• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.487-494
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• 1993

In order to establish a fully automatized pest control in the a greenhouse , the authors developed a prototype of microcomputer installed spraying vehicle which traveled along the furrows. Since a power sprayer mounted on the vehicle was driven by gasoline engine, plants grown in the greenhouse might be injured by the gas exhausted from the engine. Thus , effects of exhausted gas on photosynthetic rate and the shedding of flowers and buds of plants were examined. At first, effects of exhausted gas on photosynthetic rate of potted sweet pepper (Capsicum annuum L.) and eggplant(Solanum melongena L.) plants were examined. In a closed vinyl house the engine was operated for 5 minutes and plants were exposed to the gas for 2hours in the daytime on a fine day. Photosynthetic rate did not significantly decreased by the treatment in both species. Secondly, effects of ehtylene on the shedding of flowers and buds of sesame (Sesamum indicum L. ) were examined. In the closed and partiall opened vinyl house, the engine was operated for 5 minutes and potted sesame plants were exposed to the gas for 12 hours in the night. In partially opened vinyl house, ethylene concentration decreased to 0 ppm 3 hours after the engine was stopped and flower and bud did not shed. In contrast, when vinyl house was closed ethylene concentration was 0.75 pm even 12 hours after the engine was stopped and flowers and buds shed markedly and epinasty was observed in upper young leaves. As mentioned above , it was revealed that injury of plants in the greenhouse caused by the gas exhausted from a gasoline engine could be prevented by providing suitable ventilation.

• Journal of Ginseng Research
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• v.33 no.3
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• pp.212-218
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• 2009

Triterpenoid saponins were synthesized in Panax ginseng C.A. Meyer via the isoprenoid pathway by cyclization of 2,3-oxidosqualene to give primarily oleanane (beta-amyrin) or dammarane triterpenoid skeletons. The triterpenoids are backbone and undergoes various modifications (oxidation, substitution and glycosylation), mediated by cytochrome P450 (CYP)-dependent monooxygenases, glycosyltransferase and other enzymes. This is likely to be due in part to the complexity of the molecules and the lack of pathway intermediates for biochemical studies. A cDNA clone encoding a putative CYP gene was isolated from flower bud of ginseng and transformed into the plant(Nicotiana tabacum cv. Xanthi) and confirmed by PCR analysis. The CYP gene (PgCYP) contained an open reading frame(ORF) encoding mature protein of 500 amino acids. The expression of PgCYP were investigated in transgenic tobacco by reverse transcriptase-polymerase chain reaction (RT-PCR).

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.4
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• pp.630-637
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• 2010

The object of this study was to evaluate the effect of Lonicerae Flos, aqueous extracts of the dried flower bud part of Lonicera japonica on the 6-n-propyl-2-thiouracil (PTU)-induced rat hypothyroidism. Aqueous extracts of Lonicerae Flos (LF yield = 23.80%) were administered, once day for 42 days from 2 weeks before start of PTU treatment as an oral dose of 500 and 250 mg/kg (body weight), and hypothyroidism was induced by daily subcutaneous treatment of PTU 10 mg/kg for 28 days. The changes on the body weight, thyroid gland weights, serum thyroid hormone - thyroid stimulating hormone (TSH), tri-iodothyronine ($T_3$) and thyroxine ($T_4$), serum lipid profiles - total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL) and triglyceride were observed with liver antioxidant defense system - lipid peroxidation, $H_2O_2$, superoxide dismutase (SOD) and catalase (CAT) and serum asparte aminotransferase (AST) and alanine aminotransferase (ALT) analysis. Results were compared with Levothyroxine ($LT_4$) 0.5 mg/kg treated rats. As results of PTU treatment, marked decreases of body weights, serum thyroid hormone levels and triglyceride contents, liver $H_2O_2_3$ and SOD activities were observed with increases of serum AST and HDL contents, liver CAT activities, thyroid gland weight. However, these PTU induced hypothyroidism were dose-dependently inhibited by treatment of LF extracts, and LF extracts effectively regulated the hypothyroidism related changes on the antioxidant defense system. The results obtained in this study suggest that LF extracts have favorable effects on the thyroid hormone productions with beneficial effects on the hypothyroidism mediated by the modulatory effects on the antioxidant defense system.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.373-377
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• 2000

