• 한국미생물·생명공학회지
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• 제28권5호
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• pp.291-297
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• 2000

A strain producing high levels of compaction was isolated from soil and identified as Penicillium sp. Y-8515 based on the morphological characteristics and ribosomal RNA sequence analysis. Optimization of several different carbon and nitrogen sources for the effective production of compaction was performed resulting in the medium compositions containing 5%(w/v) glucose, 1.0 % soybean meal, 0.5% yeast extract, 0.5%(NH$_4$)$_2$$SO_4$, 0.25%,$ NaH_2$$PO_4$, 0.25% $CaCO_3$. The fixed con-centration of glucose(5%, w/v) and relatively lower concentrations(less than 2.5%, w/v) of soybean meal stimu-lated the transformation of the growth morphology from filamentous to pellet form. Comparing to that by filamentous form, the production of compactin by pellet form increased up to 1.5 folds. In a fed-batch fermentation, continuous feeding of the mixture of glucose and nitrogen source at the ratio of 10:1 showed 3.5-fold more produc-tion yield of compaction comparing to the batch mode.

• Geomechanics and Engineering
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• 제31권3호
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• pp.281-289
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• 2022

Bio-CaCO₃ is a blowout environment-friendly materials for soil improvement and sealing of rock fissures. To evaluate the chemical characteristics, shape, size and productivity of soybean urease induced CaCO₃ precipitates (SUICP), experimental studies were conducted via EDS, XRD, FT-IR, TGA, BET, and SEM. Also, the conversion rate of SUICP reaction at different time were determined and analyzed. The Bio-CaCO₃ product obtained by SUICP is comprehensively judged as calcite based on the results of EDS, XRD and FT-IR. The SUICP calcite precipitates are detected as spherical or ellipsoidal particles 3-6 ㎛ in diameter with nanoscale pores on their surface, and this morphology is novel. The median secondary particle size d₅₀ is 39-88 ㎛, indicating the agglomeration of the primary calcite particles. The Bio-calcite decomposes at 650-780℃, representing a medium thermal stability. The conversion rate of SUICP reaction can reach 80% in 24h, which is much more efficient than microbially induced CaCO₃ precipitation. These results reveal the knowledges of SUICP, and further direct its engineering applications. Moreover, we show an economic channel to obtain porous spherical calcite.

• 한국약용작물학회지
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• 제24권4호
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• pp.294-302
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• 2016

Background: Crop rotation plays an important role in improving soil chemical properties, minimizing the presence of disease pathogens, and assists in neutralizing autotoxic effects associated with allelochemicals. Methods and Results: Five rotation crops of sudan grass, soybean, peanut, sweet potato, and perilla were cultivated for one year with an aim to reduce yield losses caused by repeated cropping of ginseng. In 2-year-old ginseng grown in the same soil as a previous ginseng crop, stem length and leaf area were reduced by 30%, and root weight per plant was reduced by 56%. Crop rotation resulted in a significant decrease in electrical conductivity, $NO_3$, and $P_2O_5$ content of the soil, whereas organic matter, Ca, Mg, Fe, Cu, and Zn content remained-unchanged. Soil K content was increased following crop rotation with sudan grass and peanut only. Rotation with all alternate crops increased subsequent ginseng aerial plant biomass, whereas root weight per plant significantly increased following crop rotation with perilla only. A significant positive correlation was observed between root rot ration and soil K content, and a significant negative correlation was observed between ginseng root yield and the abundance of actinomycetes. Crop rotation affected the soil microbial community by increasing gram negative microbes, the ratio of aerobic microbes, and total microbial biomass whereas decreases were observed in actinomycetes and the ration of saturated fatty acids. Conclusions: In soil exhibiting crop failure following replanting, crop rotation for one year promoted both soil microbial activity and subsequent ginseng aerial plant biomass, but did not ameliorate the occurrence of root rot disease.

• 유기물자원화
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• 제4권1호
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• pp.53-60
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• 1996

혐기적으로 1차 분해된 하수슬러지를 건물 중 기준으로 0, 1, 3, 그리고 5톤/10a 비율로 포장에 시용한 후, 대두 및 당근의 수량과 무기성분 흡수 등 몇가지 화학적 특성에 미치는 영향을 검토하였다. 슬러지 시용의 결과는 토양의 몇가지 화학적 특성을 증진시킨 반면, 작물에서의 Pb, Cd, Cr, As 및 Hg과 같은 유해 중금속의 흡수는 나타나지 않았다. 슬러지 시용은 작물의 N, P, K 및 Ca 등의 무기성분 흡수를 증가시켰고, 슬러지중 과량의 Al은 작물의 Al흡수에 별다른 영향을 주지 않았다. 또한 슬러지는 두 작물의 수량을 증가시킨 반면, 슬러지 미부숙으로 인해 당근의 외관적 품질을 저하시켰다. 결론적으로 하수슬러지의 작물 생육효과가 긍정적으로 평가된 반면, 농업적으로 이용할 때는 반드시 퇴비화와 같은 슬러지의 안정화가 선행되어야 한다.

