• Title/Summary/Keyword: brown rot

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Decay Resistance of Borate-Modified Oriented Strandboard: A Comparison of Zinc and Calcium Borate

  • Lee, Sun-Young;WU, Qinglin
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.5
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    • pp.1-10
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    • 2008
  • Decay and mold resistance of zinc borate (ZB) and calcium borate (CB) modified oriented strandboard (OSB) from southern mixed hardwood and southern yellow pine was investigated in this study. Brown rot fungus Gloeophyllum trabeum and white-rot fungus Trametes versicolar were used to examine the decay resistance of the OSB. The OSB test specimens were colonized by brown and white rot fungal mycelium in both the brown and white-rot culture bottles after 8 and 12 weeks, respectively. The wood species and fungus type had the significant effects on the decay resistance. Brown rot decay was evident for all untreated southern pine and mixed hardwood controls. The white-rot decay, however, did not show significant weight loss at both species control samples. The incorporation of ZB and CB composites provides suitable protection against brown-and white-rot fungi. No significant weight loss was observed from the borate treated OSB.

Identification of Pathogens Associated with Bulb Rot of Lily during Storage and Effects of Bulb Disinfection on Development of Lily Bulb Rot (백합 저장중 구근부패에 관여하는 병원균의 동정과 종구 소독효과)

  • Hahm Soo-Sang;Oh So-Young;Lee Eun-Mo;Yu Seung-Hun
    • Research in Plant Disease
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    • v.12 no.1
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    • pp.20-24
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    • 2006
  • Several pathogens associated with bulb rot of lilies in storage house were identified with respect to rot types. Rot patterns were grouped into four different types; brown rot of bottoms, brown rot of shoots, water-soaked rot and blue mold. Brown rot of bottoms was the highest in frequency with 72.5%, and brown rot of shoots the least with 23.0%. Dominant pathogens were differed with rot patterns, brown rot of bottoms by Fusarium oxysporum, blue mold and brown rot of shoots by Penicillium brevicompactum and P. fellutanum. In wound-inoculation tests, Penicillium and Fusarium isolates caused severe rot on the bulbs. Bulb disinfection before storage by captan showed the most prominent control value of 95.2% followed by thiophanate-methyl with 85.6%.

X-Ray Diffractional and IR Spectral Characteristics in Brown-Rotted Woods Decayed by T. palustris and G. trabeum (갈색부후목재(褐色腐朽木材)의 X선(線) 회절(回折) 및 IR 분석(分析))

  • Choi, Ji-Ho;Han, Ok-Soo;Kim, Yoon-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.20 no.3
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    • pp.55-60
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    • 1992
  • Japanese red pine (Pinus densiflora S. et. Z.) decayed by brown-rot fungi Tyromyces palustris and Gloeophyllum trabeum were subjected to X-ray diffraction analysis and infrared spectral examinations. Pine woods decayed by T. palustris showed the increase of relative crystallinity in the initial stage of degradation. When the weight loss was above 30%, then the crystallinity went down slowly. In contrast, the wood samples degraded by G. trabeum showed the decrease of crystallinity from the beginning stage of decay. The changes of crystallinity in brown-rotted woods suggested that the degradation rate of crystalline cellulose was varied with the brown rot fungal species. X-ray diffraction analyses also indicated that crystalline cellulose was much more slowly broken down than the amorphous one. The most notable difference in the IR spectra of the brown-rotted wood samples was that the adsorption band centered at 1,730$cm^{-1}$ was significantly diminished in the decayed wood. indicating the degradation of hemicellulose by brown-rot fungi. However, no marked changes of intensities at 1,000, 1,060 and 1,040$cm^{-1}$ were observed in the brown rotted wood samples, suggesting that crystal line cellulose was resistant against the attack by brown rot fungi.

