• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.43-49
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• 2013

This work was conducted to obtain some information about stable production of high quality seed-tubers in the late season cultivation of virus-free sweet potato [Ipomoea batatas (L.) Lam.]. Growth characteristics and storage root yield between virus-free and farmer's slips in 9 cultivars were investigated using black-film vinyl mulching cultivation with $75{\times}25cm$ planting density on July 10. At 30 days after planting, vine length, vine diameter, number of node, and number of branch in virus-free slips were significantly increased than those in farmer's slips. The vine growth was significantly different among cultivars, and vine elongation was excellent in 'Kogeonmi', 'Shincheonmi', 'Shinhwangmi', 'Shinyulmi', and 'Yeonhwangmi' compared to the other cultivars. At 110 days after planting, vine length, vine diameter, number of node, number of branch, and fresh weight were significantly different among cultivars, but no significant differences between virus-free and farmer's slips were seen except number of node. Total yield in virus-free slips was increased by 12-49% among cultivars than that in farmer's slips. The mean yields between virus-free and farmer's slips were 1,625 kg/10a and 1,230 kg/10a, respectively, and it was significantly different between virus-free and farmer's slips. Percentage of marketable storage root in virus-free slips was 65.6%, and it was significantly higher than 57.8% in farmer's slips. Marketable yields ($40g{\leq}$) between virus-free and farmer's slips were 1,067 kg/10a and 710 kg/10a, respectively. Marketable yield in 'Shincheonmi', 'Shinyulmi' and 'Shinzami' was more than 1,300 kg/10a, and these cultivars showed to be highly adaptable for the late-season cultivation among 9 tested cultivars.

• Korean Journal of Weed Science
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• v.16 no.1
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• pp.21-27
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• 1996

This experiment was conducted to find out an effective propagation method for reed(Phragmites communis Trin.), ensuring a continuous herbicide screening for reed control. Reed propagation methods were compared under a greenhouse condition using tour different materials; seeds, rhizomes, depressed stolons of P. japonica Steud., and stem cuttings. Although reed seeds were easy to harvest and store, their germination rate(${\leq}$5%) was very low and seedling growth from the seeds was slow. Rhizomes were difficult to harvest and their harvest time was limited from November to March. Furthermore, reed propagation using rhizomes had problems of a relatively low germination rate(46%), no uniformity in size and shape, individual differences at the early stage of growth, and difficulties in material storage. Rate of reed growth from rhizomes was higher in commercial soil mix(Boo Nong soil) than in sand or in sand+upland soil(1:1). Depressed stolons of P. japonica had a moderate germination rate(65%) and were relatively easy to harvest. However, their harvest time was limited only from August to September. Propagation method using stem cuttings had several advantages over the above methods using other materials. Reed plants could uniformly be propagated from the stem cuttings with a relatively high germination rate(75%). Stem cuttings of central nodes showed a higher germination rate compared to those of upper or lower nodes. Stem cuttings from the field should be used immediately after harvest, since their germination rate decreased rapidly when they were stored under a wet- or a dry-refrigerated condition. Furthermore, the germination of stem cuttings tended to decrease when they were collected from the field after August. This indicates that there is a limitation of harvest time for stem cuttings. However, a year-round propagation of reed using stem cuttings is possible if parent plants are grown in a greenhouse, and thus herbicide screening for reed control could continuously be performed.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.277-287
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• 2010

Several species of the genus Aphidius are used in biological control programs against aphid pests throughout the world and their behavior and physiology are well studied. While the importance of sensory organs in their behavior is understood, their antennal structure remains largely unknown. In this study, the external morphology and distribution of the antennal sensilla on the antennal of both female and male adults of A. colemani were described using scanning electron microscopy (SEM). Generally, the filiform antennae of males ($l,515.2{\pm}116.5\;{\mu}m$) are longer than females ($l,275.1{\pm}103.4\;{\mu}m$). Antennae of this species are made up of radicle, scape, pedicel and flagellomeres. Male and female antennae differed in the total number of flagellomeres as 15 in males and 13 in females. The result of SEM observation was characterization and grouping of seven types of receptors into morphological classcs: Bohm bristles, Sensilla placodea, 2 types of S. coeloconica and S. trichodea, and S. basiconica as with a tip pore and with wall pores. In addition, the possible functions of the above sensilla types arc discussed in light of previously published literature; mechanoreception (Bohm bristles, S, coeloconica I & II and S. trichodea) and chemoreception (S. placodea, S. basiconica type I & II).

