• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.564-573
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• 2016

This research was performed to develop mass propagation method of round-leaved sundew (Drosera rotundifolia L.) for improving horticultural usefulness. Seeds were collected around Hwaseong-si, Gyeonggi-do in October of 2011 and experimented upon while being dry-stored at 4 ± 1.0℃ (darkness). Seed length of a major and minor axis were 1.58 ± 0.060 and 0.21 ± 0.016 ㎜, respecrively, and weight of 1,000 seeds was 6.24 ± 0.172 ㎎. Seeds were thus classified as ‘dwarf seeds’. Regarding the dormancy type, since round-leaved sundew seeds were dormancy broken and germinated at 20~30℃ under the light condition after wet-chilling treatment for 12 weeks, seeds were estimated to have physiological dormancy. Germination conditions of dormancy broken seeds were found to be 20℃ and light condition (54.7%), but germination decreased at higher temperature. Percent germination (PG), germination energy (GE), mean germination time (MGT) and T₅₀ were effectively improved by chemical treatment such as GA₃ 200 ㎎/L + kinetin 20 ㎎/L and wet-chilling treatment for 14 weeks. In conclusion these optimal conditions were thought to be a useful method for raising seedling uniformly.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.71-75
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• 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
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• v.7 no.3
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• pp.155-161
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• 1999

This study was carried out to develop the propagation system using in vitro induced- microtubers of yams (Dioscorea alata L.). Effects of kinds of media, mineral composition, sucrose concentration (0, 2, 4, 6, 8, 10%), photoperiod (0, 8, 12, 16, 24h), and growth regulators (NAA, IAA, ZR, JA-Me, ABA) on the development of microtubers, roots, and shoots in nodal stem segment cultures of D. alata L. were evaluated. Microtuberization in nodal stem segment occurred on all the media supplemented with growth regulator and sucrose. Among basic media, 1/2MS medium was the best in microtuber induction. NAA was shown to be the most effective among the growth regulators. Optimal NAA concentration was 1mg/l. The microtuberization was the highest at the concentration of 6% sucrose. When the nodal stem segment were cultured under darkness, the tuberization was increased markedly compared to those cultured under light condition. It was also noticeable that the culture in medium with NAA produced only microtubers and roots, but no shoots, in nodal segments. In this study, the optimal medium composition for microtuberization in nodal stem segment was found to be 1/2MS medium supplemented with 1mg/l NAA and 6% sucrose under dark condition at $25^{\circ}C$.

• Journal of Korean Society of Forest Science
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• v.94 no.1 s.158
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• pp.39-44
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• 2005

An effective micropropagation system for Liriodendron tulipifera L via somatic embryogenesis was established using immature seeds. Immature seeds from five individual trees were bisected longitudinally and cultured on two basal media (MS and B5) containing different combinations of 2,4-D and TDZ to induce callus and embryogenic tissue under light ($40{\mu}mol\;m^{-2}s^{-1}$, 16 hr/day) or complete darkness at $25{\pm}2^{\circ}C$. There was no distinctive difference on callus and embryogenic tissue induction between the two basal media with PGRs. Optimum culture medium appeared to be MS medium supplemented with 1.0mg/L 2,4-D and 0.01mg/L TDZ plus 3% sucrose. Nonembryogenic callus induction rate was not significantly different among the genotypes. However, However, the embryogenic callus induction frequency differed greatly by the genotypes ranging from 55% to 72% when cultured in the dark. Generally, the cultures maintained in the dark tended to show normal somatic embryo development as well as embryogenic tissue formation and this was confirmed by histological examination. Above results suggest that a proper selection of mother tree and dark culture condition are necessary to optimize somatic embryogenesis system of Liriodendron tulipifera.