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The Change of Ultrasonic Transmission Velocity by Wood Decay

  • Hwang, Won-Joung;Lee, Hyun-Mi;Park, Young-Ran;Lee, Dong-Heub
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.2
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    • pp.214-221
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    • 2014
  • The deterioration in wood by the brown-rot fungus (Fomitopsispalustris) and the white-rot fungus (Trametesversicolor) were measured using ultrasonic velocity. Those were used for the decay exposure and 4 wood species of wood as the test specimens, Pinusdensiflora, Larixkaempferi, Pinuskoraiensis and Pinusrigida, were chosen with both the brown- and white-rot culture petridish during 12 weeks. After 12 weeks, the decrease rate of ultrasonic velocity was measured at 10~15%. In both brown- and white-rot exposure experiments, P. rigida showed significant decrease in ultrasonic velocity (20%), L. kaempferi on the other hand did not show decrease in ultrasonic velocity. After the fungal exposure experiment, the inside of specimens was investigated by computer tomography (C/T). After C/T investigation, bending tests were performed.

Screening of Antagonistic Bacillus against Brown Rot in Dendrocalamus latiflorus and Preparation of Applying Bacterial Suspension

  • Fengying Luo;Hang Chen;Wenjian Wei;Han Liu;Youzhong Chen;Shujiang Li
    • The Plant Pathology Journal
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    • v.40 no.1
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    • pp.1-15
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    • 2024
  • The aim of this study was to isolate biocontrol bacteria that could antagonize brown rot of Dendrocalamus latiflorus, optimize the culture conditions, and develop an effective biocontrol preparation for brown rot of D. latiflorus. This study isolated a bacterium with an antagonistic effect on bamboo brown rot from healthy D. latiflorus rhizosphere soil. Morphology, molecular biology, and physiological biochemistry methods identified it as Bacillus siamensis. The following culturing media and conditions improved the inhibition effect of B. siamensis: the best culturing media were 2% sucrose, 1.5% yeast extract, and 0.7% potassium chloride; the optimal culturing time, temperature, pH, and inoculation amount were 48 h, 30℃, 6, and 20%. The optimum formula of the applying bacterial suspension was 14% sodium dodecyl benzene sulfonate emulsifier, 4% Na2HPO4·2H2O, 0.3% hydroxypropyl methylcellulose thickener, and 20% B. siamensis. The pot experiment results showed the control effect of applying bacterial suspension, diluted 1,000 times is still better than that of 24% fenbuconazole suspension. The applying bacterial suspension enables reliable control of brown rot in D. latiflorus.

Brown Rot of Apricot and Mume Caused by Phomopsis vexans

  • Kim, Wan-Gyu;Hong, Sung-Kee;Cho, Weon-Dae;You, Chang-Hyun
    • The Plant Pathology Journal
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    • v.19 no.5
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    • pp.231-234
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    • 2003
  • Brown rot symptoms severely occurred on fruits of apricot and mume grown in Changnyeong, Suwon and Yeongi in Korea during a disease survey in June 2002. A total of 32 isolates of Phomopsis sp. was obtained from the fruit rot symptoms. All isolates were identified as Phomopsis vexans based on their morphological and cultural characteristics. Four isolates of the fungus were tested for pathogenicity to fruits of apricot and mume by artificial inoculation. All isolates induced brown rot symptoms on the fruits of apricot and mume by wound inoculation. Unwounded inoculation also induced symptoms on mume fruits but not on apricot fruits. The symptoms on the fruits induced by artificial inoculation were similar to those observed in the orchard. The pathogenicity tests revealed that mume was more susceptible to the pathogen than apricot. This is the first report of brown rot of apricot and mume caused by P. vexans.

