• Title/Summary/Keyword: Young root

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Morphology of Arbuscular Mycorrhizal Roots and Effects of Root Age and Soil Texture on the Mycorrhizal Infection in Panax ginseng C.A. Meyer

  • Lee, Kyung-Joon;Park, Hoon;Lee, In-Sik
    • Journal of Ginseng Research
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    • v.28 no.3
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    • pp.149-156
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    • 2004
  • The objectives of this study were to investigate the morphology of mycorrhizal roots, and the effects of root age and soil texture on the mycorrhizal infection in ginseng (Panax ginseng C. A. Meyer) growing in Korea. Ginseng roots at ages of two to six years were collected from fields in late June. Their infection by arbuscular mycorrhizal fungi(AMF) was studied by clearing the roots and staining fungal hyphae with trypan blue. Root infection varied greatly depending on the developmental stages of young roots. Young tertiary roots, in diameter of smaller than 0.8 mrn, formed during the current growing season had root hairs and were frequently and in some cases heavily infected by AMF. Hyphal coils and arbuscules were abundant, while vesicles were rarely observed. Older secondary or tertiary roots in diameter of bigger than 1.0 mm with fully differentiated primary xylem formed during the previous growing season had no root hairs, and were not infected at all. The rates of mycorrhizal infection in the young tertiary roots were not affected by the age of the ginseng plants, suggesting that fungal populations might have not much changed during the aging of the cultivated fields up to six years. The differences in the infection rates among the different ages of ginseng were caused by differences in the amount of young tertiary roots in the samples. Soil texture, either sandy loam or clay loam, did not affect the rate of root infection. There were large variations in the infection rates among the different farms and locations within a farm. It strongly suggested that infection rates of the ginseng roots by AMF would be influenced by the practice of the farmers, possibly by avoiding consecutive planting, introduction of new topsoil, and the ways of handling the soil before transplanting the ginseng, such as fumigation or sterilization that might have affected indigenous inoculum sources of the AMF.

SCANNING ELECTRON-MICROSCOPIC STUDY OF THE EFFECT OF CITRIC ACID AND TETRACYCLINE HCL CONDITIONING ON DISEASED ROOT SURFACE (구연산과 염산트라싸이클린이 치근면 탈회에 미치는 효과에 대한 주사전자현미경적 연구)

  • Kim, Young;Kwon, Young-Hyuk;Lee, Man-Sup
    • Journal of Periodontal and Implant Science
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    • v.25 no.1
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    • pp.24-34
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    • 1995
  • The purpose of this study was to compare effects of demineralization of citric acid and tetracycline HCI on periodontally involved root surface. Twelve periodontally involved single rooted teeth were used. After scaling and root planing, root conditioning with citric acid and tetracycline HCI were carried and the teeth were processed scanning electron microscopic observation.The results were as follows: The scaled root surface was covered by much debris and calculus. The effect of demineralization of citric acid and tetracycline HCI was more reduced on scaling group than root planing group, because of hypermineralization of cementum surface and demineralization effect on root surface of tetracycline HCI showed tendency to reduction. The root planed group displayed more smooth root surface than scaling group, the surface was covered by smear layer, thus no exposure of dentinal tubule opening and collagen fiber, especially after root planing, citric acid and tetracycline HCl treated group showed exposure of dentinal tubule and collagen fiber, thus it was thought that new connective tissue attachment could be acquired.

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Quality Evaluation by Root Weight Distribution in White Ginseng Package (근중 분포에 의한 포장된 백삼의 품질평가)

  • Park, Hoon;Kim, Young-Hee;Yang, Cha-Bum
    • Journal of Ginseng Research
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    • v.17 no.3
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    • pp.219-223
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    • 1993
  • Assessment of root weight grade system for the numeral definition in Korea ginseng was tried by investigation of 13 boxes of the 15-root-grade of 4-year-old white ginseng as a model. In this case satisfaction to theoretical value was 58% in root weight and 50% in root number. The coefficient of variation (CV) was high (35%) for individual root weight in package. The CV of tap root weight 1 among package is low (7.1%) even though there was no significant correlation between tap root weight : and lateral root weight among roots. The mean percentage of tap root to root weight in each package ranged 61 to 74% with CV range of 16.5 to 33.2%. The CV was not much different between 1st and 2nd lateral root weight and the means was above 60%. Strict practice of numeral definition of root weight grade system will be prerequisite for chemical standardization of Korea ginseng.

