• Korean Journal Plant Pathology
• /
• v.14 no.2
• /
• pp.125-129
• /
• 1998

Phytopathogenic bacteria causing soft-rot many vegetables; extracellular enzymes produced by them, pectate lyase(Pel) is important pathogenicity facotrs which cause tissue maceration and cell death. Ten of seventeen plant pathogenic bacteria showed weak Pel activity, four of them showed low Pel activity and Erwinia acrotovora subsp. carotovora, E. chrysanthemi, Pseudomonas marginalis and Xanthomonas campestris pv. campestris showed high Pel activity in the polygalacturonate yeast extract agar (PAY) plate. High Pel activity of the four bacteria species produced the highest Pel activity when pectin or polygalacturonic acid (PGA) was added to minimal salts (MS) medium. Pel activity of the four bacterial species was the highest at 2$0^{\circ}C$ among different temperature conditions. The rate and amount of maceration of potato tuber tissue were highest at 2$0^{\circ}C$ in E. carotovora subsp. carotovora, E. chrysanthemi and P. marginalis, while those were the highest at $25^{\circ}C$ in X. campestris pv. campetris.

• Korean Journal of Plant Tissue Culture
• /
• v.24 no.2
• /
• pp.83-86
• /
• 1997

To produce and supply the healthy potato, basic seed potatoes were produced by stem cutting, microtuberization and hydroponic culture. The total number of tubers and the total tuber weight per $\textrm{m}^2$ of potato were more in hydroponic culture as each products were 1, 152 and 4, 492g than in the stem cutting (75 and 4, 136g) or microtuberization (1, 080 and 1, 080g) using petridishes. The total yield per 10a in the field was propagated highly stem cutting > propagated microtubers > hydroponics > microtubers. The number of tubers per 10a produced by hydroponics (33, 064) was higher than any other methods. This indicated the hydroponic culture can be used in the multiplication of basic seed potatoes.

• Korean Journal of Plant Tissue Culture
• /
• v.28 no.5
• /
• pp.283-287
• /
• 2001

Differential display based on PCR was employed to identify genes expressed during tuber-developing stage of potato (Solanum tuberosum L. cv. Irish Cobbler). An eukaryotic initiation factor 5A (eIF-5A) clone isolated from a cDNA library constructed with developing micro-tuber using a probe of PCR fragment. We isolated three positive clones and ore of them contained open reading frame. This clone revealed high sequence similarity to tomato eIF 5A cDNA. At the DNA level, there is 94.8% identity with the tomato eIF-5A4, whereas at the protein level there is a high identity with 97.5%. The potato eIF 5A clone is 716 bp in length and contains a single open reading frame from 57 to 539 bp, a 56 bp 5'-untranslated region and a 177 bp 3'-untranslated region. The deduced protein composed of 160 amino acid residues, with a predicted molecular mass of 17.4 kD and an estimated pl of 5.5. The sequence of 12 (STSKTGKHGHAK) amino acids among eIF-5A proteins is perfectly conserved from yeast to human. That sequence in potato eIF-5A protein is also conserved at position 46 to 57 amino acid. This region embeds the post-translational modification site of the lysine residue (at the seventh K) to hypusine that is crucial to eIF-5A activity. The northern blot analysis of eIF5A has shown abundant expression, mainly in flower organs (stamen, ovary, petal, sepal), fruit and stolen.

• Korean Journal of Medicinal Crop Science
• /
• v.1 no.1
• /
• pp.28-37
• /
• 1993

The low seed propagation is one of the problem needed a lot of seed tuber for the propagation in yam. Therefore this experiment was carried out to understand the possiblility of seed tuber propagation by tissue culture of yam. In-vitro stem node of yam was cultured by concentration treatments of 1/2, 1/4 and 1/8 with MS medium additted with each concentration levels of IAA, NAA, IBA, kinetin and BA. Acorrding to the Iower concentration than MS medium, length of shoots was promoted, leaf emergence shoots and rooting shoots were increased at 1/8 MS medium during the culturing period of stem node in yam. Fixed IBA and kinetin under the concentration of MS mdeium was inhibited severely by the heigh concentration additted with lAA $1mg\;/\;{\ell}\;and\;NAA\;4mg\;/\;{\ell}$. But fixed IBA $5mg\;/\;{\el}l\;and\;kinetin\;2mg\;/\;{\ell}$ with concentration of 1/8MS medium was remarkably promoted leaf emergence shoots and rooting shoots by $1mg\;/\;{\ell}$ of additted lAA and NAA. Percentage of induced shoots was increased by combination treatments of lAA. $1.5mg\;/\;{\ell}\;and\;kinetin\;2mg\;/\;{\ell}$, also leaf emergence shoots and rooting shoots were promoted by combination treatments of lAA $1.5mg\;/\;{\ell}\;and\;kinetin\;2mg\;/\;{\ell}$.

