• 제목/요약/키워드: leaf analysis

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Morphology and Molecular Characteristics of Alternaria sonchi Causing Brown Leaf Spot on Sonchus asper in Korea

  • Luo, Huan;Park, Myung Soo;Yu, Jun Myoung
    • 식물병연구
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    • 제27권3호
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    • pp.107-114
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    • 2021
  • During a disease survey on weeds and minor cultivated crops in Korea, a brown leaf spot disease was observed on Sonchus asper. Leaf lesions were round or irregular in shape, and grayish brown to brown with a purple margin. In severe infection, lesions enlarged and coalesced, resulting in blighting of the leaves. The isolates from these leaf lesions were identified as Alternaira sonchi based on morphological characteristics and phylogenetic analyses of Internal transcribed spacer region, Alternaria allergen a1, glyceraldehyde 3-phosphate dehydrogenase, RNA polymerase II, and translation elongation factor genes. This study provides a comprehensive description of the morphological characteristics and phylogenetical traits of A. sonchi causing brown leaf spot on S. asper in Korea.

First Report of Leaf Spot in Water Spinach Caused by Ectophoma multirostrata

  • Gyo-Bin Lee;Hong-Sik Shim;Weon-Dae Cho;Wan-Gyu Kim
    • 한국균학회지
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    • 제50권4호
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    • pp.367-372
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    • 2022
  • Leaf spot symptoms were observed in water spinach (Ipomoea aquatica) plants growing in fields in Ansan and Hongseong, Korea, during disease surveys in 2019 and 2020. The symptoms appeared as brown to dark brown circular or irregular spots on the leaves of the plants. The disease incidence on the plant leaves in the fields investigated at the two locations ranged from 1% to 20%. Five single-spore isolates of Phoma sp. Were obtained from lesions of the diseased leaves. All the isolates were identified as Ectophoma multirostrata based on their cultural and morphological characteristics, as well as molecular analysis. Two isolates of E. multirostrata were tested for pathogenicity on water spinach leaves using artificial inoculation. The tested isolates caused leaf spot symptoms in the inoculated plants. These symptoms were similar to those observed in plants from the investigated fields. To our knowledge, this is the first report of E. multirostrata causing leaf spot in water spinach.

크리핑 벤트그라스 훼어웨이에서 관수회수.예지물과 질소시비수준이 엽조직 및 토양 질소함유량에 미치는 효과 (A Three-year Study on the Leaf and Soil Nitrogen Contents Influenced by Irrigation Frequency, Clipping Return or Removal and Nitrogen Rate in a Creeping Bentgrass Fairway)

  • 김경남;로버트쉬어만
    • 아시안잔디학회지
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    • 제11권2호
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    • pp.105-115
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    • 1997
  • Responses of 'Penncross' creeping bentgrass turf to various fairway cultural practices are not well-established or supported by research results. This study was initiated to evaluate the effects of irrigation frequency, clipping return or removal, and nitrogen rate on leaf and soil nitrogen con-tent in the 'Penncross' creeping bentgrass (Agrostis palustris Huds.) turf. A 'Penncross' creeping bentgrass turf was established in 1988 on a Sharpsburg silty-clay loam (Typic Argiudoll). The experiment was conducted from 1989 to 1991 under nontraffic conditions. A split-split-plot experimental design was used. Daily or biweekly irrigation, clipping return or removal, and 5, 15, or 25 g N $m-^2$ $yr-^1$ were the main-, sub-, and sub-sub-plot treatments, respectively. Treatments were replicated 3 times in a randomized complete block design. The turf was mowed 4 times weekly at a l3 mm height of cut. Leaf tissue nitrogen content was analyzed twice in 1989 and three times in both 1990 and 1991. Leaf samples were collected from turfgrass plants in the treatment plots, dried immediately at 70˚C for 48 hours, and evaluated for total-N content, using the Kjeldahl method. Concurrently, six soil cores (18mm diam. by 200 mm depth) were collected, air dried, and analyzed for total-N content. Nitrogen analysis on the soil and leaf samples were made in the Soil and Plant Analyical Laboratory, at the University of Nebraska, Lincoln, USA. Data were analyzed as a split-split-plot with analysis of variance (ANOVA), using the General Linear Model procedures of the Statistical Analysis System. The nitrogen content of the leaf tissue is variable in creeping bentgrass fairway turf with clip-ping recycles, nitrogen application rate and time after establishment. Leaf tissue nitrogen content increased with clipping return and nitrogen rate. Plots treated with clipping return had 8% and 5% more nitrogen content in the leaf tissue in 1989 and 1990, respectively, as compared to plots treated with clipping removal. Plots applied with high-N level (25g N $m-^2$ $yr-^1$)had 10%, 17%, and 13% more nitrogen content in leaf tissue in 1989, 1990, and 1991, respectively, when compared with plots applied with low-N level (5g N $m-^2$ $yr-^1$). Overall observations during the study indicated that leaf tissue nitrogen content increased at any nitrogen rate with time after establishment. At the low-N level treatment (5g N $m-^2$ $yr-^1$ ), plots sampled in 1991 had 15% more leaf nitrogen content, as compared to plots sampled in 1989. Similar responses were also found from the high-N level treatment (25g N $m-^2$ $yr-^1$ ).Plots analyzed in 1991 were 18% higher than that of plots analyzed in 1989. No significant treatment effects were observed for soil nitrogen content over the first 3 years after establishment. Strategic management application is necessary for the golf course turf, depending on whether clippings return or not. Different approaches should be addressed to turf fertilization program from a standpoint of clipping recycles. It is recommended that regular analysis of the soil and leaf tissue of golf course turf must be made and fertilization program should be developed through the interpretation of its analytic data result. In golf courses where clippings are recycled, the fertilization program need to be adjusted, being 20% to 30% less nitrogen input over the clipping-removed areas. Key words: Agrostis palustris Huds., 'Penncross' creeping bentgrass fairway, Irrigation frequency, Clipping return, Nitrogen rate, Leaf nitrogen content, Soil nitrogen content.

