• Journal of The Korean Society of Grassland and Forage Science
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• v.4 no.2
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• pp.147-151
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• 1983

In order to know the effect of planting date and cutting management on Jerusalem Artichoke (Helianthus truberosus L.) as a new forage or energy crop, JA tubes were planted from April 7 to June 27 with 20 day interval. Growth and yield could stay high as normal planting if tuber planting had been done until late May. The delayed planting after June caused deterioration of seed tuber, produced poor emergence and retarded growth. Previous harvested field did not need additional planting every spring because there were enough leftover tubers usually small size, less than 3gr., to provide a dense seedling establishment. This plot had too dense in population to adjust its spacing by thinning some of seedlings. One or two times cutting for forage or silage production reduced tuber yield very significantly. Therefore, it was not a good management to harvest for both forage and tuber production. Topping at 20cm from growing point in early July prevented from lodging and assured tuber yield.

• Horticultural Science & Technology
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• v.18 no.1
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• pp.9-13
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• 2000

Cultivation of onions in Korean peninsula is so restricted to Southern region, mainly due to inadequate air temperature for the growth of onions in this region. This sometimes resulted in unstable supply of onions. The fluctuation of market prices mainly results from the limited production of onions in such restricted areas. Onions are usually transplanted at the end of fall and cultivated until the beginning of next summer. This study was designed to examine the possibility of extending production region of onions by adopting the plug seedling system, and the effects of plug seedling age, transplanting date, plug cell volume, and variety on the yield of onions were investigated. Transplanting date (Mar. 15 or Apr. 15) did not affect the yield of onions. However, 60-day-old seedlings produced significantly greater bulb yield (107.2 ton/ha) than those of 30- or 90- day-old seedlings. Bulb yields of seedlings raised in 128 and 72 cell trays were 125.0 and 120.8 ton/ha, which were significantly greater than those in other cell trays. Yield of seedlings raised in 406 cell trays was the lowest. Seedlings of mid-late 'Chenjuwhang' yielded 130.5 Ton/ha, which was significantly higher than those of other varieties. Considering the rainy season during early summer, we suggest that seedlings of onions raised for 60 days and transplanted on Mar. 15 should be advantageous in producing of marketable bulbs and that an early 'Yongbongwhang' should be the best variety.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.508-515
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• 1998

An antihypercholesterolemic effect was observed by intraperitoneal injection of the seaweed Porphya yezoensis extract. Hypercholesterolemia was induced by intraperitoneal injection of Triton WR-1339 (600 $\mu$g/g-body weight) into a mouse. Maximum level of blood cholesterol was reached at 20 hours after Triton injection. By simultaneous injection of the p. yezoensis extract (30 $\mu$g/g-body weight) with the Triton into each right and left sides of the peritoneal cavity, levels of total cholesterol and low density lipoprotein were decreased to $37\%$ and $24\%$ compared to Triton injection only. For histochemical changes, hepatic tissues obtained at 40 hours after injection of the Triton and the p. yezoensis extract were fixed in fromol-calcium solution. Numbers of lipid drops and cholesterol particles decreased in the portal space of the hepatic cytoplasm. This indicates that the accumulation of lipid, including cholesterol, caused by Triton was prevented by the antihypercholesterolemic effect of extract from the seaweed p. yezoensis.

• Journal of Yeungnam Medical Science
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• v.26 no.1
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• pp.30-37
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• 2009

Purpose : To radiologically differentiate renal oncocytoma from other renal solid tumors, we analyzed and characterized, retrogradely, radiologic findings of renal oncocytomas. Materials and Methods : Radiologic findings of pathologically proven renal oncocytoma were analyzed in 9 patients. CT was performed in all patients, ultrasonography in 4 patients and MRI in 3 patients.(51) Results : On ultrasonography, the echogenicity of the mass was slightly more hyperechoic than normal renal parenchyma in all 4 cases. Two cases were homogeneous and the remaining two cases were relatively homogeneous. On CT, all 8 cases showed iso-density to slightly low density compared to normal renal parenchyma and 5 cases were homogeneous but the central portion of the mass was of a slightly lower density than the peripheral portion in 3 cases. All six cases had an arterial phase scan and were heterogeneously enhanced. An irregular, lower-enhancing portion was found in the central portion of the mass. Segmental inversion of contrast enhancement was found in 5 of 6 cases that had a dynamic enhancement study. On MR T1-weighted imaging, the mass was of iso-signal intensity to normal renal parenchyma and the central portion of the mass had a slightly hypo-signal intensity than the peripheral portion. On T2-weighted imaging, 2 cases were heterogeneous; the peripheral portion was of low signal intensity and central portion was of higher signal intensity than normal renal parenchyma. One case was relatively homogeneous and showed a slightly lower signal intensity than that of normal parenchyma, except for a central small portion showing high signal intensity. For 2 cases that had a dynamic study, a segmental inversion of contrast enhancement was noted. Conclusion : Renal oncocytoma is seen as a well-marginated solid mass lesion. On enhanced scans it is heterogeneously enhanced and segmental inversion of contrast enhancement may be seen. The possibility of oncocytoma can be suggested in cases showing these radiologic findings.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.405-411
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• 2007