This study was carried out to verify the effect of fruit thinning on fruit development, and the results were as follows. The number of cells between fruit epidermis and periphery vascular bundle during 35 to 184 days after full bloom (DAFB) were constant with 14~17 cells, regardless of thinning at pink bud stage, fruitlet stage or non-thinning. However, the distance between epidermis and vascular bundle was longest in the fruit thinned at pink stage followed by fruits thinned at fruitlet stage and control. Therefore, it was seemed that the fruit size increment during 35 to 184 DAFB was due to the increment of cell size. Thinning time affected fruit size and the earlier the thinning times were the bigger the fruits were. However, there were no direct relationships between thinning time and the starch or tannin particle development in the cells of the fruit.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.1
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• pp.51-58
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• 2002

PSI-H is an intrinsic membrane protein known to be essential for efficient electron flow in PSI complex. We isolated a cDNA clone encoding a PSI-H subunit homolog from Chinese cabbage (Brassica campestris L.). The cDNA, designated bpsaH, had an insert of 435 bp and a full open reading frame that would encode a protein of 145 amino acids. The amino acid sequence deduced from the cDNA sequence is 79.3% identical to that of spinach, suggesting the cDNA most likely encodes Chinese cabbage PSI-H subunit. The bpasH was expressed at high level in leaf tissue and low level in flower bud, whereas it was undetectable in root tissue.

• Korean Journal of Plant Resources
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• v.29 no.3
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• pp.331-338
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• 2016

The present study aimed to compare and investigate the morphological characteristics and yield components according to ploidy level of diploid and tetraploid Platycodon grandiflorum under vinyl-greenhouse and open field conditions. Plant height of diploid and tetraploid P. grandiflorum was 51.3 ㎝, 54.0 ㎝, respectively. The results revealed that the plants grown in the vinyl-greenhouse showed significantly higher growth compared to those grown in the open field. Regardless of the growing place, diploid and tetraploid of P. grandiflorum showed the rapid elongation of internodes after 4 and 3 internodes respectively and elongation tends to be decreased as entering the flower-bud differentiation period. The starting day of flowering in vinyl-greenhouse cultivation was found to be faster than that of the open field cultivation by 2∼3 days and tended to be delayed by about 5∼6 days in tetraploid P. grandiflorum compared to diploid. Fresh weight of roots from the vinyl-greenhouse cultivation showed a high quantity as 34.2g and 49.4g in diploid and tetraploid P. grandiflorum, respectively and especially tetraploid P. grandiflorum was found to be increased by approximately 44.4% compared to other plots.

• Korean Journal of Environmental Agriculture
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• v.40 no.2
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• pp.73-82
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• 2021

BACKGROUND: The successful management of jujube trees depends on maintaining a balance between reproductive and vegetative growth. In general, heading cuts of trunk stimulate rather vegetative growth, but could decrease flower initiation. This study was conducted to establish a heading-back pruning severities at planting in the one year old 'Daeneung' jujube whip nursery tree by investigating vegetative growth and fruit yield. METHODS AND RESULTS: The heading back pruning severity was assigned as 5 different ranges as follow: one bud (TR-10, heading back pruning was 10 cm above the ground), three buds (TR-30), five buds (TR-50), seven buds (TR-70), and nine buds (TR-90) were left of scion. The number of buds on whip trunk was correlated to the central leader length and increment of trunk cross-sectional area, negatively, and to the tree height and canopy volume, positively. The yields in the TR-50 treatment were higher about 2 times than other treatments. The fruit diameter was not significantly different among the treatments. CONCLUSION: These results indicated that the optimum location of heading-back pruning in one year old 'Daeneung' jujube tree was 50 cm above the ground as evaluated by the balance of reproductive and vegetative growth.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.2
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• pp.129-138
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• 2021

