• Journal of Life Science
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• v.18 no.7
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• pp.907-911
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• 2008

Radish (Raphanus sativus L.) is one of very important crop plants in the world. It is very important to determine hybrid seed quality in the production of hybrid Brassica vegetable seeds to avoid unacceptable contamination with self-inbred (sib) seeds. The allozyme for evaluating seed purity in a commercial $F_1-hybrid$ radish cultivar is demonstrated. Three hundred sixty seeds from the male and female harvest were subsequently screened for seed purity using 27 isozyme loci. Especially, F1 hybrids of radish, Per-1 ($aa{\times}bb$), Lap-1 ($aa{\times}bb$), Est-1 ($aa{\times}bb$) were presented clear hybrid bands. Est-1 locus revealed that 15 (8.3%) seeds from the female harvest and 26 (14.4%) seeds from the male harvest were sibs. It maintains higher than average level of genetic diversity compared with their correspondent parents. Shannon's index of phenotypic diversity (I) of hybrids was the highest of all accessions (R. sativus L. cv. Daepeng, R. sativus L. cv. Backza, and their hybrids). The allozyme may lead to a better insight into the hybrid seed purity.

• Journal of Life Science
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• v.17 no.10
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• pp.1336-1340
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• 2007

The regeneration and growth of bulblets from the bulb scale segments of Hyacinthus orientalis L. cv. Pink Pearl were more efficient in IBA than IAA at the same concentrations (1.0 and 3.0 mg/l). The normal (base-down) orientation of explants was more effective for bulblet regeneration and root growth than the inverted (base-up) orientation. The growth of bulblets and roots was increased higher in the perlite than the agar medium. These results suggested that the alternate culture system, first cultured in the agar medium for bulblet regeneration, and then in the perlite medium for bulblet growth, may be more useful for efficient in vitro culture of hyacinth (H. orientalils) cv. Pink Pearl.

• Food Science and Preservation
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• v.23 no.4
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• pp.585-590
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• 2016

In this study, the antioxidant and tyrosinase inhibitory activities of aqueous ethanolic extract from the immature fruits of Malus pumila cv. Fuji were evaluated. The antioxidant capacities of the extract was investigated employing radical scavenging assays using DPPH and $ABTS^+$ radicals. The skin-whitening effect of M. pumila cv. Fuji extract was tested using mushroom tyrosinase assay. In addition, the total phenolic content was measured by a spectrophotometric analysis. All tested samples showed a dose-dependent radical scavenging and tyrosinase inhibitory activities. Among the tested samples, the ethyl acetate (EtOAc)-soluble portion from the immature fruits of M. pumila cv. Fuji was showed the significant DPPH and $ABTS^+$ radicals scavenging activities. Also, the tyrosinase inhibitory activity of the ethyl acetate (EtOAc)-soluble portion from immature apples was higher than other solvent-soluble portion. These results suggest that unripe fruits of M. pumila cv. Fuji could be considered as a new valuable source of natural antioxidant and skin-whitening agents. Systematic investigation of immature fruits of Malus pumila cv. Fuji will be performed for the further development of its biological properties.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.69-74
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• 2001

Calli were induced on MS medium supplemented with 0.5 mg/L 2,4-D by using the leaf explants of haploid which were derived from the diploid and haploid of Nicotiana tabacum cv BY4. These calli were subcultured on MS medium with the combination of 2.0 mg/L 2,4-D, 1.0 mg/L kinetin and 0.1 mg/L BAP. Cell propagation of diploid plants were good in a combination of 2.0 mg/L 2,4-D, 0.1mg/L BAP in vitro conditions, suspension cultures were conducted in equal condition. Homogenized suspension cultured cells were smeared 2.0 mL each on MS medium with 0~100 $\mu$M PFP, to select the resistant colony to PFP, and were examined after 10d, 20d and 30d. Measurment of fresh weight of cells after 30d of culture shows that with more concentration of PFP in medium the fresh weight of the cells decreased. In case of diploid, selected callus was the highest in vitro treated with 5 $\mu$M PFP. It was higher than control until 100 $\mu$M PFP. The active degree of catalase was the highest in vitro with 5 $\mu$M PFP but the lowest in vitro with 10 $\mu$M PFP on the other hand, in case of haploid plant, the active degree of peroxidase and catalase was the highest in vitro treated with 50 $\mu$M PFP. It's sure that enzyme active degree of between diploid and haploid had big differences.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1549-1551
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• 2001

Cyclic aging for 14 days is performed to remove a large amount of the volatiles found in freshly manufactured cable. In this paper, we examined lightning impulse characteristics of 22.9 kV CV power cable before and after cyclic aging for 14days. As the result, the breakdown voltage after aging under normal temperature was lower than that before aging, and the breakdown voltage after aging under hot temperature was lower than that before aging. We found that the dispersion of lightning impulse breakdown voltage before 14 cyclic aging test were reduced rather than those after 14 cyclic aging test.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.328-332
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• 2011