Characterization of a Brown Rot Fungus Isolated from Dwarf Flowering Almond in Korea

  • Shim, Myoung-Yong;Jeon, Young-Jae;Kim, Seong-Hwan
    • Mycobiology
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    • v.35 no.1
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    • pp.30-35
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    • 2007
  • The fruits showing brown rot symptom on dwarf flowering almond were found in Gongju, Chungchungnam-Do in Korea in July 2005. Small water-soaked lesions on the fruits were initiated, and gradually developed to soft rot covered with gray conidia. Then the diseased fruits were shrunk and became grayish-black mummies. A fungus was isolated from the diseased fruit and its morphological, cultural and molecular genetic characteristics were investigated. Typical blastospores of Monilinia spp. were observed under a light microscope both from tissues of the diseased fruits and from PDA-grown cultures. The fungus grew well at $25^{\circ}C$ and on PDA. The ITS ribosomal DNA region (650 bp) of the fungus was amplified by PCR and analyzed. Comparative data on ITS sequence homology among Monilinia spp., ITS sequence-based phylogram and morphological characteristics showed that the fungus is Monilinia fructicola. This is the first report on Monilinia fructicola causing brown rot on fruits of dwarf flowering almond in Korea.

Effect of Brown-rotted Wood on Mechanical Properties and Ultrasonic Velocity

  • Lee, Sang-Joon;Kim, Gyu-Hyeok;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.5
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    • pp.24-32
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    • 2008
  • Artificial brown-rot decay was induced to two wood species, Pinus densiflora and Pinus radiata. A modified direct inoculation method was used and the decay indicators of mass loss and two compressive mechanical properties, maximum compressive strength (MCS) and compressive stiffness, were estimated over the period of 8 weeks of fungal exposure. Measurable mass loss occurred 2 weeks after the fungal attack, with 15% to 22% of the loss occurring 8 weeks after fungal exposure with Fornitopsis palustris and Gloeophyllurn trabeurn. Mechanical properties proved to be far more sensitive than mass loss detection: approximately five to six times by quantity. Of the two mechanical properties, MCS was more sensitive to and consistent with progressive brown-rot decay. An ultrasonic test was performed to determine the feasibility and accuracy of this method for nondestructive detection of brown-rot decay. The ultrasonic test is highly sensitive at qualitative detection of the early stages of brown-rot decay.

Bacterial Brown Rot of Scarlet Kafir Lily (Clivia spp.) Caused by Erwinia cypripedii (Erwinia cypripedii에 의한 군자란의 세균성 갈색부패병)

  • 한광섭;최재을
    • Korean Journal Plant Pathology
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    • v.10 no.4
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    • pp.333-335
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    • 1994
  • In 1991, the leaves and roots brown rot disease of scarlet kafir lily were found in Taejon and Seoul. The symptoms were appeared as dark-brown and water soaked on leaves. The discolored area of the leaves become halo. The roots revealed blight gray and water soaked. The pathogenic bacteria were isolated from the diseased leaves of the scarlet kafir lily were identified as Erwinia cypripedii on the bais of bacterial characteristics. E. cypripedii is first described bacteria which cause the disease on scarlet kafir lily in Korea. Therefore, we would like to propose to the name of scarlet kafir lily disease caused by E. cypripedii as“bacterial brown-rot of scarlet kafir lily”hereafter.

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Enzymatic sccharification of lignocellulosic biomass by enzyme system of brown-rot fungi (갈색부후균의 효소시스템을 이용한 목질계 바이오매스의 효소당화)

  • Yoon, Jeong-Jun;Cha, Chang-Jun;Kim, Yeong-Suk;Kim, Young-Kyoon
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.529-532
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    • 2006
  • Recently the production of ethanol from lignocecllulosics has received much attention due to immense potential for conversion of renewable biometerials into biofuels and chemicals. Fomitopsis palustris causes a typycal brown-rot and is unusual in that it rapidly depolymerize the cellulose in wood without removing the surrounding lignin that normally prevents microbial attack. This study demonstrated that the brown rot basidiomycete F. palustris was able to degrade crystalline cellulose. This fungus could also produce the three major cellulases (BGL, EXG and EG) when the cells were grown on 2.0% Avicel. The fungus was able to degrade both the crystalline and amorphous forms of cellulose from woody biomasses. Moreover, we found that this fungus has the processive EG like CBH which are able to degrade the crystalline region of cellulose. To establish the cellulase system in relation with degradation of woody biomass, we performed that purification, characterization and molecular cloning of a BGL, EGs and GLA from F. palustris grown on Avicel.

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