This study was carried out to measure insoluble phosphorus fractions content fixed in different soil type and isolate a superior phosphate solublizing bacteria(PSB) producing free phosphate in citrus orchard soil. Distribution of insoluble phosphate fraction ordered Al-P>Ca-P>Fe-P in the investigated citrus orchards. Insoluble phosphate fraction such as Al-P, Ca-P, Fe-P were higher in volcanic ash than in non-volcanic ash soil. A PSB with high holo zone in PDA-P medium isolated from citrus orchard soil. This strain identificated by MIDI system as Bacillus sphaericus. The optimum growth of pH and temperature were at 4~5, $30^{\circ}C$, respectively. When Bacillus sphaericus cultured at $25^{\circ}C$, 150 rpm condition in LB broth medium included different phosphate. Bacillus sphaericus produced free phosphate in the culture broth medium from tricalcium-phosphate(207.0 ppm), aluminium phosphate(324.5 ppm) and hydroxyapatite(334.8 ppm) and Phosphatase activity of Bacillus sphaericus was higher at $35^{\circ}C$ culture condition than that of $25^{\circ}C$. Two type preparation inoculated Bacillus sphaericus made with carrier materials such as Bentonite, $CaCO_3$, Sodium alginate. Density of PSB in this preparation conserved at $10^5c.f.u.\;g^{-1}$ level during storage in different temperature condition for 7 month. It also showed that free phosphate produced at PDA-P medium.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.447-451
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• 2008

'Goamibyeo', a mid-late maturing ecotype with high amylose content in kernels, was developed by the rice breeding team of National Yeongnam Agricultural Experiment Station(NYAES) in 2000 and released in 2001. This variety was derived from the three way cross of Milyang 95//Kimcheonaengmi/$2^*Ilpumbyeo$ (in 1992 summer) through the pedigree breeding method and designated as 'Milyang 168' in 1997. The heading date of 'Goamibyeo' was Aug. 18 in ordinary season with culm length of 85 cm. However, 'Goamibyeo' showed susceptible to bacterial leaf blight, stripe virus and leaf blast disease. The amylose content of 'Goamibyeo' in milled rice kernels is about 26.7% with translucent and clear in chalkness. Thus, 'Goamibyeo' is expected to be used as a source grain for rice noodle industries. The milled rice yield potential of 'Goamibyeo' is about 5.38 MT/ha in local adaptability test of three years and it would be adaptable to Yeongnam plain of Korea.

• Korean Journal of Organic Agriculture
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• v.27 no.1
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• pp.77-86
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• 2019

This study was carried out to investigate the effect of legume cover crop culture on earthworm fauna in organic farmland. We compared sod culture with two kinds of legume crops of hairy vetch and crimson clover on organic citrus orchard to natural sod culture and conventional orchards in Jeju Island. We analyzed the soil characteristics and investigated the density of earthworms from the orchards. Organic matter content did not show much difference in soil analysis between organic and conventional orchard. But the biomass of earthworms in organic orchards is 3.8 times to 7.0 times higher than that in conventional cultivated orchards, and individuals of earthworms on organic orchards were 2.3~18 times higher than conventional orchards. The biomass of earthworms on hairy vetch and crimson clover cultivation was 44.8 g, 47.2 g in 2016, and 78.7 g, 31.8 g in 2017, respectively, which were higher than 32.8 g and 9.5 g of those on natural sod cultivation. Through this study, we found that hairy vetch and crimson clover cultivation improve the earthworm occurrence density in the soil on organic citrus orchard.