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ANTIMICROBIAL EFFECT OF ROOT CANAL CEMENTS ON MICROORGANISMS FROM INFECTED ROOT CANALS (수종 근관 충전재의 항균 효과에 관한 연구)

  • Koh, Young-Hoon;Choi, Ho-Young
    • Restorative Dentistry and Endodontics
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    • v.16 no.1
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    • pp.190-199
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    • 1991
  • The purpose of this study was to evaluate the antimicrobial effect of root canal cements such as AH-26, Sealapex, Canals and Apatite root sealers(Type I, II, III) and to determine the efficacy of their activities. S.mutans(AHT), S.sanguis(NCTC 9811) and B.gingivalis(381) were streaked on blood agar and the PVC tybes filled with root canal cements were applied on. Then the microorganisms were cultured for 48 hours, anaerobically. B.cereus(KCTC 1012) was streaked on nutrient agar, PVC tubes were applied on and were cultured for 48 hours, aerobically. The inhibition zones of root canal cements were measured with vernier caliper. The data statistically analyzed, and the results were as followed. 1. Apatite root sealers(Type I, II, III) showed no inhibition zones. 2. AH-26, Sealapex and Canals had inhibition zones with varying degrees. The inhibition zone of AH-26 was greatest and followed by Canals and Sealapex(P<0.01). 3. As time goes by after mixing the root canal cements, AH-26, Canals and Sealapex showed significantly reducing inhibition zones(P<0.01). 4. There were the least inhibition zones of all the root canal cements on S.mutans and followed in such order as; B.gingivalis, S.sanguis and B.cereus(P<0.01).

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Studies on the Constituents of the Chicory Root (치코리뿌리 성분(成分)에 관(關)한 연구(硏究))

  • Kim, Taik-Young;Yoon, Young-Jin;Lee, Kyung-Woong
    • Korean Journal of Food Science and Technology
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    • v.10 no.2
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    • pp.258-262
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    • 1978
  • Proximate composition, minerals and fatty acid in dried chicory root (moisture content 7.0%) are analyzed and subsequent results are as follows: Crude protein, crude fat, crude fiber, total sugar and ash content in chicory root are 8.6%, 1.6 %, 6.9%, 58.5% and 4.2%, respectively. Mineral content of Ca, P, Fe, Mg and Si in the root are 1,560, 180, 10,600 and 180 mg%, respectively. Other minerals such as K, Na, Al, Zn, Ag, Cu and Ti are also determined. Unsaturated fatty acid content in total fat of the root is 65.4%, Particularly high in linoleic acid. Uridine-5'-diphospho-glucose, as sole nucleotide-sugar in the root, was detected.

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Effect of Exogenous Metalaxyl Seed-Soaking on Root Initiation and Elongation of Young Rice Seedling (벼 어린모 뿌리의 분화 및 신장에 미치는 Metalaxyl의 종자침청처리 효과)

  • Kim, Je-Kyu;Park, Kwng-Ho;Lee, Moon-Hee;Oh, Yun-Jin
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.38 no.6
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    • pp.545-553
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    • 1993
  • The metalaxyl seed-soaking treatment markedly increased the root-mat formation of the young rice seedling(8- to l0-day-old) for machine transplanting. This experiment was conducted to find out a possible rooting mechanism of the young rice seedling in relation to the exogenous metalaxyl seed-soaking treatment. The rice seeds of Hwaseongbyeo variety were soaked in the solution of metalaxyl for 24 hours at room temperature. Metalaxyl(25% wettable powder), a fungicide, was used at the concentration of 200ppm as a promoting substance on the root-mat formation of the young rice seedling. Seeding rate of the young rice seedling was 220g per seed tray(30${\times}$60${\times}$depth 3cm). Metalaxyl seed treatment was highly effective in root initiation and elongation of the young rice seedling in terms of root activity, the number and length of root, and amino acid content of roots. The exogenous metalaxyl application would also increase the chlorophyll content and photosynthetic rate in the young rice seedling. Those factors resulted in vigorous root-mat formation of the young rice seedling. In particular, alanine is a lead compound of metalaxyl which biochemically plays an important role in energy intermediate of the rice plant. Alanine conjugation with a glucose (N-${\beta}$-glucoside) is probably the mechanism in enhancement of initiation and elongation of rice roots of young rice seedling.