• Journal of Marine Life Science
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• v.1 no.2
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• pp.109-116
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• 2016

We determined the effects of different water temperatures (15, 20, and 25℃) and photoperiod cycles (24L:0D, 12L:12D, and 0L:24D) on the oxygen consumption of the offspring of a cultured Japanese strain (JJ), a selected Korean strain (KK), and intraspecific hybrid strains (JK and KJ) of red seabream, Pagrus major, under starvation conditions. The different fish strains, water temperatures, and photoperiod cycles had effects on the mean oxygen consumption of fish. Oxygen consumption increased with increasing water temperatures for all photoperiod treatments (p<0.001). Fish held in continuous darkness (0L:24D) used consistently less oxygen than fish exposed to continuous light (p<0.05). The oxygen consumption of fish exposed to the light phase in a 12L:12D photoperiod was higher than that of fish in the dark phase of the 12L:12D cycle, and differences were significant in three of the strains: JJ (15℃), KK (15 and 20℃), and KJ (25℃). The oxygen consumption of the inbred (JJ and KK) and intraspecific hybrid (JK and KJ) strains varied with differing water temperatures and photoperiod cycles. The JK strain displayed significantly higher oxygen consumption than the other strains under all experimental conditions except 15℃ with a 0L:24D photoperiod. The JK and KJ strains usually showed the highest and lowest oxygen consumption values, respectively, whereas the inbred strains exhibited intermediate values. Oxygen consumption in the JJ and JK strains was usually higher than that of the KK and KJ strains. We propose that differences in the thermal sensitivity and photosensitization properties of the strains contribute to differences in their ability to adapt to changes in water temperature and photoperiod, thus resulting in differences in the amplitude of their metabolic rates.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.4
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• pp.605-610
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• 2006

The objective of the present experiment was to determine the effects of slaughtering at different ages and the use of a commercial probiotic (115-Biogallinox) in broiler diets on the color properties of carcasses, during the first 24 h following slaughter. Ross 308 male broiler chickens obtained from a commercial hatchery were raised to either 35 or 42 days of age. Chickens were fed with different levels of probiotic ($P_0$: 0.0%, $P_1$: 0.1% and $P_2$: 0.2%) containing Saccharomyces cerevisiae during the experimental period. At the end of the trial all birds were slaughtered and then stored at $3^{\circ}C$ for 24 h. The pH and skin colour of carcasses were determined 1, 3, 7, 10, 13, 17 and 24 h after slaughter. Although the use of probiotic and post-mortem ageing time affected the pH (p<0.01), it was not affected by slaughter age (35 and 42 days) (p>0.05). The highest pH values occurred in carcasses of broilers fed 0.2% probiotic. The pH values of carcasses decreased with post-mortem ageing time (p<0.01). Main factors (treatment, slaughter age and post-mortem ageing time) had an effect on colour ($L^*$, $a^*$ and $b^*$) values (p<0.01). $L^*$ values of 42d-old slaughter and $P_2$ group were lower than those of 35d-old slaughter and other probiotic groups. The $a^*$ and $b^*$ values of 35d-old slaughter were lower than those of 42d-old slauhgter. The $a^*$ and $b^*$ values increased during post-mortem ageing (p<0.01). It was determined that changing of the colour traits of broiler carcasses was correlated with probiotic, pH and post-mortem ageing time. Also, it was observed that darkness of carcass colour increased as time progressed.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.3
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• pp.390-395
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• 2016

This study was conducted to investigate the effect of nocturnal light pulses (NLPs) on the feed intake and metabolic rate in geese. Fourteen adult Chinese geese were penned individually, and randomly assigned to either the C (control) or NLP group. The C group was exposed to a 12L:12D photoperiod (12 h light and 12 h darkness per day), whereas the NLP group was exposed to a 12L:12D photoperiod inserted by 15-min lighting at 2-h intervals in the scotophase. The weight of the feed was automatically recorded at 1-min intervals for 1 wk. The fasting carbon dioxide production rate ($CO_2$ PR) was recorded at 1-min intervals for 1 d. The results revealed that neither the daily feed intake nor the feed intakes during both the daytime and nighttime were affected by photoperiodic regimen, and the feed intake during the daytime did not differ from that during the nighttime. The photoperiodic treatment did not affect the time distribution of feed intake. However, NLPs lowered (p<0.05) the mean and minimal $CO_2$ PR during both the daytime and nighttime. Both the mean and minimal $CO_2$ PR during the daytime were significantly higher (p<0.05) than those during the nighttime. We concluded that NLPs lowered metabolic rate of the geese, but did not affect the feed intake; both the mean and minimal $CO_2$ PR were higher during the daytime than during the nighttime.