• 한국지역사회생활과학회지
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• 제17권3호
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• pp.89-97
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• 2006

This study was conducted to compare soybean growth and yield and the degree of weed emergence according to no-tillage and conventional tillage system in two different drained paddy fields, loam of Chilgok series and silty clay loam of Deokpyeong series. In both soil conditions, the maturing time of the soybeans by the no-tillage system was two days earlier than that by the conventional tillage system. In the loam of Chilgok series, the stem length of the soybeans in the no-tillage system was 5.7 cm longer than that in the conventional tillage system. The miss-planted rate and diseased plants of black root rot (Calonectria iliacola) in the no-tillage system were 9.2% and 2.8% lower, respectively than those in the conventional tillage system. Also, the nodulation and seed yield in the no-tillage system were 32% and 13% more, respectively, than those in the conventional tillage system. In the silty clay loam of Deokpyeong series, the stem length of the soybeans in the no-tillage system was 4.6cm shorter than in the conventional tillage system. The diseased plants of black root rot (Calonectria iliacola) in the no-tillage system were 4.2% lower than those in the conventional tillage system. Also, no significant difference in the seed yield between the no-tillage and conventional tillage systems was observed. On the other hand, there was a lower occurrence of weed in the no-tillage system than in the conventional tillage system, and the income increased by 19% owing to yield increase and reduced management costs.

• The Plant Pathology Journal
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• 제35권6호
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• pp.654-661
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• 2019

The soybean cyst nematode, Heterodera glycines, is a major plant-parasitic nematode that has caused important economic losses to Korea's soybean production. Four species of cyst nematodes, H. schachtii, H. glycines, H. trifolii, and H. sojae, all belong to schachtii group are coexist in field soil in Korea. The rapid identification of the nematode is crucial for preventing crop damage and in decision making for controlling this nematode. This study aimed to develop a species-specific primer set for quantitative PCR (qPCR) assay of H. glycines. The specific primer set (HGF1 and HGR1) for H. glycines was designed based on the cytochrome c oxidase subunit I (COI) sequence of mitochondrial DNA. After optimization, it is possible to identify the H. glycines using a qPCR assay with DNA extracted from a single cyst and single second-stage juvenile (J2). The specificity was confirmed by the absence of SYBR fluorescent signals of three other Heterodera species. A serial dilution of DNA extracted from a single cyst was obtained for the sensitivity test. The result showed that the standard curve of the test had a highly significant linearity between DNA concentration and Ct value (R² = 0.996, slope = -3.49) and that the detection limit concentration of DNA of the primer set was 10 pg of DNA per reaction. Our findings suggested that H. glycines could be distinguished from H. sojae and other Heterodera species when a qPCR assay is used with a specific primer set.

• 생명과학회지
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• 제12권5호
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• pp.544-548
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• 2002

대두의 질소고정 근류균들 중 우리나라 토착균, USDA110, USDA122, RJl-29, R2l4 등으로 종자분의접종한 삼남콩을 폿트에 재배하여 개화기에 한발처리한 것과 관행으로 폿트에 재배한 것과의 근류균별 질소고정력 조사와 콩의 제요인에 미치는 근류균의 영향, 한발조건시 근류균 질소고정력과 협중과의 상관관계, 식물체 호흡량과 엽면적과의 상관관계 등을 시험한 결과를 요약하면 다음과 같다. 관행재배에서는 근류균의 질소고정력이 R2l4와 토착균이 높게 나타났으나, 개화기에 한발처리를 한 구에서는 토착근류균 보다 R2l4와 Rll-29의 균들이 질소고정력을 높게 나타내었다. 토착근류균에 비하여 USDA122와 RJl-29의 근류균을 접종한 구가 한발조건에서 식물체 호흡량을 적게 유지하여 엽면적 및 협중의 상대지수를 높게 나타내었다. 한발조건에서 근류균 질소고정력과 협중 상대지수와의 상관관계는 r=0.85'로서 유의적인 정의 상관관계를 나타내었다. 한발조건에서 식물체 호흡량과 엽면적 상대지수와의 상관관계는 r=-0.89'로서 유의적인 부의 상관관계를 나타내었다.