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Influence of different strains of Agrobacterium rhizogenes on hairy root induction and growth in Scutellaria baicalensis (Agrobacterium rhizogenes strains이 황금 모상근 유도와 생육에 미치는 영향)

  • Park, Woo-Tae;Kim, Young-Seon;Park, Nam-Il;Kim, Haeng-Hoon;Lee, Sook-Young;Park, Sang-Un
    • Korean Journal of Agricultural Science
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    • v.38 no.2
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    • pp.213-217
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    • 2011
  • Agrobacterium rhizogenes, a gram-negative soil bacterium, is one of the most widely studied among them. A, rhizogenes can transfer T-DNA, excised from Ri (root inducing)-plasmids from the bacterial to the plant cell. It is the causal agent of 'hairy root' diseases in plants, and has been used for the production of hairy root cultures from a multitude of species. Five different strains of Agrobacterium rhizogenes differed in their ability to induce Scutellaria baicalensis hairy roots and also showed varying effects on the growth in hairy root cultures. A. rhizogenes R 1000 is the most effective strain for the induction (57.3%) and growth (11.9 g $L^{-1}$) in hairy root of Scutellaria baicalensis. Our results demonstrate that use of suitable strains of A. rhizogenes may allow study of the regulation of flavone biosynthesis in hairy root cultures of Scutellaria baicalensis.

Defoliation Effects on Root and Rhizome Development of Kura Clover

  • Kim, B.W.;Albrecht, K.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.5
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    • pp.690-694
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    • 2006
  • There is limited information on the relationship between defoliation and root and rhizome development of kura clover (Trifolium ambiguum M. Bieb.). To determine the effects of defoliation severity on root and rhizome growth of young kura clover plant (seedling about 8 wk old), this research was conducted in 2002 (Experiment 1) and 2003 (Experiment 2) in a glasshouse at the University of Wisconsin-Madison. Four kura clover entries were used in this experiment: two were started from seed materials (ARS-2678 and 'Rhizo') and two were clones from mature, field-grown Rhizo kura clover plant. Three defoliation frequencies (2-, 4- and 6-wk intervals) and two defoliation intensities (complete and partial defoliation) were imposed on each of the four kura clover entries. Root, rhizome, and leaf dry matter (DM) generally increased with less frequent defoliation, however, the increase in rhizome DM was not significant between 4- or 6-wk defoliation periods. The root and leaf DM under complete defoliation (CD) were significantly lower than under partial defoliation (PD). In Exp. 1, rhizome DM was not significantly different between CD and PD; it was significantly lower under CD in Exp. 2. ARS-2678 showed excellent root development characteristics, however, its rhizome DM was significantly lower than Rhizo clones. The rhizome development from Rhizo clones was greater than that from seed materials. If maximum root and rhizome growth are expected from young kura clover plant, the intensity and frequency of defoliation should be minimized or defoliation should be avoided.

A Study on the Mock-up Test of Waterproofing/Root Penetration Resistance Technology for the Application to an Eco-bridge (생태교량 적용을 위한 방수·방근공법의 Mock-up 시험 연구)

  • Seon, Yun-Suk;Choi, Su-Young;Kim, Meong-Ji;Choi, Sung-Min;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.230-231
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    • 2014
  • This study is concerned with the root penetration resistance competence and constructability of a waterproofing and root penetration resistance layer of an eco-bridge which is applied with various types of seeding. For the review of root penetration resistance competence, the competence was tested using herbs, woody plants, and tall trees. As a result, there was no tear of or damage to the waterproofing and root penetration resistance layer as well as the sweeping-down phenomenon of a waterproofing and root penetration resistance layer by soil. Also, the effect of the root growth of herbs, woody plants, and tall trees on the root penetration resistance system was confirmed.

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