• Journal of Plant Biotechnology
• /
• v.34 no.4
• /
• pp.331-338
• /
• 2007

One-node stem pieces ca. 1 cm in length containing a axillary bud and a fully expanded leaf were obtained from it in vitro plants of potato (Solanum tuberosum L.). Leaves were removed and the nodes were cultured on the MS medium to investigate the effects of temperature, day length, sucrose, and CCC in microtuber formation and development. The fresh weight of microtubers after 80 days increased significantly at 8% sucrose and $20^{\circ}C$ compared with $28^{\circ}C$. The tuberization and development were reduced at $28^{\circ}C$ except short-day treatment of 8 hours at 8% sucrose. The fresh weight and diameter were increased on the culture medium added CCC 500 mg/L. The potato tuberization was promoted under short daylength, and it showed great effect by treatment with the CCC. Though the tuberization was promoted at low temperature of $20^{\circ}C$ in a histologic change of an axillary bud part cell of a potato, the cells were able to observe the swelling growth. Swelling growth of tissue was stimulated in the darkness and was more remarkable by addition of CCC. In particular, in the visual ratio of cell division for each position in the tissue, the cortex part showed larger ratio of cell expansion than that of the pith part. The effect of CCC was identified at 8% sucrose in the darkness. The effect of CCC was not showed in sucrose 3% under long daylength of 16 hours. As a result, the fact of a substance with AGPase important for starch composition was certified by the result with the inclose of AGPase activity on high concentration of sucrose, CCC, and dark treatment by which tuber formation and development are promoted.

• Korean Journal of Plant Tissue Culture
• /
• v.24 no.2
• /
• pp.71-75
• /
• 1997

For the establishment of early selection of heat-tolerant clones through in vitro tuberization of true potato seeds, different temperature treatments for in vitro tuberization were investigated. The ratios of tuberization at 2$0^{\circ}C$ on var. Superior and DTO-33 treated with 5 mg/L of BAP and 500 mg/L of CCC, were 85% and 92%, respectively. At 3$0^{\circ}C$, the ratio of tuberization on DTO-33 was 37%, which revealed strongly heat-tolerant clone. In culture system of in vitro tuberization, the number of tubers per flask at 2$0^{\circ}C$ on non-subculture incubation was more than that on subculture incubation. The condition of non-subculture and short-day treatment for 4 weeks was good for production as 10.6 tubers per flask, which was very similar to that of long-day treatment. On the other hand, tuber diameter on long-day treatment was greater as 11.2 mm than on short-day treatment. Therefore, in vitro tuberization from true potato seeds could be induced under the condition of long-day treatment at darkness.

• Korean Journal of Medicinal Crop Science
• /
• v.5 no.1
• /
• pp.21-27
• /
• 1997

This experiments were conducted to determine the effect of thidiazuron on forming tuberlets and plant regeneration of Pinellia ternata T. by tissue culture. The addition of $5\;{\mu}M$ TDZ to the medium had better regeneration than that of any other treatments of NAA and TDZ. At the combination treatments of NAA and TDZ, as the level of thidiazuron increased, the rate of shoot regeneration was incresed while the increment of NAA concentration inhibited the rate of shoot regeneration. The supplement of $5\;{\mu}M$ thidiazuron produced the best number of micro-tubers per explant and the number of micro-tuber formed was 25 in MS medium and 29 in MG medium on 30 day culture, respectively. Microtuber formation was the best on MG medium with 1.0 mg/l NAA and $5\;{\mu}M$ thidiazuron. MG medium was superior to MS and B5 medium for the growth of tuberlets. Half strength of MS medium with NAA 2 mg/l was the most effective for root formation. Rooting ability on nursery soil of plantlets produced in in vjtro was good as a 80% after 3 weeks.

