• Title/Summary/Keyword: Mali

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Isolation and Identification of Antagonistic Microorganisms for Biological Control to Major Diseases of Apple Tree(Malus domestica Borkh) (사과 주요 병해 방제를 위한 길항미생물 분리 및 동정)

  • 박흥섭;조정일
    • Korean Journal of Organic Agriculture
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    • v.5 no.1
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    • pp.137-147
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    • 1996
  • For the purpose of acquiring microbial agents that can be utilized to biologically control the major airborne diseases to apple trees, such as canker(Botryosphaeria dothidea), bitter rot(Glomerella cingulata), alternaria leaf spot(Alternaria mali), root rot(rosellinia necatrix), canker(Valsa ceratosperma) and gray mold rot(Botrytis cinerea), the effective microorgaisms were isolated, tested for antagonistic activity to the pathogens causing major diseases to apple trees and identifed. Screening of more than 5,000 species of microorganisms collected in nature for them antagonistic action to the pathogens causing 5 major diseases to apple trees resulted in selection of effective species. Out of the 11 species, one species designated as CAP134 demonstrated outstanding activity. The bacterial strain, CAP134 exerted antagonistic efficiency of 57% on an isolated strain and 40% on a donated strain of Botryosphaeria dothidea., 52% on an isolated strain and 46% on a purchased strain of Alternaria mali, 60% on Valsa ceratosperma 25% on Glomerella cingulata, and 64% Rosellinia necatrix. The CAP134 was identified as a bacterial strain to Bacillus subtilis ATCC 6633 based on morephology, culture conditions, and physio-biochemical characteristics.

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Geochemical Exploration for the Bougouni Area in Mali (말리 부구니 지역에 대한 지화학탐사)

  • Kim, In-Joon
    • Economic and Environmental Geology
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    • v.41 no.5
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    • pp.563-575
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    • 2008
  • The ore depositional and geochemical exploration on Bougouni area in Mali, central-western Africa covering $2,000\;Km^2$ was conducted for determining the detailed survey area. According to the results of this exploration, the highly potential area for the zinc-tin-gold-silver mineralization was found in Kolani and Riarako areas. The contents of zinc in heavy sand collected in the stream sediments range from 14 to 8,600 ppm, while the mean values of zinc in this area are 543 ppm with threshold($x+2{\sigma}$) of zinc anomalies being 1,000 ppm in Bougouni area. Generally zinc anomalies are associated with the tin and molybdenum anomalies and hence the anomalous area was selected for the detailed survey area for tracing the primary zinc and precious ore deposits related to these anomalies in following project.

Antimicrobial Effects of Chamaecyparis obtusa Essential Oil (편백정유의 항균효과)

  • 이현옥;백승화;한동민
    • Microbiology and Biotechnology Letters
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    • v.29 no.4
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    • pp.253-257
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    • 2001
  • Essential oil of Chamaecyparis obtusa showed antimicrobial on relatively broad spectrum of bacterial and fungal species. Staphylococcus epidermidis was highly sensitive to the essential oil but Streptococcus aureus and Streptococcus mutans were not. Vibro parahemolyticus, Pseudomoas aeruginosa and Pseudomoas putida showed sensitivity at the concentration higher that 400 ppm, Thegrowth of a pathogenic yeast Candida albicans was inhibited by the essential oil above 200ppm. The radialgrowth of several filamentous fungi was also inhibited The antifungal activity of the essential oil was effective on two plant pathogens Fusarium oxysporum and Altenaria mali. These results sug-gest that essential oil of Chamaecyparis obtusa has an antimicrobial activity by inhibiting bacterial and fungal species.

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Antifungal Activity of Extract of Common Purslane (Portulaca oleracea L.) (쇠비름 즙액(汁液)의 항균작용(抗菌作用))

  • Park, Jong Seong;Kwon, Jin Sook;Lee, Kyu Seung
    • Korean Journal of Agricultural Science
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    • v.11 no.2
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    • pp.190-193
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    • 1984
  • Extracts of common purslane(Portulaca oleracea L.) showed to possess some antifungal substances which inhibited the mycelial growth of the phytopathogenic fungi tested;Valsa mali, Alternaria kikuchiana and Pyricularia oryzae. These antifungal substances were found to be soluble in methanol and were regarded as kinds of lipid. In order to isolate the antifungal substances, the extracts of common purslane were concentrated by evaporation under reduced pressure and extracted with methanol The methanol solution was subjected to silica gel-florisil column and divided into lipid and non-lipid fractions. Lipid fractions only showed antifungal activity against the fungi tested. The effective substances contained in the extracts of common purslane inhibited not only the mycelial growth but also the spore germination of the fungi.