Living modified organisms (LMOs) are managed by seven government agencies according to their use in South Korea. The Ministry of Environment is responsible for LMOs used for environmental remediation. This study aimed to develop guidelines for assessing potential risks posed by transgenic plants used for remediation to insect ecosystems by investigating arthropod communities in sunflower fields. A total of 2,350 insects and spiders belonging to 134 species of 10 orders and 71 families were collected from sunflower fields over four growth stages ranging from anthesis to seed maturity. At the R3 phase of flower-bud formation, Chironomidae sp. of a decomposer insect guild presented the highest density, while Apis mellifera of a pollinator guild was the most abundant in the R5.8 phase of flowering. During the R7 seed-filling phase and the R9 phase of seed maturity, herbivorous Pochazia shantungensis predominated. During the R9 phase, richness and diversity indices of arthropod communities were distinctly lower whereas their dominance indices were significantly higher than those at other phases. In addition, the composition of arthropod communities was strongly correlated not only with the sampling date, but also with the sampling method depending on the growth stage of sunflowers. Our results suggest that appropriate sampling timing and methods should be considered in advance and that long-term field trials that cover a variety of environmental conditions should be carried out to evaluate potential risks to insect ecosystems.

• Journal of Bio-Environment Control
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• v.17 no.3
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• pp.221-225
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• 2008

Lilium formolongi 'Fl August' plantlets with scale-leaves and scale-bulb were treated at 10, 15, 20, $25^{\circ}C$ for 15, 30, or 45 days and planted in February, March, April and May. In the April planting, flowering percentage was below 10% and in the May planting no flowering occurred. Sprouting and flowering percentages were lower at the late planting times. Days to flowering of the April planting was 110.8 days compared to 128 days for the February planting. Plant height and numbers of leaves were reduced to 7.2 in May planting, compared to 40.5 leaves in February planting, and almost no flowers emerged in either the April or May plantings. Plantlets exposed to 10 or $15^{\circ}C$ flowered at 80 percent or higher at all treatment durations, but at 20 or $25^{\circ}C$ flowering percentages were lower, with 30% or less in the $25^{\circ}C$ treatment. In the $15^{\circ}C$ treatment days to flowering were less than 100 days, while the number of flowers and flower bud differentiation were greatest in the $15^{\circ}C$ treatment. Cytokinin and auxin were analyzed in bulblets grown at 15, 20 and $25^{\circ}C$. T-zeatin content was three times greater in the $15^{\circ}C$ treatment than at $25^{\circ}C$, but the content of indoleacetic acid (IAA) was less at $15^{\circ}C$ than at 20 and $25^{\circ}C$. In the $15^{\circ}C$ treatment, T-zeatin content was about twice the IAA content in the scale- bulblet. The auxin and cytokinin balance may affect flower bud differentiation. $15^{\circ}C$ with 30 days was most effective for flowering in scale-bulblet and planting of February and March were effective for flowering too.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.4
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• pp.185-198
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• 2001

This study was conducted to reveal the effects of local climatic conditions on reproductive growth in a mature stand of Korean white pine based on climatic estimates. For this, the reproductive growth such as production and characteristics of cone and seed were first measured and summarized for seven years from 1974 to 1980. The local climatic conditions in the study site were also estimated by both a topoclimatological method and a spatial statistical technique. The local climatic conditions were then correlated with and regressed on the growth factors to reveal the relationships between the climatic estimates and the reproductive growth. Average number of conelet formation per tree showed highly negative correlation with some climatic variables related to minimum temperature in the year of flower bud differentiation. Especially, the most significant negative correlation were found between average of the minimum temperature for June and July of flower bud differentiation year and the number of conelet formation. There was no significant correlation between the number of cone production and climatic variables. However, total precipitation from December of the flowering year to February of the cone production year showed the most high correlation (r=0.6036) with the number of cone production. It was found that significant climatic variables affecting the amount of cone drop and cone drop percentage were the sum of cloudy days from June of the flowering year to August of the cone production year. Positive correlation was significantly recognized between the average weight of empty seed per cone and total precipitation from December of the flowering year to February of the cone production year. For the percentage of empty seed, five climatic variables among 19 variables were significantly correlated at 10% level. The average weight of a cone showed negative correlation with total precipitation from June of the flowering year to August of the cone production year. It was also found that average weight of a seed had highly negative correlation with total precipitation from December of the flowering year to February of the cone production year. The average weight of cone coat was negatively correlated with two climatic variables derived from clear days, which are sum of clear days from November of the flowering year to March of the cone production year and sum of clear days from December of the flowering year to February of the cone production year. On the other hand, it showed positive correlation with mean temperature of May in the flowering year. The exactly same results were obtained in correlation analysis for the percentage of cone coat.