• The Plant Pathology Journal
• /
• v.19 no.1
• /
• pp.13-18
• /
• 2003

From 1996 to 1999, potato-growing areas in Korea were surveyed for identification and distribution of potato scab pathogens. Potato scab was widely distributed in the mass cultivation areas, especially in Jriu island, southern areas of Chonnam and Gyounggi provinces, and the alpine area of Gangwon province. Jeju island was the most affected area by this disease. A total of 55 Streptomyces strains were isolated from potato scab lesions, among which 40 strains were pathogenic on progeny tubers. Among the pathogenic strain, 21 strains were identified as previously described S. scabies, 7 Strains as S. turgidiscabies, and 5 Strains as S. acidiscabies, while 7 strains were observed as having distinct phenotypic properties. These strains were classified into six distinct clusters based on phenotypic characteristics and selected representative strains for each cluster. S. scabies (S33) had grey spores in a spiral chain. Mean-while, S. turgidiscabies (S27) had grey spores, S. acidiscabies (S71) had white spores, S. luridiscabiei (S63) had yellow-white spores, S. puniciscabiei (S77) had purple-red spores, and S. niveiscabiei (S78) had thin and compact white spores, all in a rectiflexuous chain. Pathogenicity was determined by the production of thaxtomin A and homologs of necl and ORFtnp genes. In TLC, representative strains S27, S71, S63, S77, and S78 produced a yellow band that co-migrated with the authentic thaxtomin A. However, thaxtomin A was not detected in chloroform extracts from oatmeal broth culture and Slice tuber tissue of S. luridiscabiei (S63) and S. puniciscabiei (S77) by HPLC analysis. In addition, no homologs of necl and ORFtnp genes in S. acidiscabies (S71), S. luridiscabiei (S63), S. puniciscabiei (S77), and S. niveiscabiei (S78) were detected by PCR and Southern hybridization analysis.

• The Journal of Natural Sciences
• /
• v.4
• /
• pp.103-142
• /
• 1991

These studies were carried out to select somatic hybrid using selectable marker genes of Nicotiana glauca transformed by NPTII gene and Solanum tuberosum transformed by T- DNA, and to study characteristics of transformant. The results are summarized as follows. 1. Crown gall tumors and hairy roots were formed on potato tuber disc infected by A. tumefaciens Ach5 and A. rhizogenes ATCC15834. These tumors and roots could be grown on the phytohormone free media. 2. Callus formation from hairy root was prompted on the medium containing 2, 4 D 2mg/I with casein hydrolysate lg/l. 3. The survival ratio of crown gall tumor callus derived from potato increased on the medium containing the activated charcoal 0. 5-2. 0mg/I because of the preventions on the other hand, hairy roots were necrosis on the same medium. 4. Callus derived from hairy root were excellently grown for a short time by suspension culture on liquid medium containing 2, 4-D 2mg/I and casein hydrolysate lg/l. 5. The binary vector pGA643 was mobilized from E. coli MC1000 into wild type Agrobacteriurn tumefaciens Ach5, A. tumefaciens $A_4T$ and disarmed A. tuniefaciens LBA4404 using a triparental mating method with E. ccli HB1O1/pRK2013. Transconjugants were obtained on the minimal media containing tetracycline and kanamycin. pGA643 vectors were confirmed by electrophoresis on 0.7% agarose gel. 6. Kanamycin resistant calli were selected on the media supplemented with 2, 4-D 0.5mg/1 and kanamycin $100\mug$/ml after co- cultivating with tobacco stem explants and A. tumefaciens LBA4404/pGA643, and selected calli propagated on the same medium. 7. The multiple shoots were regenerated from kanamycin resistant calli on the MS medium containing BA 2mg/l. 8. Leaf segments of transformed shoot were able to grow vigorusly on the medium supplemented with high concentration of kanamycin $1000\mug$/ml. 9. Kanamycin resistant shoots were rooting and elongated on medium containing kanamycin $100\mug$/ml, but normal shoot were not. 10. For the production of protoplast from potato calli transformed by T-DNA and mesophyll tissue transformed by NPTII gene, the former was isolated in the enzyme mixture of 2.0% celluase Onozuka R-10, 1.0% dricelase, 1.0% macerozyme. and 0.5M mannitol, the latter was isolated in the enzyme mixture 1.0% Celluase Onozuka R-10, 0.3% macerozyme, and 0.7M mannitol. 11. The optimal concentrationn of mannitol in the enzyme mixture for high protoplast yield was 0.8M at both transformed tobacco mesophyll and potato callus. The viabilities of protoplast were shown above 90%, respectively. 12. Both tobacco mesophyll and potato callus protoplasts were fused by using PEG solution. Cell walls were regenerated on hormone free media supplemented with kanamycin after 5 days, and colonies were observed after 4 weeks culture.