• Journal of Life Science
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• v.28 no.11
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• pp.1262-1267
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• 2018

The patchiness of local environments within a habitat is assumed to be a primary factor affecting the spatial patterns of plants. In this study, a randomization procedure was developed to test the null hypothesis that only spatial association with patches determines the spatial patterns of plants. Oplismenus undulatifolius (Ard.) P. Beauv. var. undulatifolius is an herbaceous plant and a member of the genus Oplismenus in the family Poaceae. Oplismenus hirtellus subsp. undulatifolius occurs in temperate, subtropical, and tropical areas of the world. The spatial pattern of O. undulatifolius var. undulatifolius was analyzed using dispersion indices in different sizes of plots according to several patchiness indexes, population uniformity, or aggregation. Population densities (D) at Mt. Hanwoo varied from 0.453 to 4.375, with a mean of 2.387. The small and mid-sized plots ($2m{\times}2m$, $2m{\times}4m$, $4m{\times}4m$, $4m{\times}8m$, and $8m{\times}8m$) of O. undulatifolius var. undulatifolius were aggregated in the forest community. However, O. undulatifolius var. undulatifolius was uniformly distributed in three large plots ($8m{\times}16m$, $16m{\times}16m$, and $16m{\times}32m$). The greatest mean crowding ($M^*$) and patchiness index (PAI) showed positive values. Aggregation is mainly caused by environmental factors. Many plants on Mt. Hanwoo are being disturbed by climbers, which is preventing these plants from inhabiting their realized niches on Mt. Hanwoo.

• Journal of Life Science
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• v.29 no.7
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• pp.762-768
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• 2019

Doellingeria scabra Thunb. (syn. Aster scaber Thunb.), a perennial herb in the family Asteraceae, is frequently found in the wild mountain regions of Korea. This aim of this work was to measure the characteristics of patchiness of D. scabra in a local population on Mt. Maebong in Taeback-ci, Gangwon-do. The spatial distribution pattern of this species was estimated by analyzing ecological data by methods including the index of dispersion, Lloyd's mean crowding, and Morisita's index. The mean population density of the D. scabra population was 2.94. The D. scabra individuals were uniformly or randomly distributed in small-scale plots and were aggregately distributed in two large-scale plots ($16{\times}32m^2$ and $32{\times}32m^2$). The mean crowding ($M^*$) was 0.916. The mean patchiness index (PAI) was 0.796. Morisita's coefficient tended to decrease the density of the population as the plot size increased. The expected value of Eberhardt's index ($I_E$) in the local population was 2.623. Moran's I of D. scabra significantly differed from the expected value in 6 of 8 cases (75.0%). The first five classes were positive, with four showing statistical significance, indicating similarity among individuals in the first four distance classes (I-IV, 8 m), The results presented here could provide a theoretical basis for the conservation of D. scabra (Korean: chamchwi) and for the rehabilitation and sustainable management of forest ecosystems on Mt. Maebong, as well as on other mountains.

• Korean Journal of Environmental Biology
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• v.37 no.1
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• pp.31-41
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• 2019

The toxic dinoflagellate Gymnodinium catenatum isolated from the southern coast of Korea was described under light and scanning electron microscopy, and its large subunit (LSU) rDNA was sequenced. In addition, the effects of temperature and salinity on its growth were investigated. The cells of G. catenatum, as viewed under the electronic microscope, were green-brown color, $38.1-77.4{\mu}m$ in length and $26.1-40.8{\mu}m$ in width. The epicone was conical, while the hypocone was trapezoidal. The nucleus was located at the central part of the cell. The apical groove was horseshoe-shaped and small pores were irregularly distributed on the cell surface. Molecular phylogeny based on LSU rDNA gene sequences showed that the Korean G. catenatum and previously reported species formed a monophyletic clade within Gymnodinium sensu stricto clade. The maximum growth rate of $0.37day^{-1}$, was obtained at $25^{\circ}C$ and 35 psu, and the maximum cell density of $1,073cells\;mL^{-1}$, was observed at $20^{\circ}C$ and 25 psu. However, G. catenatum did not grow at temperature < $15^{\circ}C$ and < $30^{\circ}C$. These results suggest that environmental conditions of summer and autumn in the southern coast of Korea may be favorable for the growth of G. catenatum.