After preparation of acetone, ethanol, methanol, and water extracts (10 g/300 mL) of dried persimmon (Diospyros kaki cv. Fuyu) flower-buds, total phenolic contents (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (RSA), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) RSA, reducing power (RP), and tyrosinase inhibitory activity of the extracts were evaluated. The methanol extracts produced the highest TPC (113.39 mg gallic acid equivalents/g), DPPH RSA ($IC_{50}=40.25\;{\mu}g/mL$), ABTS RSA ($IC_{50}=58.17\;{\mu}g/mL$) and RP ($IC_{50}=69.43\;{\mu}g/mL$) activities while the water extracts generated the lowest values. The ethanol extract showed the highest tyrosinase inhibitor activity (88.90%) at a concentration of 1 mg/mL. These results indicated that persimmon flower-buds may be a useful source of natural antioxidants.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.245-250
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• 1999

Plantlets derived from leaf blade-segment culture of a variegated tobacco (Nicotiana tabacum L. cv. BY-4) that was induced by a heavy-ion ($^{14}N$) beam irradiation to proembryos, were characterized. When explants from both white and green sections of leaves of the variegated plant were cultured on MS medium containing 0.1 mg/L NAA and 1.0 mg/L BAP, the white sections yielded only white shoots, whereas the green sections generated approximately 47.2% green, 37.4% white and 15.4% variegated shoots. In the F1 generation of a green tobacco derived from the leaf blade-segment culture, the segregation ratio of green to white was 1,651:54. Furthermore, reciprocal crosses showed that all of the progenies was green, indicating that the variegation is not maternally inherited. When the signal intensity of photosynthesis genes was determined by DNA gel blot analysis using the variegated leaves derived from green sections of variegated leaves, there were more of the rbcL, psbA, 16S rDNA and 23S rDNA chloroplast genes in the white sections than the chloroplast genes in wild type and green sections of the variegated plants.

• Korean journal of applied entomology
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• v.32 no.3
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• pp.323-329
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• 1993

These studies were conducted to evaluate the five comparative test methods for detecting chemical resistance and to investigate resistant level of field populations of diamondback moth (Plutella xylostella L.). Leaf disc method was practically rocomrnendable because of its rapidity and low CV(l1.4%). Topical application method was a precise replicabiliLy(CV=8.00/0) but it was time consuming and difficult in mampulation. The other 3 methods showed higher CV ranging from 14.9% to 21.4%. Based on $LC_{50}$ values by topical application method, field populations of diamondback moth collected from 4 different regions, Kwangju, Kimhae, Jeju, and Inje to prothiofos showed from 3.3 to 61.1 times higher resistance than the susceptible strain, whereas to cypermethrin, Lhey were from 7.5 to 141.7 times higher than the susceptible. To cartap hydrochloride, they showed from 10.5- to 33.3-fold resistant levels as high as the susceptible. Finally, based on $LC_{50}$ values to Bacillus thuringiensis by leaf disc technique, the resistant levels of the field populations were from 1.9 Lo 8.1 times as compared to the susceptible.

• Journal of Plant Biotechnology
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• v.31 no.4
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• pp.279-283
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• 2004

To lily (Lilium longflorum cv. Georgia) pollen, impacts by some physical, chemical and biological factors were examined in respects of its growth and transient gene expression via agro-infiltration. Rolling movement in liquid medium or vacuum pressure during Agro-infiltration was regarded as a impact that should be minimized for normal pollen growth. Pollen growth was maintained well in relatively broad range of temperature (19 to 27$^{\circ}C$) or pH (5.0 to 8.0). Chemical factors such as cefotaxime (up to 300mg/L), acetosyringone (up to 800 $\mu$M) and syringealdehyde (up to 800 $\mu$M) did not show any harmful effects but kanamycin severely did even at concentration as low as 25mg/L in some cases. For GUS gene expression, acetosyringone at 200 to 400 $\mu$M slightly improved the efficiency while syringealdehyde did not. Brief agro-infiltration followed by 18 hr of co-incubation of pollen along with Agrobacterium was suggested as a condition basically required for the transient expression system using lily pollen regardless of the presence of acetosyringone.

• Korean Journal of Plant Tissue Culture
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• v.28 no.4
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• pp.179-184
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• 2001

We evaluated a possibility of the use of chloroplast number per guard cell pairs as a measure for ploidy level in the different ploidy levels of tobacco plant (Nicotiana tabacum L. cv. BY-4) . The guard-cell chloroplast numbers of leaves of haploid plant were a half of wild-type plant. Furthermore, the number of chloroplast per guard cell pairs of the leaves of doubled-haploid plant increased in two times compared with that of haploid plant. In addition, the chloroplast number was not changed in the F$_1$ progenies. The change of the chloroplast number by leaf stage was not observed. The results indicate that there is a strong relationship between ploidy level (2x and 4x) and chloroplast number per guard cell pairs. This relationship was also, observed in both in vitro and pot cultured plants. It was determined that the measurement of chloroplast number in guard cells of leaf epidermis is simple to use and less labour intensive, and hence can be considered a practical alternative to the chromosome counting methods or flow cytometry in the tobacco plant.