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Production of Triploid Somatic Hybrids Between Mandarin and Grapefruit through Electrofusion

  • Kunitake, Hisato
    • Journal of Plant Biotechnology
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    • 제2권2호
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    • pp.109-113
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    • 2000
  • Somatic hybrids were produced by electrofusion between embryogenic callus protoplasts of 'Syougun' mandarin and leaf protoplasts of grapefruit. Hybridity of the two plants was confirmed by leaf morphological characteristics and random amplified polymorphic DNA (RAPD) analysis. The cpDNA analysis using PCR-RFLP could not distinguish those of both parents. These plants showed normal growth and had chromosome number of 27. These unexpected triploid somatic hybrids might be derived from fused cells between diaploid protoplast of embryogenic calli and diploid protoplast of leaf, because polysomaty, a mixture of haploid cells and diploid cells was observed in the lactose medium-pretreated embryogenic calli of 'Syougun' by flow cytomehy analysis.

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Orient종 잎담배의 이면교잡에 의한 양적 형질의 유전연구 II. 분산분석과 유전자분포 상태 (The Analysis of Inheritance of Quantitative characters with Oriental Tobacco Varieties (Nicotiana tabacum L.) in Diallel Cross. II. Gene Distribution and Analysis of Variance for each character in $F_1$ Generation.)

  • 정석훈;황주광;손세호
    • 한국연초학회지
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    • 제4권1호
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    • pp.15-20
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    • 1982
  • This experiment was carried out to investigate the degrees and directions of dominance, and gene distributions by analysing diallel crosses of oriental varieties. The analysis of Wr-Vr indicated non-allelic gene interaction for days to (lowering and number of leaves. Five Plant characteristics showed different degrees of dominance : incomplete dominance for Plant height and leaf shape, over dominance for , wield and sugar, and complete dominance for nicotine. It was shown that additive genetic variance was predominant for plant height, leaf shape, and total sugar. More number of dominant genes were present in Kavala and canthi for Plant height; Basma, Samsun and Izmir for leaf shape ; and Basma and Samsun (or nicotine. Their directions of dominance were tall height, narrow leaves, and low nicotine, respectively.

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계면 요소의 구성과 이를 이용한 겹판스프링의 강성도 평가 (Formulation of an Interface Element and Stiffness Evaluation of an Leaf Spring)

  • 정정희;임장근
    • 한국자동차공학회논문집
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    • 제5권6호
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    • pp.141-147
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    • 1997
  • For the effective finite element analysis of the structures including material interfaces or contact surfaces, interface elements are proposed. Most of early works in this problem require not only iterative computation but also complex formulation because of the kinematic nonlinearities caused from the discontinuous behavior and the stress concentration phenomena. The proposed elements, however, are consistently formulated using relative displacements and tractions between top and bottom regular finite elements. The effectiveness of these elements are shown by solving various numerical sample problems including an leaf spring and comparing with results of general finite element analysis. As a result, more stable solutions are conveniently obtaines using interface elements than regular finite elements.

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GC/MS에 의한 잎담배중 Phenolic Acid의 분석 (Analysis of Phenolic Acids in Tobacco Leaf by GC/MS)

  • 박진우
    • 약학회지
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    • 제26권2호
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    • pp.129-132
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    • 1982
  • A GC/MS method was developed to analyze phenolic acid extract from tobacco leaf. Extracted acids were converted to their methyl esters by refluxing with 3M hydrogen chloride in methanol, and the esters were reacted with his (trimethylsilyl) trifluoroacetamide plus 10% trimethylchlorosilane to silylate the phenolic groups. Derivatives of standard salicylic, p-hydroxybenzoic, vanillic, gentisic, p-coumaric, syringic, ferulic, and sinapic acids prepared by this procedure were analyzed by GC/MS on $20m{\times}0.2mm$ column of SE-54 glass capillary. GC/MS analysis of the extract from tobacco leaf revealed the presence of salicylic, p-hydtoxybenzoic, vanillic, gentisic, protocatechuic, p-coumaric, syringic, gallic, ferulic, caffeic, sinapic, and quinic acids, respectively. The quantitative analysis of these phenolic acids were achieved by using multiple ion selection technique.

