• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.406-414
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• 2010

Antioxidative activity, including inhibitory activities of angiotensin I converting enzyme(ACE), aminopeptidase N(APN) and $\alpha$-amylase, was investigated in the methanol extracts from Theaceae plants native to Jeju island, in order to select the plant species containing bioactive materials for functional food or medicines. ACE inhibitory activity was above 50% in Ternstroemia japonica(stem bark) and Cleyera japonica(leaf), and APN inhibitory activity was low to be positive only in C. japonica(leaf, stem bark) and T. japonica(stem bark). $\alpha$-Amylase inhibitory activity was above 30% in Camellia japonica(fruit), Eurya emarginata(stem), T. japonica(stem bark) and Thea sinensis(stem). The antioxidative activity, estimated by the DPPH radical scavenging capacity, was above 30% in C. japonica(stem bark), T. japonica(stem bark) and T. sinensis(leaf). Particularly, the antioxidative activity analyzed by dot-blot test was very high in C. japonica(stem bark) relatively to those of other plants, and remained high in the low concentration($1.25\;{\mu}g/m{\ell}$). From the TLC analysis of antioxidative compounds, EGC(Rf 0.26) was found to have high activity in stem bark of C. japonica and EGCG(Rf 0.09) was found to have high activity in stem bark of C. japonica, E. emarginata, and T. japonica. Five bands (Rf 0.54, 0.46,0.44, 0.16, 0.03) which were not identified as compared with catechins were detected as polyphenolic compounds on the TLC plates sprayed with the Folin-Ciocalteu solution or the Ferric chloride-alcohol solution. These results suggests that Theaceae plants except E. japonica could be potentially used as a resource of bioactive materials for functional foods or medicines and further research is reguired to identify the bioactive substances and determine the functions of them.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.26-35
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• 2013

This study was conducted to select superior provenances of Scots pine (Pinus sylvestris L.) well adapted to Korean environment for timber production. In 1976, twenty-two provenances of Scots pine were introduced from Sweden and the seeds were sown in seed beds in March. After one year, the seedlings were transplanted to nursery beds. The resulting 1-1 seedlings of 22 provenances were planted at Whaseong in 1978. Randomized complete block design with 3 replications were used for test plantation. Each provenance was planted with 20-tree row plot in each block and at a spacing of $1.8{\times}1.8m$. The growth performance of each provenance was monitored up to 33-years after planting. There were significant differences among provenances in volume growth. F3001 provenance showed the best volume growth of 33-years after planting ($0.160m^3$), which was 2.2 times greater than that of the lowest provenance W2027 ($0.072m^3$). The ranking of provenances was stabilized after 14 years. Comparing to reference tree species, Japanese red pine (Pinus densiflora), all Scots pine provenances showed poor growth performance. In other words, volume growth of Japanese red pine at age 28 and 33 were 2.1 and 3.3 times greater than that of Scots pine, respectively. Moreover, survival rate of Scots pine was lower than that of Japanese red pine. Based on these results, it was suggested that Scots pine was not suitable to Korean environments. The cause of maladaptation of Scots pine and the implications of introduction breeding were discussed.

• Korean Journal of Plant Resources
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• v.31 no.1
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• pp.77-85
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• 2018

The cultivation area of rapeseed (Brassica napus L.) has been increased for oil production and landscaping purpose in Korea. However, as the color of rapeseed flower is very simple, diversified flower color is necessary to improve landscape effect. Interspecific and intergeneric crosses between rapeseed (Brassica napus) and three Cruciferae crops were performed in order to grow diverse flower color of rapeseed. The silique formation rate of interspecific cross rapeseed with cabbage (B. oleracea L) was relatively high (65.8%) and higher than intergeneric cross with rapeseed and radish (Raphanus sativus L.), rapeseed and Orychophragmus, respectively. During silique developing period after artificial pollination, there were many siliques without seeds due to the failure of fertilization. The average number of seed per silique obtained from cross rapeseed and cabbage, rapeseed and radish, rapeseed and O. violaceus were 0.12, 0.4 and 0.12, respectively. The phenotypes of $F_1$ hybrid plants from cross rapeseed and Cruciferae crops were mostly similar to maternal line, but leaf length and leaf width were increased. The interspecific cross of rapeseed and cabbage generated ivory color of flower which is the medium color of parents, and intergeneric cross of rapeseed and O. violaceus created entities with larger flowers which seems to enhance landscape effect. The fatty acid composition of most hybrid seeds intermediated of the two parents for oleic acid, linoleic acid and linolenic acid, content. Whereas hybrid of rapeseed and radish produced less erucic acid than radish parent.