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.149-153
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• 1998

This experiment was carried out to obtain a basic information for new variety development. The local soybean (Glycine max. L) lines used were endowed from Chungnam Agricultural Research and Extension Services. These lines were planted at upland farm of Chungnam Nat'l Univ., College of Agri. after treatment with mutagen $\gamma$-ray. All characteristics measured were decreased due to the $\gamma$-ray treatment than check except the branches of main stem of the Hannam and plant height of the Sobak. Especially the Sobak and the Eunha among these lines were shown very sensitivly than others treated with $\gamma$-ray of 15Krad. Of characteristics surveyed the nodes per plant was very sensitive to $\gamma$-ray, while the grain weight per plant, the pods per plant and the branches per plant were gradually decreased to further radioactivity about $\gamma$-ray treatment. In the Pungsan and the Sobak lines there were not shown significant between major characteristics at treatments including check. Other lines were also not shown positive correlation among characteristics except between stem diameter and branches(0.64*), grain weight and plant height(0.77**) at check of the Eunha, between stem nodes and stem diameter(0.65*) at check of the Kwangan and between number of pods and stem diameter(0.70*) at check of the Danyeop. From result this experiment, some of lines used were to be appeared characters of interest, for example, such as the short stem and the early flowering. Therefore these lines were needed more advanced generations for stability and performance.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.87-87
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• 2019

현대인의 생활수준의 향상에 따른 관상식물의 관심이 증가하여, 자생초화류를 활용하기 위한 연구가 진행되고 있다. 산꼬리풀[Veronica rotunda var. subintegra (Nakai) T.Yamaz.]은 국내 특산식물로서 산지의 초원에서 자생하고, 쪽빛을 내는 화기는 청아한 느낌을 주어 관화식물로서 이용가능성이 높다. 본 연구는 산꼬리풀의 분화 재배기술을 확립하고자 2018년 7월 2일부터 10월 15일까지 수행하였다. 대조구는 플라스틱 화분 10호에 원예상토를 충진한 다음 200구에 셀당 4립 파종하여 생산된 유묘를 정식하였다. 실험은 식재용기(플라스틱 8, 10, 12호 화분, 비닐포트 3, 4치), 토양종류[원예상토 단용, 중화 피트모스:펄라이트(3:1, 4:1), 마사토:중화 피트모스(2:1, 3:1)], 묘의 소질[파종립수(1, 2, 4, 6립), 파종용기(162, 200, 288구 트레이)] 등이 생육에 미치는 영향을 분석하였다. 연구의 결과, 식재용기에 따른 생육은 플라스틱 화분 12호에서 왕성하였고, 포트의 용적량이 클수록 경직경, 측지수, 마디수, 엽수, 개화율이 유의적으로 증가하였다. 토양종류에 따른 생육은 원예상토에서 가장 왕성하였고, 측지수, 경직경, 마디수, 엽수 및 개화율이 모두 우수하여 관상용 재배에 적합하였다. 피트모스 혼용토는 생육이 억제되는 동시에 잎이 황화되는 현상이 나타났다. 마사토 혼용토의 경우, 생육이 억제되는 결과를 보였다. 셀당 파종량을 달리한 유묘를 정식하여 재배한 결과, 초장, 절간장은 파종량이 증가할수록 감소하였고, 포트당 마디수와 엽수는 증가하였으나, 1립 파종묘를 제외하고 유의적인 차이는 없었다. 개화율은 4립 파종묘(44.4%)가 1, 2, 6립 파종묘(20.8~25.0%)보다 높았다. 육묘용기별 생육은 초기생육이 우수하였던 162구 생산묘가 정식 후 재배에도 왕성한 생육을 나타내었다. 결론적으로, 산꼬리풀의 최적의 분화재배를 위해 플라스틱 화분 12호에 원예상토를 충진한 다음 162구 트레이에 포트당 엽수와 개화율이 높은 4립 파종하여 생산된 유묘를 정식하여 재배하는 것이 우수할 것으로 판단된다. 경제적 측면을 고려하여 토양은 비교적 생육이 양호하였던 마사토의 활용방안을 검토하는 것이 좋을 것으로 생각된다.