• 한국작물학회지
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• 제35권2호
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• pp.156-164
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• 1990

A field experiment was conducted to study both the distribution characteristics of photosynthetically active radiation (PAR) in the soybean canopy and their relationships with dry matter production. The soybean cultivars 'Hwanggeumkong' and 'Paldalkong' were sown with the spaces of 60$\times$15cm and 30$\times$15cm at Suwon on May 20 and on June 20 in 1989. The ratio of PAR to the total shortwave radiation was estimated by the empirical equation derived from sunshine hours and direct incoming radiation. The functional relationships between the PAR interception and the leaf area index were expressed as a function of Beer's law. The extinction coefficients(k) in the functions ranged from 0.77 to 0.92. The values of k were greater at higher planting density, but they were affected neither by planting dates nor by varieties. The reflection ratio of PAR($\alpha$) was determined by the exponential function as below; $\alpha$=$\alpha$p-($\alpha$p-$\alpha$o) exp(-kㆍLAI) where $\alpha$p was the reflectance at the maximum LAI and $\alpha$o was that of the bare soil. The ap ranged from 0.025 to 0.035 and $\alpha$o ranged from 0.11 to 0.12, respectively. The reflected PAR ranged from 0.049 to 0.064 and the transmitted PAR ranged from 0.168 to 0.340 until maximum dry weights were observed. The slope from the linear regression of dry matter on absorbed PAR, conversion efficiency, ranged from 1.30 to 2.3g MJ$^{-1}$ during the growing season until maximum dry weight was reached. The total dry matter yield above ground (TDM) increased with the increases in the conversion efficiency. TDM was higher in Hwanggeumkong than Paldalkong and higher in the space of 30$\times$15cm than 60$\times$15cm, Paldalkong showed higher harvest index than Hwanggeumkong. than Hwanggeumkong.

• Journal of Plant Biotechnology
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• 제3권2호
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• pp.95-100
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• 2001

To select the section with shoot formation ability, the calli and shoot formation from three sections (first leaf including cotyledonary node, hypocotyl and cotyledon explants) of 5-days-seedlings of soybean were induced on MS medium supplemented with 1.0 mg/L BAP, 3% sucrose, and 0.3% gelrite for one month. The first leaf section exhibited the highest shoot formation rate (51%), followed the hypocotyl section (10%) and the cotyledon section (0%). The shoot formation rates and shoot number of the four excised sections (whole first leaf, a half of the first leaf, a third of the first leaf and only node) of the first leaf were also investigated on the same medium. A half of the first leaf explant and the third of the first leaf explant had higher shoot formation rates (76-80%) and numbers (3-4 / explants) than those in other two explants. Effects of six cytokinins (kinetin, zeatin, BAP, 2iP, PBA, and TDZ) on shoot formation were determined, using the half of the first leaf explants. Zeatin (1.0 mg/L) exhibited the highest in shoot formation rate (94%) and numbers (8 / explant). In addition, the combined effects of three cytokinins (zeatin, BAP, and TDZ; 0.5, 1.0, 2.0 mg/L, respectively) and an auxin (IAA; 0.0, 0.5, 1.0, 2.0 mg/L) were determined. The combination (1:1, v/v) of zeatin (1.0 mg/L) and IAA (1.0 mg/L) exhibited the highest in shoot formation rate (96%) and numbers (16 / explant), twice more than zeatin (1.0 mg/L) alone. The shoot cuttings were transferred and cultivated on the rooting media supplemented with only auxin, IBA at various concentrations. The highest root formation (8 / shoot) was achieved on the medium supplemented with 1.5 mg/L. After 4 weeks of cultivation, the plantlets with an extensive root system were transplanted in pots with a soil mixture of vermiculite and fine sand. Transferred to field, about 75% of the plantlets survived.

• 한국작물학회지
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• 제52권3호
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• pp.320-324
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• 2007

본 실험은 내습성 품종과 감수성 품종을 5엽기에 9일간 침수 처리한 후 잎과 배축을 대상으로 횡단면을 해부학적 특성을 광학현미경으로 관찰하여 그 결과 다음과 같다. 1. 엽록소함량, 광합성, 책상조직 수, 엽두께 및 잎 건물중은 습해에 의해 급격히 감소되었으며 풍산나물콩보다 소백나물콩의 감소가 더 많았다. 2. 잎 조직의 책상조직의 치밀함은 습해에 의해 급격히 감소되었고 품종간 차이도 관찰되었으며, 풍산나물콩은 주맥의 통도조직 중 목부의 발달을 볼 수 있었다. 3. 배축의 통기조직 형성은 소백나물콩은 보이지 않았으나 풍산나물콩은 피층에 파생통기조직이 형성되는 것을 볼 수 있었다.