• Korean Journal of Plant Resources
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• v.33 no.1
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• pp.15-23
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• 2020

There is high vulnerability of soil loss in sloping and highland used for agricultural production due to the low surface covering in summer rainy season. This study evaluated the surface-covering rate of landscape crop in reducing soil loss in the highland. The experiment was conducted in a 55% sloped lysimeter with three treatments of planting density using Korean native chrysanthemum, and investigated the soil coverage rate, run-off water, and soil erosion. The three treatments according to the degree of soil covering are bare soil as the control treatment TC, coverage rate of 43-59% for treatment T1, and, coverage rate of 63-81% for treatment T1, and T2. During the cultivation period, the average reduction of run-off water was 71% for treatment T1 and 76% for treatment T2, which are better, compared with the control. The reduction in eroded soil was 84% in treatment T1 and 98% for treatment T2, which is also better than the control treatment. Therefore, it is possible to alleviate the soil loss in sloping lands by planting chrysanthemum, which is superior among the perennial plant species and considered as a crop with economic value.

• Korean Journal of Plant Resources
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• v.33 no.5
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• pp.516-535
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• 2020

This study was conducted to provide information on local resource plants by identifying aquatic and Riparian flora. We investigated the aquatic and riparian floras in 3 streams(Byeongseong-cheon, Buk-cheon, Oeseo-cheon) from February to October 2019. 321 taxa (i.e. 300 species, 5 subspecies, 15 varieties 1 Cultivars from 203 genera of 78 families) of the vascular plants were found in the survey area. Byeongseong-cheon is 133 taxa, Buk-cheon is 233 taxa and Oeseo-cheon is 132 taxa. Among 321 taxa, we found 5 endemic species, 3 red list plants, and However, endangered plants were not found in 3 streams. Aquatic and Riparian plant 138 taxa(i.e. Aquatic plant 20 taxa, Riparian plant 118 taxa). Life forms is annual plant 43 taxa, biennial plant 24 taxa, perennial plant 71 taxa. Aquatic plant growth forms emergent hydrophyte 13 taxa, floating leaved hydrophyte 1 taxa, submerged hydrophyte 6 taxa. The number of floristic regional indicator plants was 15 (i.e. 1 species of IV degree, 3 taxa of III degree, 5 taxa of II degree, and 6 taxa of I degree). Approved foreign export plants 31 taxa. In addition, 52 naturalized plants were identified, and the percentage of Naturalized Index (NI) and Urbanization Index (UI) were 16.1%, and 16.2%, respectively. Vascular plant usability and reclassification result is Edible 213 species (66%), Medicinal 244 species (76%), Flavor 10 species (3%), Industrial 136 species (42%), Ornamental 137 species (36%), Restoration 117 species (36%), Compost 155 species (48%), Unknown 7 species (5%). We hope that our results provide reference data to set up strategy of resources plants, conservation of biodiversity in the 3 streams and Sangju-si areas.

• Korean Journal of Plant Resources
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• v.33 no.5
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• pp.446-459
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• 2020

This study analyzed the phenotypes and chemotypes of 74 tartary buckwheat (Fagopyrum tataricum) germplasms using principal component analysis and cluster analysis. The average seed size of tartary buckwheat germplasm was 5.2 × 3.4 mm, which is smaller than the seed size of common buckwheat. The dark browned colored ovate or elliptic shape was mostly observed in collected germplasm. The average content of rutin was 1,393 mg per 100 g dry weight (DW) in tartary buckwheat seed. Similarly, the flavonoid and polyphenol contents ranged from 253 to 2,669 and 209 to 1,823 mg, respectively, per 100 g DW in the collected germplasm. The three components (PC1, 2, and 3) of principal component analysis revealed 68.55% of the total variance of the collected accessions. Cluster analysis using descriptors showed that 74 accessions were clustered into five groups. The study showed that the most interesting resources for functional breeding programs are: Five resources (HLB1004, HLB1005, HLB1007, HLB1009, and HLB1013) due to the rich rutin, polyphenol, and flavonoid.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.677-697
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• 1995

The analysis of long- period sea level variations with tidal record data around Korea, Japan, and Russia shows that about half of the variations are due to atmospheric influences. The sea level variation by water movements is the largest in the coasts along the Tsushima Current, and becomes smaller in the distant areas. It suggests that the sea level varications are related with the Tsushima Current. The effect of sea level variations to ocean circulation has been studied with a numerical model allowing barotropic sea level fluctuations, like the result with GCM (Semtner) model by Pang et al.(1993), the present model also shows that waters basically flow along isobaths over the last China Sea after geostyophic adjustment around Taiwan. However, barotropic sea level fluctuation makes the basic circulation in the Yellow Sea, which waters flow into the central Yellow Sea and out along the west coast of the Korean Peninsula. Besides this, barotropic sea level fluctuation makes long period waves over the shelf area as the Kuroshio varies. By the waves, the basic circulation in the Yellow Sea is disturbed, so that the flow pattern of oppositely flowing into the Yellow Sea along the west roast of the Korean Peninsula appears. In the Yellow Sea circulation, it seems that northwest winds strengthen the basic circulat ion In winter, and southeast winds strengthen the disturbed circulation in summer. Another point appeared by the long period wave is that the Tsushima Current possibly originates in different areas. There have been two opposing argues on the area in which the Tsushima Current originates the southwest sea of Kyushu Island and the adjacent sea of Taiwan. Through this study, we found that both of them seem to be important areas for the origin of the Tsushima Current, and one of them is possibly strengthened by long period waves. The long period waves given by the variation of the Kuroshio Current in the adjacent sea of Taiwan propagate to the Korea Strait as forced waves. The wave continuously propagates to the last Sea through the eastern channel, but reflects in the western channel due to bottom topography. The reflected waves propagate southwestward along the last China Sea as free waves and determine the sea level variations with forced waves.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.238-245
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• 1996