• 건강소식
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• v.36 no.7
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• pp.16-19
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• 2012

그루지야(Georgia)는 스위스와 비슷한 면적에 인구 약 530만 명의 작은 나라이다. 아직까지 아시아로 직접 연결되는 비행기노선도 거의 없는 상태이다. 그러나 이스탄불뿐만 아니라 런던, 파리, 프랑크푸르트, 뮌헨 등 유럽의 도시를 통해서 들어갈 수 있다. 나는 먼저 이스탄불로 가서 비행기를 갈아탄 후 2시간 만에 수도인 트빌리시에 도착했다. 대부분 국토는 산악지역으로 구성되어 있다. 북쪽으로는 흑해에서 카스피해로 이어지는 캅카스 산맥에 4,000m가 넘는 수많은 산들이 있다. 캅카스 산맥에 의해서 러시아와 국경을 이루고 있고, 동부에는 아제르바이젠, 남부에는 아르메니아, 동남부에는 터키가 위치하고 있으며, 서쪽에는 흑해가 있다. 한 마디로 동양과 서양이 만나는 곳에 위치하고 있다.

• Journal of Educational Research in Mathematics
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• v.14 no.1
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• pp.1-17
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• 2004

According to the 7-th curriculum, irrational number should be introduced using repeating decimals in 8-th grade mathematics. To do so, the relation between rational numbers and repeating decimals such that a number is rational number if and only if it can be represented by a repeating decimal, should be examined closely Since this relation lacks clarity in some text books, irrational numbers have only slight relation with repeating decimals in those books. Furthermore, some text books introduce irrational numbers showing that $\sqrt{2}$ is not rational number, which is out of 7-th curriculum. On the other hand, if we use numeral 0 as a repetend, many results related to repeating decimals can be represented concisely. In particular, the treatments of order relation with repeating decimals in 8-th grade text books must be reconsidered.

• Horticultural Science & Technology
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• v.35 no.4
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• pp.490-498
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• 2017

The in vitro growth of virus-free sweet potato [Ipomoea batatas (L.) Lam.] plantlets was investigated under different light sources: fluorescent lamp (control); red (660 nm), blue (460 nm), white light-emitting diodes (LED), and two mixtures of blue and red LED (R:B = 8:2, and 7:3). Single node explants (10 mm) of three cultivars ('Matnami', 'Shincheonmi', and 'Yeonhwangmi') were cultured on Murashige and Skoog medium supplemented with $0.2mg{\cdot}L^{-1}$ 6-benzyladenine for 4 weeks. Explants were exposed to $150{\pm}5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux at a distance of 20 cm, constant temperature of $25^{\circ}C$, and under 16/8-h (day/night) photoperiod. Using the same method, the in vitro growth of 10 cultivars under red LED was also compared. After 3 weeks, vine length was highest in plantlets cultured under red LED, and lowest in plantlets cultured under blue LED. Fresh and dry weights were also greatest in plantlets cultured under red LED. Compared to the control, vine thickness was significantly higher in plantlets grown under white LED and the 7:3 R:B LED mixture. Significant differences were observed among the 10 cultivars grown under red LED. 'Matnami', 'Shincheonmi', and 'Shinhwangmi' all had excellent vine lengths, and fresh and dry weights. Compared to the control, vine elongation of sweet potato plantlets was most effective under red LED, and culture duration was about 1 week shorter.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.342-347
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• 2001

The experiment was carried out to examine the effect of culture media and seawater on growth and mineral concentrations in Glasswort (Salicornia herbacea). Glassworts were grown in a greenhouse with 0, 10, 30 and 90% seawater and with or without nutrient media. The salinity tolerance affected on shoot height and Na, K and Ca concentrations significantly. The shoot height was increased with 10 and 30% seawater concentrations. At the higher seawater concentrations, more Na accumulated in a shoot was obserbed. The application of seawater concentration was effective on increasing Na, Mg, and Fe, concentrations and green leaf area rate and on decreasing K concentration. K/Na ratio of shoot was decreased at high seawater concentration, whereas Na concentrations was lowered at a low seawater concentrations. The mineral concentrations were changed according to the growing season. Na, K and Mg were high in June and Ca and P in September, respectively.

• Food Science and Preservation
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• v.18 no.2
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• pp.250-255
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• 2011

As part of our continuing search for novel bioactive natural products, antioxidant and pancreatic lipase inhibitory activities of the aqueous ethanolic extract of Polygonum aviculare were investigated. In addition, the total phenolic content was quantified by a spectrophotometric method. The antioxidant properties of the extract were evaluated by radical scavenging assays such as DPPH and $ABTS^+$ radicals. The anti-obesity efficacy of P. aviculare extract was tested by porcine pancreatic lipase assay. All tested samples showed a dose-dependent pancreatic lipase inhibitory and radical scavenging activities. In terms of the $IC_{50}$ value, the ethyl acetate (EtOAc) soluble portion was most potent than other solvent soluble portions. The results suggested that P. aviculare could be considered as a new potential source of natural antioxidant and anti-obesity agent for food, nutraceutical, cosmetics industries.