 20 mg/L thiamine. Regeneration of L. peruvianum PI 251301 and PI 128652 was better on medium with 30 and 10mg/L thiamine, respectively.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.2
• /
• pp.83-87
• /
• 2000

To investigate the effect of growth regulators and antioxidant in anther floating cultures of rice, anthers were cultured in liquid media supplemented with different growth regulators, and the effect of antioxidant mixture : (Sigma Chemical Co.) on callus induction and plant regeneration were investigated. N6 medium with 1 mg/L 2,4-D and 1 mg/L kinetin was the best for rice anther floating cultures, which showed 48.5% of callus induction and 6.8% of green plant regeneration. The callus induction was not affected by antioxidant mixture in liquid medium, and antioxidant mixture (250 mg/L) was effective for the reduction of brownish callus and improvement of plant regeneration Antioxidant mixture showed better effectiveness when it was supplemented to both media for callus induction and plant regeneration.

• Korean Journal of Plant Tissue Culture
• /
• v.28 no.5
• /
• pp.277-281
• /
• 2001

Embryogenic callus induction and plant regeneration methods were developed for native Kentucky bluegrass (Poa pratenes L.) ecotypes. Mature caryopses and immature inflorescences (20 mm in length) of 4 native ecotypes and 5 foreign cultivars were plated on MS medium (30 g/L sucrose, 3 g/L Phytagel) supplemented with 1 mg/L 2,4-D, and cultured in the dark at 24$^{\circ}C$. Most explants formed calli, but more embryogenic calli were induced from the explants of immature inflorescences than caryopses which produced mostly non-embryogenic rooty calli. In P77 ecotypes, immature inflorescence explants formed embryogenic calli with the rate of 62~95%, and those of field-grown plants were more efficient than greenhouse-grown ones in embryogenic callus induction. Plantlets were regenerated from the embryogenic calli when they were transferred to hormone-free MS medium, and grew to maturity without morphological variations in greenhouse.