Vertical profiles of $^{210}Po\;and\;^{210}Pb$ were measured for the upper 100 m of water column at six stations in the middle region of the Korean East Sea during March 1993. The distribution patterns of these radionuclides with the water mass and controlling factors on their distributions were also discussed. $^{210}Pb$ activities were generally high at surface water and gradually decrease with depth. Vertical profiles of $^{210}Po$ were relatively homogeneous except for at station E3, where chlorophyll-a concentration was the highest and $^{210}Po$ activity in the upper 30 m was lower than below 50 m. The $^{210}Po$ activities relative to its parent $^{210}Pb$ at all stations were deficient at the upper 30 m, but were excess or nearly equilibrated values below 50 m. The magnitude of $^{210}Po$ deficiency was relatively high at station E3 and E6, where strong thermocline occured. However, $^{210}Pb$ activities showed strong excess in the upper 100 m of all stations, compared with its parent $^{226}Ra$. The residence time of $^{210}Po$ ranged from 1.0 to 7.8 years, and was relatively short at station E3 and E6. The data obtained at the upper 50 m water column during $1992\~1994$, also showed that removal rate constant of $^{210}Po$ and inventories of chlorophyll-a was negatively related. This indicates that the primary production plays an important role in controlling the distributions of $^{210}Po$ at the upper water column of the Korean last Sea in spring. While, inventories of excess $^{210}Pb$ was generally decreasing with increasing density difference between 50 m and 100 m, suggesting that $^{210}Pb$ concentrations in the upper water column were controlled by stability of water column.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.1
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• pp.151-159
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• 2006

In these days, the importance of sludge treatment is emerging due to the London Convention, so this study was conducted to propose the alternatives for the improved sludge treatment on the organic wastewater and sewage sludge with JAR test and settling column equipped with stirrer. The minimum coagulant dosage to earn the optimum sludge settling efficiency resulted from 200mg/l and each critical sludge settling interface showed no distinct difference when PAC was dosed over 200mg/l. Accordingly, Clarification Rate(CR) with 200mg/l dosage was calculated to CR=(Ho-Ht) / Ho=1-0.4=0.6 because the critical sludge settling height stopped at 0.4. The settling velocity of sludge interface was decreased with the increase of MLSS concentration but rather increased with MLSS concentration over 1,000mg/l. This resulted from positive effect of interacted coagulation for floc formation by transfer to the zone of compressed settling when MLSS concentration increased over 1,000mg/l. The settling velocity of sludge interface showed $28.66{\times}10^{-3}/min$ for average settling velocity of sewage sludge which is 6.7 times higher than $4.25{\times}10^{-3}/min$ for average settling velocity of organic wastewater sludge. The increasing rate of CR for organic wastewater activated sludge was higher than that of settling velocity under 200mg/l of PAC dosage but settling velocity was higher than CR over 200mg/l of PAC dosage. However, in case of sewage sludge, the differential rate of CR was low when PAC dosage was increased but the settling velocity was suddenly increased with over 200mg/l dosage. Therefore coagulation effect was more efficient to MLSS settling velocity rather than SS removal effect in the supernatant.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.2
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• pp.79-89
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• 1995

Changes of microbial activity and physicochemical environment during composting of papermill sludge(PMS) in the pilot plant equipped with an agitated bed reactor were monitored for establishing the efficient composting system. Microbial activity determined as the evolution of $CO_2$ increased for the first 10 days after introduction of PMS to the reactor and decreased thereafter. Population changes of microorganisms in the reactor-PMS were not typical as in windrow system. The ratio of thermophilic bacteria to mesophilic bacteria, however, increased slowly even 23 days after introduction. Temperature of PMS increased rapidly from the first day and reached $62^{\circ}C$ at 7 days after introduction and decreased slowly thereafter. The acidity of PMS was pH 6.8 initially, increased to pH 8.0 after 7 days and decreased to pH 7.4 after 23 days. Redox potential(Eh) of PMS was -320mV at the beginning of composting, but it was increased with time to reach -15mV after 23 days composting. However, Eh of PMS pre-sterilized before measurement was average 50mV, regardless of composting periods indicating the major role of microorganisms during composting process. Water content of PMS was 67% initially and decreased to about 50% after 23 days composting in the reactor. Less than 13 days-old compost inhibited growth of radish in the container mixture with bed soil. Based on statistical analysis of microbial and physicochemical parameters of PMS during composting, an equation was developed for determining compost maturity. A number of experiments using various organic wastes are required before application of the formular to the practical use.