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Isolation and structure elucidation of antifungal compounds from the antarctic lichens, Stereocaulon alpinum and Sphaerophorus globosus

  • Kim, Young-Shin;Lim, Chi-Hwan
    • Korean Journal of Agricultural Science
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    • v.47 no.1
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    • pp.183-191
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    • 2020
  • Lichens are composite organisms consisting of a symbiotic association of a fungus with a photosynthetic partner (the photobiont or phycobiont), usually either a green alga or cyanobacterium. According to more recent studies, the biological activities of lichens and lichen substances include an antibiotic activity, antitumor and antimutagenic activity against human immunodeficiency virus (HIV), allergenic activity, plant growth inhibitory activity, and enzyme inhibitory activity. This study screened lichen extracts with a potent in vitro antifungal activity against plant diseases caused by phytopathogenic fungi. The compounds were isolated from Stereocaulon alpinum and Sphaerophorus globosus, and their chemical structures were identified as methyl hematommate, methyl β-orsellinate, 5-hydroxyferulic acid, sphaerophorin, and 2-heptyl-4,6-dimethoxybenzoic acid by electron ionization mass spectrometry (EI-MS) and nuclear magnetic resonance (NMR) spectral analyses. In vitro disease control against Alternaria mali, Cochliobolus miyabeanus, Colletotrium gloeosporioides, and Verticillum dahliae was evaluated. And among the five compounds, only methyl hematommate was effective against A. mali, C. miyabeanus, and C. gloeosporioides. The compounds were isolated from these lichens, which have a similar biosynthetic pathway, respectively. This is the first report of these compounds being isolated from these lichens.

Evolutionary Relationships of the Genus Trichoderma and Related Taxa Based on the Partial Sequences of 18S Ribosomal RNA (18S 리보좀 RNA 부분 염기서열에 의한 Trichoderma속 및 관련 불완전균류의 진화학적 유연관계)

  • Lee, Goang-Jae;An, Won-Gun;Lee, Jae-Dong;Joo, Woo-Hong
    • The Korean Journal of Mycology
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    • v.23 no.4 s.75
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    • pp.318-324
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    • 1995
  • The evolutionary relationships of the genus Trichoderma and related taxa were assessed using partial sequencing of 18S ribosomal RNA. Phylogenetic tree divided into three major groups; 1. Saccharomyces cerevisiae-Geotrichum klebahnii-Alternaria mali group; 2. Neurospora crassa-Aspergillus-Penicillium-Chrysosporium pannorum-Scopulariopsis sp. group; 3. Trichoderma group. The genus Trichoderma seemed to be phylogenetically separated from Saccharomyces cerevisiae, Aspergillus and Penicillium groups, and have passed through it's own evolutionary pathway.

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Control of Fungal Diseases with Antagonistic Bacteria, Bacillus sp. AC-1

  • Park, Yong-Chul-
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 1994.06a
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    • pp.50-61
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    • 1994
  • Biological control of important fungal diseases such as Phytophthora blight of red pepper, gary mold rot of vegetables, and powdery mildew of many crops was attempted using an antagonistic bacterium, Bacillus sp. AC-1 in greenhouses and fields. The antagonistic bacterium isolated from the rhizosphere soils of healthy red pepper plant was very effective in the inhibition of mycelial growth of plant pathogenic fungi in vitro including Phytophthora capsici, Rhizoctonia solani, Pyricularia oryzae, Botrytis cinerea, Valsa mali, Fusarium oxysporum, Pythium ultimum, Alternari mali, Helminthosporium oryzae, and Colletotrichum gloeosporioides. Culture filtrate of antagonistic Bacillus sp. AC-1 applied to pot soils infested with Phytophthora capsici suppressed the disease occurrence better than metalaxyl application did until 37 days after treatment in greenhouse tests. Treatments of the bacterial suspension on red pepper plants also reduced the incidence of Phytophthora blight in greenhouse tests. In farmers' commercial production fields, however, the controlling efficacy of the antagonistic bacteria was variable depending on field locations. Gray mold rot of chinese chives and lettuce caused by Botrytis cinerea was also controlled effectively in field tests by the application of Bacillus sp. AC-1 with control values of 79.7% and 72.8%, respectively. Spraying of the bacterial suspension inhibited development of powdery mildew of many crops such as cucumber, tobacco, melon, and rose effectively in greenhouse and field tests. The control efficacy of the bacterial suspension was almost same as that of Fenarimol used as a chemical standard. Further experiments for developing a commercial product from the antagonistic bacteria and for elucidating antagonistic mechanism against plant pathogenic fungi are in progress.

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Effects of Fungicides on Sporulation of Apple Leaf Spot Alternaria mali Roberts (사과 반점낙엽병의 포자형성에 대한 살균제의 효과)

  • LEE Chang Un;KIM Moon Ho
    • Korean journal of applied entomology
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    • v.19 no.3 s.44
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    • pp.169-174
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    • 1980
  • Regardless of the kind of the apple orchards whether received various fungicides application or not Rovral exhibited the most efficient inhibitory effect on the sporulation of Alternaria mali with the spotted leaf disks at the recommended dose $0.5{\mu}g/ml$ as well as the lower or the higher doses. When applied at the recommended doses $0.7{\mu}g,\;0.75{\mu}g,\;and\;0.7{\mu}g/ml$ of Antracol, Dithane M-45, and Dikar, respectively, these fungicides showed complete inhibitory effects on the sporulation. At the lower levels of application, they allowed the sporulation of 10,000 to 25,000 conidia/ml. Polyoxin and Difolatan, when applied on the leaf disks from the orchard that had received the fungicides application, exhibited low effects allowing the sporulation of around 20,000 conidia/ml. On the leaf disks from the orchard that had received no fungicide application, however, both fungicides showed relatively high inhibitory effects of the sporulation. The inhibitory effects of Captan, Dakonil, and Spat on the sporulation were lower than those of the aforementioned fungicides. Bayleton was the least effective among the fungicides used in the present investigation. Benlate showed promoting effect on the sporulation of the apple leaf spot fungus rather tan inhibiting.

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