• Korean Journal of Agricultural Science
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• v.13 no.1
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• pp.52-61
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• 1986

Mycelial growth of Colletotrichun dematium and C. gloeosporioides isolated from anthracnose of Lycium chinense was favorable on V-8 Juice Agar media and Oatmeal Agar media of the four different media tested. Sporulation of C. dematium was favorable on PDA media and V-8 Juice Agar media and that of C. gloeosporioides was favorable on all media tested. The optimum temperature for mycelial growth of C. gloeosporioides and C. dematium was $25^{\circ}C$ and $28^{\circ}C$, respectively and sporulation of the fungi was stimulated under alternating NUV light and darkness. Of the seven nitrogen sources tested, gelatin was the most favorable for mycelial growth of C. gloeosporioides and glycin and gelatin were favorable for that of C. dematium. Of the eleven carbon sources tested, dextrin and sorbitol were favorable for mycelial growth of C. gloeosporioides and dextrin was the most favorable for that of C. dematium. Among the eleven fugicides tested, Benomyl, Folpet, Dithianon, Carbendazim and S-3308L were found superior for the inhibition of mycelial growth and spore germination of the fungi. They were, also, found superior for the control of anthracnose disease of L. chinense when they were applied to the plants in the field.

• Korean Journal of Plant Resources
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• v.22 no.4
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• pp.304-311
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• 2009

This study was conducted to develop functional sprout vegetables with antioxidant effects using seeds of Arctium lappa. The seeds germinated vigorously under light at $25^{\circ}C$, reaching germination rate of 82% within 4 days. Germinated seeds were placed under darkness at various temperatures to force growth in length, and it was demonatrated that $20^{\circ}C$ was optimum temperature. Greening treatment reduced growth in length, but promoted growth of cotyledons. Harvested A. lappa sprout vegetables maintained freshness longer at $10^{\circ}C$, rather than $4^{\circ}C$. Ventilation holes in storage containers had no effects on storage periods. Antioxidant activity of vegetable that received greening treatment for 1-3 days was investigated, and it was shown that free radical scavenging effects and ferrous ion chelating effects was higher than those of commercially available brocoli, cauliflower, pea and bean sprout. Contents of total polyphenol and flavonoid were also higher, especially by 3 day greening. The longer the treatment, the more the inhibition on peroxidation of linoleic acid. Sprout vegetable of A. lappa had higher antioxidant activity compared with adult plant. In conclusion, sprout vegetable of A. lappa has great potentiality for use as one of sprout vegetables.

• The Korean Journal of Ecology
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• v.4 no.3_4
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• pp.114-123
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• 1981

Diurnal acid fluctuations, stomatal resistance, and morphology and anatomy were investigated in leaves and stems P. oleracea L. growing under the natural environmental condition. A CAM-like pattern of acid fluctuation was exhibited not in leaves of the young purslane but in its stems. Defoliated stems showed a decreased in diurnal changes of total acidity as compared with normal stems. Excised stems stored in continuous darkness exhibited diurnal acid rhythms, and they showed light deacidifications for three days. Kranz-type arrangement was observed in leaves, but not in stems. Micrography of cross sections of stems showed cells with relatively large vaculoles and a few chloroplasts. The number of stomata was 3,275cm-2 in leaves, while the stomata could not be observed in stems. Stomatal resistance was high at night and low in daytime in leaves of the young purslane, and the range of its value was 5~40 sec.$\textrm{cm}^{-1}$. But stomatal resistance in leaves of the water-stressed plant was comparratively high in day time, and its value was 30 sec.$\textrm{cm}^{-1}$. The result of these studies showed the possibility that the stem of P.oleracea L. possesses CAM under certain stressed conditions.