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범프로 지지되는 다엽 포일을 갖는 가스 포일 베어링의 성능 해석 (Performance Predictions of Gas Foil Bearing with Leaf Foils Supported on Bumps)

  • 김태호;문형욱
    • Tribology and Lubricants
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    • 제34권3호
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    • pp.75-83
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    • 2018
  • Microturbomachinery (< 250 kW) using gas foil bearings can function without oil lubricants, simplify rotor-bearing systems, and demonstrate excellent rotordynamic stability at high speeds. State-of-the-art technologies generally use bump foil bearings or leaf foil bearings due to the specific advantages of each of the two types. Although these two types of bearings have been studied extensively, there are very few studies on leaf-bump foil bearings, which are a combination of the two aforementioned bearings. In this work, we illustrate a simple mathematical model of the leaf-bump foil bearing with leaf foils supported on bumps, and predict its static and dynamic performances. The analysis uses the simple elastic model for bumps that was previously developed and verified using experimental data, adds a leaf foil model, and solves the Reynolds equation for isothermal, isoviscous, and ideal gas fluid flow. The model predicts that the drag torques of the leaf-bump foil bearings are not affected significantly by static load and bearing clearance. Due to the preload effect of the leaf foils, rotor spinning, even under null static load, generates significant hydrodynamic pressure with its peak near the trailing edge of each leaf foil. A parametric study reveals that, while the journal eccentricity and minimum film thickness decrease, the drag torque, direct stiffness, and direct damping increase with increasing bump stiffness. The journal attitude angle and cross-coupled stiffness remain nearly constant with increasing bump stiffness. Interestingly, they are significantly smaller compared to the corresponding values obtained for bump foil bearings, thus, implying favorable rotor stability performance.

잎담배중 Duvatrienediol에 관한 연구 (Studies of Duvatrienediol in Tobacco Leaf (Nicotiana tabacum L.))

  • 지상운;안기영;이문수;박영수;정찬선
    • 한국연초학회지
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    • 제14권2호
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    • pp.159-167
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    • 1992
  • It would be clear that the constituents of the leaf surface lipid is ye비 important as an evaluation index of tobacco leaf quality since the quality of tobacco specific aroma with leaf species depends on the contents of the lipid and the strength of the aroma is determined by the amounts of the lipid secreted. For the reason, a rapid and peproducible method to quantify DVT, which is a kind of lipid, has been studied. The biosynthesis procedure of DVT in leaf growing processes, and the volatile or decompositional characters of DVT in leaf drying processes were also discussed. In consequence, it might be possible to get the data available to the cultivation of better tobacco leaf and the manufacture of cigarettes with better aroma and taste. The results obtained from this study are as follows. 1. Chloroform/dichloromethane solvent was better than chloroform alone for DVT extraction. The extraction yields of the leaf surface lipid were about 5% 2. The extractives with dichloromethane were treated by silylation with BSTPa and the quantitative analysis of DVT was carried out using SE -54 fused silica capillary column. It was found that rapid and reproducible data could be obtained from these methods. 3. In flue - cured tobacco species, DVT contents were $30.3\mu\textrm{g}/cm^2$ in the beginning stage of leaf drying processes and $12.1\mu\textrm{g}/cm^2$ corresponded to 30% levels of the beginning stage, in the end stage. 4. DVT contents in Burley mere 2 times as large as those in fluecured tobacco. DVT in the upper stalk position of leaf was 3 times larger than that in the lower stalk position. 5. DVT of tobacco leaves was decomposed by $SO_2$ gas or the sun light. The decomposition rate was largest in the sample used methanol as a extraction solvent.

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Pharbitis nil 개화 요도시 엽단백질 변화에 대한 면역학적 분석 (Immunological Analysis of Proteins in the Leaf of Pharbitis nil during Photoinduction of Flowring)

  • 맹주선
    • Journal of Plant Biology
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    • 제25권4호
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    • pp.169-174
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    • 1982
  • Using double immunodiffusion and immunoelectrophoretic techniques, attempts were made to detect any protein changes in leaf tissues of a short-day plant, Pharbitis nil Chois. variety Violet during floral induction under 8 hr light, 16 hr dark cycles. Immunoprecipitin systems shwoed at least four proteins newly appeared in the induced leaf tissues. Accumulation of the proteins were observed as the induction proceeded.

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